抄録
With a view to investigate the possible reasons behind the yield reduction in chilli due to the application of higher than recommended doses of insecticides, the present studies were under taken with BHC and Nuvacron. It was observed that both germination and survival effected in all the treatments of BHC and Nuvacron and the injurious effect of Nuvacron on germination and survival was more than BHC. Similarly, both BHC and Nuvacron produced abnormalities in dividing PMCs and the frequency of these abnormalities was higher in Nuvacron than in BHC. Pollen sterility which was observed in 9th day after spray was very low in BHC and comparatively high in Nuvacron. Within each insecticide the decrease in germination and survival and increase in percent of anbormal meiotic cells and percent of pollen sterility followed an increasing trend. Yield was uneffected if BHC treatments, while it has increased in normal concentration (0.04%) of Nuvacron and decreased in highest concentration (0.12%). The yield is on par with control in Nuvacron 0.08 percent. It was concluded that 0.04 percent concentration of Nuvacron was the safest for the effective pest control and yield increase. The farmer should be more careful for not to use higher than the recommended dose since there is danger of break-down of genetic purity of the variety due to the chromosomal abnormalities besides the yield reduction at higher concentration of Nuvacron.
