Effect of seed quality on the performance of hybrid Argentine canola in early- and late-seeded plots

with conventional and minimum tillage

Final Report No. 5Saskatchewan Canola Development Commission

November 2007

Bob Elliott, Larry Mann and Owen OlfertSaskatoon Research Centre

Agriculture and Agri-Food Canada107 Science Place

Saskatoon, SK S7N 0X2E-mail: elliottb@agr.gc.ca

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ABSTRACT

Laboratory and field tests were conducted on 14 seed lots of hybrid Argentinecanola (45H21) to determine the influence of seed quality on the performance of theseed lots in conventional tillage (CT) and minimum tillage (MT). Seed lots wereevaluated in the standard germination test (SGT), pre-chill test (PCT), controlleddeterioration test (CDT) and electrical conductivity test (ECT). Green seed content and1000-seed weights were also assessed. Vigour indices were calculated from the 1000-seed weight and final % germination/100. Seed lots were evaluated in CT and MT in2005 and 2006. Seed lots were planted in early to mid May and in late May or earlyJune. Assessments focussed on flea beetle damage, seedling establishment, shootgrowth, biomass accumulation and seed yield. Laboratory data were correlated withfield data to identify seed attributes that provided the best indication of establishment,growth and yield. Linear regression was used to quantify relationships between seedquality and the performance of the seed lots under different growing conditions andtillage practices.

Seed lots of 45H21 differed with respect to 1000-seed weight (3.1-5.4 g), greenseed content (0.4-5.2%), electrical conductivity (57-80 µS cm-1 g-1) and final germinationin the SGT (88-99%), PCT (90-99%) and CDT (60-98%).

Flea beetle damage after 21 days averaged only 1% in tests with MT and 3-9%in tests with CT. Damage in the latter tests increased by 6% when seeding was delayedfrom early May until late May.

The overall performance of the seed lots varied depending on the year, tillagepractice and seeding date. Stand establishment in cool moist soil in 2005 was 10-20%higher in early- and late-seeded plots with CT than in early- and late-seeded plots withMT. Stand establishment in warm moist soil in 2006 was only 3% higher in early-seeded plots with CT than in early-seeded plots with MT. Early seeding reducedestablishment in MT by 10% in 2005 and 2006. Early seeding also reduced shootgrowth and biomass accumulation in CT and MT. In each year of testing, shootbiomass after 28 days was 2-9 times higher in late-seeded plots than in early-seededplots. In contrast, seed yields in CT and MT were 25-35% higher when seed lots wereseeded in early to mid May rather than in late May or early June. Early seedingimproved yields in CT and MT by 7-9 bu/acre.

Establishment of hybrid seed lots differed in all tests. Establishment in cool moistsoil in 2005 ranged from 83-96% in early-seeded plots with CT, from 82-93% in late-seeded plots with CT, from 58-77% in early-seeded plots with MT and from 69-82% inlate-seeded plots with MT. Establishment in warm moist soil in 2006 ranged from 74-86% in early-seeded plots with CT, from 71-81% in early-seeded plots with MT andfrom 81-89% in late-seeded plots with MT. Establishment of hybrid seed lots in 2005was positively correlated with germination of the seed lots in the SGT and PCT. Germination in the PCT provided the best indication of stand establishment in coolmoist soil. With each 1% increase in germination in the PCT, establishment improvedby 1.0-1.3% in early-seeded plots and by 0.4-0.6% in late-seeded plots. Germination in

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the SGT, PCT and CDT provided a poor indication of stand establishment in warmmoist soil in 2006. Establishment in MT declined as the conductivity of the seed lotsincreased.

Shoot weight differed among seed lots after 14, 21 and 28 days in all tests. In2005 and 2006, shoot weights of some seed lots were 1.2-2.0 times higher than thoseof other seed lots. Shoot weights were strongly correlated with 1000-seed weight. Seedlots with seed weights below 4.0 g had the lowest shoot weight whereas seed lots withseed weights above 5.0 g had the highest shoot weights. Shoot weights in CT and MTin 2005 and 2006 increased by 10-22% with a 1.0 g increase in 1000-seed weight.

Shoot biomass differed among seed lots after 14, 21 and 28 days in all tests. Biomass accumulation in 2005 and 2006 was 1.2-2.0 times higher in some seed lotsthan in others. Shoot biomass was strongly correlated with the vigour index of seed lotsin the SGT and PCT. Seed lots with a vigour index below 4.0 had the lowest shootbiomass whereas seed lots with a vigour index of 5.0 or above had the highest shootbiomass. With a 1.0 unit increase in the vigour index, shoot biomass increased by 9-29% after 14, 21 and 28 days. Vigour indices in the PCT provided the best indication ofbiomass accumulation in early-seed plots. Vigour indices in the SGT provided the bestindication of biomass accumulation in late-seeded plots.

Yields differed among seed lots in all tests. Yields of hybrid seed lots in 2005ranged from 63-71 bu/acre on early-seeded plots with CT, from 55-62 bu/acre in late-seeded plots with CT and from 43-54 bu/acre in early-seeded plots with MT. Yields ofhybrid seed lots in 2006 ranged from 41-44 bu/acre in early-seeded plots with CT or MTand from 30-36 bu/acre in late-seeded plots with MT. Yields were positively correlatedwith the vigour index of seed lots in the SGT and PCT. Seed lots with a vigour indexbelow 4.0 had the lowest yields whereas seed lots with a vigour index of 5.0 or abovehad the highest yields. Yields in CT and MT improved by 2-7% with a 1.0 unit increasein the vigour index.

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INTRODUCTION

Seed quality has been shown to have a significant effect on the performance of open-pollinated Argentine canola. Germination in the standard germination test (SGT) andpre-chill test (PCT) was strongly correlated with stand establishment in warm and coolmoist soils (Elias and Copeland 1997, Elliott et al. 2005, 2007a). Germination in thecontrolled deterioration test (CDT) was positively correlated with establishment in drysoil (Larsen et al. 1998, Elliott et al. 2007a) whereas conductivity in the electricalconductivity test (ECT) was negatively correlated with stand establishment in light- andheavy-textured soils with reduced tillage (Elliott et al. 2007a). Seed size and seedweight had a significant effect on shoot growth of Polish and Argentine canola (Elliott etal. 2007c, 2007d). Compared to small light seeds, large heavy seeds improved shootweight, shoot biomass and seed yield of Argentine canola by 1.6-2.0, 3.0-3.5 and 1.5times, respectively. Results indicated that seedlings from large seeds are morevigorous and tolerant to flea beetle damage than seedlings from medium or smallseeds. Vigour indices of open-pollinated Argentine seed lots in the PCT provided thebest indication of biomass accumulation in warm and cool soils (Elliott et al. 2005).

Limited research has been conducted on the influence of seed quality on theperformance of hybrid Argentine canola. The objective of this study was to investigatethe effect of seed quality on the performance of hybrid seed lots under different growingconditions and tillage practices. Experiments focussed on identifying seed attributesthat provide the best indication of stand establishment, shoot growth, biomassaccumulation and potential yield in early- and late-seeded plots with conventional tillageand minimum tillage.

EXPERIMENTAL METHODS

Seed samplesFourteen seed lots of a spring-type, hybrid Argentine canola, Brassica napus L.

(cv. 45H21), were provided by Pioneer Hi-Bred. Seed lots were produced at variouslocations in Alberta in 2003 and 2004. All seed lots were Certified No. 1 canola.

Seed quality testsSeed lots were stored at -17°C and 5-7% moisture content until testing.

Thousand-seed weights were determined from five 200-seed subsamples. Green seedcontent was assessed by crushing five 100-seed subsamples and determining thepercentage of distinctly green seeds.

Seed lots were evaluated in the standard germination test (SGT), pre-chill test(PCT), controlled deterioration test (CDT) and electrical conductivity test (ECT). Each

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test had four 50-seed or 200-seed replicates of 14 seed lots arranged in a randomizedcomplete block design.

The SGT was conducted using standard procedures (AOSA 2000, CFIA 2001). Fifty untreated seeds were placed on a moist blotter (13 ml water) in a plasticgermination box (11.0 x 11.0 x 3.5 cm), covered and transferred to a controlledenvironment chamber (Conviron® model PGV 36) for 7 days. Chambers weremaintained at alternating 25/15°C, 16 h light/8 h dark (16L/8D) photoperiod and 270µmol s-1 m2 light intensity. Numbers of normal seedlings, abnormal seedlings andungerminated seeds were assessed after 4-7 days using recommended guidelines(AOSA 2000, CFIA 2001). In the SGT and subsequent tests, the vigour index of eachseed lot was calculated by multiplying the 1000-seed weight by the final %germination/100.

In the PCT, 50 seeds were placed in a germination box containing one measuredcup (240 cc) of Bell’s premium potting mix (4 parts) and sand (1 part). Seeds werecovered with 5 mm of potting mix, moistened with 30 ml water and placed in the dark at5 ± 1°C for 7 days (Elliott et al. 2005). Samples were transferred to chambersmaintained at alternating 25/15°C and 8 L/16 D photoperiod for 5 days. Numbers ofnormal seedlings were assessed after 10-12 days.

