Status of above-ground pests in organic vegetable production under greenhouse conditions in Izmir province

Status of above-ground pests in organic vegetable production under greenhouse conditions in Izmir province Experiments according to principles and methods for organic agriculture were conducted at Ege University Faculty of Agriculture (Izmir) between 2005 and 2008 in polyethylene (PE)-covered greenhouses. Side and roof ventilation of greenhouses were covered with insect net. Lettuce (cv. Paris Island) (2005-2006) was grown in two winter periods, tomato (cv. Gokce) (2006-2007) and cucumber (cv. Sardes) (2007-2008) were grown in two spring growing periods for each. Cultural methods for pest management were applied before seedling transfer. Weeds and plant remains were removed carefully during production cycles regularly. Yellow sticky traps were used during growing periods. Observations were made once a week to monitor the pests. Thrips, aphids, leafminers and spider mites were observed as pests. Population of whiteflies was not high enough to damage plants and leafminers were not important because of removal of the damaged leaves and yellow sticky traps in all three plant cultures. Aphids did not cause any damage in all two growing periods of lettuce and tomato and first growing period of cucumber. However, notable damages of spider mites, thrips and aphids were encountered in second production period and they were suppressed by application of potassium soap and sulfur. As a conclusion, yield data obtained in all growing seasons showed that organic lettuce, tomato and cucumber production could be realized under greenhouse conditions when the pests are under control in our region.