Effect of wheat cultivars and sown dates on aphid infestation in Egypt.
The current study was conducted to determine the influence of wheat cultivars and wheat sown dates on aphids populations. Three cultivars of wheat (Gemiza-9; Giza-168 and Sakha-93) were sown on five sown dates (1st October, 16th October, 31st October, 15th November and 1st December) throughout two successive seasons 2011 and 2011 at Qalyubiya Governorate, Egypt. Three aphids species; Rhopalosiphum maidis, Rhopalosiphum padi and Sitobion avenae were found infesting wheat plants. R. maidis was the most abundant species followed by R. padi and S. avenae. Plants that sown on early December were significantly infested by aphids. The Gemiza-9 appeared to be the most resistant cultivar, while Giza-168 appeared to be the most susceptible one for aphid infestations. It is concluded from the study that suitable wheat sown date is from early October until mid November and the Gemiza-9 cultivar is resistant to the attack of aphid's population, this cultivar should be promoted in the areas of high aphid infestation. The selection of suitable wheat cultivar and wheat sown date can be important tool for IPM program in this area ecosystem.