Agriculture, Aquaculture and Fisheries - A Simple Technique to Test for the Presence of Phytophthora erythroseptica in Soil

Abstract: Pink rot, caused by Phytophthora erythroseptica, is one of the most important potato tuber diseases worldwide. A simple, cost-effective technique was developed to test for the presence of P. erythroseptica in soil. Positive (vermiculite and sterilized field soil mixed with P. erythroseptica inocula) and negative (vermiculite and sterilized field soil free of P. erythroseptica) controls were included. A hole, 5 mm wide and 20 mm deep, made at the stem end of disease-free, surface sterilized potato tuber was filled with 1 g of soil and then sealed with the part of the removed core. Tubers were incubated in moist chambers at 10 °C and 95% relative humidity. Three weeks later, when tubers were longitudinally cut and exposed to air for 30 minutes, positive controls showed pink-black flesh discoloration. When tested, P. erythroseptica was recovered from infected tissues. Negative controls did not yield any symptoms. This simple technique can be used to identify P. erythroseptica infested fields in three weeks' time.