Pink Disease Caused by Erythricium salmonicolor (Berk. & Broome)Burdsall: An Epidemiological Assessment of its Potential Effect on Cocoa Production in Ghana

Abstract

Pink disease caused by Erythricium salmonicolor (Berk. & Broome) Burdsall has been reported on Theobroma cacao, L (cacao) in Ghana for many years but has not been studied in detail. During an epidemiological assessment of the potential effect of the disease on cocoa production in the Western region of Ghana, the disease was found on 393 out of 25,600 cacao trees inspected and on 46 out of 128 farms surveyed. Typical symptoms of pink disease were observed on infected branches and four different growth forms, cobwebby, pink to salmon encrustation, creamy pustules and orange fruiting bodies were identified. Based on the symptoms in the field, microscopic examination of the fruiting bodies and pathogenicity tests, all the isolates were identified as E. salmonicolor, Berk. & Broome. Generally, pink disease significantly (p<0.05) reduced cocoa pod production but the reduction was more pronounced in the canopy (8.6 pods/tree) than on the trunk (6.7 pods/tree). Reduction in pod production also increased with increase in disease severity. Differences were observed in disease control with the different fungicides evaluated but Kocide 2000 DF proved most effective in controlling the disease. Pink disease is potentially important on cacao in Ghana, and this study provides a foundation for further research on the disease.