Boron and zinc inhibit embryonic development, hatching and reproduction of Meloidogyne incognita

Nematodes have difficult control and complex handling, but considering the physiological and biochemical changes that micronutrients promoting in plants, there is possibility that the supply with these chemicals increases the resistance of plants against nematodes. Thus, the present study aimed to assess the effect of the application of boron and zinc on the reproduction of Meloidogyne incognita, embryonic development and juvenile nematode hatching. Nematode reproduction was evaluated in tomato plant inoculated with 2000 eggs and treated in the aerial part with boron or zinc at the following doses: 0, 1/2, 1x, 2x and 4x the manufacturer's recommendation (100 and 30 g/L, respectively), with the plants assessed 60 days after inoculation. For assessment of embryonic development and juvenile hatching, 1 mL nematode suspension was placed in Petri dishes containing 9 mL of the same doses of boron and zinc, and assessment occurred four and eight days after incubation. Results obtained showed that boron controlled nematode population at the dose of 400 g/L and promoted juvenile hatching when used at maximum dosage on the eighth day. Zinc reduced the number of galls and the number of eggs at the dose of 60 g/L, but did not exhibit direct effect on nematode.