In the CDT, seeds were placed on moistened filter paper for 90 minutes to adjustthe moisture content to 20% (Powell 1995, Hampton and TeKrony 1995, Powell andMatthews 2005). Seeds were placed in foil pouches (James Dawson Enterprises Ltd.,Lachine, Quebec), equilibrated at 10°C for 24 hours and deteriorated at 45°C for 24hours. After deterioration, four 50-seed replicates were incubated at 20°C and 16 L/8 Dphotoperiod for 7 days. Numbers of normal seedlings were determined after 4-7 daysusing methods outlined previously.

In the ECT, seed lots were placed on moistened filter paper for 20 minutes toadjust the moisture content to 10 ± 1%. Seeds were equilibrated in foil pouches at 7-8°C for 24 hours (modified after Hampton 1995, Hampton and TeKrony 1995, AOSA2002). Seeds were weighed, placed in 60 ml de-ionized water and soaked for 24hours. Conductivity after 4 and 24 hours (µS cm-1) was calculated from the conductivityof the seed sample minus conductivity of the blank. Electrical conductivity (EC),measured in µS cm-1 g-1, was determined by dividing the conductivity by the weight ofthe seed sample.

Land preparationField tests were conducted in conventional tillage (CT) and minimum tillage (MT)

at the Agriculture and Agri-Food Canada Research Farm, Saskatoon Research Centrein 2005 and 2006. Tests in CT were seeded May 11 and May 25 in 2005 and May 11 in2006. Tests in MT were seeded May 12 and May 26 in 2005 and May 16 and June 2 in2006. Fertility requirements were based on yearly soil test recommendations for canolaproduction. In plots with CT, a fertilizer blend (N/P/K/S) was banded into summer fallowat a 5-10 cm depth in the fall (early seeding) or spring (late seeding). In plots with MT,the fertilizer blend was side-banded into tilled wheat stubble at planting. In plots withCT, a pre-plant herbicide (Advance 10G™, trifluralin) was applied in the fall or early

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spring at 10.7 kg/ha and incorporated with a cultivator and harrows. In plots with CTand MT, a pre-plant herbicide (Roundup™, glyphosate, 356 g a.i./L) was applied at 1.2 Lproduct/ha in 2006. A post-emergent herbicide for grassy weeds (Select™, clethodim,240 g a.i./L) was applied at 197.6 ml product/ha in 2005 and 2006. A post-emergentherbicide for broad-leafed weeds (Muster™, 75% ethametsulfuron-methyl) was appliedat 2.5 g product/ha in 2005.

Agronomic assessmentsFlea beetle damage to 20 cotyledons in each plot (n = 10 seedlings) was

assessed 21 days after seeding (DAS) using a 10-point scale that corresponded to thepercentage of leaf surface eaten by flea beetles (Palaniswamy et al. 1992). Seedlingsalong a centre row of each plot were counted 14 and 21 DAS. Shoot growth wasevaluated by harvesting 10 plants from the outer rows of each plot 14, 21 and 28 ± 1DAS. Samples were placed in plastic bags, labelled and transported to the laboratory incoolers. Shoots were cleaned and weighed to determine shoot fresh weight (mg/plant). Samples were dried at 60°C for 4-7 days to assess shoot dry weight. Shoot biomasswas calculated from the number of seedlings/m-row and shoot fresh weight. The fourcentre rows of each plot were swathed and harvested at maturity with a small-plotcombine to determine seed yield. In 2005, late-seeded plats with MT were notharvested because of flooding.

Statistical analysesData were analyzed using the General Linear model procedure (SAS Institute

1999). Fisher’s protected LSD test was used to compare means among seed lots. Laboratory data were correlated with field data. Pearson’s correlation coefficient wasused to identify attributes in laboratory tests that provided the best indication of seedlingemergence, stand establishment, shoot fresh weight, shoot biomass and seed yield. Linear regression was used to quantify the relationship between attributes of seed lotsin the lab and their performance in the field.

RESULTS AND DISCUSSIONSeed quality

Certified seed lots of 45H21 differed in several respects (Table 1). Thousand-seed weights ranged from 3.10 g in seed lot L1 to 5.4 g in seed lot L14. Green seedcontent was relatively low, ranging from 0.4% in seed lots L1 and L2 to 5.2% in seed lotL14. Final germination of the seed lots ranged from 88-99% in the SGT, from 90-99% inthe PCT and from 60-98% in the CDT. Based on current guidelines (CFIA 2001, 2006),all seed lots exceeded the minimum tolerance (90 ± 6%, n = 200 seeds) for CertifiedNo. 1 seed. Seed lot L1 had the highest germination in the SGT, PCT and CDT. Seedlot L4 had the lowest standard germination and least tolerance to cool temperature inthe PCT. Seed lots L13 and L14 had the least tolerance to high temperatures in theCDT. Electrical conductivity after 24 hours soaking ranged from 57 µS cm-1 g-1 in seedlot L8 to over 80 µS cm-1 g-1 in seed lots L4 and L14.

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Soil temperature and moisture are key factors limiting seedling establishment incanola (Anonymous 2002, Thomas 2003, Elliott et al., 2005, 2007a, 2007b). In thecurrent study, soil temperatures at planting depth were lower in 2005 than in 2006(Table 2). Temperatures in 2005 averaged 7-10°C in early-seeded plots and 9°C inlate-seeded plots. Temperatures in 2006 averaged 14-17°C in early-seeded plots and22°C in late-seeded plots. Soil temperatures in plots with CT and MT differed by 3°C orless in each year of testing. Moisture conditions were excellent in all tests. Precipitationthroughout the growing season was higher in 2005 (295 mm) than in 2006 (210 mm).Less rainfall in August limited yields in all tests in 2006.

Flea beetle damagePrevious investigations have shown that flea beetle damage is higher with

conventional tillage than with minimum or zero tillage (Milbrath et al. 1995, Dosdall et al.1999). In some studies, seeding date had no effect on flea beetle damage (Dosdall andStevenson 2005, Elliott et al. 2007b). However, in other studies, flea beetle numbersand damage declined when seeding was delayed from mid May until mid June (Milbrathet al. 2005). In the present study, flea beetle damage after 21 days was consistentlylower in tests with MT than in tests with CT (Table 2). Damage averaged only 1% infour tests with MT and 3-9% in three tests with CT. In the latter tests, damage in 2005increased by 6% when seeding was delayed from May 11 until May 25.

Agronomic performanceThe overall performance of hybrid seed lots varied depending on the year, tillage

practice and seeding date (Table 3). In 2005, seedling emergence in early- and late-seeded plots after 14 days averaged 86% and 90%, respectively, with CT and 64% and68%, respectively, with MT. In 2006, emergence after 14 days averaged 78% in early-seeded plots with CT, 58% in early-seeded plots with MT and 82% in late-seeded plotswith MT. Stand establishment after 21 days also varied from test to test. In 2005,establishment in early- and late-seeded plots averaged 90% with CT and 67% and77%, respectively, with MT. In 2006, establishment after 21 days averaged 80% inearly-seeded plots with CT, 77% in early-seeded plots with MT and 86% in late-seededplots with MT. Early seeding reduced stand establishment in MT by 10%. Early seedingalso reduced shoot growth and biomass accumulation. In each year of testing, shootfresh weights and shoot biomass after 14, 21 and 28 days were 1.2-3.8 times higher inlate-seeded plots than in early-seeded plots. Differences in shoot growth betweenseeding dates were greater after 28 days than after 14 days. Shoot biomass after 28days was 2.0-3.8 times higher in late-seeded plots than in early-seeded plots. Incontrast, seed yields in CT and MT were 25-35% higher when seed lots were seeded inearly to mid May rather than in late May or early June. With early seeding, yieldsimproved by 7-8 bu/acre in CT in 2005 and by 9 bu/acre in MT in 2006.

Seed lot performance in 2005Seedlings/row after 14 and 21 days varied among seed lots in each test (Table

4). In early-seeded plots with CT, seedling establishment after 21 days ranged from 165

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seedlings/row in seed lots L4 and L14 (82% establishment) to 192 seedlings/row inseed lot L5 (96% est.). In late-seeded plots with CT, seedling establishment rangedfrom 165 seedlings/row in seed lot L4 (82% est.) to over 180 seedlings/row in seed lotsL3, L5, L7, L10, L11 and L12 (> 90% est). Results indicated that seeding date hadrelatively little effect on establishment of hybrid seed lots in CT. In early-seeded plotswith MT, establishment ranged from 116 seedlings/row in seed lots L6 and L7 (58%est.) to over 150 seedlings/row in seed lots L11 and L12 (75% est.). In late-seededplots with MT, establishment ranged from 139 seedlings/row in seed lot L4 (70% est.) toover 160 seedlings/row in seed lots L7 and L9 (80% est.). Results indicated thatseeding in early May rather than in late May reduced establishment of hybrid seed lotsin MT by 5-12%.

