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VOL. 54 NO.3 SUMMER 1984 .•..• .,VOL. 54 NO 3 ETE 1984 LlBRA'RY USE

1+

VOL. 54 NO.3 SUMMER 1984

THE LIGHTER is published quarterlyby Agriculture Canada. Its purpose is to

provide information on the progress and

development of the tobacco industry in

Canada. Statistical and marketing infor-

mation is provided by arrangementwith Statistics Canada and AgricultureCanada's International liaison Service.

Any article in this publication may be

reprinted without special permissionprovided credit is given to THELIGHTER. Reprinted articles must not

be associated with advertising material.

Where excerpts only are to be used,permission of the authors should first be

obtained. The use of trade names in

articles published in this journal impliesno endorsement of the products named

nor any criticism of similar products notmentioned.

EDITORIAL BOARD

C. F. Marks, Ph.D.

P. W. Johnson, Ph.D.

N. L. longmuirJ. P. F. Darisse

CoordinatorTerry Phalen

HON. RALPH FERGUSON, MINISTERJ.P. CONNEll, DEPUTY MINISTER

ISSN 0024-340X

VOL. 54 NO 3 En~1984

LE BRIQUET est une publicationtrimestrielle d' Agriculture Canada. Ellerenseigne sur les prognls de I'industrie du

tabac au Canada. les statistiques et

donnees sur les marches sont pnjpareesen collaboration avec Statistique Canadaet Ie Service de liaison internationaled'Agriculture Canada.

Tout article qui para it dans la presentepubl ication peut {!He njimprime sans

permission speciale, a condition de

mentionner LE BRIQUET. les articles

reimprimes ne doivent faire partie

d'aucune reclame. lorsqu'on desire citerun extrait, it faut au prealable obtenir la

permission des auteurs. l'emploi de

noms commerciaux dans ces articles neconstitue pas I'approbation du produit

nomme au detriment de produits

sembi abies qui ne sont pas mentionnes.

COMITE DE REDACTION

C. F. Marks, Ph.D.

P. W. Johnson, Ph.D.N. l. longmuir

J. P. F. Darisse

CoordonnateurTerry Phalen

HaN. RALPH FERGUSON, MINISTREJ.P. CONNEll, SOUS-MINISTRE

CONTENTS 85 '"v~

Monitoring Leaf Wetnessat Delhi ResearchStationSurveillance de I'humidite des feuilles a la Station de recherches deDelhiS.K. Gayed and D.A. Brown .. 0 0 •• 0 • 0 0 • 0 •• 0 0 • 0 0 0 0 0 •• 5

Progressof the Canadian Tobacco CropLe point sur la culture du tabac au Canada 9

Tobacco Greenhouse Construction Costs 0 12

Flue-Cured Tobacco Seedlings: Effects of Seedling Age, TransplantingTime, and Seeding Density on Seedling Growth and Crop ProductionFactorsE.K. Walker .. 0 0 0 0 0 0 0 0 0 • 0 0 0 0 •• 0 •••• 0 •• 0 0 0 0 • • •• 16

Influences of Seed Size, Vermiculite Cover, and Watering Regime onGermination, Survival and Growth of Flue-Cured Tobacco SeedlingsUnder GlassE.K. Walker, L.B. Reynolds and W.O. Rogers. 0 • 0 0 • 0 0 0 • 0 •• o' 22

Control of Cryptogams in Growth Media UsedFor Flue-Cured TobaccoSeedling CultureEoK.Walker and L.B. Reynolds. 0 0 • 0 0 ••• 0 •• 0 • 0 0 • 0 •••• 0 31

Flue-Cured Tobacco Seedling Culture in Containers; Tray Filling andSeedingE.K. Walker and L.B. Reynolds. 36

Publication Summaries . 0 0 42

World Tobacco NewsCompiled by N.L. Longmuir o. 0 0 0 0 0 0 43

Leaf Tobacco Production and Value-1983 45

Statistics. 0 0 0 0 0 •• 0 0 0 0 0 •• 0 0 0 • 0 46

Climatic Conditions in Tobacco Growing Areas - CanadaSoN.Edey 48

Postscript . 0 0 0 0 0 0 • 0 0 0 • 0 • 0 • 0 0 • 0 • 0 0 0 • 0 • • 50

COVER Tobacco researcher Ne-ville Arnold checks cigar tobaccoat L'Assomption ExperimentalFarm

COUVERTURE Arnold Neville,chercheur, inspecte Ie tabac acigare a la Ferme experimentalede l'Assomptiono

Tobacco greenhouseunder construction at the L'Assomption Experimental Farm

Une serre tabacole en construction a la Ferme experimentale de L'Assomption

Fertilizer experiment on the Charlottetown ResearchStation

Essaisde fertilisants a la Station de recherchesde Charlottetown

THELIGHTER

LEBRIQUET

MONITORING LEAF WETNESSAT THE DELHIRESEARCH STATION

S. K. GAYED AND D. A. BROWN

The moisture level in the phyllos-phere or leaf surface environment,particularly the duration of leaf wet-ness, is an important factor in thedevelopment of foliar diseases. Downymildews such as blue mold of tobacco,Peronospora tabacina Adam, require afilm of water on the leaf surface of3 hours duration for conidial germina-tion and leaf penetration. Intermittentlight rain aids the liberation and dis-semination of conidia in tobacco fieldsinfected with blue mold. Long andheavy showers wash down conidiasuspended in the air.

During the 1983 growing season,tobacco leaf wetness was monitoredin the field from June 16 to August 31at the Delhi Research Station. AnApple Scab Monitor Series 100 CropTechnology was used for this purpose(Fig. 1). The equipment consisted of abattery-operated computer unit housedin a steel box, a paper-tape printer anda sensor unit. The date and duration ofleaf wetness periods were recorded by

Dr. Gayed is a research scientist and Mr.Brown is a technician at Agriculture CanadaDelhi Research Station.

SURVEILLANCE DEL'HUMIDITE DES FEUILLESA LA STATION DERECHERCHES DE DELHI

S.K. GAYED ET D.A. BROWN

Le degre d'humidite dans la phyl-losphere ou I'ambiance de la surfacefoliaire, en particulier la duree deI'etat d'humidite, constitue un facteurimportant dans la developpement desmaladies foliaires. Les mildious commela moisissure bleue du tabac, Pereno-spora tabacina Adam, ont besoin dela presence d'une pellicule d'eau surla surface foliaire d'une duree detrois heures pour permettre la germi-nation des conidies et la penetrationdu champignon dans les feuilles.Des pluies legeres intermittentes con.tribuent a la liberation et a la disse-mination des conidies dans les champsde tabac infectes par cette maladie.En revanche, les averses longues etviolentes font tomber les conidies ensuspension dans I'air.

Au cours de la saison de vegeta-tion de 1983, Ie degre d'humidite desfeuilles de tabac au champ a Mereieve du 16 juin au 31 aoOt a la Sta-tion de recherches de Delhi. Unavertisseur de tavelure, Series 100

S. K. Gayed est chercheur et D. A. Brown,technicien, a la Station de recherches d'Agri-culture Canada, a Delhi.

5

A

B

cD

Fig. 1. Diagram of the Leaf WetnessMoni-tor. A: wooden cage 8: computerbox C: printout and paper tapeD: battery housing E: keyboardF: sensorcells G: sensorassembly.

the computer on paper tape. Thesensor assembly was clipped to a retortstand which was moved to the canopyof a tobacco plant (Fig. 1) and wasadjusted in height as the plant grew.The sensor assembly was attached tothe computer by means of a 4.5 mlong cable. The computer box andassembly were housed in a woodencage for further protection.

RESULTS AND DISCUSSION

In 1983, dew was the main sourceof leaf wetness while rain was the nextmajor source. Leaf wetness from irriga-tion was minimal (Table 1). The aver-age duration of daily leaf wetness in-creased with the progression of theseason until August 15, and thendropped off slightly from August 15to August 31 (Table 2). The maximumleaf wetness during the first half ofAugust exceeded 20 hrs, whereas theminimum period was about 6.6 hrs.

6

Fig. 1. Diagramme de I'avertisseur d'etatd'humidite des feuilles. A: cage enbois 8: boite logeant I'ordinateurC: papier et impression D: loge-ment de la pile E: clavier F: cel-lules detectrices G: assemblagedudetecteur.

Crop Technology, a ete utilise a cettefin (Figure 1). L'appareil se composed'un ordinateur actionne par pile etloge dans une borre en acier, d'uneimprimante et d'un detecteur. Ladate et la duree des periodes d'humi-dite foliaire ont ete enregistrees parI'ordinateur sur bande de papier.L'assemblage du detecteur etait at-tache a un support installe au niveaudu feuillage d'un plant de tabac(F igure 1) et sa hauteu r eta it regleea mesure selon la croissance du plant.Le detecteur etait relie a I'ordinateurau moyen d'un long cable de 4,5 m.La borre contenant I'ordinateur et Iemontage etait logee dans une cage enbois pour assurer une meilleure protec-tion.

RESULTATS ET DISCUSSION

En 1983, la rosee a ete la princi-pale source d'humidite des feuillessuivie de pres par la pluie. L'humidit~

TABLE 1. SOURCE AND PERIOD OF LEAF WETNESS DURING THE 1983GROWING SEASON

Hours of Leaf WetnessTotal

Dew Rain Irrigation (hrs)

June 16-30 83 26 109July 1 -31 295 32 3 330August 1-31 318 34 352

TABLE 2. MAXIMUM,MINIMUMANDAVERAGEPERIODOF LEAFWETNESSPER DAY DURING THE 1983 SEASON

Hours of Leaf Wetness/day

June 16-30July 1-15July 16-31August 1 -15August 16 - 31

Maximum

13.516.515.420.117.6

Minimum

3.56.07.96.61.2

Average

7.210.211.413.211.5

With the exception of a few daysin late August, the duration of dailyleaf wetness from June 16 to August31 was in excess of 3 hrs. Thus, inthe 1983 growing season, there wassufficient moisture on the leaf surfaceto allow the germination of bluemold conidia and the subsequentinfection of the toabcco leaf.

On the basis of this finding, ifconidia of the blue mold organismP. tabacina do arrive in this area inthe future, symptoms of blue moldshould be readily observed within6-10 days of their introduction intoan unprotected tobacco field.

due a I'irrigation etait negligeable(Tableau 1). La duree moyenne deI'etat d'humidite quotidien des feuillesa augmente avec I'avancement de lasaison jusqu'au 15 aoQt, et a ensuiteregresse legerement du 15 au 31aoQt (Tableau 2). L'humidite maxi-male des feuilles au cours de la pre-miere moitie du mois d'aoQt a depasse20 heures, contre une duree minimaled'environ 6,6 heures.

A I'exception de quelques joursa la fin d'aoQt, la duree de I'etatd'humidite quotidien des feuilles du16 juin au 31 aoQt a depasse 3 heures.Ainsi, au cours de la saison de vegeta-tion de 1983, iI existait suffisammentd'humidite a la surface des feuillespour permettre la germination desconidies de la moisissure bleue, etdonc I'infection subsequente de lafeuille de tabac.

Compte tenu de ces resultats,si ides conidies de la moisissure bleue,

7

TABLEAU 1. SOURCE ET DUREE DE L'ETAT D'HUMIDITE DES FEUILLESAU COURS DE LA SAISON DE VEGETATION DE 1983

Nombre d'heures d'humidite des feuilles

Rosee Pluie Irrigation Total(heures)

Du 16 au 30 juin 83 26 109Du 1er au 31 juillet 295 32 3 330Du 1er au 31 aoOt 318 34 352

TABLEAU 2. DUREE MAXIMALE, MINIMALE ET MOYENNE DE L'ETATD'HUMIDITE DES FEUILLES PAR JOUR AU COURS DE LA SAISON DEVEGETATION DE 1983

Nombre d'heures d'humidite des feuilles/jour

Du 16 au 30 juinDu 1er au 15 juilletDu 16 au 31 juilletDu 1er au 15 aoOtDu 16 au 31 aoOt

Maximal Minimal Moyen

13,5 3,5 7,216,5 6,0 10,215,4 7,9 11,420,1 6,6 13,217,6 1,2 11,5

P. tabacina, font leur apparition danscette region, les sympt6mes de lamaladie devraient etre facilementobservables dans les 6 a 10 jourssuivant leur introduction dans unchamp de tabac non protege.

8

PROGRESS OF THECANADIAN TOBACCO CROP

ONTARIO

FLUE-CURED TOBACCO Marketingof the 1983 crop was completed onMarch 15. Total sales amounted to96,692,728 kg at an average priceof $3.60/kg.

Seeding of greenhouse plant bedsfor the 1984 crop occurred duringthe last few days of March and thefirst week of April. Although no majorproblems occurred during the green-house season, cool, wet weather inlate May delayed field planting insome locations. With the arrival ofwarm, dry weather the first of June,planting conditions have become idealand the crop is now (June 5) about85% planted with excellent prospectsfor its completion by the end of thisweek.

The Ontario Flue-Cured To-bacco Growers' Marketing Board(OFCTGMB) and the Canadian To-bacco Manufacturers' Council (CTMC)have not, as of this date, reachedagreement on either crop size orguaranteed minimum price for the1984 crop. A production target of76,500,000 kg, felt sufficient to meetthis year's requirements for bothdomestic and export markets, hasbeen set by the OFCTGMB. Thisrepresents a reduction of 20,250,000kg or approximately 21% below the1983 target level.

