Alternative seeding dates (fall and April) affect Brassica napus canola yield and quality

2000 ◽  
Vol 80 (4) ◽  
pp. 713-719 ◽  
Author(s):  
Ken J. Kirkland ◽  
Eric N. Johnson

Brassica napus L. canola production on the Canadian prairies often is limited by hot, dry growing conditions in early July and a short growing season. Brassica napus canola seeded in the fall just prior to freeze-up or in the early spring as soon as fields are passable may allow canola to avoid these adverse conditions. Our objective was to determine if late October (fall), or mid- to late April (April) seeding dates improve canola yield and quality relative to a mid-May (15 to 20 May) seeding date. Plant density and height, phenological development, seed yield, seed weight and seed oil content were assessed in plots sown to herbicide-tolerant B. napus canola at three seeding dates on five fallow sites and three stubble sites at Scott, SK, from 1994 to 1998. A thinner plant stand occurred for the fall compared with spring seeding dates; however, this difference rarely corresponded with less canola yield. Fifty percent flowering occurred 20 d earlier (June rather than July), reproductive growth (50% flowering to maturity) was 10 d longer, plants were 23 (fall) or 8 (April) cm shorter, and maturity occurred 13 d earlier when canola was seeded in the fall and April compared with mid-May seeding. Canola seed yield was 38% greater when seeded on the alternative dates rather than the more traditional mid-May seeding date. The yield advantage for alternative seeding dates was greater and more consistent on stubble than on fallow likely because of lack of soil crusting and temperature and wind protection from stubble. The response of seed weight to seeding date was similar to that for seed yield, indicating that a portion of the positive yield response to alternative seeding dates was associated with larger seed size. Oil content also was greater for the fall and April compared with mid-May seeding dates, but the improvement was smaller (6%) than that for seed yield. Fall- and April-seed-ed canola tolerated spring frosts and avoided adversely hot, dry weather during the flowering period, thus improving canola seed yield and quality. Alternative seeding dates provide canola producers in semi-arid regions with a sustainable option to diversify their cropping systems. Key words: Seeding date, dormant, stubble, fallow, herbicide tolerant, alternative cropping practice

1981 ◽  
Vol 61 (2) ◽  
pp. 175-183 ◽  
Author(s):  
D. F. DEGENHARDT ◽  
Z. P. KONDRA

The effects of seeding date and seeding rate on the agronomic characteristics of five genotypes of Brassica napus L. were studied for 2 yr at two locations in western Canada. Delayed seeding resulted in a significant increase in vegetative and total yield but a significant decrease in seed yield, harvest index, plant density, racemes per plant and racemes per unit area. Seeding date had no significant effect on seed yield per plant, 1000-seed weight and plant height. Increased seeding rate resulted in a significant increase in plant density, and racemes per unit area, but a significant decrease in harvest index, racemes per plant, seed yield per plant and plant height. Seeding rate had no significant effect on seed, vegetative or total yield and 1000-seed weight. There were significant differences due to genotypes for all variables except for total yield and racemes per unit area.


2004 ◽  
Vol 84 (2) ◽  
pp. 419-430 ◽  
Author(s):  
G. W. Clayton ◽  
K. N. Harker ◽  
J. T. O’Donovan ◽  
R. E. Blackshaw ◽  
L. M. Dosdall ◽  
...  

More flexible and effective weed control with herbicide-tolerant B. napus canola allows for additional seeding management options, such as fall (dormant) and early spring (ES) seeding. Field experiments were conducted at Lacombe and Beaverlodge (1999–2001), Didsbury (1999–2000), and Lethbridge (2000–2001), Alberta, Canada, primarily to evaluate the effect of fall (late October-November), ES (late April-early May), and normal spring (NS) (ca. mid-May) seeding dates on glufosinate-, glyphosate-, and imidazolinone-tolerant canola development and yield. Fall seeding resulted in 46% lower plant density and nearly double the dockage than spring seeding. ES-seeded canola had 19% higher seed yield and 2.1% higher oil content than fall-seeded canola. ES seeding significantly increased yield compared to fall-seeded canola for 8 of 10 site -years or compared to NS seeding for 4 of 10 site-years; ES-seeded canola equalled the yield of NS-seeded canola for 6 of 10 site-years. Yield response to seeding date did not differ among herbicide-tolerant cultivars. Seeding date did not influence root maggot damage. Seeding canola as soon as possible in spring increases the likelihood of optimizing canola yield and quality compared to fall seeding and traditional spring seeding dates. Key words: Dormant seeding, seeding management, root maggot, herbicide-resistant crops, yield components, operational diversity