Previous investigations have shown that seed quality has a pronounced effect onestablishment of open-pollinated Argentine canola. Germination in the SGT and PCTwas strongly correlated with establishment in warm and cool moist soils (Elias andCopeland 1997, Elliott et al. 2005, 2007a). Germination in the CDT was stronglycorrelated with establishment in dry soil (Larsen et al. 1998, Elliott et al. 2007a). Greenseed content and electrical conductivity were negatively correlated with establishmentunder normal field conditions (Elias and Copeland 1997) and establishment withreduced tillage in light- and heavy- textured soils (Elliott et al. 2007a). In the currentstudy, germination after 7 days in the SGT was positively correlated with establishmentof hybrid seed lots in early- and late-seeded plots with CT (r=0.57-0.60) and late-seeded plots with MT (r=0.53)(Table 5). Conductivity of hybrid seed lots after 4 and 24hours soaking was negatively correlated with establishment in early-seeded plots withCT (-r=0.64-0.70). Correlations between conductivity and establishment were notsignificant in the remaining tests. Germination after 10-12 days in the PCT had thehighest correlation with establishment in early-seeded plots with CT (r=0.69-0.75), late-seeded plots with CT (r=0.59-0.69) and early-seeded plots with MT (r=0.49-0.55).Correlations indicated that germination in the PCT provided the best indication of standestablishment of hybrid seed lots, particularly with early seeding.

Hybrid seed lots with the lowest germination in the SGT had the poorestestablishment in most tests in 2005 (Figure 1). With each 1% increase in germination inthe SGT, establishment improved by 0.9-1.0% in early-seeded plots and by 0.6-0.7% inlate-seeded plots. Coefficients of determination (R2) indicated that differences ingermination among seed lots in the SGT accounted for 33-35% of the variation inestablishment in early- and late-seeded plots with CT and 16-28% of the variation inestablishment in early- and late-seeded with MT. Conductivity after 4 and 24 hourssoaking provided a better indication of stand establishment in early-seeded plots withCT (Fig. 2). Establishment declined by 3% with each 10 µS cm-1 g-1 increase inconductivity after 24 hours soaking. Differences in conductivity accounted for 49% ofthe variation in establishment in early-seeded plots with CT. Seed lots with the lowestgermination in the PCT had the poorest establishment in most tests (Fig. 3). With each1% increase in germination in the PCT, establishment improved by 1.0-1.3% in early-seeded plots and by 0.4-0.6% in late-seeded plots. Differences in germination amonghybrid seed lots in the PCT accounted for more of the variation in establishment in

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early-seeded plots with CT (R2=0.47) than in late-seed plots with CT (R2=0.34), early-seeded plots with MT (R2=0.30) or late-seeded plots with MT (R2=0.10).

Shoot fresh weights differed among seed lots after 14, 21 and 28 ± 1 days ineach test (Table 6). Shoot weights on each of the three sampling dates were usuallylowest in early-seeded plots with MT and highest in late-seeded plots with CT. In mostinstances, seed lots L1, L2 and L4 had the lowest shoot weights whereas seed lotsL12, L13 and L14 had the highest shoot weights. Depending on the test, shoot weightsafter 27-28 days were 1.2-1.9 times higher in seed lots L12, L13 and L14 than in seedlots L1, L2 and L4.

Seed size and seed weight have been shown to have a significant effect onshoot growth of Polish and Argentine canola (Elliott et al. 2005, 2007c, 2007d). Shootweights in each species increased in direct proportion with an increase in 1000-seedweight. In the present study, green seed content, electrical conductivity and germinationin the SGT, PCT and CDT were poorly correlated with the shoot weights of hybrid seedlots on most sampling dates of each test (Table 7). In contrast, 1000-seed weights andseed weights in the ECT were strongly correlated with shoot fresh weights after 14, 21and 28 ± 1days in early-seeded plots with CT (r=0.54-0.86), late-seeded plots with CT(r=0.77-0.88), early-seeded plots with MT (r=0.43-0.92) and late-seeded plots with MT(r=0.46-0.77).

Thousand-seed weights had a significant effect on the shoot fresh weight ofhybrid seed lots after 13-14 days (Fig. 4), 20-21 days (Fig. 5) and 27-28 days (Fig. 6). Shoot weights on each of the three sampling dates increased linearly as 1000-seedweights increased. Seed lots with seed weights below 4.0 g had the lowest shootweights whereas seed lots with seed weights above 5.0 g had the highest shootweights. Depending on the test, a 1.0 g increase in 1000-seed weight improved shootweights by 9-19 mg/plant after 13-14 days (19-23% increase), by 17-116 mg/plant after20-21 days (10-26% increase) and by 117-629 mg/plant after 27-28 days (10-23%increase). Improvements in shoot growth with heavier seed after 27-28 days weregreatest in the early MT planting. Differences in 1000-seed weight among seed lotsaccounted for 60-84% of the variation in shoot growth after 13-14 days, 23-71% of thevariation in shoot growth after 20-21 days and 24-69% of the variation in shoot growthafter 27-28 days.

Shoot biomass differed among hybrid seed lots after 14, 21 and 28 ± 1 days ineach test (Table 8). Shoot biomass on each of the three sampling dates was 3-9 timeshigher in late-seeded plots with CT than in early-seeded plots with MT. In most tests,seed lots L1, L2 and L4 had the lowest shoot biomass whereas seed lots L12, L13 andL14 had the highest shoot biomass. Biomass accumulation after 27-28 days was 1.2-1.9 times higher in seed lots L12, L13 and L14 than in seed lots L1, L2 and L4.

In previous tests, vigour indices of open-pollinated seed lots in the SGT and PCTwere highly correlated with shoot biomass in all field trials (Elliott et al. 2005). Vigourindices in the PCT provided the best indication of biomass accumulation in warm andcool moist soils. In the present study, the vigour index of hybrid seed lots in the SGTwas strongly correlated with shoot biomass after 14, 21 and 28 ± 1 days in early- andlate-seeded plots with CT (r=0.47-0.87) and in early- and late-seeded plots with CT(r=0.43-0.83) (Table 9). Shoot biomass in each test increased linearly as the vigour

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index of seed lots in the SGT and PCT increased (Figs. 7-12). Seed lots with a vigourindex below 4.0 had the lowest shoot biomass whereas seed lots with a vigour index of5.0 or above had the highest shoot biomass. With a 1.0 unit increase in the vigour indexof seed lots in the SGT, shoot biomass increased by 0.2-0.6 g/m-row after 13-14 days(19-22% increase), by 0.6-4.0 g/m-row after 20-21 days (15-25% increase) and by 3-20g/m-row after 27-28 days (9-27% increase) (Figs. 6-9). Depending on the test,differences in the vigour index among seed lots in the SGT accounted for 64-76% of thevariation in shoot biomass after 13-14 days, 19-66% of the variation in shoot biomassafter 20-21 days and 21-54% of the variation in shoot biomass after 27-28 days. With a1.0 unit increase in the vigour index of seed lots in the PCT, shoot biomass in the fieldimproved by 0.2-0.6 g/m-row after 13-14 days (19-25% increase), by 0.6-4.2 g/m-rowafter 20-21 days (15-27% increase) and by 3.4-21.0 g/m-row after 27-28 days (9-29%increase) (Figs. 10-12). Depending on the test, differences in the vigour index of seedlots in the PCT accounted for 66-77%, 21-68% and 22-64% of the variation in shootbiomass after 13-14 days, 20-21 days and 27-28 days, respectively. Vigour indices inthe PCT provided the best indication of biomass accumulation in early-seeded plots. Vigour indices in the SGT provided the best indication of biomass accumulation in late-seeded plots.

Seed yields differed among seed lots in each test (Table 10). Yields in early-seeded plots with CT ranged from 351 g/m2 (62.5 bu/acre) in seed lot L1 to 398 g/m2

(70.8 bu/acre) in seed lot L13. Yields in late-seeded plots with CT were lower, rangingfrom 309 g/m2 (55.0 bu/acre) in seed lot L4 to 346 g/m2 (61.6 bu/acre) in seed lot L13. In early-seeded plots with MT, yields ranged from 239 g/m2 (42.5 bu/acre) in seed lot L1to 303 g/m2 (54.0 bu/acre) in seed lot L14.

Thousand-seed weights, seed weights in the ECT and vigour indices in the SGTor PCT were strongly correlated with seed yield in early-seeded plots with CT (r=0.68-0.74) or MT (r=0.76-0.80) (Table 11). Seed lots with a vigour index below 4.0 had thelowest yields whereas seed lots with a vigour index of 5.0 or above had the highestyields. With a 1.0 unit increase in the vigour index in the SGT, yields increased by 12.5g/m2 (3%) in early-seeded plots with CT and by 18.4 g/m2 (7%) in early-seeded plotswith MT (Fig. 13). Differences in the vigour index among seed lots in the SGTaccounted for 48% of the variation in yield in early-seeded plots with CT and 58% of thevariation in yield in early-seeded plots with MT.

Seed lot performance in 2006Seed lots from 2005 were re-evaluated in the field in 2006. Seedlings/row after

14 and 21 days differed among seed lots in each test (Table 12). In early-seeded plotswith CT, seedling establishment after 21 days ranged from 147 seedlings/row in seedlot L9 (74% est.) to 171 seedlings/row in seed lot L5 (85% est). In early-seeded plotswith MT, establishment ranged from 142 seedlings/row in seed lot L1 (71% est.) to over160 seedlings/row in seed lots L5 and L9 (> 80% est.). In late-seeded plots with MT,establishment ranged from 163 seedlings/row in seed lot L4 (82% est.) to 178seedlings/row in seed lot L11 (89% est.). Results indicated that seeding in mid Mayrather than in early June reduced establishment of hybrid seed lots by 9-11% in MT.

