NEMATICIDAS NO MANEJO DE NEMATOIDES NA CULTURA DA SOJA

Abstract

The phytonematoids Heterodera glycines and Pratylenchus brachyurus have been causing severe damage to soybean crop worldwide. Thus, control methods have been studied in order to find solutions that integrate with nematode management. Therefore, the present work aimed to evaluate the performance of chemical molecules and biological agents with nematicidal effect in the control of H. glycines and P. brachyurus nematodes in soybean under naturally infested field conditions with mixed population. The trial was conducted in Ipameri - Go, Brazil, in the 2018/19 crop under rainfed conditions and naturally infested field. The experiment was arranged in a randomized block design with eleven treatments and four replications: T1- Witness, T2- Abamectina (Avicta), T3- Cadusafós (Rugby), T4- Imidacloprido + Thiodicarb (Cropstar), T5- Fluensulfone (Nimitz), T6- Paecilomyces lilacinus + Trichoderma harzianum (Nemat + Ecotrich), T7- Pochonia chlamydosporia (Rizotec), T8- Bacillus subtilis + B. licheniformes (Presence), T9- B. amyloliquefaciens + T. harzianum (NemaControl) + (StimuControl), T10- Pasteuria nishizawae (Clariva), T11- B. methylotrophicus (Onix). An initial soil population was evaluated at 40, 60 and 90 DAS, in which root fresh mass (MFR), H. glcyines females/g root, eggs/female, cyst/100cm3 were evaluated of soil, P. brahyurus/10g of root and productivity. Data were subjected to analysis of variance and means compared by the ScottKnott test at 5% significance. Fresh soybean root mass was not influenced by the treatments used. Abamectina expressed a rate of reduction in the amount of females and H. glycines cyst at 60 and 90 DAS. Cadusafós and B. methylotrophicus presented a reduction rate in the number of females/g of root at 40, 60 and 90 DAS. Cadusafós also promoted a reduction in the number of eggs/female at 60 and 90 DAS at 12.1 and 12.4%, respectively. P. lilacinus + T. harzianum, Pochonia clamydosporia and B. methylotrophicus showed a reduction rate of P. brachyurus in the root over the analyzed periods. Pasteuria nishizawae and B. methylotrophicus promoted yield increases of 20.3 and 24.7% compared to control, equivalent to 4.7 and 5.8 more soybean bags per hectare.