بررسی تأثیر آبیاری بارانی روی تغییرات جمعیت زنجرک Psammotettix alienus روی محصول ذرت

Maize crop in recent years has widely cultivated in Chaharmahal Va Bakhtiyari province. This crop has two types of foraging and seedy maize in the region, that most of the area under cultivation is foraging maize, because this province is the best region of animal husbandry in the country and need of this crop is so prevalent, also extensive research in the field of pest of it is necessary in the region. Maize has many pests and leafhopper Psammotettix alienus Dahlbom is one of the most important sucking pests of this crop, that it has both direct and indirect damage (with transmission of viral diseases and etc.). Recently the population of this pest in Chaharmahal Va Bakhtiyari area has gone up and its damage has lowered crop function and farmers have to choose a way to control. One of the environmental factors that effects on this pest population dynamics, is relative humidity, also the amount of pest activity related with fluctuations in temperature and relative humidity, that in this study to investigate the effect of this factor, two fields were selected and sampling in these was conducted by sweeping net of 10 samples per week by systematic sampling method. fields. Sampling data and other collected data were recorded in special tables and analyzed by SAS statistical software in a randomized complete block design. The results showed that, there is two peak populations of this leafhopper in field with flood irrigation (traditional irrigation), respectively, in the third week of July and the third week of September, but in field with sprinkler irrigation on these dates, population was at its lowest level during the maize growing season. Study of population dynamics graphs, showed that, population of leafhopper decreases by using of sprinkler irrigation. Also data analysis showed that the effect of sprinkler irrigation on the leafhopper population dynamics were significant in five percent level. Also relative humidity and rainfall showed a negative correlation with the population of leafhoppers. According to the results of this research and also, due to damage of this pest and huge increase of its population in maize fields in recent years, can recommends to farmers to use of sprinkler irrigation method to reduce the population and finally reduce the damage of this pest, because this method of irrigation increases the relative humidity that it causes to reduce the population and thus damage of this leafhopper.