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In 2005, germination in the PCT provided the best indication of standestablishment in hybrid seed lots. In 2006, electrical conductivity and germination in theSGT, PCT and CDT were poorly correlated with stand establishment in all tests (Table13). Seed lots with the lowest germination in the SGT and PCT had relatively goodestablishment in all tests (Figs. 14 and 15). Differences in germination among seed lotsin each test accounted for less than 5% of the variation in establishment of hybrid seedlots in early-seeded plots. Conductivity of the seed lots after 4 and 24 hours soakingprovided a better indication of establishment in some tests(Fig. 16). Establishment ofhybrid seed lots in early- and late-seeded plots in MT tended to decline (P=0.07-0.09)as the conductivity after 24 hours increased.

Shoot fresh weights differed among seed lots after 14, 21 and 28 days in eachtest (Table 14). Shoot weights on each of the three sampling dates were 1.4-2.0 timeshigher in late-seeded plots with MT than in early-seeded plots with MT. In mostinstances, seed lots L2 and L4 had the lowest shoot weights whereas seed lots L12,L13 or L14 had the highest shoot weights. Depending on the test, shoot weights after28 days were 1.3-1.9 times higher in seed lots L12, L13 and L14 than in seed lots L2and L4.

In 2006, green seed content, electrical conductivity and germination in the SGT,PCT and CDT were poorly correlated with shoot weight in all tests (Table 15). Thousand-seed weights and seed weights in the ECT were strongly correlated withshoot weights in early-seeded plots with CT (r=0.65-0.87), early-seeded plots with MT(r=0.53-0.74) and late-seeded plots with MT (r=0.54-0.84).

As in 2005, 1000-seed weights had a significant effect on the shoot fresh weightof hybrid seed lots in 2006. Shoot weights after 14 days (Fig. 17), 21 days (Fig. 18) and28 days (Fig. 19) increased as 1000-seed weights increased. Seed lots with seedweights of less than 4.0 g had the lowest shoot weights whereas seed lots with seedweights of more than 5.0 g had the highest shoot weights. Depending on the test, a 1.0g increase in seed weight improved shoot weights by 12-22 mg/plant after 14 days (13-22% increase), by 67-162 mg/plant after 21 days (13-17% increase) and by 463-780mg/plant after 28 days (10-16% increase). As in 2005, improvements in shoot growthwith heavier seed were greatest in the early MT planting. Depending on the test,differences in seed weight among seed lots accounted for 37-75%, 36-70% and 29-42% of the variation in shoot growth after 14, 21 and 28 days, respectively.

Shoot biomass differed among hybrid seed lots after 14, 21 and 28 days in eachtest (Table 16). Shoot biomass was 1.4-2.5 times higher in late-seeded plots with MTthan in early-seeded plots with MT. Seed lots L12, L13 and L14 had the highestbiomass in most tests. Biomass accumulation after 28 days was 1.3-2.0 times higher inseed lots L12, L13 and L14 than in seed lots L2 and L4.

In 2006, the vigour index of hybrid seed lots in the SGT and PCT provided thebest indication of shoot biomass after 14, 21 and 28 days in early-seeded plots with CT(r=0.78-0.90), early-seeded plots with MT (r=0.58-0.70) and late-seeded plots with MT(r=0.60-0.83) (Table 17). Shoot biomass in each test increased as the vigour indexincreased (Figs. 20-25). Seed lots with a vigour index of less than 4.0 had the lowestshoot biomass whereas seed lots with a vigour index of 5.0 had the highest shootbiomass. With a 1.0 unit increase in the vigour index of seed lots in the SGT, shoot

12

biomass increased by 0.3-1.6 g/m-row after 14 days (16-25% increase) by 2.3-5.5 g/m-row after 21 days (15-21% increase) and by 15-27 g/m-row after 28 days (15-21%increase) (Figs. 20-22). Differences in the vigour index among seed lots in the SGTaccounted for 33-80%, 44-74% and 35-62% of the variation in shoot biomass after 14,21 an 28 days, respectively. With a 1.0 unit increase in the vigour index of seed lots inthe PCT, shoot biomass increased by 0.3-1.7 g/m-row after 14 days (17-26% increase),by 2.5-5.7 g/m-row after 21 days (16-22% increase) (Figs. 23-25). Depending on thetest, differences in the vigour index among seed lots in the PCT accounted for 35-80%,48-72% and 33-63% of the variation in shoot biomass after 14, 21 and 28 days,respectively. As in 2005, vigour indices in the PCT provided the best indication ofbiomass accumulation in early-seeded plots.

Yields differed among seed lots in each test in 2006 (Table 18). Yields in early-seeded plots with CT ranged from 229 g/m2 (40.8 bu/acre) in seed lot L4 to 247 g/m2

(43.9 bu/acre) in seed lot L13. Yields in early-seeded plots with MT ranged from 231g/m2 (41.1 bu/acre) in seed lot L4 to 249 g/m2 (44.3 bu/acre) in seed lot L12. Yieldswere lowest in late-seeded plots with MT, ranging from 168 g/m2 (29.8 bu/acre) in seedlot L2 to 203 g/m2 (36.1 bu/acre) in seed lot L12.

Seed quality was poorly correlated with seed yields in early-seeded plots with CT(Table 19). Germination in the SGT and PCT had the highest positive correlation(r=0.55-0.67) with yield in early-seeded plots with MT. Yields were negatively correlated(-r=0.54-0.57) with conductivity after 4 and 35 hours soaking. The vigour index of seedlots in the SGT and PCT had the highest correlation (r=0.70) with yields in late-seededplots with MT. Seed lots with a vigour index of less than 4.0 in the SGT had the lowestyield (Fig. 26). Yields improved by 9.5 g/m2 (5%) with a 1.0 unit increase in the vigourindex. Differences in the vigour index of seed lots in the SGT accounted for 49% of thevariation in yield in late-seeded plots with MT.

ACKNOWLEDGEMENTS

We thank our summer students Jessica Williams, Jordan Bue, Heather Ferguson,Shannon Hamilton and Christine Donley for their assistance. Funding from theSaskatchewan Canola Development Commission and Canola Council of Canada isgratefully acknowledged.

REFERENCES

Anonymous 2002. Factors that affect canola germination, seed and seedling vigour.Canola Council of Canada publication. 4 pp.

AOSA 2000. Rules for Testing Seeds. Assoc. Offic. Seed Anal., Las Cruces, NM, USA.

AOSA 2002. Seed Vigor Testing Handbook. Contribution No. 32. Assoc. Offic. SeedAnal., Lincoln, NE.

13

CFIA 2001. Canadian Methods and Procedures for Testing Seed. Canadian FoodInspection Agency. Ottawa, Canada.

CFIA 2006. Seeds Act and Regulations. Canadian Food Inspection Agency. Ottawa,Canada.

Dosdall, L.M., Dolinski, M.G., Cowle, N.T. and Conway, P.M. 1999. The effect of tillageregime, row spacing and seeding rate on feeding damage by flea beetles, Phyllotretaspp. (Coleoptera: Chrysomelidae), in canola in central Alberta, Canada. Crop Protection18: 217-224.

Dosdall, L.M. and Stevenson, F.C. 2005. Managing flea beetle (Phyllotreta spp.)(Coleoptera: Chrysomelidae) in canola with seeding date, plant density and seedtreatment. Agron. J. 97:1570-1578.

Elias, S.G. and Copland, L.O. 1997. Evaluation of seed vigor tests for canola. SeedTechnol. 19: 78-87.

Elliott, R.H., Mann, L.W. and Olfert, O. 2005. Vigor tests for evaluating the performanceof Argentine canola (Brassica napus L.) under different growing conditions. SeedTechnol. 27: 273-285.

Elliott, R.H., Mann, L.W., Johnson, E.N., Brandt, S., Vera,C. Kutcher, H.R., Lafond, G.and May, W.E. 2007a. Vigor tests for evaluating establishment of canola under differentgrowing conditions and tillage practices. Seed Technol. In Press.

Elliott, B., Mann, L. and Olfert, O. 2007b. Effect of neonicotinoid seed treatments onflea beetle damage and performance of Argentine canola (Brassica napus) in 2003-2006. Final report to SCDC. 79 pp.

Elliott, R.H., Mann, L.W. and Olfert, O.O. 2007c. Effects of seed size and seed weighton seedling establishment, seedling vigour and tolerance of summer turnip rape(Brassica rapa) to flea beetles, Phyllotreta spp. Can. J. Plant Science 87: 385-393.

Elliott, R.H., Franke, C. and Rakow, G.F.W. 2007d. Effects of seed size and seedweight on seedling establishment, vigour and tolerance of Argentine canola (Brassicanapus) to flea beetles, Phyllotreta spp. Can J. Plant Sci. In Press.

Hampton, J.G. 1995. Conductivity test. In: Seed Vigour Testing Seminar (ed H.A. vande Venter) pp. 10-28. International Seed Testing Assoc., Zurich, Switzerland.

