Investigations on integrated control of witches’ broom disease off cocoa in Rondonia State, Brazil

Abstract

Abstract Investigations were conducted in Rondonia State, Brazil, for two years to evaluate the effectiveness of integrated control involving phytosanitation and fungicide sprays in reducing pod losses due to witches’ broom disease of cocoa (Theobroma cacao L.) caused by Crinipellis perniciosa (Stahel) Singer. The fungicides tested were cuprous oxide, tebuconazole and tank mixtures of cuprous oxide with tebuconazole or chlorothalonil. All fungicide treatments significantly reduced the incidence of pod disease in both years. However, use of integrated measures clearly exerted more disease control than fungicide use alone. None of the formulations tested protected the vegetative shoots from infection. Cuprous oxide was seen as the fungicide most likely to be adopted for commercial use. The results are discussed with suggestions for further investigations on chemical control of witches’ broom disease.