Influence of nitrogen levels on yield of French bean (Phaseolus vulgaris) under different irrigation regimes

Abstract

The proper irrigation and nitrogen fertilizer management are crucial for sustainable and potential production of French bean as a legume crop overall favoring human nutrition. Therefore, a field experiment was conducted during November 2018 to April 2019 at Agronomy Field Laboratory, Bangladesh Agricultural University to assess the impact of irrigation and nitrogen at the yield performance on French bean. The stages of irrigation viz., no irrigation, one irrigation during flowering at 40 days after sowing (DAS), two irrigations during flowering (40 DAS) and pod formation stage (60 DAS), and three levels of nitrogen viz., no nitrogen fertilizer, 90 kg N/ha at 100% basal application, 45 kg N/ha at 50% basal application and 45 kg N/ha at 50% pod development stage (60 DAS) were utilized in a Split-plot layout allocating irrigation to the whole plots. The treatments were replicated three times. Yield and yield attributes were appreciably influenced by both irrigation and nitrogen treatments. From irrigation treatment, the highest plant, quantity of pod/plant, length of pod, number of seed/pod, number of seed/plant, weight of 1000 grains, stover yield, biological yield and harvest index were observed in one irrigation at flowering stage at 40 DAS which consequently produced the best grain yield (2.07 t/ha); while the least grain yield (1.48 t/ha) found in control or no irrigation treatment. Considering nitrogen, the best seed yield was recorded in (45+45) kg nitrogen/ha. In interaction, the highest plant (42.87cm), number of pod/plant (5.64), length of pod (15.24), weight of 1000 grains, grain, stover, and biological yields (2.52, 3.76, and 6.29 t/ha, respectively) and the harvest index were observed in one irrigation during flowering (40 DAS) and 90kg N/ha at 50% (45 kg) basal application and 50% (45 kg) at pod development stage (60 DAS). The experiment results indicated to the scope of increasing the yield of French bean by irrigation at flowering stage and proper doses of nitrogen fertilizer. Therefore, the application of one-time irrigation during flowering stage along with 90 kg nitrogen/ha at 50% (45 kg) as basal and 50% (45 kg) at pod development stage (60 DAS) can be recommended as the promising technique for French cultivation.