Hampton, J.G. and TeKrony, D.M. (ed.) 1995. Handbook of Vigor Test Methods. Thirdedition. International Seed Testing Assoc., Zurich, Switzerland.

14

Larsen, S.U., Povlsen, F.V., Eriksen, E.N. and Pedersen, H.C. 1998. The influence ofseed vigour on field performance and the evaluation of the applicability of the controlleddeterioration vigour test in oil seed rape (Brassica napus) and pea (Pisum sativum).Seed Sci. Technol. 26: 627-641.

Milbrath, L.R., Weiss, M.J. and Schatz, B.G. 1995. Influence of tillage system, plantingdate, and oilseed crucifers on flea beetle populations (Coleoptera: Chrysomelidae).Can. Entomol. 127: 289-293.

Palaniswamy, P., Lamb, R.J. and McVetty, P.B.E. 1992. Screening for antixenosisresistance to flea beetles, Phyllotreta cruciferae (Goeze) (Coleoptera: Chrysomelidae),in rapeseed and related crucifers. Can Entomol. 124: 895-906.

Powell, A.A. 1995. The controlled deterioration test. In: Seed Vigour Testing Seminar(ed. H.A. van de Venter) pp. 73-87. International Seed Testing Assoc., Zurich,Switzerland.

Powell, A.A. and Matthews, S. 2005. Towards the validation of the controlleddeterioration vigour test for small seeded vegetables. Seed Testing International 129:21-24.

SAS 1999. SAS/STAT® User’s Guide. Version 8, Vol. 2. SAS Institute, Inc., Cary NC.

Thomas, P. 2003. Canola Growers Manual. Canola Council of Canada. Winnipeg,Manitoba.

Table 1. Quality and vigour of hybrid seed lots in different laboratory tests in 2005 and 2006.1

Seed

lot

1000-

seed wt.

(g)

Green

seed (%)

SGT (% germ)

Vigour

index

PCT (% germ) Vigour

index

CDT (% germ)Vigour

index

ECT (:S cm -1g-1)Seed

wt. (g)4 days 7 days 10 days 12 days 4 days 7 days 4 hours 24 hours

1 3.10 0.4 93 99 3.05 99 99 3.08 35 98 3.04 24.7 66.0 0.66

2 3.14 0.4 92 99 3.09 98 98 3.08 32 96 3.01 26.3 65.8 0.65

3 3.76 4.4 77 94 3.53 96 96 3.61 14 89 3.33 30.1 78.4 0.77

4 3.86 1.2 64 88 3.40 85 90 3.47 16 86 3.32 32.1 85.7 0.78

5 3.90 2.2 78 98 3.80 98 98 3.82 16 95 3.69 26.7 62.3 0.79

6 4.08 3.6 74 97 3.94 94 94 3.84 12 90 3.65 30.9 73.4 0.80

7 4.09 1.0 72 96 3.91 93 96 3.91 12 92 3.76 29.0 64.4 0.83

8 4.27 2.8 76 98 4.16 97 98 4.16 12 92 3.93 22.2 56.7 0.89

9 4.30 1.8 73 98 4.21 98 99 4.24 12 90 3.87 24.1 59.7 0.87

10 4.41 3.4 70 96 4.23 97 98 4.30 24 91 3.99 25.5 59.5 0.90

11 4.58 3.2 81 96 4.40 96 97 4.42 24 92 4.19 24.9 65.2 0.88

12 5.07 1.4 77 97 4.92 95 97 4.89 14 88 4.44 26.1 66.1 0.98

13 5.16 3.0 78 95 4.90 93 95 4.88 6 73 3.74 26.7 69.0 1.06

14 5.45 5.2 71 94 5.12 90 92 4.99 3 60 3.27 37.5 83.9 1.05

LSD 10 4 0.18 4 4 0.18 12 16 0.83 3.6 7.6 0.041 SGT = standard germination test. PCT = pre-chill test. CDT = controlled deterioration test. ECT = electrical conductivity test.

Table 2. Summ ary of tillage practices, planting dates, meteorological conditions and flea beetle damage in seed lot evaluations in 2005

and 2006.1

Planting

date

Soil

temp (°C)

Precipitation (mm)Flea beetle

damage (%)Year Tillage Conditions Jan-April May-June July-Aug

2005 CT May 11 7 cool, moist 86.5 188.0 107.0 3

May 25 9 cool, moist 86.5 188.0 107.0 9

MT May 12 10 cool, moist 86.5 188.0 107.0 1

May 26 9 cool, moist 86.5 188.0 107.0 1

2006 CT May 11 14 warm, moist 107.0 147.8 62.0 5

MT May 16 17 warm, moist 107.0 147.8 62.0 1

June 2 22 warm, moist 107.0 147.8 62.0 11 CT = conventional tillage. MT = minimum tillage. Soil temperature at 2.5 cm. Precipitation data from Environment Canada. Flea beetle damage 21 days after seeding.

Table 3. Overall performance of hybrid seed lots in early- and late-seeded plots with conventional tillage (CT) and minimum tillage (MT) in 2005

and 2006.1

Seeding

date

Seedlings/row Shoot fresh weight (mg) Shoot biomass (g/m-row) Seed yield

Year Tillage 14 DAS 21 DAS 14 DAS 21 DAS 28 DAS 14 DAS 21 DAS 28 DAS (g/m 2) bu/acre

2005 CT May 11 171.7 180.5 51.9 202.4 1228.4 1.5 6.0 36.3 371.6 66.1

May 25 180.4 179.6 104.8 793.1 4666.5 3.1 23.4 136.1 327.3 58.3

MT May 12 127.2 134.5 41.0 179.4 833.0 0.9 4.0 18.5 277.2 49.3

May 26 135.5 153.4 67.7 515.7 2839.8 1.5 13.1 71.2 NA NA

2006 CT May 11 156.9 160.0 258.2 997.8 6919.2 6.7 26.3 182.0 239.0 42.5

MT May 16 117.1 153.9 85.3 525.5 2947.6 1.6 13.3 74.4 240.4 42.5

June 2 164.6 171.6 136.8 611.7 5353.4 3.7 17.3 150.6 188.3 33.51 Means based on 14 seed lots. Each seed lot was planted at 200 seed per 6.1 m row. NA - not assessed because of flooding.

Table 4. Number of seedlings/row of hybrid seed lots after 14 and 21 days in early- and late-seeded plots with conventional tillage (CT)

and minimum tillage (MT) in 2005.1

Seed lot

Seedlings/row - early CT Seedlings/row - late CT Seedlings/row - early MT Seedlings/row - late MT

14 DAS 21 DAS 14 DAS 21 DAS 14 DAS 21 DAS 14 DAS 21 DAS

1 168.3 173.0 179.5 176.0 133.5 147.3 125.0 153.0

2 179.5 186.3 183.5 180.0 137.3 133.3 128.0 143.5

3 174.3 184.8 186.0 185.8 129.5 136.5 133.8 145.5

4 156.0 166.3 167.0 164.8 117.0 120.5 121.0 138.8

5 178.5 191.8 183.8 182.0 133.5 138.3 136.0 156.0

6 172.8 180.5 183.5 178.0 104.8 116.3 148.3 155.5

7 175.0 181.5 179.8 180.5 109.3 116.3 145.0 160.0

8 173.5 183.8 178.8 178.0 118.3 122.5 135.8 153.3

9 178.8 185.8 177.5 179.5 133.5 142.5 142.8 163.3

10 174.8 182.0 187.0 186.8 132.8 137.3 135.5 148.0

11 173.8 187.0 185.0 183.3 135.3 154.0 140.8 159.0

12 171.0 177.5 178.0 182.3 140.0 155.8 125.5 157.5

13 164.5 180.0 177.3 177.5 122.0 130.0 132.5 152.8

14 154.5 165.0 175.8 177.5 119.3 126.5 136.3 155.5

LSD 14.5 8.8 8.5 8.6 21.2 21.9 26.5 20.6

1 Seed lots planted at 200 seeds per 6.1 m row.

Table 5. Statistical correlations between seed attributes and numbers of seedlings/row of hybrid seed lots after 14 and 21 days in early-

and late-seeded plots with conventional tillage (CT) and minimum tillage (MT) in 2005.

Seed attribute

Seedlings/row - early CT Seedlings/row - late CT Seedlings/row - early MT Seedlings/row - late MT

14 DAS 21 DAS 14 DAS 21 DAS 14 DAS 21 DAS 14 DAS 21 DAS

% green seed - 0.27 - 0.07 0.26 0.32 - 0.25 - 0.15 0.41 0.08

1000-seed wt. - 0.42 - 0.25 - 0.21 0.12 - 0.12 0.06 0.21 0.41

SGT - germ 4 d 0.39 0.31 0.41 0.23 0.51 0.46 - 0.23 0.02

- germ 7 d 0.72** 0.60* 0.60* 0.57* 0.40 0.40 0.29 0.53*

- index 7 d - 0.30 - 0.15 - 0.11 0.22 - 0.05 0.12 0.26 0.51

PCT - germ 10 d 0.83*** 0.75** 0.73** 0.69** 0.55* 0.49 0.21 0.33

- germ 12 d 0.81*** 0.69** 0.61* 0.59* 0.61* 0.55* 0.08 0.32

- index 12 d - 0.29 - 0.13 - 0.11 0.24 - 0.02 0.16 0.24 0.49

CDT - germ 4 d 0.37 0.19 0.35 0.10 0.52 0.42 - 0.37 - 0.32

- germ 7 d 0.74** 0.57* 0.40 0.19 0.29 0.24 - 0.01 - 0.04

- index 7 d 0.27 0.34 0.16 0.40 0.14 0.34 0.32 0.55*

ECT - 4 hours - 0.67** - 0.64* - 0.33 - 0.32 - 0.49 - 0.47 0.03 - 0.23

-24 hours - 0.77** - 0.70** - 0.46 - 0.51 - 0.36 - 0.32 - 0.28 - 0.47

- seed wt. - 0.41 - 0.23 - 0.23 0.10 - 0.13 0.01 0.18 0.38

*, **, *** Pearson correlation coefficient (n = 14 seed lots) significant at P = 0.05, P = 0.01 and P = 0.001, respectively.

