Population Dynamics of Mustard Aphid, Lipaphis erysimi (Kalt.) on Mustard in Relation to Weather Parameters

The population dynamics of mustard aphid, Lipaphis erysimi (Kalt.) on mustard in relation to weather parameters was studied at Students' Instructional Farm of Narendra Deva University of Agriculture and Technology, Narendra Nagar (Kumarganj), Faizabad (U.P.) during the Rabi 2009-2010 and 2010-2011 crop season. This study will provide an opportunity to face the pest challenge by manipulating the manageable ecological parameters in the form of planting or harvesting time adjustment, varietal selection, correct time of pesticide application, etc. The natural appearance of mustard aphid population was started from 2^nd week of January during the both year and reached its peak in 8^th standard week with 219.07/10cm terminal shoot and 199.10/10cm terminal shoot during 2009-2010 and 2010-2011. Studies indicated that mustard aphid incidence was higher when maximum and minimum temperature ranged between 9.30 to 25.90°C and 8.20 to 25.20°C, relative humidity during hours 64.75 and 67.6 per cent, rainfall 0.4 and 1.4 mm and sunshine hours 7.50 and 7.20 during 2009-2010 and 2010-2011, respectively. Mustard aphid population was build up showed a non significant positive correlation with maximum temperature (°C), humidity, rainfall, sunshine and non-significant negative correlation with minimum temperature during both the year.