Survey on Population Changes of Aphis gossypii (Glove.) on Cluster Cultivars in Ultra Narrow Row system in the Field Cotton Golestan Province of Iran.

In the planting system, the row spacing is very narrow, where the spacing of the planting rows is considered to be between 20 and 40 cm. In this system, the number of bolls per plant is reduced. Experiments to survey and compare populations Aphis gossypii on 3 cluster cultivars and one control, using the method of narrow planting distance of 20 × 20 and 20 × 80 cm as a factorial design in the form of a randomized complete block design with 3 replications in Hashemabad cotton research station in Gorgan during two years 2018- 2019 was evaluated. A sampling of different stages of cotton aphids was recorded weekly in the tested treatments and recorded in special tables. Based on the studies, the results of combined analysis of variance show that the yield in the cultivars tested in Sajedi cultivar with a distance of 80 cm with an average wash of 3392 kg/ha in the plot and Golestan cultivar 80 cm with 3245.8 kg/ha in the plot with the highest yield and T2 cultivar With a distance of 20 cm, 1694 kg/ha in Crete had the lowest yield. Infestation rate of cluster cultivars tested in very narrow cultivation of green aphid population density on Sajedi cultivars with a distance of 80 cm and the khorshid with a distance of 20 cm with densities of 41.39 and 40.36 aphids per leaf, respectively, with the highest aphids per leaf and cultivars T2 and the khorshid with a distance of 20 cm with 23.59 and 29.04 aphids, respectively. They had the least infestation in the leaves.