The main varieties grown this yearwill be Delgold on 75% of the hectar-age and our new variety, Candel on21% of the hectarage with smallplantings of Newdel, Delhi -76, Nordel.and Virginia 115 making up thebalance.

DR. P. W. JOHNSON

LE POINT SUR LA CULTUREDU TABAC AU CANADA

ONTARIO

TABAC JAUNE Les ventes de lan!colte de 1983 se sont terminees Ie15 mars. Elles ont atteint un volumetotal de 96 692 728 kg, au prix moyende 3,60 $/kg.

Les semis en serre pour la saison1984 ont ete effectues au cours desderniers jours de mars et de la pre-miere semaine d'avril. Bien qu'aucunprobleme majeur ne se soit produitdurant la saison de la culture en serre,Ie temps frais et hum ide de la fin maia retarde Ie repiquage en plein champen certains endroits. Avec I'arriveedu temps chaud et sec Ie 1er juin,les conditions de plantation sontdevenues ideales et les cultures sontmaintenant (Ie 5 juin) repiquees aenviron 83 % et tout devrait etretermine d'ici la fin de la semaine.

L'Office de commercialisation dutabac jaune de l'Ontario (OCTJO) et IeConseil canadien des fabricants desproduits du tabac ne sont pas encoreparvenus a un accord sur I'importancedes cultures ni sur Ie prix minimumgaranti pour 1984. L'OCTJO a fixeun objectif de production de76500000 kg, juge suffisant poursatisfaire les besoins du marche inte-rieur et de I'exportation. Cela repre-sente une reduction de 20 250 000 kg,ou environ 21 %, par rapport a I'objec-tif de I'annee precedente.

Cette annee, les principales varietescultivees seront Delgold, 75 % dessurfaces, et la nouvelle varillte Candel,21 % des surfaces. Le reste des planta-tions seront composees de Newdel,de Delhi -76, de Nordel et de Virginia115.

P.W. JOHNSON9

QUEBEC

FLUE-CURED TOBACCO Trans-planting was delayed because offrequent heavy rains in late May.In early June, planting was almostcompleted on about 130 farms. Thenumber of farms is thus 10 fewer,as a result of the introduction of aproduction quota. The cultivar Del-gold, which makes up about 90% ofthe crop area, is gradually beingreplaced by the new cultivar Candle.

On several farms, retransplantingwill have to be done over areas total-ling between 2 and 8 ha, as a result ofa wind storm on June 2.

CIGAR TOBACCO In 1983, cigartobacco production totalled 425,220kg, down 28,000 kg from the pre-vious year. The crop brought an aver-age price of $2.12/kg, for a totalvalue of $903,600. For the currentyear, demand is substantially the sameas in 1983. After heavy precipitation.which delayed soil preparation, trans-planting is now progressing normally.

PIPE TOBACCO A total of 17.4ha of pipe tobacco were grown in1983, up slightly from a year earl ier.Production totalled 22,600 kg (4,000kg more than in 1982), and the cropfetched an average price of $2.87 /kg.It is expected that about 20 ha will begrown this year, which would beroughly the same as last year.

FERNAND DARISSE

MARITIMES

Transplanting of the 1984 Mari-time tobacco crop is expected tobegin about June 1.

Weather conditions were normalduring the month of April, however,

10

QUEBEC

TABAC JAU NE La transplantation aete retardee par des pluies abondanteset frequentes a la fin de mai. Au de-but juin, la plantation est presqueterminee chez environ 130 produc-teurs, soit une diminution d'environ10 fermes a la suite de I'imposition ducontingentement de la production. Lecultivar Delgold qui constitue environ90 % de la superficie en culturecede graduellement sa place en faveurdu nouveau cultivar Candle.

Plusieurs producteurs devrontremplacer des plants sur des superficiesvariant de 2 a 8 ha a la suite d'unetempete de vent violent qui est sur-venue Ie 2 juin.

TABAC A CIGARE En 1983, laproduction interieure de tabac acigare a ete de 425220 kg, soit unediminution d'environ 28000 kg parrapport a I'annee precedente. Leprix moyen a ete de 2,12 $/kg pourune valeur totale de 903600 $. Lademande est sensiblement la memeque pour 1983 et la transplantationprogresse normalement apres les fortesprecipitations qui ont retarde Ietravail du sol.

TABAC A PIPE Produit sur 17,4ha en 1983, ce type de tabac a rap-porte 22 600 kg a un prix moyen de2,87 $. La superficie cultivee etaitlegerement superieure a celie de 1982et 4 000 kg de plus ont ete nkoltes.On prevoit qu'environ 20 ha serontcultives cette an nee, soit une super-ficie equivalente a celie de I'an dernier.

FERNAND DARISSE

seedling growth in most greenhouseswas delayed by lack of sunshine andcool temperatures during mid-May.

Cold wet weather conditions hasalso delayed, if not cancelled, effortsby some growers to control black rootrot by the application of soil fumi-gants.

Supply management in the form ofhectarage control will be in effect, forthe first time, in the Maritimes in1984. Hectares to be grown by eachMaritime Province are as follows:Prince Edward Island 1740, NovaScotia 263, and New Brunswick 180.

Islangold will continue to be themain variety grown in Prince EdwardIsland and New Brunswick in 1984with Delgold the main variety grownin Nova Scotia.

W.J. ARSENAULT

MARITIMES

Dans les Maritimes, Ie repiquagedoit commencer vers Ie ler juin.

Durant Ie mois d'avril, Ie tempsetait normal. Cependant, dans laplupart des serres, la croissance desplants a ete retardee par Ie manqued'ensoleillement et les temperaturesfraTches de la mi-mai.

Le temps froid et hum ide a egale-ment retarde, sinon annule les opera-tions de fumigation du sol de certainsproducteurs pour lutter contre Iepourridie noir.

Cette annee, on appliquera pour lapremiere fois dans les Maritimes lagestion des approvisionnements sousforme de limite aux surfaces cultivees.Les surfaces attribuees a chacune desprovinces maritimes sont les sui-vantes: fle-du-Prince-Edouard, 1740ha, Nouvelle-Ecosse, 263 ha, etNouveau~Brunswick, 180 ha.

En 1984, Islandgold demeurerala principale variete cultivee dansI'fle-du-Prince-Edouard et au Nouveau-Brunswick et Delgold, la principaleen Nouvelle-Ecosse.

W. J. ARSENEAULT

11

TOBACCO GREENHOUSE CONSTRUCTION COSTS

Les coOts de la production tabacole sont pour une part importante consacresa la culture de plants a des fins de transplantation. Les resultats d'une enquetesur les coOts de construction des serres en Ontario pourraient s'averer utiles pourIe producteur qui a besoin de construire. On peut se les procurer a la Direction dudeveloppement regional, Agriculture Canada, 420 -102e rue Ouest, Toronto,Ontario, M5S 1M8.

Current marketing problems intensify the cost-price squeeze plaguing tobaccoproducers. They bring into sharp focus the need for cost-cutting in all aspects oftobacco production. The role of Agriculture Canada has always been to helpfarmers become more efficient and more productive. Growing seedlings for trans-plant is an important part of the total cost of producing tobacco. In consultationwith Delhi Research Station staff, personnel of the Toronto-based Regional De-velopment Branch concluded that this cost varied widely throughout the industry.They felt that some concrete facts on greenhouse construction costs would be help-ful to a producer confronted with the need to build. As a result a greenhouse con-struction cost survey in Southern Ontario was undertaken by the Regional Develop-ment Branch and a report prepared. The purpose of the survey as stated in thereport: "There is a wide variety of types of new greenhouses from which a farmmanager may make a choice when confronted with replacement of old greenhousesor new construction. This survey was done to explore the capital cost of green-house construction and to provide some guidelines for extension workers, creditadvisors, lenders, and most of all, the purchaser, with some idea of the range ofcosts of types available." *

The survey method used was as follows:Contact was made in person to 13 suppliers and/or contractors who had ad-

vertised in trade magazines or were known to be active in the area. One majorcontractor for arch-type structures provided information about charges for con-struction. Three local farmers who had been known to use innovation were visited.All cooperators communicated freely and willingly.

Cost data was expressed in a variety of ways by the cooperators, e.g., cost persquare foot, cost per lineal foot. Such variations were converted to a commonfactor, 23 m2 of usable bed, which is the area required to establish 1 ha of to-bacco including replants, according to research and extension workers at DelhiResearch Station.

The area of effective bed was arrived at by assuming need for walkways. An8.23 m wide structure was allotted two 3.67 m beds, and a 12.19 m wide structure,three 3.67 m beds. Variations in arrangement could create small differences, asindicated by some suppliers.

* The range of types and costs developed from the survey are set out in table 1.

12

Some difference in quotations given may be due to the inclusion of, or ex-clusion of, the 7% Provincial Sales Tax. No attempt was made to rectify this be-cause final pricing could vary by that much or more, depending on the size of thestructure and payment arrangements or when discounds are available.

No costs for inside adaptation of walkways, watering devices, etc., were in-cluded in costing. There is a wide variety of sources, types and grower preferencefor these items, sufficient to warrant excluding this area from the study. Anygrower use of the data would need to add costs for such items.

Site leveling or preparation is always the responsibility of the purchaser andwas excluded from the survey.

Structures which include top ventilation, such as standard wood and glasshouses, are not charged with any mechanical ventilation costs. All steel andglass- and fiberglass-covered structures were charged with the need for fans, ventila-tors and thermostats. A rounded figure of $1800 per structure was used unlessother information was supplied. Purchasers would likely be able to obtain suchitems for less.

ANNUAL OWNERSHIP COSTS

Annual ownership costs, rarely, if ever, show up in a purchaser's records. How-ever, in a survey of this kind it is considered important to reflect:A. The opportunity income loss through having invested in a capital asset ratherthan investing the money for income. Interest on average investment was calcu-lated as follows: CaPit;1 Cost X 12%

B. Depreciation - buildings do not last forever. The straight line depreciationmethod was used to determine the annual depreciation cost.1. Metal structures were assigned 25 -year life or 4% per year depreciation.2. Wooden structures were assigned a 20-year life or 5% depreciation.3. Equipment such as fans and vents were assigned a 10-year life, so weredepreciated at 10% per year.

4. Fiberglass was assigned a 10-year life so the material replacement and laborto replace were depreciated at 10% per year.(This decision may create some controversy. It was decided on the basis ofpast experience by research and extension workers at the Delhi ResearchStation, and opinions expressed by some builders in spite of potential brandsbeing sold under "20-year life" criteria. The selection of 10-year life isconsidered "safe"; if extended life is experienced, the purchaser will gain.)

5. Polyester is considered to have a 3 -year life and so was depreciated at 331/3%per year.

6. An annual replacement cost of $60 for glass was assigned to all glass structuresregardless of size.

13

TABLE 1. RANGE OF CONSTRUCTION COSTS

Type

1. Steel arch frame, double polyester,farmer erected

2. Steel arch frame, double polyester,erected without foundation

3. Steel arch frame, double polyester,erected on foundation

4. Wood and glass, all new glass,erected on new foundation

5. Steel truss and fiberglass,erected on new foundation

6. Steel arch and fiberglass,erected on new foundation

7. Wood and fiberglass,erected on new foundation

8. Metal trusses, framing, caps and glass,erected on foundation or pillars

, 23 m2 = 247.5 square feet, which is adequate for 1 ha of tobacco.

Cost/23 m2 ofeffective bed 1

($)

656.23

767.33

1049.59

1356.95

1468.51

1485.67

1524.75

1915.80

As a guide for using the table to estimate costs, the following explanation andexamples are presented in the report.Since 23 m2 of usable bed is considered adequate for 1 ha (2.49 acres) of to-

bacco, a producer can look over the list in table 1 and quickly determine a ball-park figure for a new greenhouse.Let us suppose that two farmers need space to produce plants for 10 ha (24.71

acres) of crop. Farmer A choosestype #1 at a cost of $656.23/23 m2 so his capitalcost would be:

10 X $656.23 = $6562To get the full benefit of the range of types, let us supposethat Farmer B choosestype #8 at a cost of $1915.80/23 m2, so his capital cost would be:

10 X $1915.80 = $19158.The same principle can be applied for any area.The foregoing ownership costs are for contractor erected greenhouses. Some

farmers find that they can save money by doing it themselves. Here are the costsof three farmers who erected their own.

14

FARMER A

Lumber cut from logs from own woodlot, rough sawed. Concrete foundation by contractor.All erection and application of fibreglass by owner. Fan and vents purchased locally.

Cost per 23 Square Metres of Usable Bed

10 hectare crop16 hectare crop

FARMER B

Total

$923.04$9230.00

$14769.00

Annual Ownership Cost

$131.71$1317.00$2107.00

Railway ties used for posts on sidewalls, set and cut off after using transit to mark them. Roughsawed lumber used for rafters and framing along with some old kiln hangers. Fibreglass usedfor cover on top and sides. Fan purchased locally. Most of labour was supplied by owner.Structure is 5 years old.



FARMER C

Total

$665.84$6658.00

$10653.00


$98.20$982.00

$1571.00

Railway ties used for sidewalks, set and cut off after using transit for marking. Rough sawedlumber and some lumber from old kilns used for rafters and framing. Some plywood used forstripping. Sidewalls are fibreglass covered. Rafters are on 60.96 em (24 inch) centres. de.cided to use single layer of 6 mil. poly. because of cost and changes taking place in fibreglass.Poly. has survived two years and likely will do three. Long range plan is to install fibreglass. Alllabour supplied by owner. Fans and vents purchased locally.