Author(s):  
Veneranda Stramkale ◽  
Aldis Stramkalis ◽  
Ļubova Komlajeva ◽  
Māra Selecka ◽  
Māra Vikmane ◽  
...  

Flax cultures give dual-purpose production – flax fibre and seeds. Flax varieties adapted to local climate conditions have breeded but up to now the profound research of its quality was not carried out. In our investigation we analysed flax varieties of Latvia selection for seed yield and quality in comparison with standard varieties ‘Vega 2’ and ‘Lirina’. In Latgale Agricultural Scientific Centre 10 Latvian flax varieties are cultivated and seed yield, 1000-seed weight, seed oil content (extracted by hot pressing method) and fatty acid content in flax seed oil (detected with gas chromatography method) have evaluated. Seed yields of fibre flax Latvian varieties are significantly higher in comparison with standard variety ‘Vega’. All analysed seed samples have high oil content (27- 47%) and there is high percentage of polyunsaturated fatty acids in oil (linoleic acid 10,6-16,9%, linolenic acid 54,7-62,1%). There is little difference in 1000-seed weight, content of oil in seeds, percentage of linoleic, linolenic, oleic, palmitic and stearic acid in oil between fibre flax and oil seed flax varieties. The difference between the varieties is more influential. Flaxes seeds from Latvian varieties are in high quality and can be used for food, medical and technical purposes.


1998 ◽  
Vol 49 (7) ◽  
pp. 1057 ◽  
Author(s):  
K. H. M. Siddique ◽  
S. P. Loss ◽  
K. L. Regan ◽  
D. L. Pritchard

The growth and seed yield response of lentil (cv. Digger) to sowing rate (20-120 kg/ha) was studied at 13 sites over 3 seasons in the cropping regions of south-western Australia. The economic optimum plant density was estimated by fitting an asymptotic model to the data and calculating the sowing rate above which the cost for additional seed was equivalent to the revenue that could be achieved from the extra seed yield produced, assuming a 10% opportunity cost. On average across all sites and seasons, only 51% of sown seeds emerged. Increasing sowing rate resulted in greater dry matter production at ˚owering and maturity, and fewer pods per plant. Harvest index (0·31-0·36), number of seeds per pod (1·13-1·84), and mean seed weight (2·9-3·6 g/100 seeds) remained relatively stable with changes in sowing rate. The asymptotic models fitted to seed yields accounted for 1-73% of the total variance in the data, except at one site where a model could not be found to provide an adequate fit to the data. In addition to this site, another 5 sites were excluded from further consideration where the percentage of variance accounted for was <25% or the predicted optimum densities and seed yield potentials were well beyond the range of the data. The economic optimum of the remaining 7 sites ranged from 96 to 228 plants/m2, with a mean of 146 plants/m2. These results suggest that lentil yields may be improved by increasing sowing rates beyond those currently targeted in southern Australia (100-125 plants/m2). On the basis of these results, targeting a density of about 150 plants/m2 by using a sowing rate of approximately 90-110 kg/ha is recommended, depending on mean seed weight and germination percentage of the seed. Even higher sowing rates may be optimum where the growing conditions are unfavourable and individual plant growth is limited.


2007 ◽  
Vol 87 (1) ◽  
pp. 13-26 ◽  
Author(s):  
C. L. Vera ◽  
R. K. Downey ◽  
S. M. Woods ◽  
J. P. Raney ◽  
D. I. McGregor ◽  
...  