Table 6. Shoot fresh weight of hybrid seed lots after 14, 21 and 28 days in early- and late-seeded plots with conventional tillage (CT)

and minimum tillage (MT) in 2005.1

Seed lot

Shoot wt. - early CT (mg) Shoot wt. - late CT (mg) Shoot wt. - early MT (mg) Shoot wt. - late MT (mg)

13 DAS 20 DAS 27 DAS 13 DAS 20 DAS 27 DAS 14 DAS 21 DAS 28 DAS 14 DAS 21 DAS 28 DAS

1 47.0 155.1 981.8 87.2 724.8 4001.0 31.0 166.2 636.0 56.2 421.1 2393.0

2 41.8 168.4 1315.8 88.1 757.8 4582.0 32.1 157.3 685.5 61.8 487.7 2439.8

3 50.3 217.9 1309.5 98.3 690.3 4742.3 34.1 195.6 732.0 59.0 521.8 2791.5

4 45.5 138.7 1139.3 98.7 653.3 4274.3 35.6 147.2 690.3 46.8 404.5 2346.8

5 47.5 174.0 1102.8 92.7 732.5 4600.8 36.3 167.4 868.5 66.3 598.0 3082.3

6 44.8 165.6 1093.5 97.1 772.5 4460.8 39.6 176.7 804.5 65.3 480.1 3322.8

7 54.6 201.4 1363.2 105.8 771.5 4758.8 40.8 187.8 850.1 61.7 440.3 3444.8

8 55.9 208.1 1254.8 107.0 818.5 4687.5 41.9 165.1 785.3 74.6 495.9 2990.7

9 53.4 185.9 1268.5 96.9 709.5 4410.8 38.7 151.7 679.3 79.1 566.9 2524.0

10 54.5 233.0 1171.3 109.8 913.6 4429.0 45.0 173.2 959.0 69.7 554.8 2567.8

11 49.2 244.6 1486.3 103.9 827.8 4790.3 51.3 196.4 904.3 64.3 496.5 2372.3

12 68.8 246.0 1318.5 141.3 996.8 5244.5 49.5 246.6 1140.1 87.3 646.1 2999.3

13 59.7 251.4 1388.3 117.8 933.3 5701.3 50.6 194.0 1227.3 73.0 534.5 2846.3

14 65.6 279.8 1391.8 128.5 913.3 5870.0 48.0 171.2 906.3 91.0 636.7 3745.8

LSD 11.6 50.5 264.4 15.5 161.8 857.2 8.0 53.4 301.1 20.7 173.4 1447.9

1 Assessments based on 40 plants.

Table 7. Statistical correlations between seed attributes and shoot fresh weight of hybrid seed lots after 14, 21 and 28 days in early- and

late-seeded plots with conventional tillage (CT) and minimum tillage (MT) in 2005.

Seed attribute

Shoot wt. - early CT Shoot wt. - late CT Shoot wt. - early MT Shoot wt. - late MT

13 DAS 20 DAS 27DAS 13 DAS 20 DAS 27 DAS 14 DAS 21 DAS 28 DAS 14 DAS 21 DAS 28 DAS

% green seed 0.33 0.63 * 0.32 0.35 0.31 0.52 0.46 0.14 0.30 0.40 0.45 0.46

1000-seed wt. 0.85*** 0.84*** 0.58* 0.88*** 0.78** 0.83*** 0.92*** 0.48 0.80*** 0.77** 0.66 * 0.49

SGT - germ 4 d - 0.32 - 0.17 - 0.10 - 0.37 - 0.06 - 0.18 - 0.33 0.05 - 0.22 - 0.14 - 0.15 -0.34

- germ 7 d - 0.01 0.02 - 0.08 - 0.15 0.19 - 0.13 - 0.07 0.12 0.00 0.34 0.25 0.01

- index 7 d 0.86*** 0.86*** 0.57* 0.87*** 0.82*** 0.82*** 0.92*** 0.51 0.81*** 0.84*** 0.71** 0.49

PCT - germ 10 d - 0.17 - 0.05 - 0.13 - 0.34 - 0.01 - 0.31 - 0.22 0.04 - 0.12 0.11 0.17 -0.24

- germ 12 d - 0.17 - 0.13 - 0.19 - 0.35 - 0.04 - 0.41 - 0.26 0.04 - 0.15 0.04 0.07 -0.35

- index 12 d 0.87*** 0.86*** 0.58* 0.87*** 0.81*** 0.80*** 0.93*** 0.52 0.82*** 0.82*** 0.71** 0.44

CDT - germ 4 d - 0.60* - 0.47 - 0.39 - 0.57* - 0.29 - 0.68** - 0.50 - 0.20 - 0.44 - 0.53* - 0.44 -0.69**

- germ 7 d - 0.63* - 0.66 * - 0.44 - 0.64* - 0.49 - 0.84*** - 0.56* - 0.12 - 0.46 - 0.55* - 0.46 -0.52

- index 7 d 0.51 0.46 0.34 0.55* 0.55 * 0.21 0.72** 0.60 * 0.66 * 0.46 0.42 0.08

ECT -4 hours 0.14 0.16 0.10 0.24 - 0.02 0.41 0.04 - 0.06 0.01 0.06 0.11 0.55 *

-24 hours 0.00 0.01 0.04 0.14 - 0.17 0.27 - 0.07 - 0.05 - 0.10 - 0.18 - 0.10 0.20

- seed wt. 0.86*** 0.83*** 0.54* 0.85*** 0.77** 0.82*** 0.89*** 0.43 0.80*** 0.76** 0.63 * 0.46

*, **, *** Pearson correlation coefficient (n = 14 seed lots) significant at P = 0.05, P = 0.01 and P = 0.001, respectively.

Table 8. Shoot biomass of hybrid seed lots after 14, 21 and 28 days in early- and late-seeded plots with conventional tillage (CT) and

minimum tillage (MT) in 2005.1

Seed lot

Shoot biomass - early CT

(g/m-row)

Shoot biomass - late CT

(g/m-row)

Shoot biomass - early MT

(g/m-row)

Shoot biomass - late MT

(g/m-row)

13 DAS 20 DAS 27 DAS 13 DAS 20 DAS 27 DAS 14 DAS 21 DAS 27 DAS 14 DAS 21 DAS 28 DAS

1 1.3 4.4 27.8 2.6 20.9 113.3 0.7 4.2 16.3 1.1 10.5 58.1

2 1.2 5.2 40.1 2.7 22.5 134.8 0.7 3.4 14.7 1.3 11.6 57.0

3 1.4 6.6 39.0 3.0 21.0 143.8 0.7 4.4 17.5 1.3 12.6 66.9

4 1.2 3.8 31.9 2.7 17.7 115.3 0.7 2.9 13.4 0.9 9.2 55.0

5 1.4 5.5 34.0 2.8 22.0 135.2 0.8 3.7 19.2 1.5 15.4 79.0

6 1.3 4.9 32.9 2.9 22.6 129.3 0.7 3.4 14.3 1.6 12.4 84.3

7 1.6 6.0 40.4 3.1 22.8 138.5 0.7 3.6 15.1 1.5 11.6 87.9

8 1.6 6.3 37.9 3.1 23.9 135.7 0.8 3.5 16.6 1.7 12.4 72.2

9 1.6 5.7 37.7 2.8 21.1 126.6 0.9 3.6 16.4 1.9 15.2 64.9

10 1.6 6.9 34.9 3.4 28.0 134.1 1.0 3.9 21.9 1.6 13.6 62.6

11 1.4 7.5 45.7 3.2 24.8 143.4 1.1 5.0 23.0 1.5 13.1 61.8

12 1.9 7.1 38.4 4.1 29.9 155.8 1.1 6.3 28.2 1.8 16.7 76.1

13 1.6 7.4 40.5 3.4 27.1 164.9 1.0 4.2 25.0 1.6 13.9 73.4

14 1.7 7.6 38.1 3.7 26.6 169.9 0.9 3.6 19.9 2.1 16.6 98.4

LSD 0.4 1.5 7.5 0.5 5.1 26.9 0.2 1.5 7.8 0.7 5.3 42.2

1 Assessments based on 40 plants.

Table 9. Statistical correlations between seed attributes and shoot biomass of hybrid seed lots after 14, 21 and 28 days in early- and

late-seeded plots with conventional tillage (CT) and minimum tillage (MT) in 2005.

