CONTROLE QUÍMICO DO NEMATOIDE DE GALHA, Meloidogyne spp. NA CULTURA DA BATATA

Abstract

Among the main diseases that affect the potato, nematodes have been causing great concern in the cultivation fields due to the wide dissemination and high aggressiveness. Nematodes of the Meloidogyne genus are the most important for vegetables, including potatoes. Currently, the main management used for phytopathogenic nematodes control is the chemical environment. The lack of new molecules, less toxic and efficient in the market, was the motivation of the present study. Thus, the objective was to evaluate the effect of a molecule that is in the RET III (Temporary Special Registration) phase in different doses applied in the planting furrow for Meloidogyne spp. Control in potato plants. For the experiments, two products were used: Rugby, which is a commercial agrochemical registered for the crop and RET, which is in the testing phase. Five treatments were used, alternating the doses and products applied in the furrow and the treatment of absolute control, which is, without nematicide. The treatments are summarized as follows: T1: RETIII dose of 1.0 l ha-1, T2: RETIII dose of 1.5 l ha-1, T3: RETIII dose of 2.0 l ha-1, T4: RETIII dose of 2.5 l ha-1, T5: RETIII dose of 3.0 l ha-1. T6 RUGBY 100 GR dose of 30 l ha-1 and T7: without nematicide. From these, phytotoxicity, vigor, presence of galls, identification and nematode count in the roots and tubers and, finally, the final yield of the potato in each treatment were evaluated. The data were submitted to analysis of variance and the means compared by the Tukey test to the (P≤0.05) probability using the Sisvar version 5.6 program. The percentage of control efficiency was calculated using the ABBOTT Formula (1925): E% = t-p / t * 100 (t - control and p - treatment). It was found that the nematicide (RET) being applied by spraying in the planting furrow over the tubers, from the dose of 1500 mL p.c. ha-1 was efficient in the control of the gall nematode (Meloidogyne javanica) in potato culture. The product under test and RUGBY 100 GR did not cause phytotoxic effects on the plants of the potato crop, in the doses and application mode tested in this experiment, indicating that they are selective and safe to the crop.