Abstracto

EFFECT OF TEMPERATURE AND RELATIVE HUMIDITY ON POPULATION DYNAMICS OF WHITEFLY (BEMISIATABACI) (ALEYRODIDAE: HEMIPTERA) ON SOWING DATES OF COTTON CROP IN RAHIM YAR KHAN ZONE

Asma Aslam*

The cotton variety NAIB-787 was sown on different dates on the field area of Entomological section KhwajaFareed UEIT University in Punjab, Pakistan during kharif season of 2022. The experiment was conducted through randomized complete block design with three replications was used with five sowing dates (SD1 = 1st April, SD2 = 15th April, SD3 = 30thMay SD4 = 15thMay, SD5 = 30th May). The purpose of this study was how abiotic variables affect the population dynamics of the whitefly on different dates of sowing as whitefly is the major pest of cotton. Whitefly population was monitored on a weekly basis but mean value per month listed in table, data of relative humidity and temperature was taken from metrological department. The data indicated the significant effect of sowing dates on population dynamics of white fly. The sowing of crop was also important for the attack of whitefly. The early and timely sown cotton crop was less attacked by whitefly while the late sown crop was observed much attack of this pest. It was observed that there are positive correlation between whitefly (7.8 per leaf) and maximum temperature 50.1C0 while there was negative correlation between whitefly (1.22per leaf) and relative humidity (59.8%) when temperature not high than (37.3C0). Whitefly population was observed high when temperature and relative humidity both are high because whitefly like warm and humid weather conditions. Overall, crop sown at normal dates in the month of April was less affected by infestation of whitefly then late sown crop in May. The results reviled that whitefly population remained low up to last week of June and there after increase gradually and reached its peak in the month of July and August and decline irrespective of sowing date. The population was recorded higher in late sown as compared to early sown crop throughout the season. This paper report would be helpful in developing efficient whitefly management strategies to get more production from cotton crop.