No abstract

A field experiment to evaluate some IPM modules against major pests viz., Aphis gossypii, Myzus persicae, Bemisia tabaci and their natural enemies viz., coccinellids and spiders occurring in king chilli Capsicum chinense Jacquin was carried out during rabi (2014-16) at Jorhat, Assam. The results revealed that module M2 with seedling root dip treatment with imidacloprid 17.8 SL @ 40g a.i./ ha + growing of border crop (okra)+ spraying of imidacloprid 17.8SL @ 40g a.i./ ha at 20 days after transplanting at 15 days interval is the most effective in suppressing aphids and whitefly followed by lambdacyhalothrin instead of imidacloprid in both the seasons. The insecticidal treatment modules had a significant effect on the pest and the viral diseases, thereby increasing the yield, with maximum yield obtained in module M2 (3564.44 kg/ ha) and with a maximum cost-benefit ratio of 1: 4.85.

A transmission study was conducted to identify and confirm the insect vectors of viral diseases of king chilli Capsicum chinense Jacquin, at the Virology Laboratory, Assam Agricultural University, Jorhat. The study reveals that Cucumber Mosaic Virus (CMV), Potato Virus Y (PVY) and Chilli Leaf Curl Virus (ChLCV) were the viral diseases transmitted by Aphis gossypii (Glover), Myzus persicae (Sulzer) and Bemisia tabaci (Gennadius), respectively. The detection of CMV and PVY were done through DAS-ELISA assay and ChLCV was done through PCR technique. The results showed that A. gossypii and M. persicae were successfully transmitting the CMV and PVY (40% each). DAS-ELISA revealed that 57.14% of the plant and 66.67% of A. gossypii samples were found to be positive to CMV. While, 42.17 and 60.00 % of PVY detection was observed from plant and M. persicae samples, respectively. B. tabaci also successfully transmitted ChLCV with 80% of the tested plant and the PCR results revealed that the primer pair ChLCV F1 and ChLCV R1 successfully yields 550bp at annealing temperature of 48oC from the infected plant as well as from B. tabaci samples and fail to detect from healthy plants, aphids, and leafhoppers samples.

Aim: The study was conducted for management of foliar nematode, Aphelenchoides besseyi through different treatment modules in tuberose, Polianthes tuberose. Methodology: A field experiment was carried out with seven treatment modules with four replications to assess the efficacy of treatment modules to manage the foliar nematode in tuberose variety, Calcutta Double. Observations on germination percentage and spike emergence as well as initial and final nematode population in bulbs and plant growth parameters were analysed.? Results: The experiment was conducted with naturally infected plant of tuberose bearing an initial nematode population per five bulbs. The per cent change over treated bulb was found significantly different from the control. The experiment revealed that the germination percent of tuberose bulbs increased under the treatment modules compared to untreated control. Emergence of 55 per cent and 100 per cent spike in treatment modules was earlier than the untreated check. Plant growth parameters were superior in treatment modules as compared to control. Symptoms like stunted growth of plants prickle like structures on the scape and flower and hardy brown flowers in untreated plants were not found in the treated plots.? Interpretation: Symptom development in different parts of tuberose plants increased with increase in population of foliar nematode rendering to the unmarketable tuberose plants. Therefore, an urgent need of management of foliar nematode is documented with seven treatment modules and the modules were found effective in managing the nematode population in field condition.