Influence of Planting Date on Canola and Crambe Production

Abstract

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. Research Question Planting date can have a profound influence on crop performance. Plantings too early risks frost damage to developing seedlings whereas late plantings result in a shortened growing season for crops with possible frost damage before maturity. This study examines the effect of planting date in North Dakota on seed yield, yield components, and other plant growth characteristics of canola and crambe. Literature Summary Previous research indicates that delayed planting usually resulted in decreased seed yield. Heat and moisture stress during anthesis and seed filling reduced seed yield of later plantings. Yield reductions from delayed planting for canola and crambe, which are cool season crops, can be substantial. Canola species may respond differently to date of planting depending on geographic location. Study Description Field studies to determine the response of canola and crambe to planting date were conducted at Prosper, Carrington, and Langdon, ND, during the 1989 and 1990 growing seasons. Results at Carrington in 1990 were not obtained due to poor seedling emergence and subsequent insufficient plant stands at several of the planting dates. Three canola cultivars and one crambe cultivar were planted at four dates beginning 1 May, with 15 d intervals. Data collected included seed yield, yield components, harvest index, plant height, seed oil concentration, days to anthesis and physiological maturity, and duration of reproductive development. Applied Questions At what planting date was canola seed yield the highest? Seed yield was greatest at the 1 May and 15 May planting dates and decreased when planting was delayed beyond 15 May. Reduced seed yield with later plantings was associated with fewer pods per plant and lower harvest index. Early planting avoided hot and dry conditions during reproductive development that reduced seed yield at the later planting dates. Did either species of canola/rapeseed exhibit a seed yield advantage? The later maturing Brassica napus cultivars produced a higher seed yield than the earlier B. campestris cultivar the second year of the study at Langdon and Prosper. This trend was not apparent at the same test sites the first year of the study where yield was severely limited by extremely hot and dry growing conditions. Cultivar yields the first year of the study were 15 to 50% of the yield they produced the second year. Later maturing cultivars appear to have a greater yield potential. At what planting date was crambe seed yield the highest? Higher seed yield was observed from the two earliest plantings than from the two later plantings at Langdon in 1989 and 1990 and Prosper in 1990. Planting date did not affect yield at Carrington in 1989, while at Prosper in 1989 yield was the greatest from the latest planting date due to timely rainfall. Unusual extremely hot and dry growing conditions prevailed at each of these environments, which severely reduced yield. Recommendations Plant canola and crambe before I5 May in North Dakota to achieve the greatest seed yield.