Study on different egg-plant cultivars for infestation to two spotted spider mite (tetranychus urticae complex) in varamin region

Two spotted spider mite (Tetranychus urticae complex) is an important pest of egg-plant in Iran. In the present study, population of eggs and active stages and amount of losses of the spider mite were determined on upper and lower leaves of nine egg-plant cultivars in Varamin during 2001-2002. The experiment was in a randomized complete block design with three replications. Each plot consisted of four rows and on each row ten egg-plants were cultivated. Spider mite population on all cultivars was checked at weekly samplings, from July to October. Number of mites (eggs and active stages) on upper and lower leaves were then counted by stereo binocular microscope. Loss percent of mite was assessed by measuring the weight of ten randomly selected fruits of each cultivar in three replications at fifteen day intervals during fruiting period. Analysis of variance on data showed significant differences of mite population on upper and lower leaves of different cultivars and also among the cultivars. In 2000, the highest mean populations of active mites on lower leaves, 37.80 and 46.87, and on upper leaves, 27.19 and 38.08 were recorded on Borazjan cv. in naturally and artificially infested treatments, respectively. In 2001, egg and active mite populations on cultivar were significantly different only in artificially infested treatment. The maximum numbers of eggs (63.47) and active stage (107.94) were recorded on Imami 905 cultivar. Maximum and minimum losses of 69.42% and 12.86% were recorded on Imami 905 and Ghalami Varamin cultivars. These cultivars were determined as the most susceptible and resistant cultivars to mite damage, respectively