Incidence of Major Pests of Pongamia (Milletia pinnata L.) as Influencedby Weather Parameters

摘要

The incidence of major pests of pongamia in relation to weather parameters was observed during 2016-17 at Zonal Agricultural Research Station, UAS, GKVK, Bangalore. The important pests recorded on pongamia were blotch miner (Acrocercops anthrauris Fabricius), spiralling whitefly Aleurodiccus disperses (Russel), flower gall producing Aspondyliapongamiae Mani and the eriophyid mite, Aceriapongamiae Channabasavanna causing leaf galls. Correlation between A. pongamiae with weather variables of the preceeding fortnight revealed that, it had highly significant and positive correlation with maximum temperature and minimum temperature (r= 0.563, r= 0.868, p<0.01), respectively. Leaf gall number was significantly and positively correlated with minimum temperature (r = 0.583, p<0.01), rainfall (r= 0.478, p<0.05) and wind speed (r = 0.463, p<0.05). Regarding correlation with corresponding fortnight weather data, A. pongamiae incidence was significantly and positively correlated with maximum temperature (r = 0.465, p<0.01) and minimum temperature (r= 0.842, p<0.05) leaf gall number due to A. pongamiae was significantly and positively correlated with minimum temperature (r = 0.597, p<0.01), and rainfall (r = 0.541, p<0.01). Blotch miner incidence was significantly and positively correlated with maximum temperature (r = 0.421, p<0.01) and minimum temperature (r = 0.767, p<0.01) of the preceding week. Spiralling whitefly incidence was significantly positively correlated with maximum temperature (r = 0.652, p<0.01) and minimum temperature i.e., (r=0.541, p<0.01). Flower galls caused by A. pongamiae showed significant and positive correlation with afternoon relative humidity (r = 0.733, pO.Ol) and minimum temperature (r= 0.311, p<0.05). Regarding correlation with the corresponding week weather parameters, blotch miner showed significant and positive correlation with minimum temperature (r=0.725, p<0.01), maximum temperature (r = 0.310, p<0.05), afternoon RH (r= 0.341, p<0.05) and wind speed (r= 0.325, p<0.05).Spiralling whitefly, incidence showed significantly positive correlation with maximum and minimum temperature i.e., (r = 0.518, pO.Ol and r=0.522, p<0.01), whereas, flower galls were significantly and positively correlated with afternoon relative humidity (r = 0.688, pO.Ol), minimum temperature (r= 0.342, p<0.05) while it was significantly and negatively correlated with maximum temperature (r = -0.303, p<0.05) and total rainfall (r = - 0.594, p<0.01)