Effect of Bed Disinfectants and Seasonal Incidence of Silkworm Diseases in Different Types of Rearing Houses

摘要

Abstract During silkworm culture Bombyx mori become susceptible to different types of microbial infection due to domestication. To minimize the crop loss due to disease fanners are using various bed disinfectants viz., vijetha hydrated lime, bundh powder, active lime, captan, dithane M-45. RKO, ankush, vijetha supplement, resham jyothi, labex and formalin chaff. Among these most commonly used bed disinfectants by the farmers are active lime, hydrated lime, bundh powder, vijetha which are being used in large quantities without any justification. In addition to provision of good quality leaves, good aeration, sufficient spacing, required number of feedings, proper bed cleaning and proper disposal of bed refuse and dead worms during disease occurrenceare considered as prime factors. However there was variation in application of bed disinfectants 2-4 kg/100 dfls which was found to be common in zone-5. Out of these ankush was found to be universal bed disinfectants used by these farmers. There was variation noticed with type of silkworm rearing house and cocoon yield. Further, among ten farmers the summer rearing recorded disease incidence ranged from 4 to 20%, and cocoon yield of 65-95 kg/100 dfls. A farmer no. 5 not used vijetha and ankush, but vijetha+lime powder was used and recorded highest cocoon yield of 96 kg/100 dfls in the small stone house category (30x 10-40x20 ft). The mean data from six farmers of RCC rearing house revealed that, a range of 2-5%. 4-5% and 4-20% disease incidence was recorded in rainy, winter and summer seasons respectively. On contrary cocoon yield of 73-96 kg/100 dfl was recorded in case sample number 1 and 3. Even in this type of rearing house the farmers are using 0-4 kg of bed disinfectants/100 dfls (vijetha, limeand vijetha+B powder. The same trend was seen in brick house. As the quantum of bed disinfectants used there was tremendous increase in the cocoon yield as reflected in the cocoon data.