Yield Stability of Winter Oil‐Seed Rape (Brassica napus L.) as Affected by Stand Establishment and Nitrogen Fertilization

Abstract

The effects of stand establishment and nitrogen fertilizer on yield and yield stability of winter oil‐seed rape (Brassica napus L.) were investigated in two field experiments in north eastern Germany (Mecklenburg‐Vorpommern). During six years of testing from 1984/85 to 1989/90 three sowing dates (10 Aug, 20 Aug, 5 Sept) as combined with three plant densities (60, 100, 140 plants/m2 in autumn) were compared. Although seed yield did not respond to the main effects of these treatments, the two‐way classification resulted in significant differences from the average yield. August sowing combined with lower plant densities caused comparably high yields, while delayed sowing was somewhat effective only with higher plant density. Highest yield stability was achieved at early sowing when combined with lower plant densities. From 1986/87 to 1988/89 nitrogen top‐dressings were applied during early March, at start of stem extension and shortly before start of flowering at five locations. 200 kg N/ha in one dose resulted in lowest yield performance and enhanced instability. Contrastingly, the 240 kg N/ha treatment advanced yield stability regardless of split regimes. Nevertheless, split application to 100 kg N/ha + 50 kg N/ha + 50 kg N/ha also guaranteed that high yield performance and optimum yield stability were reached simultaneously and, that the total nitrogen input could be limited to 200 kg N/ha.

Effects of the nutrient supply and sowing time on the yield and the phytopathological traits of winter oilseed rape (Brassica napus var. napus f. biennis L.) on chernozem soil

“…Similarly to the experiments of Boelcke et al (1991) (optimal N = 240 kg ha -1 ), our research results confirmed the high nutrient demand of oilseed rape (in our experiments the optimum was N = 240 kg ha -1 ). Due to the traditional, non-long-term experiment, the yield increasing effect of fertilization varied between 800 and 1300 kg ha -1 , depending on the cropyear.…”

“…The optimal NPK dose was significantly influenced by the soil traits (Máthé-Gáspár et al 2007, Máthé-Gáspár et al 2008. According to the differences of the genotype and the agroecological factors, Gulzar Ahmad et al (2011) found N = 120 kg ha -1 , while Boelcke et al (1991) N = 240 kg ha -1 fertilizer doses as the most favourable ones for the yield of oilseed rape. In their experiment not only the yield maximum was realised but the yield stability was also the most favourable.…”

Effects of nutrient supply and sowing time on the yield and pathological traits of winter oilseed rape

“…Although August sowing was more favourable in all three years, the yield decrease after sowing in midSeptember was not considerable (0-270 kg ha -1 depending on the year). As in the experiments of Boelcke et al (1991) (optimal N = 240 kg ha -1 ), the results confirmed the high nutrient demand of oilseed rape (optimal N = 210 kg ha -1 ). In this traditional, non-long-term experiment, the yield-increasing effect of fertilization varied between 800 and 1300 kg ha -1 , depending on the year.…”

“…The optimal NPK dose was significantly influenced by the soil traits (Máthé-Gáspár et al, 2007;. Depending on the genotype and the agro-ecological factors, the most favourable fertilizer doses for the yield of oilseed rape were found by Ahmad et al (2011) to be N = 120 kg ha -1 and by Boelcke et al (1991) to be N = 240 kg ha -1 . In addition to achieving the yield maximum, the yield stability was also the most favourable at these rates.…”

Evaluation of effect of autumn nitrogen dose and nitrogen nutrition status on oilseed rape yield

“…According to Boelcke et al (1991), divided application ensured that high yield performance and optimum yield stability were achieved simultaneously. Spink (2009) pointed out that late nitrogen is required to maintain pod filling.…”