Abstract:
Mixed over sole cropping is advantageous under the rainfed conditions in Pakistan. This avoids risk of complete crop failure and may returns higher income. The study aimed to investigate appropriate seed-rates combination for wheatBrassica as mixed- or intercropped in rainfed conditions. Experiments were conducted at National Agricultural Research Center (NARC), Islamabad Pakistan during winter 2004-05 and 2005-06 using 10 treatments for wheat and Brassica as sole and mixed- or intercropped with 100 and 5 kg ha-1 for sole crop and 100 kg ha-1 for wheat with 40, 50, 60, and 70% lower than the recommended for Brassica. Sowing was done in 3rd week of October each year, in lines spaced 30cm. Fertilizer was applied N 48, P2O5 34 and K2O 18 (kg ha-1). Brassica was manually removed for fodder at flowering. Seed rate (SR) significantly (p<0.05) affected wheat grain yield. Cropping system (CS) significantly (p<0.05) affected grain yield of
Brassica. Interactions of CS and SR were also significant (p<0.05) for both species. Planned mean comparison for grain yield was found significant (p<0.05) for wheat and brassica. Grain yield for sole wheat was 4.28t ha-1 but reported higher in mixed than intercropped. Grain yield of wheat decreased with increase in seed rate of Brassica as intercropped. Higher grain yield (4.39 t ha-1) of wheat was recorded for seed rates combinations 100:50 (%) as wheat:Brassica intercropped. The land equivalent ratio (LER) for mixed or intercropped system was higher than the sole crop and it increased with increase in the seed rate of Brassica as mixed crop but decreased as intercropped. The high LER was associated to treatment 100:50 (%) seed rates combination for wheat:Brassica as intercropped. Intercropped resulted the greater LER (1.78) than the mixed crop (1.66) and was found most effective for sustainable production in the rainfed areas for a higher net return.