Total

$321.30$3213.00$5141.00


$46.11$461.00$738.00

To obtain the full text of the report, anyone considering building a tobaccogreenhouse is invited to contact; the Delhi Research Station, Agriculture Canada,P.O. Box 1B6, Delhi, Ontario N4B 2W9, or Regional Development Branch, Agri-culture Canada, 420-102 Bloor Street West, Toronto, Ontario M5S 1MB.

15

This is the first in a series of articles on growing tobacco seedlings pre-pared by E.K. Walker and colleages at the Delhi Research Station. Thearticles will be published in sequence in this and subsequent issues ofthe Lighter.

FLUE-CURED TOBACCO SEEDLINGS: EFFECTS OF SEEDLINGAGE, TRANSPLANTING TIME, AND SEEDING DENSITY ONSEEDLING GROWTH AND CROP PRODUCTION FACTORS

E. K. WALKER

L'age du plant de tabac au moment de sa transplantation a un effet sur sa crois-sance et sur la recolte, qu'on etudie dans cet article. Dans les experiences relatees,on a fait varier I'epoque de la transplantation et la densite des plants.

Variations of seedling age, transplanting time and seeding density may havea significant effect, alone or in combination, on seedling growth characteristicsand on subsequent survival, days to flower, quality and yield in the field. Anexamination of the effects of transplanting time, in conjunction with differingmethods of seedling culture, in a previous publication (2) revealed that days toflower, weight of sucker growth and level of total alkaloids decreased with delayof transplanting within the period May 25 to June 8, whereas number of leaves,grade index, and level of reducing sugars were relatively unaffected. In a subsequentseedling hardiness study (3), field survival improved with a reduction of seedingdensity from 0.17 to 0.10 g per m2. An increase in density also was associated witha reduction in seedling size at transplanting, longer days to flower and lower yield.Since no previous information has been obtained concerning the effects of seedlingage at transplanting time on seedling growth and crop production factors, thepresent study was undertaken. Transplanting time and seeding density also werevaried to obtain further information on effects of these factors on seedling growthand crop production as well as determine their effects, if any, on responses toseedling age.

MATERIAL AND METHODS

Seedlings of flue-cured tobacco cv. Delhi 76 were grown in an unheated glassgreenhouse using pelleted seed in wooden flats (0.186 m2) containing about 6.36cm of steam-sterilized muck (organic soil) pre-fertilized with 4-30-8 tobacco green-house fertilizer at the rate of 25 kg per 100 m2. Pellets were carefully distributedin the flats to achieve seeding densities of 0.10, 0.13 and 0.17 g per m2 of non-pelleted seed. For this purpose, 200, 250, and 330 pellets were required per flat

Mr. Walker is a research scientist at Agriculture Canada Research Station. Delhi, Ontario.

16

for densities of 0.10, 0.13 and 0.17 g per m2. The seed was covered with about0.6 cm of tobacco grade vermiculite to enhance germination, reduce 'tipping-over' of newly germinated seedlings and minimize watering. Flats were seeded onApril 5, 12 and 19 to obtain 45 day plants by May 26, June 2 and June 9 trans-planting dates, respectively. Similarly, flats were seeded on March 29, April 5 and15 to obtain 52 day plants, and on March 22, 29 and April 5 to obtain 59 dayplants on the same transplanting dates. Age was measured from the appearance offirst visible growth rather than from seeding date. The first visible growth usuallywas 7 days :t 1 day from the seeding date, so that seedling ages of 45, 52 and 59days from first visible growth were approximate rather than actual. The flats allwere located at grade level and the seedlings were grown under a conventionalregime of temperature, water application and hardening procedures. Starting aboutthe middle of May, the seedlings were hardened through reduced water applica-tion and temperature levels.

At times of transplanting 10 representative seedlings from each treatment werecollected for measurement of shoot and root weights, and other plants were trans-planted by hand into quadruplicate single-row field plots. Percentage plant survivalwas recorded about two weeks after transplanting, while days to flower, whichwas the days from transplanting to opening of the first bloom, was recorded indivi-dually for each plant in each plot. Conventional production practices for fertiliza-tion, irrigation, control of nematodes, weeds, insects, diseases and suckers, andcultivation were followed, except that fertilizer was banded a few days after trans-planting rather than at time of transplanting. The plots were harvested in fiveprimings and cured in small, electrically-heated chambers of 15 lath capacity.End plants in each plot were not harvested and extended yield was based on actualnumber of plants rather than plot area. Grade indices (1). yield and crop returnswere calculated for the cured leaves.


Seedling GrowthSeedling age at time of transplanting, transplanting date and seeding density

all affected seedling growth characteristics (Table 1I. Examination of the meanvalues (Table 31 shows that shoot and root weight increased and shoot/root de-creased from 45 to 59 day old plants. Changes were consistent with age differences,except that shoot weight for 52 day plants was less than that for 45 day plants.Also, shoot weight and shoot/root increased while root weight, decreased withdelay of transplanting date, and shoot and root weight both decreased with increas-ing density of seeding. However, shoot/root was affected little by seeding density.

Increases in shoot and root weight with seedling age, which was obtained, isthe expected result. It is also apparent from shoot/root that root weight eitherincreases proportionately more than shoot weight with increased age, or thatweight of roots retained on pulling is proportionately greater with older seedlings.It is conceivable that younger plants have a higher proportion of fine roots that arereadily lost on pulling of the seedlings.

The increases in shoot length with delay of transplanting date show that growthconditions in the greenhouse improve with longer days and higher temperatures.

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TABLE 1. GROWTH CHARACTERISTICS OF FlUE-CURED TOBACCOSEEDLINGS RELATIVE TO DIFFERENCES IN SEEDLING AGE, TRANS-PLANTING TIME, AND SEEDING DENSITY, 1977.

Treatment

Seedlingagedays

454545454545454545525252525252525252595959595959595959

Transplantingdate

May 26May 26May 26June 2June 2June 2June 9June 9June 9May 26May 26May 26June 2June 2June 2June 9June 9June 9May 26May 26May 26June 2June 2June 2June 9June 9June 9

Seedlingdensityg/m2

0.100.130.170.100.130.170.100.130.170.100.130.170.100.130.170.100.130.170.100.130.170.100.130.170.100.130.17

Shootweight

g

4.314.404.716.575.834.006.506.554.014.915.584.237.013.013.546234.543.924.106.025.557.976.354.095.766.065.33

Rootweight

g

0.300.260.230270.300200.190.140.100.420.470.310.460.130.210.230.120.100.320.510.350.600.440.310200240.24

Shoot/root

14.416.920.524.319.420.034.241.840.111.711.913.715223216.927.137.839212.811.815.913.314.413228.825.3222

Values of F (*5%)Seedling age (A)Transplanting date (B)Seedling density (C)AxBAxCBxCAxBxC

18

8.1**3.7*

23.8**2.5*3.3*12.6**2.6*

27.1 **53.5**16.2**5.5**3.1 *7.1 **3.5**

47.1 **205.7**

4.7*8.0**2.5*3.1 *3.7**

TABLE 2. CROP PRODUCTION FACTORS FOR SEEDLINGS RELATIVE TODIFFERENCES IN SEEDLING AGE, TRANSPLANTING TIME, AND SEEDINGDENSITY, 1977.

TreatmentSurvival Days

Seedling Transplanting Seedling in to Grade Cropage date density field flower index Yield returnsdays g/m2 % $/kg kg/ha $/ha

45 May 26 0.10 95 65.0 2.27 3194 725045 May 26 0.13 97.5 67.1 2.24 3215 720245 May 26 0.17 97.5 67.3 2.28 3264 744245 June 2 0.10 100 63.1 2.20 3276 720745 June 4 0.13 95 67.1 2.28 2976 678545 June 2 0.17 100 64.5 2.23 3257 726345 June 9 0.10 100 60.2 2.26 3248 734045 June 9 0.13 100 58.9 2.22 3217 714245 June 9 0.17 100 61.2 2.22 3171 704052 May 26 0.10 100 64.6 2.26 3107 700852 May 26 0.13 100 64.3 2.29 3349 766952 May 26 0.17 97.5 66.9 2.20 3271 719652 June 2 0.10 92.5 64.8 2.26 3011 680552 June 2 0.13 100 63.9 2.24 3190 714652 June 2 0.17 97.5 64.7 2.22 3190 708252 June 9 0.10 100 62.6 2.23 3161 704952 June 9 0.13 95 65.7 2.21 2816 622352 June 9 0.17 100 62.9 2.16 3136 677459 May 26 0.10 97.5 64.1 2.28 3197 728959 May 26 0.13 100 61.9 2.26 3340 754859 May 26 0.17 95 66B 2.26 3255 735659 June 2 0.10 100 61.1 2.31 3128 722659 June 2 0.13 100 62.2 2.26 3286 742659 June 2 0.17 100 63.7 2.24 3281 734959 June 9 0.10 100 58.1 2.26 3232 730459 June 9 0.13 100 582 2.26 3318 749959 June 9 0.17 100 57.9 2.26 3262 7372

-------------------- --- -- ----------Values of F (*5%; **1%)Seedling age (A) N.S. 21.4 ** N.S. 3.7* 4.0*Transplanting date (B) N.S. 49.9** 3.2* N.S. N.S.Seedling density (C) N.S. 5.1 ** N.S. N.S. N.S.AxB N.S. 5.4 * * N.S. N.S. N.S.AxC N.S. N.S. N.S. N.S. N.S.BxC N.S. N.S. N.S. N.S. N.S.AxBxC N.S. N.S. N.S. N.S. N.S.

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TABLE 3. MEAN VALUES BY AGE, TRANSPLANTING DATE AND SEEDINGDENSITY, 1977.

Measurement

Shoot Root Shoot Survival Days GradeVariable weight weight /root in to index Yield Returns

field flowerg g % $/kg kg/ha $/ha

Seedling age45 days 5.21 0.22 25.7 98.3 63.8 2.24 3202 718652 days 4.77 0.27 21.9 98.1 64.5 2.23 3137 699559 days 5.69 0.36 17.5 99.2 61.6 2.27 3255 7374

Transplanting dateMay 26 4.87 0.35 14.4 97.8 65.3 2.26 3244 7329June 2 5.37 0.32 17.8 98.3 63.9 2.25 3177 7143June 9 5.4~ 0.17 32.9 99.4 60.6 2.23 3173 7083

Seeding density0.10 g/m2 5.93 0.33 20.2 98.3 62.6 2.26 3173 71640.13 g/m2 5.37 0.29 22.5 98.6 63.3 2.25 3190 71820.17 g/m2 4.38 0.23 22.4 98.6 64.0 2.23 3232 7208

Means for experiment 5.23 0.28 21.7 98.5 63.3 2.25 3198 7185

The decrease of root weight with delay of transplanting date indicates that goodgrowth conditions promote shoot in preferance to root growth, and because of dif-ferent rates of shoot and root development under improving growth conditions,the shoot/root ratios increase with delay of transplanting date. Such increases inshoot/root may be detrimental to subsequent rate of field survival, days to flower,quality and yield in the field unless shoot/root is reduced by hardening proceduresthat restrict shoot growth (3).

All interactions were significant with many being highly significant, therebyindicating that effects of any factor on growth characteristics varied with elementor level of other factors. For instance, although seedling age had a highly significanteffect on shoot and root weight and on shoot/root, the response to seedling ageobviously varied somewhat with transplanting date and seeding density. Similarly,the responseto transplanting date varied with seedlingdensity.

Survival in Field

The percentage survival was relatively good in all treatments and differencesamong treatments were relatively small and non-significant (Table 2). The meanvalues (Table 3) do show some evidence of slight differences, particularly withrespect to variations in seedling age and transplanting date. Survival tended to im-prove with older plants, which also had lower shoot/root than younger plants.With transplanting date, however, survival tended to improve with delay of datein spite of a simultaneous increase in shoot/root. Obviously, field survival condi-tions improved with later dates thereby precluding a low shoot/root advantagefor early set transplants.

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Days to FlowerEach of the main factors had a highly significant effect on days to flower-

(Table 2). Such effect was particularly pronounced with transplanting date andseedling age. Delay of transplanting date invariably shortens days to flower (2),and the results herein provide no exception. The average difference of about fivedays between the May 26 and June 9 transplanting dates (Table 3) has much lessmeaning than the actual date of flowering. Consideration of transplanting datesand days to flower reveals that plants set out on May 26, June 2 and June 9flowered on the average by July 30, August 5 and August 9, respectively. An earlydate is much more desirable than a later date from the standpoints of crop maturityand quality, and prevention of damage from late season low temperatures. Youngerplants might be expected to take longer to reach the flowering stage than olderplants, and in fact such a result was obtained (Table 2). However, the differencesin this respect were small compared to the age differences. Days to flower for 45and 59 day plants, a difference of 14 days, only differed by two days. Days toflower also decreased somewhat with a reduction in seeding density from 0.17 to0.10 g/m2.

Grade Index, Yield and Crop ReturnsThese agronomic indices were affected comparatively little by the experimental

variations but seedling age and transplanting date did have some effect (Table 2).Since all three values tended to be slightly higher for 59 than for 45 day plantsand lowest for 52 day plants, differences lacked consistency with treatment.Contrariwise, values for each index or measurement tended to decrease slightlyamong successively later transplanting dates.

