Effect of Brassica spp. and their sowing proportions on productivity, competition and economics of wheat (Triticum aestivum) + Brassica mixed cropping system under rainfed conditions of Himachal Pradesh

An experiment was conduced during winter (rabi) season of 2003 and 2004 to identify the suitable Brassica spp. and their optimum sowing proportion for wheat (Triticum aestivum L. emend. Fiori & Paol.) + Brassica mixed cropping system. Brown sarson (Local) was more competitive than mustard (‘RCC 4’) in all the mixed cropping patterns, decreasing the total productivity by 4.9 and 6.1% respectively. Mixed cropping of wheat + mustard (‘RCC 4’) in 100% + 10% and 100% + 20% seeding proportion gave significantly higher wheat yield, total productivity and net returns compared with sole wheat and farmer's practice of wheat + brown sarson (100% + 50%), followed by wheat + brown sarson (Local) in 100% + 20% seeding proportion. These treatments gave 4.4–9.9% and 15.0–21.1% higher productivity over sole wheat and farmer's mixed cropping practice. The competitive ratio, aggressivity and LER of the main crop wheat were maximum when the mixed cropping of wheat + mustard or wheat + brown sarson was followed in 100% + 20% seeding proportion, followed by that of wheat + mustard (100% + 10%). In all other sowing patterns the wheat crop was dominant.