SUPPRESSION OF THE ROOT-KNOT NEMATODE (MELOIDOGYNE SP.) WITH CHEMICAL-ORGANIC PRODUCTS IN ONION CROP.

Abstract

The management of root–knot nematodes is a complex process in any farming system of susceptible plants, since most of the products not fumigants do not have current registration for vegetables. In the last five years, very promising results were obtained with the application of fluensulfone, a product of the fluoroalkenyle group, and offering a replacement alternative to the traditionally used chemical nematicide and generate high detrimental impact over the environment and human health. We evaluated three doses of FSF (175, 2.0 and 2.25 L / ha), one of fenamiphos (7.0 L / ha) and untreated plants were included as controls. All treatments were established under a design of complete blocks with three replications randomly. The fluensulfone in doses of 2 to 2.25 L significantly reduced populations and damage caused by Meloidogyne sp. 60 DAS, plots treated with FSF in doses of 2 to 2.25 L.ha-1 and fenamiphos (7 L.ha-1) showed lower damage with 6.33-9.00% of damping on average, reducing the damping in onion plants by more than 260%. The dose of 1.75 FSF L.ha-1 reduced the damage in a 114% compared to control plants. Commercial bulbs production was greater in plots treated with FSF (2.0-2.25 L.ha-1) and fenamiphos (7 L.ha-1) with 5.9, 6.0 and 5.9 kg.m-2, increasing performance by 11-14% relative to the control, respectively. The main advantages of the FSF is that it acts as a true nematicide, its control effect can last up to 60 days with low populations, is applied through the irrigation system prior to planting, and is not phytotoxic at the crop if it is applied following the instructions on the label.