CONCLUSIONS

Seedling growth characteristics are affected substantially by variations inseedling age, transplanting time and seeding density, although evidence was ob-tained to indicate that effects were not entirely independent. The response ofseedlings to such variations also appeared to depend upon growth conditions inthe greenhouse. In general superior seedling growth characteristics and field resultswere obtained with 59 day plants seeded at -.10 g/m2 and transplanted on May 26.

REFERENCES

1. Anonymous. 1965. Ontario Farm Products Grades and Sales Act and Regula-tions Respecting Flue-Cured Tobacco. Toronto, Ontario. pp. 10-25.

2. Walker, E. K. 1973. Comparison of flue-cured tobacco transplants variable intime of transplanting and method of culture. The Lighter 43 (3) : 18 -23.

3. Walker, E. K. 1974. Comparison of flue-cured tobacco transplants variable inprocedures for hardening. The Lighter 44 (4) : 22 -28.

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INFLUENCES OF SEED SIZE, VERMICULITE COVER, ANDWATERING REGIME ON GERMINATION, SURVIVAL, ANDGROWTH OF FLUE-CURED TOBACCO SEEDLINGS UNDERGLASS

E. K. WALKER, L. B. REYNOLDS AND W. D. ROGERS

L'etude dEkrite ci-dessous analyse I'influence de la taille de la semence, du regimed'arrosage et du type de couvert sur la germination, la resistance et la croissancedes plants de tabac jaune cultives sous verre.

A large number of factors influence the density and uniformity of flue-curedtobacco seedling stands in greenhouses. Density and uniformity in turn may in-fluence efficiency of seedling production, hardiness of seedlings, and subsequentresults in the field. Foremost among factors affecting density and uniformity ofstand are seed size; density of seeding; germination percentage of the seed; type orquality of growth medium, including such factors as pH and soluble salt levels;use of vermiculite top-dressing; fertilization practices; and the amount and fre-quency of watering.

Stand can vary by one-third or more on the basis of seed size alone. Such adifference has recently prompted registered seed growers to eliminate the smallestseed, by more efficient cleaning, and thereby decrease the range in number ofseeds per package. In general, they are attempting to reduce seed counts below14100/g (400,000/oz.) and produce samples with counts, in an average year, be-tween 11300 and 14100/g (320,000 and 400,000 oz.). Provision of a definiterange in seed count is complicated by the facts that varieties differ somewhat inseed size, and that seed size varies with year' , but variation in seed count could bereduced still further by the institution of uniform cleaning procedures by seedgrowers. Rather than try to further reduce the range in seed count among com-mercial packages, it would seem to be preferable to obtain counts in bulk lotsof seed and to show that count on packages from each lot. The germination per-centage for the bulk lot or possibly a range for several tests also could be shownon the packages therefrom. With a rather definite count and germination percen-tage on the package, the tobacco grower would be in a better position to aim foran optimum density of stand. Germination percentage itself would appear to varyconsiderably with seed size. Cundiff (2) found that the emergence potential oftobacco seed was positively correlated with seed size, and Gawande et al (4) foundthat large seed had the highest germination percentage and shortest germinationtime. Cundiff et al (3) stated that a 2 day difference in date of germinationproduced a significant difference in transplant size at time of transplanting. Al-though no such information has been published in Ontarioilrown tobacco, it islikely that germination percentage and time also vary with seed size. It is even

, Personal communication, Dr. R. S. Pandeya, Plant Breeder, Delhi Research Station.

Messrs.Walker, Reynolds and Rogers are tobacco researchers at the Delhi Research Station.

22

conceivable that potential differences in seedling population because of differingseed count may be considerably less than anticipated because of low germination,and, perhaps, poor post-germination survival of plants from small compared tolarge seed.

In addition to seed count and germination percentage, density of stand will,of course, vary with seeding rate, and with management practices such as wateringregime and use of a vermiculite topdressing during the germination and immediatepost-germination period (6). Bed surfaces are more likely to dry without a vermi-culite cover, and germination of viable seeds to be inhibited because of resultinghigh temperatures. Also, a vermiculite cover reduces incidence of "tipping over"(surface root growth). perhaps because vermiculite prevents surface packing ofmuck during water application. Most "tipped over" seedlings fail to survive. Thewatering regime during the germination and immediate post-germination periodshould be such, either with or without vermiculite, as to prevent surface dryingof the bed, but no information is currently available to indicate the optimum fre-quency and amount of water application for this purpose. With vermiculite, whichhas a high moisture-holding capacity, watering can be less frequent than with baremuck to prevent surface drying (6).

The ideal population per 0.093 m2 (1 ft2) of tobacco greenhouse beds inOntario is considered to be 110 to 120 seedlings (6). but prediction of populationfrom a specific seeding density, without control of the aforementioned variablesof seed size, germination percentage and management factors is impossible.

The present study was undertaken over a 2 -year period to examine the effectsof seed size, with and without vermiculite top-dressing and with variable wateringregimes, on germination and on post-germination survival, in an effort to furtherelucidate factors important for attaining ideal populations of seedlings.

MATERIALS AND METHODS

An initial study in 1981 concerned vanatlon in seed size only. A bulk lot oflightly-cleaned seed of Nicotiana tabacum L., cv Delgold, was separated into foursizes by forced air and screening. The seed counts for sizes designated A, B, C, andD, as obtained with an electronic tobacco seed counter (1). were 317.832; 376,998;414,477; and 571,564 per 28.35 g (1 oz.). respectively. Time and percentage ofgermination was determined from seed on wet filter paper within petri dishesunder artificial light in the laboratory. Samples of each size then were mixed withwood ash diluent and spread on flats, each 0.186 m2, and containing 5.08 cm depthof steam-sterilized much, in a heated greenhouse. Seed weights per flat were 0.025,0.024, 0.024 and 0.024 g per sizes A, B, C and D, respectively. Particular carewas taken to keep the muck surface moist during the germination period byfrequent light watering. Also, the flats were covered with kraft paper during thisperiod to reduce frequency of water application. Total germinated plants in eachflat were counted daily starting with the first appearance of seedlings.

The study of seed size was expanded in 1982 to include variations in mediaand watering regime within small flats, each 0.077 m2 with 5.08 cm depth ofmuck, in a non-heated greenhouse. Four different seed sizes were obtained froma bulk lot suitable for commercial sale of Nicotiana tabacum L., cv Delgold, byforced air and screening. The seed counts for sizes designated A, B, C and D,

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counted as in 1981, were 303,359; 327,485; 349,563; and 406,971 seeds per28.35 g (1 oz.), respectively. Time and percentage of germination also was obtainedin the laboratory as in 1981. The greenhouse experiment with 36 small flats wasstarted in April 6 after application of 0.012 g of seed in wood ashes, regardless ofseed size, to each flat. The flats were located at grade level and watered with anoverhead travelling, double boom system (5) that applied water uniformly at therate of 0.72 liters per m2 for a single pass. One-third of the flats had a vermiculitetop-dressing to a depth of 1.27 cm, another one-third had vermiculite to a depth of0.64 cm, and one-third had no vermiculite top-dressing. Four of the flats in eachgroup, one for each seed size, were watered with one pass of the sprinkler systemsix times per day on sunny days and three times per day on cloudy days. Thisschedule was designated as light frequent (LF). The next four flats in each groupwere watered the same number of times as the LF treatment, except that twopasses of the sprinkler were made at each watering. This schedule was designatedas medium frequent (MF). The last four flats in each group were watered twice onsunny days and once on cloudy days with four passes being made at each watering.This last schedule was designated as heavy infrequent (HI). These watering sched-ules were maintained during the germination period and the ensuing two weeks.Thereafter, all flats were watered identically. at transplanting time the shoot growthin each flat was removed, plants were separated into those of transplant size andthose too small for transplanting, and each shoot was weighed.


Most of the seed in the three largest size categories in 1981 germinated in 6days(Table 1), although the largest size showed a somewhat higher percentage in this timethan the next smaller sizes. All three sizes had germination percentages in 6 daysof 90 percent or higher. The smallest size (D), which had an unusually high countper unit weight, had a germination percentage of only 44 per cent after 6 days anda maximum of 55 per cent after 12 days. Germination for size A was 100 per centafter 8 days, and 92 and 97 per cent after 12 days for sizes Band C, respectively. Th ispercentage for sizes A, Band C increased by only 1,2 and 4 percent while that forsize D increased by 11 percent after that time. The data show, in general, that largeseed germinates more quickly and completely than smaller seed, although seedwith a count of about 14620 per g (400,000 per28.35 g) or less germinated very well.

Results with flats in the heated greenhouse in 1981 (Table 2) were similar tothose obtained in the laboratory, except that germination started and ended soonerthan in the laboratory. Based upon germination percentage and weight of seeddispensed per flat, the number of plants were somewhat higher or lower thanexpected. This discrepancy could be because of some inaccuracy in projecting seedcounts from a small to large weight, or slightly different germination than obtainedin the laboratory. It is obvious, however, that germination and survival for eachseed size were reasonably close to the expected.

The range in seed size in 1982 was much less than in 1981, and germinationpercentages were above 90 percent for the three largest sizes (Table 3). These sizescovered the range from 10700 to 12330 seeds per g (303359 to 349563 seeds per28.35 g). The smallest size (D), which had a germination percentage of 73.4, wasslightly larger than size C in 1981, which germinated at 97 percent. It would appear

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TABLE 1. EFFECT OF SEED SIZE ON EXTENT AND TIME OF GERMINA-TION.

Seedlot

ABCo

Seed1Percentage germination

Count Time in daysNo.lg 6 7 8 12

11,211 99 99 10013,298 90 91 91 9214,620 93 93 96 9720,161 44 49 51 55

1Counts of 317,832; 376,998; 414,477; and 571 ,564/28.35 g (1 oz.l

TABLE 2. EFFECT OF SEED SIZE ON EXTENT AND TIME OF GERMINA-TION AND ON SURVIVAL IN THE GREENHOUSE, 1981.

Time in days Time in days

Seed Seed 5 6 7 8 11 5 6 7 8 11 Germination andlot count survival of

Cumulative no. of Cumulative % of viable seedNo.lg germinated seeds final total %

A 11,211 9 185 268 281 286 3.1 64.7 93.7 98.3 100 102.1B 13.298 9 155 262 262 274 3.3 56.6 95.6 95.6 100 93.5C 14,620 9 179 272 299 320 2.8 55.9 85.0 93.4 100 94.10 20,161 9 80 197 235 275 3.3 29.1 71.6 85.5 100 103.4

TABLE 3. EFFECT OF SEED SIZE ON EXTENT AND TIME OF GERMINATIONIN THE LABORATORY, 1982.

Percentage germinationSeed Seed1lot Count Time in days

No.lg 5 6 7 8 9 10

A 10,700 10.6 61.5 86.8 92.1 94.7 95.5B 11,551 14.4 73.9 86.7 92.0 94.1 95.2C 12,330 9.1 67.5 80.7 86.3 90.4 91.40 14,355 0 3.4 22.7 53.7 70.9 73.4

from these results that relatively small seeds with counts over 400,000 seeds per28.35 g, may be more variable in germination than larger-sized seed.

All viable seed germinated within 10 days, starting 5 days after commencementof the germination test (Table 3). Practically all seed of sizes A to C had germinatedafter 8 days, whereas considerable seed of size D was still germinating on days 9and 10. In addition, very little germination of size D occurred before 7 days.

Results obtained in the greenhouse in 1982 varied considerably with mediacover, watering schedule and seed size (Tables 4 and 5). Mean values for each media

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N TABLE 4. SEEDLING COUNT AND WEIGHT IN SMALL FLATS SEEDED WITH DIFFERENT-SIZED SEED, WITH AND(l)

WITHOUT VERMICULITE COVER OVER MUCK, AND PROVIDED WITH DIFFERENT WATERING REGIMES DURINGGERMINATION AND EARLY GROWTH IN THE GREENHOUSE, 1982.

