EFFECT OF ORGANIC MANURE IN THE CONTROL OF ROOT KNOT NEMATODE IN GREENHOUSE LETTUCE

This research was carried out aiming to evaluate the effect of organic manure in the control of root knot nematodes in lettuce cv. Veronica. Organic cattle and chicken manure were evaluated. They are both used for vegetable production in the region. The experiment was carried out at Biology Experimental Station, University of Brasilia, from July to November 2008. The experiment was carried out in 3 L plastic pots in subdivided parcels with 4 pots per parcel, in a total of 120 parcels in four replicates. Parcels were represented by M. incognita (races 1 and 3) and M. javanica. The subparcels were represented by fertilization treatments: 1 - control (no fertilization); 2 - 1,5 kg.m(-2) of NPK 4: 30: 16; 3 - 1,5 kg.m(-2) of cattle manure; 4 - 3,0 kg.m(-2) of cattle manure; 5 - 4,5 kg.m(-2) of cattle manure; 6 - 6,0 kg.m(-2) of cattle manure; 7 - 0,6 kg.m(-2) of chicken manure; 8 - 1,2 kg.m(-2) of chicken manure; 9 - 1,8 kg.m(-2) of chicken manure and 10 - 2,4 kg.m(-2) of chicken manure. The nematode inoculation was performed 15 days after transplanting with 5.000 nematode eggs per vessel. Fresh and dry matter weight per plant and fresh root weight, gals' number and egg mass the root system were evaluated. Meloidogyne javanica was less affected in its biological characteristics showing to be more aggressive to the plant compared to the others. Meloidogyne incognita r 1 and 3, on the other hand, were more susceptible to cattle manure, an indication that this type of fertilization can present a suppressive effect over this particular specie of nematodes. Cattle manure doses that had supressive effect on nematodes were 4,5 kg.m(-2) for M. javanica and 3,0 kg.m(-2) for M. incognita. These doses also increased yield.