Seed attribute

Shoot biomass - early CT Shoot biomass - late CT Shoot biomass - early MT Shoot biomass - late MT

13 DAS 20 DAS 27 DAS 14 DAS 20 DAS 27 DAS 14 DAS 21 DAS 28 DAS 14 DAS 20 DAS 28 DAS

% green seed 0.25 0.61 * 0.26 0.41 0.33 0.57 * 0.30 0.02 0.25 0.52 0.43 0.48

1000-seed wt. 0.76** 0.78*** 0.44 0.86*** 0.73** 0.81*** 0.77** 0.38 0.70** 0.77** 0.71** 0.57*

SGT - germ 4 d - 0.23 - 0.11 0.00 - 0.31 - 0.02 - 0.12 - 0.09 0.25 0.02 - 0.23 - 0.14 -0.33

- germ 7 d 0.22 0.13 0.07 - 0.04 0.28 - 0.01 0.10 0.26 0.14 0.34 0.33 0.04

- index 7 d 0.81*** 0.81*** 0.46 0.87*** 0.79*** 0.81*** 0.80*** 0.43 0.74** 0.84*** 0.77** 0.58*

PCT - germ 10 d 0.09 0.10 0.06 - 0.20 0.13 - 0.15 0.04 0.23 0.10 0.11 0.20 -0.23

- germ 12 d 0.09 0.01 0.00 - 0.23 0.08 - 0.27 0.04 0.26 0.10 0.01 0.11 -0.34

- index 12 d 0.82*** 0.82*** 0.47 0.87*** 0.79*** 0.80*** 0.83*** 0.45 0.76** 0.81*** 0.76** 0.53*

CDT - germ 4 d - 0.52 - 0.42 - 0.26 - 0.52 - 0.24 - 0.60 * - 0.22 0.05 - 0.20 - 0.61 * - 0.49 -0.71**

- germ 7 d - 0.40 - 0.52 - 0.22 - 0.58 * - 0.40 - 0.75** - 0.35 0.01 - 0.33 - 0.55 * - 0.45 -0.56*

- index 7 d 0.65 * 0.54 * 0.42 0.61 * 0.60 * 0.28 0.74** 0.58 * 0.65 * 0.46 0.49 0.15

ECT -4 hours - 0.09 0.01 - 0.09 0.18 - 0.09 0.32 - 0.20 - 0.26 - 0.18 0.10 0.06 0.53*

- 24 hours - 0.27 - 0.13 - 0.15 0.04 - 0.26 0.17 - 0.22 - 0.17 - 0.18 - 0.20 - 0.17 0.17

- seed wt. 0.77** 0.77** 0.41 0.84*** 0.73** 0.79*** 0.74** 0.32 0.69** 0.75** 0.67** 0.54*

*, **, *** Pearson correlation coefficient (n = 14 seed lots) significant at P = 0.05, P = 0.01 and P = 0.001, respectively.

Table 10. Seed yield of hybrid seed lots in early- and late-seeded plots with conventional tillage (CT) and minimum

tillage (MT) in 2005.

Yield (g/m2)

Seed lot early CT late CT early MT

1 351.1 335.0 239.0

2 367.6 324.6 263.6

3 371.1 334.1 267.8

4 371.9 309.2 278.6

5 360.8 321.9 282.3

6 386.4 337.8 274.0

7 379.3 330.0 287.9

8 369.7 321.6 266.1

9 375.2 330.2 272.7

10 385.5 323.7 290.7

11 370.8 323.4 288.5

12 377.2 343.3 281.3

13 397.8 346.2 292.7

14 385.3 324.4 303.4

LSD 34.2 22.0 36.0

Table 11. Statistical correlations between seed attributes and seed yield of hybrid seed lots in early- and late-seeded

plots with conventional tillage (CT) and minimum tillage (MT) in 2005.

Seed yield

Seed attribute early CT late CT early MT

% green seed 0.51 0.06 0.53*

1000-seed wt. 0.72** 0.26 0.80***

SGT - germ 4 d - 0.55* 0.31 - 0.64*

- germ 7 d - 0.27 0.42 - 0.38

- index 7 d 0.69** 0.34 0.76**

PCT - germ 10 d - 0.40 0.29 - 0.47

- germ 12 d - 0.50 0.24 - 0.54*

- index 12 d 0.68** 0.32 0.76**

CDT - germ 4 d - 0.67** - 0.19 - 0.64*

- germ 7 d - 0.66** - 0.13 - 0.67**

- index 7 d 0.33 0.22 0.43

ECT -4 hours 0.34 - 0.14 0.45

- 24 hours 0.19 - 0.14 0.21

- seed wt. 0.74** 0.27 0.78**

*, **, *** Pearson correlation coefficient (n = 14 seed lots) significant at P = 0.05, P = 0.01 and P = 0.001, respectively.

Table 12. Number of seedlings/row of hybrid seed lots after 14 and 21 days in early- and late-seeded plots with

conventional tillage (CT) and minimum tillage (MT) in 2006.

Seed lot

Seedlings/row - early CT Seedlings/row -early MT Seedlings/row - late MT

14 DAS 21 DAS 14 DAS 21 DAS 14 DAS 21 DAS

1 156.5 159.5 114.8 142.3 174.8 177.5

2 147.0 155.0 124.8 147.5 166.8 166.8

3 152.0 150.8 94.8 145.3 166.8 169.8

4 152.8 150.3 121.3 151.3 156.3 162.8

5 161.8 171.5 130.0 161.3 170.8 175.3

6 157.3 160.8 109.0 149.8 159.3 164.0

7 167.0 165.0 118.8 153.3 165.5 171.8

8 154.3 155.5 92.3 158.5 160.5 172.3

9 148.8 147.3 134.3 160.5 165.3 176.3

10 161.0 162.8 121.0 159.8 156.3 172.0

11 161.8 165.3 128.5 160.8 172.5 178.0

12 157.8 164.5 128.5 154.0 160.5 169.3

13 159.3 165.3 102.3 158.0 167.0 172.5

14 160.0 167.0 119.0 152.8 162.8 174.5

LSD 16.2 15.8 33.8 12.1 14.3 11.1

1 Seed lots planted at 200 seeds per 6.1 m row.

Table 13. Statistical correlations betw een seed attributes and numbers of seedlings/row after 14 and 21 days in early-

and late-seeded plots with conventional tillage (CT) and minimum tillage (MT) in 2006.

Seed attribute

Seedlings/row - early CT Seedlings/row -early MT Seedlings/row - late MT

14 DAS 21 DAS 14 DAS 21 DAS 14 DAS 21 DAS

% green seed 0.21 0.19 -0.39 0.21 -0.21 0.10

1000-seed wt. 0.41 0.43 0.03 0.54* -0.30 0.18

SGT-germ 4 d -0.24 0.07 0.00 -0.41 0.73** 0.31

-germ 7d -0.04 0.20 0.13 0.10 0.46 0.48

-index 7d 0.41 0.47 0.05 0.58 * -0.24 0.26

PCT-germ 10 d -0.14 0.03 0.04 0.10 0.50 0.51

-germ 12 d -0.13 -0.01 0.13 0.09 0.51 0.53

-index 12 d 0.41 0.44 0.05 0.61 * -0.24 0.28

CDT-germ 4d -0.23 -0.13 0.25 -0.36 0.38 0.10

-germ 7d -0.18 -0.25 0.15 -0.11 0.24 -0.01

-index 7d 0.40 0.30 0.20 0.72** 0.23 0.20

ECT-4 hours 0.15 0.13 -0.04 -0.34 -0.29 -0.37

-24 hours -0.10 -0.13 -0.15 -0.49 -0.22 0.47

-seed wt. 0.40 0.40 -0.06 0.57 * -0.31 0.21

*, ** Pearson correlation coefficient (n = 14 seed lots) significant at P = 0.05 and P = 0.01, respectively.

Table 14. Shoot fresh weight of hybrid seed lots after 14, 21 and 28 days in early- and late-seeded plots with

conventional tillage (CT) and minimum tillage (MT) in 2006.

Shoot wt. -early CT Shoot wt. -early MT Shoot wt. - late MT

Seed lots 14 DAS 21 DAS 28 DAS 14 DAS 21 DAS 28 DAS 14 DAS 21 DAS 28 DAS

1 227.7 928.8 6344.8 67.3 518.4 2756.0 128.1 561.3 5888.5

2 206.0 807.4 5727.3 78.4 445.1 2653.5 137.4 509.3 4847.5

3 239.9 851.0 7604.0 78.3 445.5 2790.3 129.9 602.3 5272.8

4 217.0 859.9 6091.0 74.6 468.4 2476.6 104.3 533.0 3776.8

5 220.0 980.4 6568.3 93.6 503.1 3230.3 106.7 595.8 4416.3

6 239.0 1014.7 6667.5 76.5 490.3 2563.0 121.9 591.8 5518.0

7 207.8 827.4 5582.3 79.2 462.0 2485.5 138.1 541.8 5250.5

8 296.0 1026.0 7535.0 81.9 501.6 2149.5 134.1 666.5 5327.0

9 245.6 1020.4 7480.0 87.4 508.4 2627.5 111.3 615.0 4494.0

10 282.4 1147.2 7643.8 90.7 608.7 3079.3 162.3 651.3 4561.3

11 273.9 984.0 6722.0 89.1 604.7 3581.0 125.7 641.5 5005.5

12 306.0 1149.9 6955.0 111.0 579.2 4161.8 185.5 679.8 7266.0

13 305.8 1149.6 7992.5 97.4 719.1 3472.8 174.3 635.5 7100.4

14 347.0 1222.8 7955.8 88.8 502.2 3239.5 155.2 739.3 6223.0

LSD 50.3 199.9 1571.4 16.8 114.7 823.4 39.3 180.5 1594.0

*1 Assessments based on 40 shoots.

