Occurrence of Late Blight (Phytophthora infestans (Mont.) de Bary) in Major Potato Growing Areas of Punjab, Pakistan.

A survey on the incidence and severity of late blight (Phytophthora infestans (Mont.) de Bary) of potato was conducted in the major potato growing areas of Punjab viz., Khushab, Sargodha, Sahiwal, Okara, Jhang and Chiniot districts during the cropping seasons of 2016-2017. A total of six districts comprising of three locations in each district were surveyed for the collection of late blight infected samples. During 2016 and 2017, prevalence of disease in all the surveyed districts ranging between 34.6-24.4% and 39.3-28.6% respectively with district Okara recording the maximum (39.3%) and district Jhang the minimum incidence (24.4%) for both the years. Similarly, disease severity ranging from 19.3-16.1% and 21.1-17.4% during the year 2016 and 2017 was recorded with Okara recording the maximum (21.1%) and Sahiwal the lowest blight severity (16.1%). The results clearly depicted that this disease is present in all the surveyed districts of the Punjab during both years with varying intensities. Moreover, disease incidence and severity seems to be varied from region to region and location to location depending on the prevailing environmental conditions, soil type, prevailing of different mating types and the vulnerability of the crop under plantation. [ABSTRACT FROM AUTHOR]