Treatment1 Shoot growth on June 1 Survival

Media Watering2 Seed Small Transplantable Total Total Viablecover schedule Viable3 Total plants plants plants seed seed

--No.1 Mean Mean No.1 Mean

No.lflat flat wt. No.lflat wt. flat wt.9 9 9 % %

Nil LF 121 127 20 2.46 36 6.74 56 5.21 44.1 46.3Lf 132 139 39 2.06 34 5.62 73 3.72 52.5 55.3LF 135 148 16 2.75 40 6.01 56 5.08 37.8 41.5LF 127 172 18 2.84 18 5.17 36 4.00 20.9 28.3MF 121 127 31 1.60 45 4.31 76 3,21 59.4 61.8MF 132 139 55 1.48 31 4.10 86 2.42 61.9 65.2MF 135 148 33 1.49 37 5.67 70 3.70 47.3 51.9MF 127 172 32 1.75 31 5.16 63 3,43 36.6 49.6HI 121 127 32 2.47 26 7.71 58 4.82 45.3 47.2HI 132 139 43 1.88 40 5.55 83 3.65 59.7 62.9HI 135 148 45 2.29 28 5.21 73 3.41 49.3 54.1HI 127 172 40 2.21 29 6.08 69 3.84 40.1 54.3

0.64 cm LF 121 127 23 2.34 46 5.52 69 4.46 53.9 56.1vermiculite LF 132 139 46 2.28 35 5.04 81 3.47 58.3 61.4

LF 135 148 40 1.68 67 5.27 107 3.93 72.3 79.3LF 127 172 30 1.82 54 6.13 84 4.59 48.8 66.1MF 121 127 56 1.81 50 5.03 106 3.33 82.8 86.2MF 132 139 66 1.55 29 4.68 95 2.51 68.3 72.0MF 135 148 47 1.80 61 5.84 108 4.08 73.0 80.0MF 127 172 65 1.79 35 5.86 100 3.22 58.1 78.7HI 121 127 38 1.75 41 6.01 79 3.96 61.7 64.2HI 132 139 43 1.94 57 4.70 100 3.51 71.9 75.8

N....•

HI 135 148 61 1.83 53 5.00 114 3.31 77.0 84.4HI 127 172 63 1.85 39 6.23 102 3.53 59.3 80.5

1.27cm LF 121 127 61 2.18 42 5.79 103 3.65 80.5 83.7vermiculite LF 132 139 49 1.67 56 6.05 105 4.00 75.5 79.5

LF 135 148 52 2.14 49 5.46 101 3.75 68.2 74.8LF 127 172 53 2.14 51 6.76 104 4.41 60.5 81.9MF 121 127 67 2.11 40 4.40 107 2.97 83.6 87.0MF 132 139 60 1.84 56 4.95 116 3.34 83.5 87.9MF 135 148 87 2.03 33 3.87 120 2.53 81.1 88.9MF 127 172 49 1.81 48 5.28 97 3.53 56.4 76.4HI 121 127 5? 2.05 61 5.65 113 4.00 88.3 91.9HI 132 139 48 1.58 72 5.62 120 4.00 86.3 90.9HI 135 148 57 1.99 56 5.54 113 3.25 76.4 83.7HI 127 172 53 1.76 51 5.34 104 3.51 60.5 81.9

1Seededand first watered on April 6.2 LF = 1 pass (0.72 liters/m2) 6 times on sunny days. 3 times on cloudy days;MF = 2 passes(1.44 liters/m2) twice on sunny days. once on cloudy days.HI = 4 passes(2.88 liters/m2) three on sunny days. once on cloudy days.

3 Basedon germination percentages of 95.5. 95.2. 91.4 and 73.6% for 10.70. 11.55. 12.33 and 14.36 seeds/mg, respectively. and a seed applica-tion of 0.012 g/flat for each size of seed.

cover (Table 5) show that germination and survival of viable seed was very poorin bare muck compared to muck top-dressed with vermiculite. Also, a vermiculitecover of 1.27 cm was considerably more effective than a cover of 0.64 cm. Al-though no attempt was made to count the number of seedlings with surface rootgrowth (tipping-over) in bare muck or their survival rate, which is normally low,a large number of such seedlings were present. The association of this growthphenomenon with bare muck indicates that water application may pack the surfaceand stimulate root growth on the surface where there is a generally plentiful supplyof moisture, unless the surface is allowed to dry out, and of oxygen. There is apossibility also that water application may actually expose the roots of some youngseedlings. Further, there is evidence that incidence of tipping-over is temperature-related, as very little occurs in a heated greenhouse1 . A vermiculite cover may pre-vent pack ing of the muck surface, thereby reducing incidence of tipping-over. Atthe same time such a cover would appear to enhance germination by maintaininga more constant water supply on the surface and by prevention of damaging hightemperatures.

Germination and survival were somewhat higher for the MF watering schedulethan for the LF and HI schedules (Tables 4 and 5). It would appear that the LFschedule, in particular, provided insufficient amounts of water to ensure an opti-mum level of germination and survival. The H I schedule, in spite of greatly reducednumbers of water application, was almost as effective, on the average, as the MFschedule (Table 5). In conjunction with the 1.27 cm depth of vermiculite, whichholds more water than the 0.64 cm depth, the HI schedule was actually somewhatmore effective for optimizing germination and survival than the MF schedule.

Germination and survival by seed size appeared to depend more upon viability(germination percent) of the seed, on the average, than upon seed size (Table 5),although the smallest seed, size D, showed a somewhat lower percentage than sizesA to C. Examination of the data for individual treatments or groups of treatmentsaccording to media cover and watering regime (Table 4) reveals, however, thatgermination and survival according to seed size varied with media cover and water-ing schedule. With each of the watering schedules without media cover, size B seedhad appreciably higher germination and survival of viable seed than other seedsizes, including size A. Since surface drying and damaging high temperatures wouldconceivably be a greater problem with no media cover, it would appear that thelargest seed was somewhat more subject to damage than slightly smaller seed. Inthe case of the H I watering schedule, all sizes had better germination and survivalthan size A, but, in schedules with more frequent watering, sizes C and D wereinferior in th is respect to size A. Although the largest seed might be expected tohave greater resistance to damage, it is possible that smaller seed penetrated moredeeply into the growth medium. Germination and survival of the largest seed alsowas lower for size A than for smaller sizes with a 0.64 cm vermiculite cover, exceptin conjunction with the MF watering schedule. It would appear that the LF and HIschedules were insufficient to prevent damage to the largest seeds, which, as men-tioned above, may have been situated more on the bed surface than smaller seeds.Contrariwise, germination and survival of the largest seed was higher than forsmaller seeds where all seed was covered with 1.27 cm of vermiculite, regardless

1Unpublished results, ResearchStation, Delhi.

28

TABLE 5. MEAN VALUES FOR SHOOT GROWTH AND SURVIVAL RE-LATED TO VARIATIONS OF MEDIA COVER, WATERING SCHEDULEAND SEED SIZE, 1982.

Shoot growth on June 1 Survival

Variable Small plants Large plants Total plants Totalseeds

Viableseeds

Media cover

No. Weight(g)

No. Weight(g)

No. Weight(g) %

Nil0.64 em verm.1.27 em verm.

WateringLFMFHI

Seed size10.70 seeds/mg11.55 seeds/mg12.33 seeds/mg14.36 seeds/mg

33.748.257.3

37.354.047.9

42.249.948.744.8

2.111.871.94

2.201.761.97

2.091.812.002.00

32.947.351.3

44.041.346.1

43.045.647.139.6

5.615.445.39

5.804.935.72

5.685.155.325.78

66.6 3.8795.4 3.66108.6 3.62

81.3 4.1995.3 2.1994.0 3.77

85.2 3.9695.4 3.4095.8 3.7384.3 3,78

46.265.575.1

56.166.064.7

60.668.764.749.0

51.573.784.0

62.973.872.7

69.472.371.066.4

of watering schedule. It would seem that this depth was sufficient to preventdamage from surface drying.

Shoot weight per plant was negatively related to total number of plants, and"r" for paired combinations of total plants x mean weight in the 36 treatments(Table 4) was - .421 (significant at .05). This was because the number of smallplants increased with total number of plants: "r" value of + .815 (significant at.01) for total plants x small plants. In general, therefore, increasing number ofplants was associated, as would be expected, with decreasing shoot weight perplant. Further, the proportion of transplantable to small plants was influencedsomewhat by seed size. These ratios were 1.02, 0.91, 0.97 and 0.88 from thelargest to the smallest seed (A to D sizes), indicating that growth and developmentmay be enhanced with large seed. The somewhat lower ratios for sizes Band Cmay have been influenced somewhat by total plant numbers, as these sizes averaged95.4 and 95.8 plants per flat (Table 5) compared to 85.2 and 84.3 for sizes Aand D.

CONCLUSIONS

Seed germination improves with an increase in seed size, although differenceswithin the range of 325000 to 400000 seeds per 28.35 g (1 oz.) generally are small.Speed of germination also increases with size of seed. Germination of seed and sur-vival of young seedlings is enhanced by vermiculite cover over the growth medium,and improves with extra vermiculite up to at least 1.27 cm depth.

29

Optimum water per application during the germination and immediate post-germination period in an unheated glass greenhouse, using an overhead, travelling,double-boom system, is about 0.7 liters per m2 in each of the 4 succussive passes.Optimum water application per day is six such waterings on sunny days and threeon cloudy days. With respect to a standard greenhouse of 223 m2 (2400 ft.2), re-quired water per day would be 3853 and 1927 liters on sunny and cloudy days, re-spectively.

Some evidence was obtained to indicate that growth and development ofseedlings may proceed more rapidly with large than with small seed.

REFERENCES

1. Brach, E. J. and W. S. Reid. 1971. Electronic tobacco seed counter. Tob.Sci. 15: 138-143.

2. Cundiff, J. S. 1979. Tobacco seed emergence related to differences in terminalvelocity_ Tob.Sci.23: 49-51.

3. Cundiff, J. S., A. Csinos and S. C. Phatali. 1978. Variability in tobacco seedlinggrowth related to day of emergence. Tob. Sci. 22: 144-147.

4. Gawande, M., S. C. Mohopatra and W. H. Johnson. 1980. Effect of seed size andpelletization on tobacco seed germination under varing temperature regimes.Tob. Sci. 24: 49-52.

5. Walker, E. K., L. B. Reynolds and D. A. Stier. 1982. Culture of tobacco seedlingsin Todd cells. Ontario Ministry of Agriculture and Food Factsheet, Agdex 181.

6. Watson, M. C. and N. W. Sheidow. 1978. Producing tobacco transplants inOntario. Pub I. 7, Ontario Ministry of Agriculture and Food.

30

CONTROL OF CRYPTOGAMS IN GROWTH MEDIA USEDFOR FLUE-CURED TOBACCO SEEDLING CULTURE

E. K. WALKER AND L. B. REYNOLDS

Le rapport suivant traite de la lutte aux cryptogames dans les milieux de cultureemployes pour la culture des plants de tabac jaune.

Surface growth of cryptogams (algae, mosses and liverworts) in muck seedbedswithin greenhouses (glass fiberglass or polyethylene-eovered) occursto varying degrees, depending upon weather conditions during the germinationand postgermination period, and type of growth medium. Development of crypto-gam growth usually is insufficient to affect plant growth, but occasionally, with aprolonged period of cool, cloudy weather and/or growth media that holds a highvolume of water on the surface, development may be such as to impede waterpenetration, and result in non-uniform growth or even death of very young seed-lings. The extent of such development in seedbeds is impeded by sunlight andcirculation of relatively dry air over the bed. It is also impeded by allowing thebed surface to dry before evening, so that beds are not exposed to cool, moistconditions overnight. Once the plants are well established, cryptogams can bereadily controlled by such management procedures, but during the germination andimmediate postgermination period, when the media surface must be kept moistto enhance germination and eventual density and uniformity of stand, and whenweather conditions (cool weather) normally are most conductive to cryptogamdevelopment, such growth may be extensive. An even greater problem with crypto-gam development occurs with culture in containers such as Todd cells. The growthmedium is slightly below the upper cell level and air curculation is less effective indrying the surface. Also, the peat-lite mixtures containing both perlite and vermi-culite, which are used as growth media, have a high water-holding capacity. Further,frequent application of soluble fertilizers, which must be applied regularly to main-tain growth, appears to favour cryptogam development. Such development is oftenextensive enough to form a crust on the media surface that impedes water entryinto the media below. In individual cell culture this can be very serious as there isno lateral movement of moisture from cell to cell. Consequently, cells with exten-sive cryptogam development may receive little or no water with the result thatplants therein grow very slowly. In severely affected containers, growth character-istically is very slow and uneven.

Cryptogam development in tobacco seedbeds in Ontario has never been con-sidered a serious enough problem to justify chemical control. Consequently, noinformation was available to combat the more serious situation in container culture.Chemical control of cryptogams in greenhouses has been utilized, however, for along period. Such control usually is used to control such growth on walkways and

Messrs. Walker and Reynolds are tobacco researchers at the Delhi research station.

31

under benches, where there is no contact of the chemical with higher plants.Various copper compounds are the principal chemicals used for this purpose (1),but most of them are extremely toxic to the higher plants. One potentially safechemical for use on tobacco plants is basic copper dulphate (bluestone), which hasbeen used on plants for disease control. Bluestone, when combined with hydratedlime and water, is the familiar bordeaux mixture, long used for disease controlin fruit crops. Bordeaux mixture also has been used extensively in Kentucky tocontrol cryptogams and bacterial diseases in c1othcovered outside beds of burleytobacco seedlings, and is a recommended practice for these purposes (2).

The successful use of Bordeaux mixture in tobacco seedbeds in Kentucky forcontrol of cryptogams plus a need for an effective control with container culturein Ontario, prompted an examination of its effectiveness in Ontario. The presentreport concerns tests conducted over a two-year period.


Methods of preparation and application of Bordeaux mixture in Kentucky'provided the basis for these tests. For a volume of 227.3 liters and a requirementof approximately 1.13 liters per m2 of bed, preparation was as follows:

1. Fill a 227.3 liter barrel three-quarters full of water.2. Thoroughly mix 1.814 kg of fresh hydrated lime in about 18 liters of water

in a small container.3. In another small container, mix 1.36 kg of powdered bluestone in about

18 Iiters of water.4. Pour the lime paste into the barrel and stir vigorously. While stirring, add

the bluestone solution slowly.5. Add water to bring barrel to 227.3 liters.The above amount of spray was considerably above experimental requirements,

and mixtures were made up in amounts of 3 liters or less, depending upon areato be covered and rates of application, using the same procedure and proportionof ingredients. All applications were to Todd cell trays (200 cell) situated onaluminum rails above grade or to seedbeds of muck at grade level. The standardmixture above was sprayed at various rates in different tests, but all such rateswere equivalent to or higher than the rate of 1.13 liters per m2• Mixtures less con-centrated than the standard mix also were sprayed at various rates that were bothhigher and lower than the standard rate with respect to amounts of hydrated limeand bluestone applied per plant. These mixtures comprised 1.36 or 0.91 kg ofhydrated lime and 1.02 or 0.68 kg of bluestone per 227.3 liters of water.

