SUMMARY AND CONCLUSION

Transcription

1 SUMMARY AND CONCLUSION Cabbage is an important cruciferous vegetable. Insect pests are one of the major biotic factors which contribute to major economic losses both quantitatively and qualitatively. These insect pests attack different growth stages of the crop. Over the decades, continuous and indiscriminate use of synthetic chemicals have resulted, not only in the problems of resurgence and resistance, but also caused much health hazards. Plant Protection research has generated many technologies using flora and fauna. A few have been standardized for commercial application, and are claimed to provide better pest control and crop economics than the conventional chemical control, when used in conjunction with other pest control measures. The strategy is often referred to as Integrated Pest Management (IPM). Recently new technologies and practices in IPM offer better protection against insect pests, improve crop yields and net benefits to the farmers. Our ancestors, though not having benefit of scientific evaluation, still had adequate common sense and over the centuries have evolved many indigenous practices that may seem to us primitive in the era of insect pest management. Owing to the impending environmental pollution and its hazards, indigenous knowledge system in various sectors including agriculture appears to be life saving phenomenon in conjunction with many nonchemical methods of pest control. As a matter of fact, there should be an earnest scientific endeavor to probe deeply into and integrate such innovative local practices with our modern scientific technology. Much of the efforts of researchers on plant products is directed towards finding out newer application areas for the various plant products. But the basic aspects such as stabilization, shelf life, standardization etc., are inadequately attended. Biological control is the deliberate use of one organism to regulate the population size of a pest organism. The benefits of biological control are that it can provide fairly permanant regulation of devastating agricultural and environmental pests that may be difficult or impossible to manage with more traditional chemical means.the use of biological control agent is that it typically offers longer term management than the more traditional technology areas. longer term control is achieved because biocontrol agents SUMMARY AND CONCLUSION 138

2 act as if a host specific control method is continualy present and impacting the target plant. Studies on the Evaluation of different Integrated Pest Management modules on the insect pest complex of cabbage Brassica oleraceae var.capitata. was carried out in the Department of Plant Protection, SHIATS, Allahabad. Different IPM modules consisting of indigenous products, bio-agents and insecticides were studied on the following three major insect pests viz. diamondback moth (Plutella xylostella), cabbage aphid (Brevicoryne brassicae) and Tobacco caterpillar (Spodoptera litura) of cabbage. Three to four leaf stage cabbage plants were transplanted in 4x4 plots with a plant to plant spacing of 60 x 45 cm. The plots were maintained as per the package of practices recommended for cabbage under Allahabad condition. Treatments were applied, using RBD, when the economic threshold of each pest was reached. Observations were recorded after three, six and nine days after each spray. Treatments which comprised of FYM and neem cake were placed around the base of the cabbage plant, while all the other treatments were applied as a foliar spray. Based on the results of this study, the following conclusions were made: 5.1 Indigenous products against Plutella xylostella, Brevicoryne brassicae and Spodoptera litura Field efficacy of indigenous products proved to be effective against all the growth stages of Plutella xylostella, Brevicoryne brassicae and Spodoptera litura. In all three treatment applications, observations at 3, 6 and 9 days after spraying revealed that treatments 3 and 4 were superior to endosulphan, the chemical check, and treatments 1 and 2 were inferior but superior to the control (no treatment). Consequently, chilli garlic extract proved to be the most outstanding indigenous products, which gave best control against the three insect pests, while FYM was the least effective. 5.2 Bio-agents, with or without NSKE, against Plutella xylostella, Brevicoryne brassicae and Spodoptera litura The bio-agents evaluated against Plutella xylostella, Brevicoryne brassicae and Spodoptera litura, either alone or in combination with NSKE, were effective against all SUMMARY AND CONCLUSION 139

3 the growth stages of the three pests. Observation at 3,6 and 9 days after spray for the three different treatment applications showed that treatments 5 and 6 were more effective than endosulphan, the chemical check, and all other treatments were significantly less effective but superior to the control (untreated). Bacillus thuringiensis (T 6 ) was most effective in the management of Plutella xylostella, Brevicoryne brassicae and Spodoptera litura, while NSKE alone was the least effective in reducing the population of the three pests. 5.3 Insecticides, singly or in combination with NSKE, against Plutella xylostella, Brevicoryne brassicae and Spodoptera litura The evaluation of 10 chemical insecticides with or without NSKE gave varying degrees of control over Plutella xylostella, Brevicoryne brassicae and Spodoptera litura. Three different sets of applications were made and observations recorded at 3, 6 and 9 days after spraying revealed that insecticides in combination with NSKE were most effective in reducing the numbers of the three insect pests. With the exception of Chlorfenapyr alone against cabbage aphids and tobacco caterpillar, these treatments namely, Indoxacarb + NSKE, Imidacloprid + NSKE, Spinosad + NSKE, Endosulphan + NSKE and Chlorfenapyr + NSKE were consistently superior to all other treatments. Spinosad + NSKE was the most effective against the three insect pests while carbaryl was the least effective against diamondback moth and Acephate was the least effective against cabbage aphid and tobacco caterpillar. 5.4 Cost benefit ratio for indigenous products against Plutella xylostella, Brevicoryne brassicae and Spodoptera litura Among the indigenous treatments, maximum gross return (Rs.52.46) net profit (Rs 29.56) cost benefit ratio 2.29 was obtained from the treatment combination of chilligarlic extract and minimum was found with untreated control with gross return (Rs ), net profit (Rs ) and cost benefit ratio (1.88). SUMMARY AND CONCLUSION 140

4 5.5 Cost benefit ratio for bio-agents, with or without NSKE, against Plutella xylostella, Brevicoryne brassicae and Spodoptera litura Maximum gross return (Rs.53.47) net profit (Rs 31.47) cost benefit ratio 2.43 was obtained from the treatment receiving Baccillus thuringiensis and minimum was found with untreated control gross return (Rs ), net profit (Rs ) and cost benefit ratio (1.88) among the treatment of bioagents alone or in combination with NSKE. 5.6 Cost benefit ratio for insecticides, singly or in combination with NSKE, against Plutella xylostella, Brevicoryne brassicae and Spodoptera litura Maximum gross return (Rs.47.69) net profit (Rs 25.79) cost benefit ratio 2.17 was obtained from the treatment combination of spinosad+nske and minimum was found with untreated control with gross return (Rs ), net profit (Rs ) and cost benefit ratio (1.70) among the treatment of chemical insecticides singly and in combination with NSKE. SUMMARY AND CONCLUSION 141

5 CONCLUSION In conclusion, out of the 22 treatments utilizing indigenous products, bioagents and chemical insecticides, proved to be promising resources for the management of Plutella xylostella, Brevicoryne brassicae and Spodoptera litura. The most outstanding treatments were chilli-garlic extract, Bt and spinosad+nske, representing indigenous products, bioagents and chemical insecticides, respectively. As a result, it can be suggested that chilli-garlic + Bt + Spinasod in combination with NSKE be combined to form an IPM module for the management of Plutella xylostella, Brevicoryne brassicae and Spodoptera litura. However, before the adoption of this module, further studies on the compatibility among the different products should be carried out. The chemical insecticides viz Indoxacarb, Imidacloprid, Spinosad, Endosulphan and Chlorfenapyr in combination with NSKE may also be considered as possible IPM modules in combating damage caused by these three major insect pests of cabbage. Therefore it is recommended that those outstanding treatment used in 3 major insect pests of cabbage can be conducted in large area as demonstration trial,so that farmers may understand the use of IPM module. SUMMARY AND CONCLUSION 142