Control of parawilt in different Bt cotton hybrids in Punjab, India

摘要

The incidence of Parawilt on the prevalent Bt Cotton hybrids in Punjab during the Kharif 2009 & 2010 was recorded on the farmer's fields in the month of July & August. Twenty locations were selected where parawilt incidence occurs in transgenic Bt cotton hybrids during 2009 & 2010, to study the effect of Cobalt Chloride @ lOugmL~' water (which is a recommended Practice) on the Parawilt affected different transgenic Bt cotton hybrids. The incidence of parawilt was observed in MRC 6301Bt, MRC 6304 Bt,MRC 7017 Bt, MRC7031 Bt, RCH 134 Bt and RCH 317 Bt. The percent recovery was observed after the spray and also the yield of the healthy and recovered plants was noticed. The incidence of Parawilt varied from 0.5-7.5% on the different Bt cotton hybrids during 2009 and it was from 1.5-8.5% during 2010. The maximum prawilt incidence was recorded in MRC 6301, MRC 6304 in both the years. In the demonstration plots 80-97% recovery of the Parawilt affected plants was observed during the year 2009 and it was from 90-98% during the year 2010. It was observed that if the spray was done within two days of wilting of the Bt cotton plants then the whole plant revived as such and when compared with the healthy plant it was found that the recovered plants bears morenumber of bolls as compared to the healthy plant.