Evaluation of banana cultivars for resistance to the banana weevil Cosmopolites sordidus and nematode complex in western Kenya.

摘要

Banana weevil Cosmopolites sordidus (Coleoptera: Curculionidae) and parasitic nematodes are often together on the same banana mat. Both pests have been recognized as major constraints to banana production. They may cause up to 85% yield loss in banana. Hence, both pests should be investigated together to define a control strategy for this complex constraint. With this view, our investigation was carried out in a naturally nematode-weevil infested farmer's field to search for host plant resistance to both pests. Pratylenchus goodeyi, Helicotylenchus multicinctus and Meloidogyne spp. were the most commonly occurring nematodes in the experiment and were often in mixed populations. The 19 Musa cultivars (6 AAA from East Africa, 3 exotic AAA, 3 AA, 2 AB, 3 ABB bananas, and 2 AAB plantains) significantly differed in their susceptibility to C. sordidus damage and their ability to tolerate nematodes. The East African Highland bananas and the plantains were more susceptible than other cultivars. The diploid AA bananas Njeru and Muraru were tolerant to both pests. However, their potential productivity (7-11 kg bunch-1) was relatively lower than that recorded in the East African bananas ( > 25 kg bunch-1). There was no correlation between nematode and weevil attack or with nematode populations.