Swathing is an important canola (Brassica napus L.) harvest operation in western Canada. The determination of the optimum timing for this operation is worth considering, as premature swathing may lead to reduced seed yield and quality. Seed yield and quality of three canola cultivars (44A89, AC Excel and Ebony), as affected by two seeding dates and several harvest times (six or eight swathing times and one direct combined treatment) was investigated on a Black Chernozem silty loam soil at Melfort, Saskatchewan, Canada, during 1998, 2000 and 2001. Seed yield, weight, protein content (oil-free meal basis) and oil content generally increased with seed development and swathing time. Early seeding was more conducive to achieving higher seed yield, especially in good growing conditions, and resulted in heavier mature seeds with higher oil content. Seed oil composition also changed during seed development. The proportion of oleic (C18:1) and linolenic (C18:3) acids increased, while that of myristic (C14:0), palmitic (C16:0), palmitoleic (C16:1), stearic (C18:0), linoleic (C18:2) and ara chidic (C20:0) acids decreased. The levels of the long chain fatty acids eicosenoic (C20:1) and erucic (C22:1) acids were unaffected. However, the overall amount of fatty acids synthesized (mg 100 seeds-1) increased as seeds matured. Swathing was advantageous over direct combining in preventing weather-induced shattering. Key words: Brassica napus, canola, fatty acid, oil, protein, seed development, seed quality, shattering, direct combining, swathing


2008 ◽  
Vol 88 (3) ◽  
pp. 485-500 ◽  
Author(s):  
G. P. Lafond ◽  
B. Irvine ◽  
A. M. Johnston ◽  
W. E. May ◽  
D. W. McAndrew ◽  
...  

Flaxseed is known to have significant health benefits in human nutrition and when included in animal rations. There is pressing need to improve flaxseed production to meet the growing demand. The objective was to study the effects of three seeding rates (22, 45 and 67 kg ha-1), two seeding dates (early May and late May), three rates of nitrogen (66, 100 and 133% of recommended) and three cultivars (Norlin, AC McDuff and CDC Valour) and at five locations representative of the flax-growing area of the Canadian prairies from 1999 to 2001. The variables of interest were plant density, seed yield and yield formation, seed oil content and oil quality. Plant establishment was always highest with Norlin, but bolls m-2 was similar between the three cultivars. Plant density was always highest with the later plantings. No overall effect of seeding date was observed on grain yield, but the site-year by seeding date interaction showed that the later planting was favoured by the most northerly sites and early planting at the most southerly sites. The sites intermediate in latitude showed little response to seeding date. This finding provides important information with respect to the inclusion of flax in cropping systems depending on the latitude and deciding on the order of planting. Later planting resulted in a small decrease in oil content. Seed yields were increased with seeding rates going from 22 to 45 kg ha-1, which corresponded to plant populations > 300 plants m-2, with no increases thereafter. Increases in seeding rates always reduced the number of bolls plant-1 with little effect on seeds boll-1. Seeding rate had no effect on seed oil quantity and quality and maturity. A seed yield increase was observed with nitrogen when going from 66 to 100% of the recommended rate with no increases past 100%. Adding nitrogen resulted in a small drop in seed oil content. The seeding date × nitrogen rate interaction revealed a lack of response to nitrogen with the later planting date beyond 66% of the recommended N rate, suggesting reduced nitrogen rates with later plantings are possible. The absence of a site-year by seeding date by nitrogen rate interaction implies that findings of this study can be applied to a wide geographical area. In conclusion, attention needs to be given to seeding rates to target plant density > 300 plants m-2. Even with the high seeding rates, the target plant population was achieved only 60 and 73% of the time for the early and late planting, respectively. Using soil test recommendations for nitrogen will maximize seed yields under most situations. Best agronomic practices to maximize seed yield were found to maintain adequate seed oil quality and quantity. Key words: Linum usitatissimum L., nitrogen rate, seeding rate, seeding date, cultivar


