SCREENING OF IMPROVED AND LOCAL CULTIVARS OF POTATO FOR RESISTANCE TO POTATO LATE BLIGHT DISEASE (Phytophthora Infestans)

Abstract

Potato late blight disease caused by Phytophthora infestans has become an economic disease in the world and particularly in potato growing regions of Cameroon. Four improved (Pamina, Sassy, Desiree, Diaman) and two local (Belo, Banso) cultivars of potatoes were screen in the field and screen house in Regional College of Agriculture and Catholic University laboratory for resistance to potatoes late blight disease (PLBD). These potatoes cultivars were planted on four ridges per plot in the field in randomized complete block design with three replicate. These cultivars were monitored for disease incidence and severity and data was collected. Potatoes cultivars were planted in a screen house and inoculated with spore suspension of P. infestans of 2.5×104 spores / ml of distilled water to evaluate the resistance of the various potatoes cultivars. Screen house and field screening showed significant varietal difference (P≤0.05) in sensitivity to the fungus. The improved and local cultivars of potatoes from field and screen house show varying levels of resistance to (PLBD). All the improved potatoes cultivars (Pamina, Sassy, Desiree and Diaman) were highly susceptible to (PLBD) compared to the local cultivars (Belo, Banso) and improved cultivar Desiree that were susceptible. The highest mean disease severity of (PLBD) of 5.0 % was recorded on cultivars, Pamina, Sassy and Diaman at 12 weeks after planting. Diaman recorded the highest mean area of (PLBD) growth of 11.45 m2 in the screen house experiment. The local and improved potatoes cultivars that were susceptible could be planted in the field by farmer to reduced disease incidence and severity and increase productivity of the crop.