Effect of Planting Dates on Infestation with Certain Pests and Yield of Cucumber Plants During Fall Plantation in Giza Governorate.

The effect of three planting dates of cucumber seeding during fall plantation (August, 1^st, August, 22^nd and September, 12^th) on levels of infestation with four pests, aphid, Aphis gossypii Glover, whitefly, Bemisia tabaci (Genn.), thrips, Thrips tabaci Lind. And Tetranychus urticae (Koch) and on yield of this plant, were studied during two successive seasons (2014 and 2015). The degree of infestation by A. gossypii and B. tabaci  increased significantly by delaying planting date, as cucumber plants cultivated in the earliest planting date (August, 1st) were attacked by the lowest numbers and highest weight of cucumber fruits, while the plants of the latest planting date (September, 12^th) were more liabled to insects infestation with lowest weight of cucumber fruits. The results showed that, the mean rate of infestation with A. gossypii were (5.1, 9.2 and 11.9 individuals/leaf) during 2014 season and (5.5, 10.6 and 12.4 individuals/ leaf) during 2015 season for the three tested dates, respectively. So, the mean number of infestation with B. tabaci  were (8.5, 15.4  and 13.6  nymphs/ leaf)  during 2014 season,  (7.8, 13.7  and 12.2 nymphs/ leaf) during 2015 season for the three dates, respectively. also, the highest weight of cucumber yield (20.5 and 19.7 kg/ 100m² in the two seasons, respectively) was obtained. On the contrary, the populations of T. tabaci and T. urticae increased significantly with the early planting date compared with cucumber plants cultivated in the latest planting date during the two seasons. Therefore, it was concluded that, the planting date was effective on the rate of infestation with pests and yield of cucumber plants.