Manejo integrado do Nematoide-das-galhas na cultura da alface

Abstract

The objective of this study was to evaluate the effect of revolving soil combined with irrigation, associated or not, with the addition of cattle manure or soil solarisation on the management of the root knot nematode in lettuce, in a greenhouse and in the field. Firstly, a field trial was conducted in an area naturally infested by Meloidogyne incognita, with the following treatments: revolved and irrigated soil; revolved and irrigated soil + cattle manure; revolved and irrigated soil + solarisation; and a control (fallow soil). All the treatments were setup 14 days before transplanting the lettuce seedlings. The initial and final nematode populations were also determined. Fifty-one days after transplanting the lettuce seedlings, two plants were collected from each experimental unit to evaluate head diameter, fresh shoot weight, fresh root weight, number of galls and of nematode eggs per lettuce plant root system. In the revolved and irrigated soil + solarisation treatment, the population reduction was 43.4%.Two other trials were conducted in a greenhouse. The treatments tested were the same as in the field trial, plus a second control treatment. Each experimental unit consisted of a pot, containing soil naturally infested by M. incognita, taken from the same location the field trial was setup. However, in the second control treatment, the soil used in the pots was collected on the same day as the lettuce seedlings were transplanted. The evaluations were the same as in the field trial, except when determining the final nematode population, which was performed forty-seven days and sixty-six days after the lettuce was transplanted, in trials 1 and 2, respectively. In the field trial, an 89.1% reduction in the final population of J2 M. incognita was observed in the soil, in relation to the initial population, for the revolved and irrigated + cattle manure treatment. In the greenhouse, in both trials, the treatments revolved and irrigated soil, revolved and irrigated soil + solarisation and the control (fallow soil) reduced the number of galls and eggs per lettuce plant root system by more than 80%, when compared with the control (soil collected on the day the seedlings were transplanted). Integrated management is efficient at controlling the root knot nematode.