EFFECT OF GUMMOSIS CAUSED BY PHYTOPHTHORA SPP. ON LEAF AREA AND TRUNK SIZE OF CITRUS IN DISTRICT SARGODHA, PAKISTAN

Abstract

Gummosis disease of citrus, caused by Phytophthora spp. is one of the most devastating diseases of citrus in Pakistan. Considering the menace of this disease, the present study was conducted to determine the disease incidence and its effect on the trunk size and leaf area of affected plants. A comprehensive survey was conducted in 75 citrus orchards in 3 tehsils (Sargodha, Bhalwal, and Kot Momin) of the district Sargodha for the prevalence of the disease. The diseased plants were marked from each orchard, trunk size was measured and leaf area was recorded using leaf area meter. The leaves from diseased plants of tehsil Sargodha showed the highest leaf area with an average of about 2685 mm2 followed by Bhalwal 2548 mm2. There was a huge difference in the trunk size of healthy and diseased trees. The highest average healthy trunk size (102 cm) was recorded in Kot Momin while the diseased trunk in Bhalwal was found 9 cm in size. Healthy leaf area and trunk size were not significantly different from tehsil to tehsil, but diseased trees were significantly different from each other at P0.05. Gummosis is a widespread disease in citrus growing areas and continues to gain importance as a constraint in citrus production. Therefore, concerted efforts should be implemented towards educating farmers and extension personnel about the disease's spread and management.