Management of Lasiodiplodia theobromae, the causal agent of mango tree decline disease in Ghana

Abstract

Mango (Mangifera indica L.), is one of the economically most important crops in Ghana. It is recognised for its popularity in contributing to food and nutritional security. Despite its economic importance, mango tree decline disease, caused by Lasiodiplodia theobromae, poses a serious threat to the mango industry in the country. The objective of this study was to evaluate fungicides (i.e., carbendazim, zamir, mancozeb, funguran and sulphur 80) and bio pesticides (Chromolaena odorata, Azadirachta indica and Carica papaya) against L. theobromae. The results showed that all the tested fungicides, except for sulphur 80, inhibited mycelial radial growth of L. theobromae, with carbendazim and funguran improving the vegetative growth of the shoots and leaves in the field. Mango trees treated with carbendazim, after the third spray, had no disease symptoms. However, application of urea fertiliser and carbendazim (50 g 15 L-1 water), at a two-week spraying interval in the field, reduced the severity of L. theobromae. Application of biopesticides (plant extracts) showed that C. odorata had the highest efficacy, followed by A. indica and then C. papaya. Although further studies on plant extracts in the field are required, our findings provide important information for the development of integrated management strategies for the pathogen, and the disease it transmits.