Effect of seeding time of linseed (Linum usitatissimum) in rice ( Oryza sativa)-based paira cropping system under rainfed lowland conditions

Abstract

A field experiment was carried out during rainy and winter seasons of 2001 to 2003 at farmers' field, Burdwan, West Bengal, in clay loam soil to study the effect of seeding time of linseed (Linum usitatissimum L.) as paira (linseed sown broadcast in standing crop of lowland rice before its harvest) on its growth, yield attributes and yield in rice ( Oryza sativa L.)-based paira cropping system. The performance of linseed sown 2 weeks after flowering of rice significantly was better, giving maximum seed yield (672 kg/ha), oil yield (245.3 kg/ha) and harvest index (26.4%) owing to highest plant population/m² (106.4), dry-matter accumulation(220 g/m²),capsules/plant (25.9), seeds/capsule (8.35) and 1000-seed weight (7.25 g). It was followed by seed yield of 600 kg/ha when the crop was sown 3 weeks after flowering of rice. Sowing of linseed 7 days after flowering of rice reduced the crop stand due to mortality of the plants owing to excess moisture in the soil and thus adversely affected the yield (123 kg/ha) with similar trend in case of growth and yield-attributing parameters. Significantly highest plant relative water content (83.8%) of linseed was recorded with sowing of linseed at 14 days after flowering of rice. The same treatment recorded the highest net returns (Rs 21930) and benefit: cost ratio (2.46). Highest soil moisture content (9.38%) at flowering of linseed was obtained when linseed was sown after 3 weeks of flowering in rice. The lowest total N, available P and available K (1321.6,8.02 and 194.47 kg/ha respectively) in soil after the harvest of linseed was obtained when linseed was sown 2 weeks after flowering of rice. Higher uptake of nutrient and dry-matter accumulation under this treatment might be the reason for 1esser amount of these nutrients in soil after the two cycle of cropping systems.