An initial test conducted in 1982 concerned effect of the mixture on germi-nating seeds and on seedlings of different ages. Pelleted seed of flue-eured tobaccocv. Nordel was used in this and all subsequent tests. Seeds were germinated in petridishes in the laboratory with filter paper being wetted initially with 5 cc of wateror standard Bordeaux mixture. Subsequent wetting of the filter paper during thegermination period, if necessary, was with water. Seeds also were germinated in

, Personal communication: Wm. C. Nesmith, Extension Plant Pathologist, Univ, of Kentucky,Lexington.

32

peat-lite growth media within Todd trays in the greenhouse, with standard Bor-deaux mixture, being applied at rates of 1.13 or 4.52 liters per m2 to the traysright after seeding. Other trays seeded at the same time were sprayedat time of seed germination, one week after germination, or three weeks aftergermination with 1.13 or 4.52 liters per m2 of standard Bordeaux mixture. Carewas exercised to continually agitate the Bordeaux mixture while spraying.

In a second test in 1982 the standard Bordeaux mixtures as well as the two lessconcentrated mixtures described above were sprayed one week after germination toseedlings in Todd trays in the greenhouse at rates of approximately 4.7, 3.1 and1.6 cc per plant (4.08,2.72 and 1.36 liters per m2). Compared to the rate of 1.13liters of standard Bordeaux mixture per m2, which provides about 0.01 g bluestoneper plant, rates of 4.08,2.72 and 1.36 liters per m2 provided approximately 0.038,0.025 and 0.013 g bluestone per plant. Similarly, less concentrated mixtures pro-vided about 0.028, 0.019 and 0.009, and 0.019,0.013 and 0.006 g bluestone perplant, respectively. Most applications were, therefore, in excess of the standardrate of about 0.01 g bluestone per plant. Sprays for this test were applied with onlyminimum agitation.

A third test in 1982 used freshly-prepared lots of the same mixtures usedin the second test. Again, applications were 4.08, 2.72 and 1.36 liters per m2 foreach mixture. In this test most trays of seedlings were, as in the prior tests, sprayedonce at 1,3 or 5 weeks after germination, but some trays were sprayed two or threetimes. As in test 1, particular care was taken to continually agitate the mixturesduring application.

A single test conducted in 1983 concerned rates of 4.08, 2.72 and 1.36 litersper m2 for the standard Bordeaux mixture and for the less concentrated mixturecontaining 1.36 kg of hydrated lime and 1.02 kg of bluestone per 227.3 liters,all applied 1.5 weeks after germination. In addition, each mixture also was appliedat the rate of 1.36 liters per m2 both 1.5 and 3 weeks after germination. Also in1983, cryptogam-infected areas in general seedbeds and Todd trays were givenspot treatment with the standard Bordeaux mixture at the rate of 4.08 liters perm2 to determine efficacy.

Treatment evaluation consisted of determination of germination percentage,plant counts, observations on growth retardation or distortion, shoot weights orcontrol of incident cryptogams.


Wetting of the filter paper in petri dishes with Bordeaux mixture rather thanwater at the start of gemination tests delayed germination and cuased growth dis-tortion. With water only, most seeds germinated in 5 days and germination wascomplete in 7 days. With Bordeaux mixture, however, about one-third of the seedshad germinated after 7 days and germination was complete in 10 days. Germinationpercentage was 95 percent in both cases. No attempt was made to determine sur-vival rate of germinated seedlings with time by prolonging the tests beyond 10days.

Standard Bordeaux mixture applied to trays in the greenhouse right after seed-ing had little or no apparent effect on germination or appearance of germinated

33

seedlings, if applied at the rate of 1.13 liters per m2. At four times this rate, how-ever, there was an obvious effect in germination and seedling growth. At this highrate the growth was not distorted to the same extent noted in the laboratory, butmany seedlings appeared to be stunted. Subsequent observation confirmed thatabout 15 percent of the seedlings were severely stunted. Germination with thistreatment was reduced by 25 percent. Standard Bordeaux mixture applied later,that is at time of germination or at one or three weeks after germination, had noapparent effect on growth of plants, whether appl ied at 1.13 or 4.52 Iiters per m2 .

Damage to leaf tissue in the second test in 1982 was extensive regardless of mix-ture or of concentration used, but did tend to be most severe with higher con-centrations. The damage was not sufficient to kill the plants, but rather to severlyretard growth and development. Lack of agitation while applying Bordeaux mixturein this test points out the necessity for continual agitation.

The third test in 1982, which was essentially a repeat of the second test, butwith continual agitation during spray application, showed no plant damage withneither single nor multiple applications.

Continual agitation of mixtures also was practiced in 1983 and no damage oc-curred regardless of mixture, concentration, or number of sprays. Trays for thistest were seeded on March 30, and although observations indicated that plants wereunaffected by treatment, shoots of 50 seedlings from each treatment were clippedoff and weighted on May 17, about one week before the seedlings were of trans-plant size. Shoots from an untreated check had an average weight of 1.898 g.Similarly, seedlings exposed to standard Bordeaux at more than three times thenormal rate (4.08 liters vs 1.13 liters per m2) had an average weight of 1.982 g.Seedlings exposed to lesser amounts of the standard Bordeaux mixture (2.72and 1.36 liters per m2) weighed on average, 1.686 and 1.662 g. Plants treated withthe less concentrated Bordeaux mixture applied at 4.08, 2.72 or 1.36 liters perm2 had average weights of 1.520, 1.914 and 1.680 g per plant. Plants given twosprays with the standard or less concentrated Bordeaux mixtures, at the rate of1.36 liters per m2 each time, had average weights of 1.895 and 1.766 g, respec-tively. From these results it is apparent that there was little or no relationshipbetween amount or concentration of Bordeaux mixture applied and the amount ofshoot growth.

Spot treatment of cryptogams in beds and trays with standard Bordeaux mix-ture at the rate of about 4.08 liters per m2 was very effective in controlling suchgrowth. There was no further spread from treated areas and the cryptogam growthgradually disappeared over a period of one to two weeks. One treatment generallywas sufficient, and no damage to plants in the affected areas, as a result of treat-ment, was observed.

CONCLUSIONS

Bordeaux mixtures were shown to be effective and safe for controlling crypto-gams in trays and seedbeds containing tobacco plants. To prevent plant damage itis essential to subject mixtures to continual agitation during spray application,and to treat plants at time of germination or later. Application at several times the

34

concentration of a standard Bordeaux application was without deleterious effecton plants treated at time of germination or later. An appropriate treatment, whichwould provide plenty of safety margin, on the basis of results obtained herein,would be a standard Bordeaux mixture applied at 1 to 2 liters per m2 at least onceand possibly twice to affected areas starting one week after germination.

REFERENCES1. Laemmlen, F. 1979. Control of mosses and algae under greenhouse conditions.

Extension Bulletin E-1287, Cooperative Extension Service, Michigan StateUniversity, East Lansing, Mich.

2. Nesmith, W. C. and J. H. Smiley. 1982. Chemical controls for tobacco plantbed diseases - 1982. Cooperative Extension Service, College of Agriculture,University of Kentucky, Lexington, Kentucky.

35

FLUE-CURED TOBACCO SEEDLING CULTURE IN CONTAINERS:TRAY FILLING AND SEEDING

E. K. WALKER AND L. B. REYNOLDS

L'etude suivante porte sur les methodes de culture en pots des plants de tabac jaunedont les techniques de remplissage et d'ensemencement.

In recent years there has been increased interest in culture of flue-<:ured tobaccoseedlings in containers containing peat-based media rather than in seedbeds ofmuck. One of the principal disadvantages of container culture can be failure toachieve a stand of plants comparable to the stand achieved in seedbeds. A standard-sized greenhouse containing 223 m2 of seedbed will require 325,000 to 400,000seeds (28.35g). If all of this seed were to germinate and survive there would, theo-reticaly, be enough plants to transplant 18.8 to 23.1 ha at the rate of 17300 plantsper ha. In practice, most seed normally will germinate at no more than 90 per cent,unless the seed is exceptionally well cleaned to obtain only the largest seed (1).and post-germination losses may be 10 to 50 per cent of germinated seedlings de-pending upon management practices. To obtain an ideal stand of about 1300 plantsper m2 (3). there would need to be about 290,000 plants in a standard-sized green-house. This would be sufficient, if there were no further losses of plants, for trans-planting about 16.75 ha. In actual fact, however, it is considered sufficient for only10.5 ha as there always is considerable loss of small seedlings pulled prematurelywhen pulling larger plants for transplanting. With good management this capacitycan possibly be increased to about 12 ha.

In container culture, there is no loss of small seedlings on pulling as in seed.beds. Compared to the maximum potential stand of 290,000 plants in a standard-sized greenhouse, there would be, with the Todd system of container culture,2.5 cm cells, and 100 percent seed germination, a stand of about 208,000 plants,which is sufficient for 12 ha. This is reduced to 11.33 ha with omission of spaceat ends of greenhouse for positioning of an overhead watering system and to 10.75,10.2 or 9.6 ha with germination and survival percentages of 95, 90 and 85 percent,respectively. Therefore, to be equ ivalent or nearly so to the capacity of seedbeds,it is imperative that germination and survival rates with container culture be at least90 percent. This can be achieved only with seed that germinates higher than 90percent and with management practices that are conducive to attainment of maxi-mum germination and post-germination survival.

The present study compares different techniques for filling two different typesof container trays with growth media, and for seeding relative to germination andpost-germination survival.

36


Two types of rigid container trays, which contain 200 cells about 2.5 to 3.0cm square each at the top of each cell, were used over a two-year period. Thesewere Plastomer' and Todd2 trays, which are formed from plastic and styrofoam,respectively. Both types have outside dimensions of 67.3 by 34.3 cm and a celldepth of 77.6 cm. The Plastomer trays have slightly larger cells (3.0 cm2 at thetop compared to 2.54 cm2 for Todd trays) as the use of plastic in the former per-mits formation of narrower cell borders. Cell volumes are 36 and 28 cc, respec-tively, and cells in both trays taper to a small hole (approximately 0.75 cm2)at the bottom.

The trays were filled with a commercial media3 previously found suitable forculture of flue-cured tobacco in containers (2). The media was poured into thecells, trays were dropped on the loading table surface several times to settle mediaand reduce air pockets and more media was placed in position until all cells werefull to the top. Excess media was scraped from the trays. No pressure was exertedto force media into the cells during the loading operation.

After loading with media, the trays were well watered preparatory to imposi-tion of different techniques of tray preparation and seeding, and pelleted seed4cv Nordel was applied by hand to each cell of each tray according to pre-arrangedschedules. Seed was well cleaned prior to pelleting and had a germination percen-tage in laboratory tests of 96 percent before and after pelleting.

Media in some trays in 1982 was pressed with a packer, before or after seeding,and media in other trays was not pressed. The packer consisted of a solid metalbase with tapered projections (similar in shape to the tapered cells, but not as deep)of about 3.25 cm depth in a grid pattern matching that of the cells. When appliedto the tray surface, the projections pressed the media and produced tapered in-dentations in each cell that sloped to a depressed area in the centre of each cell.Seed applied after such packing was automatically centered in each cell. The depthof 3.25 cm was considered excessive, so the projections were ground down to re-duce the depth to 2.2 cm. All trays in 1983 were pressed with this packer, eitherbefore or after seeding. Each year seed in some treatments was left uncovered,whereas others received a thin covering of media. The treatments imposed in eachyear were duplicated with Plastomer and Todd trays. In addition to the foregoingtreatments an unpacked treatment situated on rails in 1982 was duplicated atgrade level to determine if results would be affected by position of tray. All othertrays in 1982 were situated on rails about 60 cm above grade, and all treatmentswere located in an unheated greenhouse. All trays in 1983, however, were situatedon a bench in a heated greenhouse. In general, temperatures in the heated green-house were held at 18 to 24C, while those in the unheated greenhouse varied be-tween 0 and 24 C depending upon time of day and weather conditions.

, Plastomer Inc., Barrie, Ontario.2 Bezemers So-Rate Mfg. Inc., Mississauga, Ontario.3Shamrock Industries, Norwich, Ontario.4Germain's Inc., Los Angeles, Cal.

37

Particular care was taken during the germination period (7 to 10 days afterseeding) to keep the media surface moist to enhance germination. This was achievedwith frequent, light water spray applications. About two weeks after germination.counts were obtained of germinated seedlings and of the number of such seed-lings that were "tipped-over" (roots showing on the media surface). Experiencehas shown that most such plants fail to survive, and those that do survive are toosmall at transplanting time to provide satisfactory transplants. Accordingly, survivalpercentage was considered as the composite of "tipped-over" plants and missesdue to lack of germination. When the seedlings were of transplantable size in 1982,some seedlings in each tray were pulled mechanically to determine the influenceof type of trays on pulling force. Pulling force was not measured in 1983. At thesame time in both years, shoots of other seedlings were weighed to determineinfluence of the variables on growth.


