Effect of Nutrients Application on Management of Mustard Aphid, Lipaphis Erysimi (Kalt ) on Indian Mustard

Abstract

The present investigation "Effect of nutrients application on management of mustard aphid, Lipaphis erysimi (Kalt.) on Indian mustard" was conducted at Sardar Vallabhbhai Patel University of Agriculture & Technology, Meerut, during Rabi 2010-11 and 2011-12. The study on population dynamics of mustard aphid; L. erysimi elicited that the aphid population first appeared in 3rd week of December i.e. 51st standard week and reached to the maximum level in the month of February (1st week of February during 2010-11 and 4th week of February during 2011-12}. The aphid intensity was observed with positive correlation with maximum and minimum temperature, while negatively correlated with relative humidity and rainfall. Avoidable yield losses due to mustard aphid were observed from 54.43 to 55.78 per cent. The aphid population 35.89 aphids/1 0 em apical shoot/ plant with 0.88 aphid index, and 36.88 aphid/1 0 em apical shoot/ plant with 1.49 aphid index during 2010-11 and 2011-12, respectively found as economic injury level (Ell) of L erysimi. The aphid population 33.22 aphids/1 0 em apical shoot/ plant with 0.61 aphid index and 26. 1 0 aphids/1 0 em apical shoot/ plant with 1.17 aphid index during 2010-11 and 2011-12, respectively found as economic threshold level (ETL) of L. erysimi. The impact of nitrogen, phosphorus, and potash fertilization on population dynamics of mustard aphid, showed that in general the increased dose of nitrogen boost up the mustard aphid population, however, the increased dose of .Phosphorus and potash present a negative trend in population of mustard aphid during both the years. The conspicuous increase/ decrease in aphid population due to independent and combined effect of nitrogen, phosphorus and potash fertilization was statistically significant only at certain weeks during both the years. Higher levels of N, P and K fertilization have a yield promoting effect on mustard crop. The highest seed yield was obtained from the plot treated with higher doses of N, P and K (120:60:30) followed by higher doses of N and P (120:60:0) and higher doses of Nand K (120:0:30) during both the years.