Castor bean as an option for Meloidogyne incognita management in cotton

Abstract

This research aimed to evaluate management of Meloidogyne incognita in cotton (Gossypium hirsutum L.) using a rotation with castor bean (Ricinus communis L.), a potential cash crop. Reproduction of the nematode on castor bean in the greenhouse and effect of its planting on nematode populations on cotton in the field were tested. The effect of castor bean cake on nematode populations and its direct effect on cotton yield were also evaluated. Castor bean was a non-host to M. incognita in the trials. In addition, a preliminary field study showed that castor bean produced 1.2 t seed/ha when used in M. incognita infested areas, reduced populations of the nematode, and improved cotton productivity in the following season. Castor bean cake also reduced M. incognita populations. However, castor bean cake cannot be applied at doses above 100 kg/ha in the cotton planting furrow due to a phytotoxic effect on the crop. The most appropriate rate was 60 kg/ha applied to the furrow, decreasing in the nematode population at 80 days after planting and gall index as well as increasing cotton yield.