Germination, amount of "tipping-over", survival, pulling force and shootweight all were affected by type of tray, tray location or seeding method (Table 1).Somewhat better survival in Plastomer than in Todd trays was the result, princi-pally, of less "tipping-over" in the Plastomer trays, as germination percentage wasrelatively high in each type of tray. The difference in "tipping-over" may have beenbecause of more heat absorption by the brown-eoloured Plastomer trays. A lowerpopulation in the Todd trays might have been expected, because of reduced compe-tition, to result in greater shoot weight with the Todd tray. Possibly, growth inthe Plastomer cells may have been enhanced by somewhat better heat absorption,or because of a slightly greater volume of med ia per cell.

Trays located at grade level had fewer "tipped-over" plants, but poorer germi-nation than those suspended on rails. The survival percentage was somewhat higherfor trays located on rails. Seedlings grown at grade level pulled easier than thoseon rails, and seedlings at grade level were slightly larger than those on rails. Thelatter difference may partly reflect less competition (fewer plants) at grade level,but it is otherwise difficult to account for the differences, albeit rather small,between seedlings grown at the two levels.

Seeding method had more effect on amount of "tipping-over" than on germina-tion. Nevertheless, germination tended to be slightly better with some methodsthan with others. The treatment resulting in the lowest germination, that is mediapressed with packer, then seed dispensed on surface also showed the most "tipping-over". This particular treatment also is the method most commonly used. From theresults it would appear that a light media covering would have prevented much ofthe "tipping-over", and improved germination as well. In covering tobacco seedcare must be taken not to provide too much cover as germination is light depen-dant, although only diffuse light is required. Packing of media appeared to haverelatively little effect on pulling force. Shoot weight was related partially to popu-lation in that the treatment with the lowest survival percentage had the highestshoot weight. On the other hand, the treatment with the highest survival percentagehad only slightly lower shoot weight.

An interesting aspect of the results is the fact that germination percentageunder greenhouse conditions equalled or actually surpassed, in some treatments,

38

Wto

TABLE 1. MEAN EFFECTS OF TYPE OF TRAY, LOCATION OF TRAY, AND SEEDING METHOD IN AN UNHEATEDGREENHOUSE ON GERMINATION PERCENTAGE, NUMBERS OF TIPPED PLANTS, SEEDLING SURVIVAL, PULLINGFORCE AND SHOOT WEIGHT, 1982.

Germination' Tipped' Survival2 Pulling force3 Shoot3Main effect Variable plants per plant weight

% % % kg kg

Type of tray Plastic tray (Plastomerl 95.2 6.4 88.6 0.34 3.21Styrofoam (Todd) 94.4 11.9 82.5 0,46 2.56

Tray location Suspended on rails 96.0 10.0 86.0 0.40 2.75At grade level 91.3 7.8 83.5 0.32 3.26

Seeding method No packing of media -seeddispensed on surface 96.0 10.0 86.0 0.40 2.75

Seeddispensed on surfacethen media pressedwith packer 97.3 9.5 87.8 0.39 2.53

Media packed with packer,then seeddispensed on surface 94.0 13.3 80.8 0.44 3.02

Media pressedwith packer,seeddispensed on surface,then given light media cover 95.5 5.3 90.3 0.45 2.87

, Germinated and tipped plants counted on April 20, two weeks after germination.2Composite of missing and tipped plants3Measured on May 28 when seedlingsof transplant size.

~ TABLE 2. MEAN EFFECTS OF TYPE OF TRAY AND SEEDING METHOD IN A HEATED GREENHOUSE ON GERMINA-TION PERCENTAGE, NUMBERS OF TIPPED PLANTS, SEEDLING SURVIVAL, AND SHOOT WEIGHT,1983.

Germination' Tipped' Survival2 Shoot3Main effect Variable plants weight

% % % kg--

Type of tray Plastic tray (Plastomer) 98.3 0.38 97.9 2.28Styrofoam (Todd) 98.5 0.25 98.3 1.97

Seeding method Seedon surface, then packedno media cover 98.5 0.25 98.3 2.25

Packed. then seeded.no media cover 99.3 0.25 99.1 1.93

Seed on surface, then packed,light media cover 98.8 0.26 97.5 2.22

Packed, then seeded,light media cover 98.0 0.51 97.5 2.10

, Germinated and tipped plants counted on April 12. one week after germination.2Composite of missing and tipped plants.3Measured on June 1 when seedlings of transplant size.

percentages obtained within more controlled conditions in the laboratory. Ob-viously, watering regimes followed during the germination period were ideal. Underless ideal conditions, when the media surface is allowed to dry out, germinationmay be severely reduced because of high temperatures or seed dessication. It isalso noteworthy that loss of seedlings from "tipping-over" represented a greaterloss with most treatments than that from non-viable seeds.

There was relatively little effect of the imposed treatments in the heated green-house (Table 2). Again, watering regimes obviously were ideal as germination per-centages again exceeded those obtained in the laboratory. The percentage of"tipped-over" plants was negligible in all treatment. It would certainly appear fromthese results that heat during this period has more effect on survival, and, princi-pally, the "tipping-over" aspect of survival, than other variables. As in 1982, seed-lings grown in Plastomer trays attained somewhat more growth than those grownin Todd trays.

The exact cause of "tipping-over" is unknown, but it has been shown to be lessprevalent in muck covered with vermiculite (1). It would appear that packing ofbare muck via water application could be a factor. Possibly, relatively poor aera-tion of packed muck leads to surface root growth, or water actually washes muckaway from the roots. It would certainly appear from results obtained herein thattemperature may be the most important factor determining the amount of"tipping-over". Higher temperatures may, through promotion of greater evapora-tion, or better growth conditions, enhance aeration and rate of root growth andpenetration into the media. The availability of sufficient heat to prevent cold in-jury is more of a requirement with container than with seedbed culture. This isprimarily because the elevated position of containers, less heat absorption of peatthan muck, and relatively small amount of heat-absorbing material compared toseedbeds leads to rapid loss of stored heat by radiation. Provision of supplementaryheat with container culture not only is essential to prevent cold injury, but shouldenhance stand by reducing the amount of "tipping-over".

REFERENCES

1. Walker, E. K. 1984. Influences of seed size, vermiculite cover, and watering re-gime on germination, survival, and growth of flue-cured tobacco seedlings underglass. The Lighter 54: In press.

2. Walker, E. K., L. B. Reynolds and D. A. Stier. 1982. Culture of tobacco seed-lings in Todd cells. Ontario Ministry of Agriculture and Food Factsheet, Agdex181.

3. Watson, M. C. and N. W. Sheidow. 1978. Producing tobacco transplants inOntario. Publ. 7, Ontario Ministry of Agriculture and Food.

41

PUBLICATION SUMMARIES

GAYED, S. K. 1983. The effect of ethylene diurea on weather fleck and on cer-tain properties of the flue-<:ured tobacco in Ontario. Tob. Sci. 27: 149-150.

The systemic antioxidant ethylene diurea (EDU) or N-[2-(2-0xO-1-imida-zolidinyl) ethyl] -N -phenyl urea significantly reduced weather fleck of flue-<:uredtobacco caused by ozone. Foliar sprays of EDU were more effective than earlysoil application and three foliar applications of 1.12 kg/ha (3.36 kg/ha total) wereefficient in protecting tobacco against weather fleck. EDU was found to becompatible with Delete, a Cs - C,o fatty alcohol used for sucker control. EDUtreatment had no undesirable effect on grade index, filling value, lamina weight,reducing sugars, total alkaloids or nitrogen content of the leaf. Residues of EDU didnot exceed 1 ppm in the cured leaf and smoke of treated tobacco was equivalent tothat of untreated tobacco in subjective panel evaluations.

GAYEO, S. K. 1984. The response of pepper and tomato cultivars to challengeinoculation by Peronospora tabacina. Can. J. Plant Sci. 64: 225 -228.

The host range of Peronspora tabacina, isolated in 1979 was investigatedby inoculating seedlings of six pepper (Capsicum annuum) and 13 tomato(Lycopersicon esculentum) cultivars three times 14 days apart. Tomato cultivarswere not infected whereas pepper cultivars Sweet Banana, Midway and Staddon'sSelect were slightly infected after the second and/or third inoculation. Differencesin host range of P. tabacina in various countries may be due to differences in geno-types of cultivars tested as well as in races of the pathogen.

I. R. SIDD~OUI and ROSA, N. 1983. Low molecular weight carbohydrates of to-bacco. Tob. Sci. 27: 130-134.

Fourteen low molecular weight carbohydrates from the 80% ethanolsolublefraction of bright tobacco (Nicotiana tabacum, Delhi 76) were characterized eitherin the crystalline form, or by the isolation of crystalline derivatives or by the re-sults of partial hydrolysis and PC, PE, GLC. and GLC-Ms. of their trimethylsllylderivatives. The average percentage composition of these components in the 80%ethanol-soluble fraction (36.5%) of cured lamina was: D-ribose, 0.11; D-xylose,0.19; D-fructose containing 0.97% D-psicose, 9.61: D-glucose, 3.24; D-sorbitol,0.01; myo-inosital, 1.04; 1-deosy-1-[ (S)-2-(3-pyridyl)-1-pyrrolidinyl ] ,-B-D-fucto-pyranose, 0.26; sucrose, 6.24; maltose, 0.34; gentiobiose, 0.01; D-glucopyranosylmyo-insitol, 0.04; eriose, 0.02 and theanderose, 0.01. Besides, malic acid (butane-dioic acid), 11.02%, three nonreducing acidic components (T 0.23,0.31 and 0.47)amounted to 0.74%, 0.09% and 0.34%, respectively. Among the unknown, threecomponents present in significant amounts (1.23, 0.09,1.11%) showed RT valuesof 2.25, 0.267 and 0.56, respectively.

42

WORLD TOBACCO NEWS

COMPILED BY N.L. LONGMUIR

ZIMBABWE

The 1984 crop is estimated at 110 000 t and auction prices have been favorable.Early estimates indicate that the price will average between $1.78 and $2.10/kgCDN. Growing conditions in the latter part of the season were favorable, with lightrains. Lugs are somewhat stressed but middle and upper position tobacco are ofexcellent quality. The 1200 growers that produced the crop on 51 000 ha areproud of the crop, as it is one of the best.Source: Standard Group of Tobacco Companies

INDIA

About 95500 t of the 1984 flue-eured tobacco crop was sold from a totalcrop of 116400 t (all types). Salesof most types are well underway. Mysore flue-cured tobacco has been somewhat restricted by the Indian Tobacco Board to15 000 t from 16 000 ha. Banks are restricting credit to farmers which would alsohelp reduce area planted.Source: Standard Group of Tobacco Companies

THAilAND

The 1984 crop was down 36% to 33 000 t from the 52 000 t produced in1983. Green-leaf buying was finished by the middle of April. Purchase quotas bythe Tahiland Tobacco Monopoly have been increased to about 15 000 t greenweight.Source: Standard Group of Tobacco Companies

MALAWI

Total production of all types is estimated at about 63 000 t for the 1984 crop.Theflue-eured crop is generally lower in nicotine with thinner leaves. About21 000 t is expected when harvest is completed. The Burley crop is expected toreach 28 000 t. Quality is about the same as the 1983 crop, but there is a lowerpercentage of non-descript and water-stained tobaccos.Source: Standard Group of Tobacco Companies

KENYA

Kenya has recently entered the export area for flue-eured tobacco with a smallshipment of about 150 t. This is a first for the country since self-sufficiency was

Mr. Longmuir is an economist with Agriculture Canada's Marketing and Economics Branchin Ottawa.

43

just recently achieved. The Kenyan industry is relatively new with only about10 years of production experience. Buyers will undoubedly be interested in thisarea as, over time, production is likely to increase.

UNITED KINGDOM

British tobacco buyers are shifting their buying preferences to lower-eostcountries inan attempt to keep their products relatively inexpensive as a result ofthe Exchequer's relentless increase in tobacco taxes. Traditional suppliers, such asCanada and the United States, have lost sales over the last decade. Countries likeZimbabwe, Malawi, India and other less.developed countries have benefited.

FACTORS AFFECTING DEMAND IN 1984

Cigarette sales increased in Ecuador, Finland, Japan, Spain and the USSRduring 1983, and indications are for continued growth in 1984. In Ecuador, thetrend is for lower-priced domestic brands instead of international brands. In Fin.land, cigarette sales increased despite price increases of 5% and 5.9%. SE ITA,the French monopoly, increased foreign tobacco purchases by 23% in 1983. How.ever, cigarette sales decreased, but American blend cigarettes increased 12%. InJapan, cigarette sales increased about 3%. Spanish cigarette production was upsharply in early 1984 to meet rising demand for American blend cigarettes.Source: FAS - USDA FT-5-84

FACTORS AFFECTING SUPPLY

Canadian production targets are sharply lower in 1984. Ontario expects toproduce 77 000 t while Quebec and Maritime growers will likely produce about10 500 t. Export sales are expected to decline as well as domestic sales since ciga-rette consunption is down 5%.Source: Agriculture Canada,Market Commentary, June 1984

UNITED STATES

Supplies are expected to remain stable during the upcoming marketing year.The overall increase in 1984 will likely offset the crop in beginning stocks. Assum-ing a normal yield, marketings could be about 10% greater than the 1983 mar.ketings of 685 000 t (1,51 billion pounds). With a larger price and unchanged pricesupport levels, auction prices are not expected to change much. The stronger U.S.dollar will likely inhibit exports and increase imports.

