CONTROLE DE Helicoverpa armigera EM FRUTOS DE TOMATE DO TIPO INDUSTRIAL POR MEIO DE QUÍMICOS SINTÉTICOS

Abstract

The incidence of insects and pathogens is still a major phytosanitary obstacle for tomato plants for industrial processing. The danger with Helicoverpa armigera (Lepidoptera: Noctuidea) is latent because plants that precede tomato in time, such as soybeans and corn, are also hosts of this pest. Chemical control method is still the one with the best operational and efficiency against insect pests in open field environments. However, new molecules need to be continually evaluated rather than being launched. The objective of this study was to evaluate the protective capacity against the tomato fruit borer by the product recently launched on the Brazilian market plinazolin (isocycloseram) (in a factory mix with emamectin benzoate), in two doses, through foliar sprays on tomato plants for industrial processing in comparison with the main insecticides registered by MAPA and used for this purpose. The experimental design was in randomized blocks with eight treatments and four replications. The treatments were: (T1) absolute control (water only), (T2) plinazolin+emamectin benzoate at a dose of 150 ml ha-1, (T3) plinazolin+emamectin benzoate at a dose of 200 ml ha-1, (T4) lufenuron+emamectin benzoate, (T5) spinetoram, (T6) chlorfenapyr, (T7) indoxacarb and (T8) cyantraniliprole+abamectin. The Helicoverpa armigera population was quantified through fruits bored at 58, 65, 72, 79, 86, 93, 100, 107 and 114 DAT (days after transplanting). Helicoverpa armigera was more abundant, representing around 98% of the samples, Tuta absoluta (Lepidoptera: Gelechiidae) represented 2% and Neoleucinodes elegantalis (Lepidoptera: Crambidae) had zero occurrence. The plinazolin+ (150 ml ha-1) and plinazolin+ (200 ml ha-1) treatments both represented average values of 1.25% boring fruits, with this value representing 3.2 times less than that tolerated by processing agro-industries. The tomato fruit borer attack was earlier in the control at 65 DAT (days after transplanting) at the control treatment. In the spinetoram and cyantraniliprole++ treatments, the onset of attacks on the fruits occurred after 86 DAT. Chlorfenapyr and indoxacarb protected fruit from borer up to 93º DAT and lufenuron+ from 100º DAT. In plots with plinazolin+ (150 ml ha-1) and plinazolin+ (200 ml ha-1), tomato fruits only showed damage from 107 DAT onwards. The percentage of bored fruits in the control reached peaks of more than 40%. In the treatments lufenuron+, spinetoram, chlorfenapyr, indoxacarb and cyantraminiliprole++ peaks between 20% and 15% of boring fruits. While in the plinazolin+ (150 ml ha-1) and plinazolin+ (200 ml ha-1) treatments the percentage of bored fruits did not exceed 5%. Our results suggest that isocicloseram can become an important phytosanitary management option against H. armigera by foliar spraying to tomato plants for industrial processing.