Production of Bt and non-Bt cotton (Gossypium sp.) and french bean (Phaseolus vulgaris) intercropping system in northern transition zone of Karnataka

Intercropping combinations of Bt and non-Bt cotton (Gossypium sp.) and french bean (Phaseolus vulgaris L.) were studied between 2005–06 and 2006–07 at Dharwad to compare productivity, economics and energetics, under rainfed condition in northern transition zone of Karnataka. French bean was grown for grain and vegetable purpose with Bt and non-Bt cotton in 2 row ratios (1:2 and 1:3), 4 sole crops (french bean for grain and vegetable, Bt-and non-Bt cotton) and Bt-non-Bt cotton + soybean (recommended intercropping of this area) were evaluated. Intercropping of Bt-cotton + french bean in 1:3 row ratio either for grain or vegetable recorded significantly higher cotton equivalent yield (2.54 and 2.51 t/ha, respectively), land equivalent ratio (1.38 and 1.37, respectively), system productivity index (2.44 and 2.42 t/ha respectively), when compared with other systems. The intercropping of Bt- cotton + french bean in 1:3 row ratio for grain recorded significantly higher area time equivalent ratio (1.16), protein (0.96 t/ha), carbohydrate (0.41 t/ha), energy yield (6.83 x 106 k cal/ha), net output energy (72.06 x 103 MJ/ha) and energy use efficiency (139.92 kg/103 MJ) when compared with Bt-cotton + french bean for vegetable in the same row ratio.