Total disappearance of flue.cured tobacco in 1983 -84 may drop about 3%from last season's 424 000 t (935 million pounds) because of reduced U.S. cigaretteoutput and reduced exports, Disappearance will likely exceed 1983 marketings,so July 1 stocks could drop further because 1984 marketings are expected to fallshort of use.Source: ERS - USDA, Tobacco Outlook and Situation Report, TS-188, June 7,1984

44

LEAF TOBACCO PRODUCTION AND VALUE

Statistics Canada has just completed its 1983 "Leaf Tobacco Survey". Leaf tobaccoproduction in Canada during 1983 amounted to 111 714 metric tonnes. This repre-sents a 59% increase from the 1982 level. Total farm value of the 1983 crop reached$400.2 million.

The accompanying table summarizes the highlights of the survey by tobaccovariety. Data secured by Statistics Canada were provided by marketing boards,private industry and provincial statisticians. For further information and completesurvey results, readers are advised to contact:

A. LandryHorticultural Crops UnitAgriculture Statistics DivisionStatistics CanadaOttawa, OntarioK1A OT6613-995-4877

Canada

All TypesFlue CuredBurleyDarkCigarPipe

Marketing Production(green weight)metric tonnes

1117141095201 37037642523

Farm Value$'000

40018839369444111 11490465

45

STATISTICS STATISTIQUES

TABLE 1. CANADA - EXPORTS, REDRIED LEAF BY TYPES

Types

Flue-cured (bright

Burley

Dark (air or fire-cu::J-edlCigar LeafRaw Leaf

Tobacco N.E.S.'

All types

U.K.Total

U.K.Total

U.K.Total

U.K.Total

U.K.Total

3-month period ending March 84

kg

3,600,2945,303,689

32,429254,184

343,346947,447

3,976,0696,505,320

, Tobacco Not Elsewhere Specified includes stems and cuttings.

TABLE 2. EXPORTS OF REDRIED LEAF BY COUNTRIES

Country

United KingdomBritish West IndiesOther CommonwealthForeign

Total

Source - External Trade DivisionStatistics Canada

46


kg

3.976.069109,638116.273

2,303.340

6.505,320

TABLE 3. CANADA - IMPORTS OF LEAF BY TYPES

Type

Flue-cured, unstemmed U.S.A.Total

Turk ish, unstemmed U.S.A.Total

Cigar, unstmmed U.S.A.Total

Cigar, stemmed U.S.A,Total

Unstemmed N.E.S.' U.S.A.Total

Stemmed N.E.S.' U.S.A.Total

All types U.S.A.Total

, Not Elsewhere Specified.

TABLE 4. IMPORTS OF LEAF BY COUNTRIES

Country

CubaIndonesiaEuropeUnited StatesOther Foreign

Total

Source - External Trade DivisionStatistics Canada


kg

2,945127,080

425,161

1,996

397,311398,584

400287532,821


kg

39,480

8,128400,29884,915

532.821

47

CLIMATIC CONDITIONS OF TOBACCO GROWING AREAS - CANADA

Air SoilTemperature °c Temp °c

Mean Mean High Low 20 50 Total Most P.E. Deg. Aecum.Max Min Max Min ems ems (mmJ Days Degree

(date) (Date) (mm) (Date) (5°C) (Date)

COMPARATIVE DATAFEBRUARYDelhiMonthly 2.8 -1.0 13.0(23) -22(1 ) 68 35(13) -30-year -1.3 -9.4 13.9 -30.0 -.1E 1.0E 56.8 61.0

HarrowMonthly 3.2 -3.3 14.0(23) -19.0(1) -1.8 0.5 19 4(10)30-year -0.2 -7.3 19.4 -28.9 0.1 1.0 53.1 55.6

RidgetownMonthly 3.5 -3.5 13.0(23) -14.0(1) 70 36(13) -30-year -0.6 -8.1 16.7 -29.4 -02E 1.2E 52.7 57.2

L' AssomptionMonthly -0.5 -8.9 9.5(23) -27.5(1) 1.0 1.8 82 25(14) -30-year -5.0 -16.2 10.0 -43.3 -0.8E 0.5E 61.5 35.6

CharlottetownMonthly 0.0 -6.8 9.0(15) -22.5(10) 1.8 2.1 90 29(4)30-year -2.9 -11.1 12.2 -29.4 0.3 1.1 81.1 50.8

KentvilleMonthly 3.0 -4.4 15.5(15) -23.0(10) 1.7 2.0 118 21 (4)30-year -0.9 -9.4 15.6 -31.1 0.2 0.9 106.8 54.6

MARCHDelhiMonthly 0.3 -7.9 8.5(15) -23.0(12) 30 12(15) -30-year 3.9 -4.4 25.0 -25.0 0.9E 1.4E 84.4 53.6

HarrowMonthly 1.3 -5.4 8.5(31) -15.0(10) -1.6 0.6 75 34(20) -30-year 5.0 -2.6 26.1 -20.6 1,2 1.5 74.7 43.7

RidgetownMonthly 5.0 -6.5 9.0(15) -17.0(9) 84 29(15) -30-year 4.4 -3.3 25.6 -23.9 1.2E 1,7E 71.8 38.9

L' AssomptionMonthly -2.3 -13.5 8.0(31) -30.5(10) 0.9 1.5 41 9(18)30-year 1.2 -8.5 23.3 -40.6 O.2E 1.0E 69.5 39.6

CharlottetownMonthly -0.5 -6.8 14.0(16) -18.5(9) 1.2 1.7 115 23(17) -30-year 0.9 -6.2 15.6 -27.2 0.5 0.9 84.6 54.6

KentvilleMonthly 1.8 -1.9 15.5(16) -19.0(9) 2.0 2.2 140 25(19) -30-year 3.0 -5.1 22.2 -27.8 0.4 0.9 98.5 48.8

..'! / r.-:RSr I Ii, &.;.. i._., '-..

48L .. .~~,~ ;JS,c~ ONL ':"

Data compiled by S.N. Edey 1984

Air SoilTemperature °c Temp °c

Mean Mean High Low 20 50 Total Most P.E. Deg. Accum.Max Min Max Min cms cms Pcpn Pcpn (mm) Days Degree

(Date) (Date) (Date) (5°C) (Days)

APRILDelhiMonthly 15.6 5.7 25.5(22) -1.0(16) 136 42(22)30-year 12.1 1.2 28.9 -15.0 5.5E 5.1 E 93.6 81.5

HarrowMonthly 12.2 3.5 23.0(26) -2.0(11) 4.3 5.6 84 17(22)30-year 12.7 3.0 30.0 -12.2 6.1 5.5 80.8 58.4

RidgetownMonthly 12.0 3.0 22.0(28) -3.5(11 ) 59 11(22)30-year 12.2 2.3 31.1 -12.2 6.0E 5.6E 84.4 75.0

L' AssomptionMonthly 11.6 0.8 23.0(28) -6.0(1) 5.0 4.1 80 19(16)30-year 10.2 -0.4 29.5 -19.4 3.6E 3.4E 71.7 42.2

CharlottetownMonthly 6.6 -1.4 16.5(30) -6.0(5) 2.5 2.3 154 27(9)3D-year 6.7 -1.1 26,7 -16.1 1.3 1.4 78.0 40.9

KentvilleMonthly 9.5 -0.5 20.0(30) -6.5( 1) 4.6 4.3 98 15(6)30-year 9.1 0.3 26.7 -15.0 3.5 3.7 82.6 43.7

SUPPLEMENTARY DATA

SPRING Frost (oC) Delhi Harrow Ridgetwn L'Assompt Chrltwn Kentville

10% June 2 May 12 May 25 May 27 May 31 June 550% May 12 May 2 May 8 May 15 May 14 May 2290% May 3 Apr. 18 Apr. 22 May 3 May 1 May 3

Seasonal Means (May 1 - Sept. 30)

Rain - mm 388 372 366 433 404 500P.E. - mm 564 574 570 551 441 545Irrigation Requirement - mm 245 213 202 189 184 184Average Annual Pcpn 935 837 850 965 1077 1178

P.E. = Potential Evapotranspiration (Estimated)

Irrigation requirements are for a storage capacity - 50 mmconsumptive.use factor - 0.75, and risk level - 10%.

30-year normals (1951-1930) are compiled by the Atmospheric Environment Service, Toronto.

Mr. Edey is an agrometeorologist with Agrometeorology Section, Land Resource Research Institute,Agriculture Canada, Ottawa.

49

POSTSCRIPTPH.D. EARNED The readerswill be inter-ested to learn that N.P. Arnold, physio-logist at L' Assomption, has been recentlygranted a Ph.D. by McGill University. Hisdoctoral dissertation was entitled: "Etiologyand control of the grey disorder in flue-cured tobacco". Dr. Arnold is now devotinghis efforts to the physiology of ornamentalplants, namely tissue culture, overwinteringand nutrition studies.

NEW BOOKS AVAILABLE Cigar loverswill like this book recently published inFrench and English editions, entitled "TheBook of the Havana Cigar" by Brian Innes(Orbis Publishing, London, England for£25.

It is a large format book with tobacco-brown text pages along with full colorillustrations. It has many classical andcurrent Havana cigar labels and bands. Thisbook is a must for the tobacco enthusiast.

"Tobacco in Jamaica" is available for£90 from the Economist Intelligence Unit,London, England. It is an assessmentofits significance to the agricultural sector,as the full title implies. Tobacco's signifi-cance to Jamaica reveals that it is a high.value crop rather than the traditional low-valued crop. The cigar industry is in goodshape.

"Smoking Control Strategies in Develop.ing Countries": This is a 92-page documentreleased by the World Health Organizationin Geneva. There are 30 specific recom-mendations on what developing countriescan do to deter smoking and other formsof tobacco use. The transnational tobaccoconglomerates or TTCs, as they are nowknown, was coined by this report. It is dif-ficult to ascertain fact from near fact insome instances. The document wouldserve as a guide to areas of concentrationduring the 1980s. Copies can be obtainedfrom the World Health Organization,Geneva,Switzerland.

50

ORGANIZATION UNO MARKTSTRATE.GIE IN TABAKA WARENFACH.GRO{3HANDEL by B. Hallier is publishedby Vanderhoeck & Ruprecht, G6ttingen,FRG, and costs OM 115. Dr. Hallier reoceived his doctorate from the Universityof Hamburg and his thesis was on the dif-ficult Tobacco Market. He analyzes themarket like a pyramid with the governmentas the most dominant player. The cigarettemarket is like a chess game played bygovernment rules. The book outlines theproblems and the future along with some90-odd surveysand a good biblography.

31ST TOBACCO WORKERS' CONFER.ENCE January 7-10, 1985, PinehurstHotel and Country Club, Pinehurst, NorthCarolina.

Yes, it's the time of year to start think.ing of your biannual trip for tobacco.This next conference is going to be veryeventful. Make your reservations early-before December 7, 1984. Extra chargeswill apply for late reservations, etc. Callor write now to: Connie McElroy/CindyAllen, Box 7401, Raleigh, North Carolina27695 - 7401, or telephone (919) 737-2261.Pleasenote office will be closed December24 through December 31, 1984.

Let's make this Conference the bestyet! Seeyou there.

AGRICULTURE CANADA

ESTABLISHMENTS AND PERSONNELINVOLVED IN TOBACCO RESEARCH

PERSONNEL AFFECTE AUX RECHERCHES SUR LE TABAC

RESEARCH STATION, DELHI, ONTARIOSTATION DE RECHERCHES, DELHI, ONTARIO

DirectorNutritionAgronomyGeneticsPhysiologyPhysiologyPathologyEntomologyChemistry

p.w. Johnson, Ph.D.J.M. Elliot, M.S.A.E.K. Walker, M.S.R.S. Pandeya, Ph.D.N. Rosa, Ph.D.B.F. Zilkey, Ph.D.S.K. Gayed, Ph.D.H.H. Cheng, Ph.D.W.A. Court, Ph.D.

DirecteurNutritionGrande cultureGemhiquePhysiologiePhysiologiePathologieEntomologieChimie

RESEARCH STATION, HARROW, ONTARIOSTATION DE RECHERCHES, HARROW, ONTARIO

Agronomy T.W. Welacky Grande culture

EXPERIMENTAL FARM, L'ASSOMPTION, QUEBECFERME EXPERIMENTALE, L'ASSOMPTION, QUEBEC

SuperintendantAgronomyAgronomyGeneticsPhysiology

J.P.F. Darisse,B.Sc. (Agr.)M. Dupre, B.S.A.M. Lamarre, M.Sc.I.S. Ogilvie, Ph.D.N. Arnold, M.Sc.

RegisseurGrande cultureGrande cultureGenetiquePhysiologie

RESEARCH STATION, CHARLOTTETOWN, P.E.1.STATION DE RECHERCHES, CHARLOTTETOWN, I.P.-E.

Tobacco Biologist W.J. Arsenault, B.Sc. lAgr.) Biol09istedu tabac

Contributors may submit articles in either English or French for publicationin the languageof the author's choice. Contributions should be addressedto THE LIGHTER, attention of the Secretary, Editorial Board, Commu-nications Branch, Agriculture Canada,Ont., K1A OC7.

Les articles destines it la publication peuvent etre presentesen anglais ou enfranvais au gre de I'auteur. Adresser toute communication aux soins dusecretaire, Comite de la redaction, LE BRIQUET, Direction generale descommunications, Agriculture Canada,Ottawa, Ont., K1A OC7.

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