Reactions of plantain and banana cultivars to black sigatoka leaf spot disease in three farming systems in the Nigerian guinea savanna

Abstract

An assessment of the severity of black sigatoka (BS), Mycosphaerella fijiensis, leaf spot disease on plantain and banana was undertaken in three farming systems in the Guinea savanna environment of Nigeria. The three farming systems were field sites, backyard sites and fadama sites. The plant crops cycle was divided into periods before flowering, at flowering and at harvest. Host response was measured throughout the stages of growth. Both symptom evolution time (Set) and incubation time (It) were faster after flowering than periods before flowering. The severity was significantly higher (p lt 0.05) in plantains and sweet bananas grown in outlying fields than in those in backyards and fadamas. At all the study sites, Bs was less severe on cooking bananas than on plantains and sweet bananas. Also, no significant differences were observed in Bs severity on cooking bananas grown in any of the three study sites, suggesting that the resistance is more of genetical than site effect. Thus, while breeding and genetic selection remain the most effective strategy against Bs, less disease develops on susceptible cultivars when they are cultivated on sites rich in organic matter.