Effects of Meloidogyne incognita on growth and storage-root formation of cassava (Manihot esculenta)

Two-node cuttings of cassava cultivar SS4 were inoculated with 1,000 infect ive juveniles of Meloidogyne incognita at 1, 14, 40, 70, 88, and 127 days a fter planting (DAP). Plant growth and root damage were assessed at 150 DAP. Meloidogyne incognita significantly reduced the number of storage-roots fo rmed in plants inoculated at 14, 40, 70, and 88 DAP and the total weight of storage-roots in plants inoculated at 1, 14, 40, 70, and 88 DAP, compared to uninoculated plants. Individual storage-root weight and plant height wer e not affected by M. incognita. Storage-root formation in cassava is initia ted when plants are 1 to 2 months old. The results of this experiment indic ate that, at this time, young cassava plants are most prone to root-knot ne matode damage in terms of storage-root formation. The production loss cause d by M. incognita to young SS4 plants was due to a reduction of storage-roo t number rather than a reduction in individual storage-root weight.