Effect of soil solarisation and mouldboard ploughing on black dot of potato, caused by Colletotrichum coccodes

Preplant soil solarisation and mouldboard ploughing to a depth of 30 and 60 cm respectively were evaluated in two held experiments for the control of Colletotrichum coccodes causing black dot of potato. Solarisation reduced d isease incidence by 45% when tarping was done for eight weeks and temperatu res reached 56 degreesC in the top 5 cm of soil. With a six week tarping pe riod and lower maximum temperature (50 degreesC) the reduction in disease w as a non-significant 25%. Mouldboard ploughing to a depth of 30 cm reduced black dot by 34% and was twice as effective as ploughing to a depth of 60 c m.