Table 15. Statistical correlations between seed attributes and shoot fresh weight of hybrid seed lots after 14, 21 and 28

days in early- and late-seeded plots with conventional tillage (CT) and minimum tillage (MT) in 2006.

Seed attribute

Shoot wt. - early CT Shoot wt. -early MT Shoot wt. - late MT

14 DAS 21 DAS 28 DAS 14 DAS 21 DAS 28 DAS 14 DAS 21 DAS 28 DAS

% green seed 0.62 * 0.53 0.75** 0.20 0.19 0.17 0.18 0.70** 0.17

1000-seed wt. 0.87*** 0.84*** 0.65 * 0.74** 0.60* 0.59* 0.60* 0.84*** 0.54*

SGT-germ 4 d -0.23 -0.28 -0.28 -0.20 -0.01 0.09 0.04 -0.29 0.24

-germ 7d -0.02 0.10 -0.01 0.14 0.08 0.08 0.14 0.07 0.24

-index 7d 0.88*** 0.86*** 0.66** 0.78*** 0.62 * 0.61 * 0.63* 0.86*** 0.58*

PCT-germ 10 d -0.16 -0.07 0.05 0.05 0.05 0.01 0.00 -0.04 0.01

-germ 12 d -0.23 -0.13 -0.07 0.04 0.05 0.01 0.02 -0.13 -0.03

-index 12 d 0.87*** 0.86*** 0.68** 0.80*** 0.65 * 0.63 * 0.63* 0.86*** 0.56*

CDT-germ 4d -0.51 -0.47 -0.53 -0.41 -0.14 -0.10 -0.20 -0.53 -0.32

-germ 7d -0.73** -0.64 * -0.60 * -0.33 -0.31 -0.32 -0.44 -0.63* -0.46

-index 7d 0.40 0.47 0.27 0.73** 0.53 0.49 0.36 0.49 0.22

ECT-4 hours 0.15 0.09 0.04 -0.13 -0.30 0.01 0.00 0.13 0.06

-24 hours 0.07 -0.06 0.02 -0.23 -0.25 0.01 -0.09 -0.01 0.04

-seed wt. 0.87*** 0.84*** 0.70** 0.73** 0.65 * 0.53 * 0.62* 0.83*** 0.54*

*,**,*** Pearson correlation coefficient (n = 14 seed lots) significant at P = 0.05, P = 0.01 and P = 0.001, respectively.

Table 16. Shoot biomass of hybrid seed lots after 14, 21 and 28 days in early- and late-seeded plots with conventional

tillage (CT) and minimum tillage (MT) in 2006.

Shoot biomass -early CT

(g/m-row)

Shoot biomass -early MT

(g/m-row)

Shoot biomass - late MT

(g/m-row)

Seed lots 14 DAS 21 DAS 28 DAS 14 DAS 21 DAS 28 DAS 14 DAS 21 DAS 28 DAS

1 5.8 24.4 166.1 1.3 12.1 64.0 3.7 16.4 171.6

2 5.0 20.5 146.0 1.6 10.9 63.8 3.8 14.0 132.5

3 6.0 21.0 188.2 1.2 10.6 65.9 3.6 16.8 146.2

4 5.5 21.2 150.9 1.5 11.5 61.3 2.7 14.2 100.5

5 5.8 27.4 184.3 2.0 13.3 85.6 3.0 17.0 127.0

6 6.2 27.0 176.9 1.4 12.1 63.8 3.2 15.9 148.9

7 5.7 22.6 150.9 1.5 11.7 62.5 3.7 15.3 147.7

8 7.5 26.2 192.1 1.3 13.0 56.1 3.5 18.8 149.7

9 6.0 24.8 182.9 1.9 13.4 69.3 3.0 17.7 129.4

10 7.5 30.6 204.6 1.8 15.9 79.9 4.1 18.5 127.6

11 7.3 26.7 182.2 1.9 15.9 94.9 3.6 18.7 146.0

12 7.9 31.0 189.1 2.3 14.6 103.7 4.9 18.9 203.5

13 8.0 31.2 215.2 1.7 18.6 90.3 4.8 18.0 200.6

14 9.1 33.4 217.9 1.7 12.6 80.9 4.2 21.4 177.8

LSD 1.5 6.3 47.0 0.6 3.0 21.2 1.1 5.4 44.31 Assessments based on 40 shoots.

Table 17. Statistical correlations between seed attributes and shoot biomass of hybrid seed lots after 14, 21 and 28 days

in early- and late-seeded plots with conventional tillage (CT) and minimum tillage (MT) in 2006.

Seed attribute

Shoot biomass - early CT Shoot biomass -early MT Shoot biomass - late MT

14 DAS 21 DAS 28 DAS 14 DAS 21 DAS 28 DAS 14 DAS 21 DAS 28 DAS

% green seed 0.64 * 0.51 0.76** -0.09 0.21 0.21 0.14 0.65* 0.16

1000-seed wt. 0.89*** 0.83*** 0.77** 0.54* 0.63* 0.65* 0.56* 0.79*** 0.55*

SGT-germ 4 d -0.27 -0.22 -0.25 -0.11 -0.09 0.01 0.18 -0.19 0.28

-germ 7d -0.04 0.13 0.05 0.18 0.10 0.10 0.21 0.15 0.28

-index 7d 0.90*** 0.86*** 0.78*** 0.58* 0.66** 0.68** 0.60* 0.83*** 0.60*

PCT-germ 10 d -0.18 -0.06 0.04 0.06 0.08 0.03 0.07 0.06 0.06

-germ 12 d -0.25 -0.13 -0.09 0.10 0.08 0.02 0.06 -0.02 0.03

-index 12 d 0.89*** 0.85*** 0.79*** 0.59* 0.69** 0.70** 0.60* 0.83*** 0.57*

CDT-germ 4d -0.51 -0.44 -0.54 -0.16 -0.20 -0.17 -0.14 -0.44 -0.29

-germ 7d -0.73** -0.62 * -0.69 * -0.15 -0.29 -0.31 -0.42 -0.59* -0.45

-index 7d 0.44 0.47 0.35 0.62* 0.62 * 0.60 * 0.30 0.45 0.23

ECT-4 hours 0.18 0.13 0.10 -0.13 -0.34 -0.06 -0.03 0.06 0.01

-24 hours 0.07 -0.07 -0.01 -0.25 -0.34 -0.09 -0.11 -0.09 -0.01

-seed wt. 0.89*** 0.83*** 0.81*** 0.48 0.68** 0.60 * 0.58* 0.79*** 0.55*

*, **, *** Pearson correlation coefficient (n = 14 seed lots) significant at P = 0.05, P = 0.01 and P = 0.001, respectively.

Table 18. Seed yield of hybrid seed lots in early- and late-seeded plots with conventional tillage (CT) and minimum

tillage (MT) in 2006.

Seed yield (g/m2)

Seed lot early CT early MT late MT

1 231.5 250.6 179.5

2 235.1 249.5 167.6

3 235.7 234.8 184.8

4 229.3 230.9 182.1

5 246.4 242.4 186.7

6 249.5 229.4 192.6

7 235.4 241.4 194.8

8 243.7 229.1 192.0

9 224.6 247.9 197.6

10 242.9 246.1 190.8

11 245.8 240.1 180.9

12 239.2 248.8 202.9

13 246.9 246.3 191.4

14 240.6 228.8 191.8

LSD 15.5 23.4 20.4

Table 19. Statistical correlations between seed attributes and seed yield of hybrid seed lots in early- and late-seeded

plots with conventional tillage (CT) and minimum tillage (MT) in 2006.

Seed yield

Seed attribute early CT early MT late MT

% green seed 0.52 -0.59* 0.27

1000-seed wt. 0.39 -0.20 0.67**

SGT - germ 4 d -0.01 0.55* -0.58*

- germ 7 d 0.16 0.54* -0.03

- index 7 d 0.42 -0.12 0.70**

PCT - germ 10 d 0.07 0.56* -0.11

- germ 12 d -0.07 0.67** -0.11*

- index 12 d 0.40 -0.10 0.70**

CDT - germ 4 d -0.23 0.52 -0.70**

- germ 7 d -0.19 0.38 -0.31**

- index 7 d 0.36 0.11 0.67**

ECT - 4 hours 0.01 -0.57* 0.03

- 24 hours -0.12 -0.54* 0.16

- seed wt. 0.38 -0.17 0.68**

*, ** Pearson correlation coefficient (n = 14 seed lots) significant at P = 0.05 and P = 0.01, respectively.