Sowing date and nitrogen rate effects on growth, yield and yield components of two summer rapeseed cultivars

The increase in interest of alternative sources for both edible and industrial usages spurred interest in the growth of new oilseed crops in North Dakota. canola and crambe were cited as having greatest potential to meet this perceived demand.Canola would be for human consumption while crambe for industrial applications. Determining the optimal planting time would allow for the fullest growth and maturation of these plants before harsher summer weather set in. Findings of studies performed were that early plantings of canola and crambe increased yield. a planting time frame for each would be May 1st to the 15th. Crambe and canola are very well adapted crops to be grown in North Dakota.

Influence of Planting Date on Canola and Crambe Production

Crop production in the upper Midwest, which has a short growing season, can be greatly affected by planting date. This study was conducted to evaluate the effect of planting date on canola (Brassica napus L. and B. campestris L.) and crambe (Crambe abyssinicia Hochst) seed yield, yield components, and plant growth characteristics. Three cultivars of canola, two B. napus and one B. campestris, and one cultivar of crambe were evaluated at four planting dates during 1989 and 1990 in North Dakota. Canola seed yield was the highest at the first two plantings, early May and mid-May, and reduced at the two later plantings, late May and mid-June. Reduced yield at later plantings was attributed to fewer pods per plant and a lower harvest index. The later maturing B. napus cultivars produced greater yield than the B. campestris cultivar in environments where growing conditions were near normal. Crambe seed yield also was greatest when planted in early and mid-May with reductions occurring at the later plantings of late May and mid-June. Crambe appears less susceptible to heat and moisture stress and higher yielding than canola when grown in North Dakota.

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McKenzie, R. H., Bremer, E., Middleton, A. B., Pfiffner, P. G. and Woods, S. A. 2011. Optimum seeding date and rate for irrigated cereal and oilseed crops in southern Alberta. Can. J. Plant Sci. 91: 293–303. High crop productivity is essential for irrigated crops and may be strongly affected by decisions of seeding date and rate. An irrigated field experiment was conducted at two locations in southern Alberta for 4 yr to compare the impact of seeding date and rate on productivity and quality of nine cereal crops and two oilseed crops. Seeding rate was only evaluated on one date in late April or early May, when maximum yields were expected. Delayed seeding reduced crop yields by 0.6 to 1.7% per day after the end of April: flax (Linum usitatissimum L.) ≤ CWRS wheat (Triticum aestivum L.), feed triticale (×Triticosecale W.) ≤ CPS or SWS wheat ≤ triticale or barley (Hordeum vulgare L.) silage ≤ durum (T. turgidum L.), feed or malt barley < canola (Brassica napus L.). Crop quality deteriorated with delayed see...

https://bioone.org/journals/canadian-journal-of-plant-science/volume-91/issue-2/CJPS10103/Optimum-seeding-date-and-rate-for-irrigated-cereal-and-oilseed/10.1139/CJPS10103.pdf

Optimum seeding date and rate for irrigated cereal and oilseed crops in southern Alberta

Optimum seeding date (OSD) and seeding rate is an important management practice to improve the performance of canola (Brassica napus L.) production. A field study was conducted to investigate the influence of seeding date and rate on plant stand count, yield components, yield, and seed oil and protein concentrations, and to develop a location-sensitive model for estimating OSD for maximizing canola yield. The factorial experiment of three seeding dates (early, intermediate, and late) and three seeding rates (2.5, 5.0, and 7.5 kg ha–¹) was performed in 2011 and 2012 at seven locations across eastern Canada. An independent dataset from an additional 2-yr field experiment at the Ottawa site was used for model verification. Our data showed that seed yield, seed oil, and pod number per plant were significantly affected by seeding date and seeding rate. The greatest yield and seed oil concentration were obtained with the early seeding in most site-years. The OSD was a quadratic function of the long-term (30 yr) average daily minimum air temperature (Tₘᵢₙ) in April and May with R² = 0.98, P < 0.01 and SE = 2.6 d. Increasing seeding rate from 2.5 to 5.0 kg ha–¹ increased seed yield for early-seeded canola in most site-years but the yield did not increase with further increases in seeding rate. Early seeding at 5.0 kg ha–¹ is therefore recommended as the optimum seeding rate across eastern Canada.

Optimizing Seeding Dates and Rates for Canola Production in the Humid Eastern Canadian Agroecosystems

The effects of seeding data and nitrogen and phosphate fertilizer on the agronomic characteristics of two rapeseed species (Brassica campestris L. and B. napus L.) were studied for a 6-yr period at two northwest Alberta locations. Seeding dates were established at weekly intervals from early May to mid-June. Two fertility levels were established; a control treatment in which no fertilizer was applied and a fertilizer treatment in which nitrogen and phosphorus were applied to meet the requirements of a 1680 kg∙ha−1 crop. Maximum yields were obtained most frequently with seeding periods of mid- to late May for B. campestris and mid-May for B. napus. Seeding date had little effect on plant density or seed quality. Nitrogen and phosphate fertilizer reduced plant densities but increased seed yield where nutrient deficiencies occurred.Key words: Brassica campestris L., B. napus L., seeding date, yield, quality

R. M. DePAUW

Papers

Effect of seeding date, nitrogen and phosphate fertilizer on growth, yield and quality of rapeseed in northwest alberta