EFFECT OF DIFFERENT LEVELS OF NITROGEN AND BORON ON MORPHOLOGICAL CHARACTERS, YIELD AND SEED QUALITY OF RAPESEED (Brassica canipestris L.)

Abstract

The experiment was conducted at the experimental Field of Sher-e-Bangla Agricultural University, Dhaka during the rabi season from November 2011 to February 2012 to evaluate the effect of different levels of nitrogen (N) and boron (B) on morphological characters, yield, oil content and germination percent of rapeseed (Brassica campexiris L.). The experiment was factorial with two factors, factor A consisted of four different N levels viz. 0, 60, 120. 180 (kg/ha) and factor B consisted of three different levels of B(boron) viz. 0. I, 2 (kg/ha). The experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. The collected data were statistically analyzed for evaluation of the treatment effect. Results showed significant variation in almost every parameter. The plant height, leaves plan(', Primary and secondary branches plant-I, length of inhiorescence at different days after sowing increased significantly with increasing rate of N. interestingly, B did not show any significant variation on above parameters. As N, application of B significantly increased siliquae on main inilorescence, seed weight of 100 siliquae, seed weight plant-i, thousand seed weight, seed yield (t hi') and harvest index as dose dependent manner. In addition, oil content of rapeseed showed varied significantly with both N and B independently, whereas N and B had no significant effect on germination percent of seed. These results indicated that N exhibited significant influence on morphological characters, yield, oil content and germination percent of seed whereas B showed differences on these parameters other than morphological characters. The interaction between different levels of N and B significantly influenced almost all morphological and yield contributing characters, seed yield and oil content of seed. The maximum value of morphological characters. yield contributing characters, seed yield and oil content of rapeseed was observed with the combined dose of 120 kg N/ha and 2 Kg B/ha (N2132) whereas the lowest values were obtained from control i.e., N0B0 treatment combination. The maximum yield of seed per hectare (1.78 t) and the maximum oil content (42.96 %) was obtained from 120 kg N/ha with 2 Kg B/ha treatment combination. Separately, the combined use of N and B did not show any significant differences on germination percent of rapeseed. Based on the present results, it can be suggested that the combined doses of 120 kg N/ha with 2 kg B/ha (N2B2) is appropriate for higher yield and quality seed production of rapeseed cv. BAR!Sarisha 14.