Investigations on varietal resistance of wheat against Schizaphis graminum (rond). under field conditions

Wheat (Triticum aestivum) is an important cereal crop which is being grown in Pakistan. The wheat crop has also many pests which damage the yield and quality of grains and are responsible for great reduction in yields. There are many species of insects which can cause damage to crop, but Aphid are known to be more dangerously damaging pests of wheat crop. To investigate the varietal resistance of wheat against Schizaphis graminum under field conditions, an experiment was conducted at the research field ofLasbela, University of Agriculture, water and Marine sciences, uthal Baluchistan, Pakistan during 2017- 2018.Five commercial wheat varieties were sown on November 2017 in a randomized complete block design with four replications in 9.8×4.6 m size plot having 10 rows, respectively. The sowing of wheat seeds was done on ridges. Observations on the infestation of wheat aphids were recorded at weekly interval. For this purpose, five plants from each replication were randomly selected. During the study we observed that aphids attack started in last two weeks of December, increased during January and March, peaked on 26th January, and then declined afterwards till complete disappearance in April. The overall mean number of aphids per plant was higher on wheat varietyShalkot (3.76±0.29/aphids per plant), which was followed by Azri (2.17±0.22aphids per plant),Sarsabz(2.68±0.19 aphids per plant)Nymber (1.43±0.16), Tajawaan (1.17±0.15 aphids per plant), However, Upcoming wheat variety Shalkot found to have susceptibility to Schizaphisgraminum, this variety was more infested by wheat aphid than rest of the varieties Tajawaan was found to be relatively less infested with insect population of 1.17±0.15/plant, which can be assumed as relatively resistance to Schizaphis graminum.The results for population of Schizaphis graminum in all Five varieties showed statisticallyhighly significant difference (F= 62.41P = 0.0000).