Optimisation of zinc and boron doses for growth and seed yield traits in early cauliflower (Brassica oleracea var. botrytis L.) cv. Sabour Agrim

Abstract

The necessity to sustain and enhance crop productivity through efficient resource utilisation is paramount. In Bihar, micronutrient deficiencies are most prevalent, with zinc (Zn) being the most common, followed by boron (B). Therefore, a study was carried out to understand the interaction effects of Zn and B on the growth characteristics, seed yield attributes and quality traits of early cauliflower. The experimental design included four levels of Zn (0, 2.5, 5 and 7.5 kg ha-1) and B (0, 1.0, 1.5 and 2.0 kg ha-1), arranged in a factorial randomised block design (FRBD) with 16 treatments replicated 3 times. Among the treatments, the application of 2.5 kg Zn and 2 kg B per hectare (Zn2.5B2.0) resulted in significant improvements in growth traits, specifically plant height (64.9 cm), number of leaves per plant (25.9) and curd diameter (22.0 cm), while reducing the number of days to 50 % curd initiation (40 days) and days to 50 % flowering (121.3 days). The Zn2.5B2.0 treatment exhibited superior performance in yield traits, including the number of pods per plant (1876.7), pod length (10.5 cm), number of seeds per pod (21.9), seed yield per plant (64.3 g plant-1), total seed yield per plant (5.0 q ha-1) and days to seed harvest (146.7 days). In addition, Zn2.5B2.0 recorded the highest benefit-cost (B : C) ratio (5.8). The study demonstrated that the combined application of Zn and B at 2.5 kg Zn ha-1 and 2.0 kg B ha-1, respectively, significantly enhanced growth traits, yield-attributing traits and achieved the highest benefit-cost ratio compared to other treatments.