The occurrence and intensity of mustard aphid Lipaphis erysimi (Kalt.) on dates of sowing in different varieties respect to yield parameter

Significantly lowest aphid intensity of 7.3 and 7.4 aphids/10 cm apical shoot on the seasonal total emergence to maturity (ST) was noticed on 15^th October sown crop during rabi 2013–14 and 2014–15, respectively, which provided significantly highest seed yield of 1800.1 and 1945.0 kg/ha in the respective year. Sowing of variety Rohini on 15^th October during both years proved to be best combination as received significantly lower mean aphid intensity, 58.6 and 60.4 aphids/10 cm apical shoot. This also gave significantly superior seed yield, 1670.7 and 1915.1 kg/ha seed yield during 1^st and 2^nd year.