Development of Meloidogyne exigua Goeldi, 1887, in coffee roots under three environmental conditions

Abstract

Coffee seedlings (Coffea arabica L.) cv. Mundo Novo showing a single pair of leaves were transplanted to pots containing 250 ml of soil. After 30 days, the pots received 600 second stage larvae and were transferred to different environmental conditions, namely a greenhouse, a constant temperature room and a coffee field. Roots collected every two days were stained and dissected for classification of the developmental stages of the nematodes found in. Results showed that Meloidogyne exigua was influenced by temperature, requiring from the penetration of pre-parasitic larvae to egg-laying female stage, 25.3 days at the mean temperature of 25.8°C in the greenhouse, 37.3 days at 22.1ºC in the room, and 38 days at 22.4°C in the coffee field. The minimum threshold temperature for development of this species was found to be 15°C in this experiment. The mean of 6,580 centigrade hours above 15°C was necessary for M. exigua to complete its development.