Effects of leaf removal and intercropping on the incidence and severity of black Sigatoka disease at the establishment phase of plantains ( Musa spp. AAB)

Two experiments in a high rainfall location of tropical west Africa investigated the effect of leaf removal and/or intercropping with a fast-growing, multi-branched cassava cultivar (TMA 30572) on the incidence and severity of black Sigatoka disease, caused by Mycosphaerella fijiensis Morelet, on young plantains ( Musa spp. AAB cv. ‘Agbagba’). Removal of older plantain leaves alone was not effective in reducing incidence and severity of the disease. However, at low to moderate cropping densities, 1600–2500 plants ha −1, removal of both the older leaves and middle position leaves (to retain four to six leaves per plant continuously) reduced disease incidence by 16% and severity by 10%. Leaf removal at the highest density studied (3333 plants ha −1) had no effect on disease incidence but reduced the severity by 18% when only four leaves were retained, and 13% when six leaves were retained per plant. Intercropping young plantains with cassava cultivar TMS 30572 reduced disease incidence and severity by 10%. Interaction of leaf removal (to retain four to six leaves per plant) and intercropping reduced disease incidence and severity by 23% and 25%, respectively, when compared with the monocropped plants with all leaves retained.