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

Andrews Y Akrofi

doi:10.4172/2157-7471.1000215

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.

Highlights

The worldwide threat to cocoa production from the major cacao pests and diseases continue to overshadow other problems of local or sporadic importance
Pink disease incidence ranged from 0.5% in the Wassa Amenfi West (Amw) district to 4.9% in the Juaboso (Jua) district (Table 1)
The disease was not found in Aowin (Aow), Mpohor/Wassa East (Mpe), Tarkwa/Prestea/Huni Valley (Tph) and Akontombra (Ako) districts indicating that pink disease is more prevalent in the eastern part of the Western region (Figure 1)

Summary

Introduction

The worldwide threat to cocoa production from the major cacao pests and diseases continue to overshadow other problems of local or sporadic importance. & Broome, Jűlich) has been known on cacao for many years [1], but has only been studied in detail as a pathogen of rubber [2]) and Eucalyptus spp. The host plants of economic importance include rubber, tea, coffee, cocoa, grapefruit, orange, nutmeg, mango, apple, coca and kola. In New Guinea and Malaysia, pink disease is associated with cover crops and shade trees such as pigeon pea (Cajanus cajan) and Crotalaria, Tephrosia, Leucaena and Gliricidia [6,7,8,9]

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