Dissection of Year Related Climatic Variables and Their Effect on Winter Rapeseed (Brassica Napus L.) Development and Yield

Abstract

Winter oilseed rape (WOSR) production is dependent on weather conditions, but is also characterized by low nitrogen (N) use efficiency. The objectives of this study were to: (i) evaluate sources of variability for the seed yield and oil content of four rapeseed cultivars under the influence of three sowing dates (SD trial) and five nitrogen dosages (N trial) during four growing seasons; (ii) understand year-related interactions and the effect of climatic variables in different growth stages; and (iii) assess the presence of interactions cultivar by year (C × Y) and treatment by year (T × Y). Six climatic factors were observed, during germination, overwintering, budding, flowering and ripening. The mixed effect split-plot analysis of variance was used, as well as factorial regression models. The C × Y interaction was the most important for the oil content in both trials. The precipitation at budding stage (75.8%), relative air humidity at overwintering (63.3%) and flowering stage (53.0%) accounted for the highest proportion of T × Y interaction for the seed yield, as well as precipitation at flowering (92.0%) and ripening (85.0%) for the oil content. Water availability was the main determinant of the seed yield and/or oil content accompanied with cooler temperatures during the seed development. The study successfully dissected the effect of year-related climatic variables on the agronomical traits in winter rapeseed. Based on this, appropriate agronomic practices can be applied at specific growing stages to ensure a high seed and oil yield.

Effect of Micro-Nutrients Foliar Application on Yield and Quality Traits of some Canola Genotypes Under Different Environmental Conditions تأثیر الرش الورقی بالعناصر الصغرى علی انتاجیة وجودة محصول بعض التراکیب الوراثیة من الکانولا تحت ظروف بیئیة مختلفة

“…These results are in accordance with those announced by Rameeh (2012), Sher et al (2017), Marjanović-Jeromela et al (2019, Jankowski et al (2020) and Sikorska et al (2020).…”

“…There are differences in the seed content of the different genotypes of canola in its oil and protein content and that probably due to the differences in their genetic makeup. These results are similar with those stated by Hamama et al (2003), Asfour (2013), Azam et al (2013), Emam (2014), Arrúa et al (2017), Sher et al (2017), Khan et al (2018), and Marjanović-Jeromela et al (2019). Regarding the micro-nutrients effect, canola plants respond to the higher rate of micro-nutrients to obtain the crest seed content of Mn, Fe, Zn, oil, and protein.…”

“…Superiority of Y1 over Y2 probably due to the suitable climatic conditions for canola growth (Table 3) which consequently reflecting a good performance index (Table 5) then produced good growth traits (Table 6). Similar results were informed by Rameeh (2012) and Jankowski et al (2020) for 1000-seed weight besides Marjanović-Jeromela et al (2019) and Sooran et al (2020) for seed yield. While Nargeseh et al (2020) mentioned that years had no significant influence in seed yield.…”

“…Y1 surely surpassed Y2 by 25.64, 52.20, and 18.28 % for Mn, Fe, and Zn respectively. Rameeh (2012) and Marjanović-Jeromela et al (2019) come to the same conclusion for the seasonal effect on seed content. The soil type's effect was significant for all seed chemical composition.…”

“…Nowadays, the world total area is about 37579575 ha produced 75001457 t by average about 2000 kg/ha (FAO, 2020). Seasonal differences on growth traits and/or seed yield and its related traits, as well as seed chemical composition, were observed by many researchers among them Rameeh (2012), Jankowski et al (2020) and Sikorska et al (2020) for the number of branches, pods per plant, 1000-seed weight, Marjanović-Jeromela et al (2019) and Sooran et al (2020) for seed yield and oil content.…”