Uso de cultivares resistentes e fungos nematófagos no manejo de Meloidogyne enterolobii em alface

Abstract

The root-knot nematodes (Meloidogyne spp.) are among the most important pathogens of lettuce (Lactuca sativa L.).The control of these organisms is difficult and the use of nematicides is not recommended for short cycle crops. Alternative methods that do not harm the environment, are the most suitable, especially the use of resistant varieties and biological control. In this study, we sought to evaluate the reaction of lettuce cultivars and the effect of Paecilomyces lilacinus and Pochonia chlamydosporia on Meloidogyne enterolobii. Eighteen lettuce cultivars were inoculated with 5000 nematode eggs in completely randomized design with 10 replications. Thirty days after the plants were evaluated for levels of galls, number of eggs and reproduction factor. In the verification of the effect of nematophagous fungi are incorporated in pots containing autoclaved soil dosages of 5 and 10 g rice not colonized and colonized with P. lilacinus and P.chlamydosporia then infested 5000 eggs infested with M. enterolobii. The experiments were conducted in a 2x5 factorial arrangement with 8 repetitions, two lettuce cultivars susceptible and five different treatments.The concentrations of inoculums the P. lilacinus and P. chlamydosporia were 4,3x 108 and 4 x 106 conidia / g rice, respectively. According to results as plants were a evaluated 30 days, as the reproduction factor. The lettuce cultivars ‘Lídia’, ‘Crespa de Verão’, ‘Isabela’, ‘Angelina’, ‘Mônica’, ‘Vanda’, ‘Regiane’, ‘Grand rapids-TBR’, ‘Mimosa’ and ‘Babá de Verão’ (Feltrin); behaved as resistant and the other behaved as susceptible to nematodes.The two fungi were effective in controlling nematodes in the dosages used, reducing the reproduction factor to values less than 1.0