1987 ◽  
Vol 67 (1) ◽  
pp. 43-51 ◽  
Author(s):  
D. I. McGREGOR

The ability of rapeseed crops (Brassica campestris L. ’Torch’ and B. napus L. ’Tower’) to recover from, and compensate for, loss of plants at the early vegetative stage of development was investigated by hand thinning plant populations established at commercial seeding rates with commercial seeding equipment. Plant density was reduced from 100-200 plants m−2 to 40 plants m−2 with less than a 20% loss in seed yield. Seeds per pod and seed weight in some instances increased with reduced plant density. However, compensation was attributed predominantly to an increased number of pods on the remaining plants, which increased from 20-90 to as many as 600. Branching increased from as few as 3 to, in some instances, almost 40. With reduced plant population there was a tendency for increased and prolonged accumulation of dry matter by the plants following flowering.Key words: Brassica campestris L., Brassica napus L., rapeseed, development, seed yield, hail.


2004 ◽  
Vol 84 (4) ◽  
pp. 971-979 ◽  
Author(s):  
G. W. Clayton ◽  
K. N. Harker ◽  
J. T. O’Donovan ◽  
R. E. Blackshaw ◽  
L. Dosdall ◽  
...  

Polymer seed coatings offer an opportunity to fall seed Brassica napus earlier in October, thus avoiding difficult seeding conditions (wet/frozen soils) common in late October or early November. A multi-year field experiment was conducted at four locations in Alberta, Canada, to investigate the effect of early (mid-October) and late fall (late October-early November) canola seeding with and without a germination-inhibiting polymer seed coat. Yield and yield components were determined in glufosinate (hybrid and open-pollinated), glyphosate (open-pollinated), and imidazolinone (open-pollinated) herbicidetolerant canola cultivars. Early-seeded canola without the polymer coat had a reduced plant density of 58% compared to late-fall-seeded canola. Application of the polymer coat on early-seeded canola increased plant density by 80% compared to uncoated seed. Seed yield and dockage were not affected by seeding date when a polymer seed coating was used. Without the polymer seed coat, canola yield was reduced 42% and dockage increased 6% when seeding occurred in early vs. late fall. Increased pod production from early-fall-seeded uncoated canola compared to other seeding dates could only partially compensate for canola yield. Cultivar interactions generally were not agronomically important. The use of polymer seed coatings with all these herbicide-tolerant cultivars will allow producers to seed earlier in fall, rather than waiting for cooler soil conditions in late fall. Key words: Canola (Brassica napus L.), dormant seeding, polymer seed coating


2002 ◽  
Vol 82 (1) ◽  
pp. 15-20 ◽  
Author(s):  
A. M. Johnston ◽  
E. N. Johnson ◽  
K. J. Kirkland ◽  
F. C. Stevenson

Brassica napus L. canola seeded in the fall (dormant) just prior to freeze-up, or in the early spring as soon as fields are passable, can improve productivity in semiarid regions on the Canadian prairies. The objective of this study was to assess N fertilizer placement options for alternative canola seeding dates. Herbicide-tolerant B. napus canola (cv. Quest) seedling density, phenological development, seed yield, seed weight, oil concentration, and protein concentration were assessed for four N (urea) placement options [banded prior to fall seeding date (only Melfort), broadcast in early-spring, side banded, and seed placed] and three seeding dates (late October, mid- to late April, and mid-May) at Scott and Melfort, SK, Canada. Nitrogen fertilizer placed with the seed often reduced seedling density. At Melfort, seed placed N fertilizer reduced the seed yield (10%), seed oil concentration (4%) and increased protein concentration (5%) of fall and mid-May seeded canola. The other N fertilizer placement options consistently maintained the highest level of canola production for all seeding dates. At Scott, seeding canola in fall or April generally maintained adequate plant stands, and often increased seed yield (43%), seed weight (18%), and oil concentration (5%) , when compared with the mid-May seeding date. Our results indicate that N fertilizer placement considerations used for the more traditional mid-May seeding date should be similar for canola dormant or April seeded. Current N fertilizer placement options, such as side banding, pre-plant banding or early-spring broadcasting, are options that resulted in equivalent crop yield responses. Given the variability in crop yield response measured with seed placement of N, we recommend that this practice should be a voided. Key words: Seeding date, dormant, direct seeding, alternative cropping practice, N fertilizer management


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