Standard Operating Procedure (SOP) for screening for resistance to Black Sigatoka (P. fijiensis) in Bananas

Abstract

Banana, and especially the cooking type known as East Africa highland banana, is a vital staple food and income crop for over 80 million people in East Africa. However, productivity has been declining, partly due to diseases such as Sigatoka leaf diseases. Sigatoka disease of banana is caused by fungi of the genus Pseudocercospora (previously called Mycosphaerella). Species associated with Sigatoka disease include; P. fijiensis, causal agent of black Sigatoka, P. musicola of yellow Sigatoka (Irish et al., 2006) and P. eumusae of Eumusae leaf spot (Carlier et al., 2000; Chang et al., 2016). Yellow Sigatoka symptoms are characterised by oval to round necrotic lesions, which first appear pale yellow on the lower surface of the leaf, and this differentiates it from black Sigatoka at early stages of lesion development. Damage is manifested as necrotic leaf lesions that reduce the functional leaf area and photosynthetic capacity, resulting in reduced crop yield and fruit quality leading to banana yield losses ranging from 20-50% (Carlier et al., 2000). Use of resistant cultivars is the most effective and sustainable solution to manage sigatoka. Therefore, screening of banana genotypes for resistance to black sigatoka is crucial for breeding programs to identify and develop resistant cultivars of bananas