Growth physiology of Brassica rapa var. yellow sarson under integrated nutrient management and seed soaking approaches in eastern sub-Himalayan plains

The field experiment was conducted at Uttar Banga Krishi Viswavidyalaya, West Bengal, India during rabi 2007-08 to 2008-09 to study the growth and productivity of yellow sarson under different nutrient managementi practices and pre-sowing seed soaking. The highest value of LAI (4.00), apart from the maximum plant height (129.97cm), dry matter accumulation (481.93g m-2) at 90 days, crop growth rate (12.29 g m-2 day-1) in between 45 to 60 days, root dry weight (1.645 g plant-1) with the highest average root diameter (0.932 mm) were observed in treatments receiving 75% recommended dose of chemical fertilizer with farm yard manure, Azotobacter and phosphate solubilizing bacteria as non-chemical source. Similarly at 45 days of crop age, significantly higher stomatal conductance (701.68 m mol m-2 s-1) and transpiration rate (4.55 m mol m-2 s-1) were reflected by the same treatment combination. These were attributed to the production of maximum seed yield (1374 kg ha-1), which was 39.91% higher than the recommended dose of chemical fertilizer application. On an average, seeds soaked with water before sowing reflected 9% lesser yield (1103 kg ha-1) against chemical soaking. Yellow sarson crop grown with integrated nutrient management practice consisting 75% of the recommended dose of chemical fertilizer along with farm yard manure (5t ha-1), Azotobacter (5kg ha-1) and phosphate solubilizing bacteria (5kg ha-1) coupled with seed soaking in 100ppm KH2PO4 confirms to be the best treatment combination from the treatment schedule considered during the study for the sub-Himalayan plains of West Bengal, India in terms of crop growth and productivity.