22.06.2011 | permalink
The yield was 463 kg per hectare when the Bt cotton area was 5.6% in 2004 and reached a mere 506 kg per hectare when the area under Bt cotton increased to 9.4 M hectares at 85% of the total 11.1 M hectares. Other concerns relate to the enhanced problems of sap-sucking insects such as leaf hoppers, aphids, whiteflies and thrips on the vast majority of susceptible Bt hybrids. New pathogens such as ”leaf streak virus,” Myrothecium and Ramularia started affecting the new Bt hybrids. Insect populations of mealybugs, miridbugs, gall midges, mosquito bugs and safflower caterpillars, which were hitherto unknown as pests, suddenly emerged as concerns after the introduction of the new Bt-cotton hybrids.