TECHNOLOGY OF WINTER OILSEED RAPE WITH FOLIAR FERTILIZATION
Background. Effective fertilizer management strategies are a prerequisite to ensure optimum seed yields and seed quality of oilseed rape. The study aimed to evaluate the effect of the autumn or autumn and spring foliar application of potassium, phosphorus, boron and molybdenum (Phostrade® BMo) on biometric features, overwintering and the quantity and quality of winter oilseed rape yield.
Material and methods. The subject of the study was winter oilseed rape, cv. ‘Chagall’, cultivated in the successive years 2013-2015, after winter wheat. This study was based on a single-factor field experiment conducted in the Kuyavian-Pomeranian region, Poland, 53°13′ N; 17°51′ E, on Alfisol, in a randomized block design, with four replications. The effect of the different time and a dose of foliar fertilizer Phostrade® BMo (P2O5 15% w/w, K2O 14% w/w, B 0.9% w/w; Mo 0.1% w/w) application was evaluated as follows: 5 dm3∙ha-1 applied in autumn at 5 leaves stage (BBCH 15) or 3 dm3∙ha-1 in autumn (BBCH 15) and 3 dm3∙ha-1 in spring at beginning of stem elongation stage (BBCH 30) and the control.
Results. This study has shown that the application of this fertilizer in autumn, at a dose 5 dm3∙ha-1 or 3 dm3∙ha-1 had a positive effect on the roots dry weight and the roots length of oilseed rape before winter. The influence of the fertilization on the shoots dry weight, the number of pods per plant and the number of seeds per pod as well as the yield of oilseed rape was higher in the year characterized by precipitation deficiency during the spring growth and the generative development. Two-time application of fertilizer, as well as single application in autumn, had a positive effect on the number of seeds per pod and the seed yield as well as the chlorophyll index and the shoots dry weight at the end of flowering.
Conclusion. Sequential application of Phostrade® BMo at doses 3 dm3∙ha-1 in autumn and 3 dm3∙ha-1 in spring, as well as single application at a dose 5 dm3∙ha-1 in autumn, increased the seed yield of open-pollinated variety ‘Chagall’ of oilseed rape. Further studies are necessary to determine the optimal method of application of this foliar fertilizer in the cultivation of hybrid cultivars of winter oilseed rape.