Hot Pepper Reaction to Field Diseases

Diseases are major constraints to hot pepper (Capsicum annum L.) production in sub-Saharan Africa. The search for cultivars resistant to the major diseases of hot pepper has been limited. This study was conducted in Uganda to evaluate exotic and local hot pepper genotypes for disease resistance. Viral diseases and Cercospora leaf spot were the most predominant and severe, followed in descending order by anthracnose, Phytophthora blight and wilt diseases. Highly significant genotypic differences (P<0.001) existed in most scored disease traits. There was no genotype resistant to field diseases of interest in this study; however, a few cultivars exhibited resistance to two or more disease infections. The Asian Vegetable Research and Development Centre (AVRDC) genotype 12 (PP97-7195-1) was exceptionally resistant to fungal and bacterial diseases, but moderately resistant to viral diseases. Highly significant genotype by season (P<0.001) interactions were observed for both disease incidences and severity indices, except for Phytophthora blight severity index. Field disease correlation stability analysis across seasons indicated significant virus and Phytophthora blight severity indices implying some stability in these scores across seasons with virus severity index being the most consistent scored disease trait. Anthracnose incidence and severity contributed more to yield loss.