Plantas de cobertura no controle de Meloidogyne incognita e Meloidogyne javanica

Abstract

Second the plants used in the inter-harvest season to produce straw, you can maximize or decrease the soil phytomatoid population. In this context, the objective of this study was evaluate the use of different cover crops in the population control of Meloidogyne sp., at field and in the green house, to help to choose what crop adopt in the rotation to decrease the population of the phytonematoids. Three experiments were developed, one on the field at the horticulture sector of the Instituto Federal do Triângulo Mineiro- Uberaba Campus and the others two in a greenhouse at the Universidade Federal de Uberlândia - Umuarama campus. All experiments had a completely randomized experimental design. The experiments installed in the greenhouse had six replicates, in one seven cover plants were tested about the control of Meloidogyne incognita: 1- Crotalaria juncea; 2- Estilosante; 3- Millet; 4- Wheat; 5- Black Mucuna; 6- Soybean var. NA 5909 RG with chemical seed treatment with nematicide; 7- Witness (Soybean NA 5909 RG without chemical seed treatment). In the other, nine cover plants were tested about the control of Meloidogyne javanica: 1- Crotalaria juncea; 2- Pigeon pea; 3- Millet; 4- Wheat; 5- Black Mucuna; 6- Canola; 7- Mustard; 8- Soybean var. NA 5909 RG with chemical seed treatment with nematicide; 9- Witness (Soybean NA 5909 RG without chemical seed treatment). The seedss were sown in pots and inoculation of the phytonematoids was carried out 14 days after sowing with 2000 eggs. pot-1 of M. incognita in one experiment and 5000 eggs. pot-1 of M. javanica in the other. The final nematode population was evaluated 60 days after inoculation, all roots and 150 cm3 of soil were collected from each pot. On the field, four different coverages were evaluated regarding the population control of phytonematoids in the infested area: 1- Crotalaria juncea; 2- Millet; 3- Soybean var. NA 5909 RG with chemical seed treatment with nematicide; 4- Fallow (spontaneous vegetation), with 5 replications. In this study the production of dry biomass (BS) in areas of 2 m2 per plot was evaluated, and soil and root samples were collected to evaluate the population of the phytonematoids at 45 and 90 days after seeding. On the field, crotalaria and millet got the highest BS, and were the most efficient plants in the population control of M. incognita. In greenhouse all the cover plants were resistant to the nematoid that had been tested, except for the canola, that was susceptible to M. javanica. There was no difference in the reproduction factor of the cover plants in relation to M. incognita, and as for M. javanica the crotalaria, the millet and the mucuna obtained the smaller ones. The chemical treatment and the control were susceptible to both phytonematoids