Effect of Sowing Date and Cultivars on Aphid Infestation in Wheat with Climate Change Adaptation Perspective

Abstract

Four field experiments, two experiments each during winter season of 2012–2013 and 2013–2014, were conducted to evaluate effect of sowing time and four wheat cultivars on population of wheat aphids. Wheat crop was found infested with Rhopalosiphum padi and Sitobion avenae in various proportions in different experiments. During vegetative crop phase, December (late) sown crop had in general higher aphid population than November (timely) sown crop, while during reproductive crop stage, timely sown crop harboured more aphids on ear heads than late planted one. October (early) and January (very late) sown crop evaded aphid attack on ear heads. Significant differences in peak aphid populations among different plantings indicated that alteration of sowing time might disturb phenological synchrony between aphids and wheat crop, affecting pest population. Aphid population was positively influenced by the temperature. Sowing dates were also found to significantly affect the crop yield. Among varieties, WR-544 was observed to have lower number of aphids than other cultivars during vegetative crop stage. Because alteration in sowing time is deemed to be one of the adaptation strategies to sustain agricultural productivity under climate change, effect of sowing time on aphid population is the need to be heeded while formulating such strategy for effective crop management.