Termos para indexação: Glycine max, ameaça fitossanitária, Heliothinae, manejo integrado de pragas, praga invasora, tempo letal. Control of Helicoverpa armigera (Lepidoptera: Noctuidae) in soybean with chemical and biological insecticidesAbstract -The objective of this work was to evaluate the performance of insecticides authorized on an emergency basis to control of Helicoverpa armigera (Lepidoptera: Noctuidae) in soybean. Seven insecticides were sprayed on the field and, 24 hours after that, soybean pointer leaves were collected and offered to 2 nd instar larvae in the laboratory. Fourth instar larvae received the last trifoliate leaf that was fully expanded at the time of spraying. Another larvae group was exposed to leaves collected from 72 hours onwards after spraying. In the field, six insecticides were sprayed, and then the plants were infested with 2 nd and 3 rd instar larvae. In the first study, flubendiamide, chlorantraniliprole, chlorfenapyr, indoxacarb, and methoxyfenozide caused 100% mortality of the 4 th instar, eight days after the beginning of exposure, while baculovirus and Bacillus thuringiensis (Bt) caused 60-75% mortality, which reached 88-90% at the end of the pupal stage. For 2 nd instar larvae, only flubendiamide and chlorantraniliprole caused 100% mortality. Flubendiamide, chlorantraniliprole, and chlorfenapyr showed the lowest lethal time for the 4 th instar, and flubendiamide and chlorantraniliprole for the 2 nd instar. Seventy-two hours after spraying, the performance of insecticides was not satisfactory. In the field, there was satisfactory efficiency of flubendiamide, spinosad, baculovirus, and Bt on 2 nd and 3 rd instar larvae.
RESUMOA contaminação do solo com cobre tem se tornado comum em regiões de mineração e agrícolas pelo uso de fungicidas a base de cobre e aplicação de dejeto líquido de suíno ao solo, causando redução na produtividade das plantas. O trabalho objetivou determinar o efeito de doses de cobre no crescimento e qualidade de mudas de Barbatimão (Stryphnodendron polyphyllum Mart.) e Cássia (Cassia multijuga Rich.). O delineamento experimental foi inteiramente casualizado num fatorial (2 x 4), sendo as duas espécies florestais, e quatro doses de cobre: 0; 150; 300 e 450 mg kg -1 , com 10 repetições. Avaliou-se a altura de planta, diâmetro do colo, peso da matéria seca radicular e da parte aérea, comprimento e área superficial específica radicular, e os índices de qualidade de mudas: relação entre altura da parte aérea e diâmetro do coleto; altura da parte aérea e peso da matéria seca da parte aérea e o Índice de Qualidade de Dickson. Os resultados demonstram que as doses de cobre testadas não influenciam a qualidade de mudas da Cássia enquanto o Barbatimão mantém a qualidade de mudas até 300 mg kg -1 de cobre adicionado ao solo. O Barbatimão apresenta maior crescimento e qualidade de mudas que a Cássia em solo contaminado com cobre. Palavras-chave: espécies florestais; metal pesado; Índice de Qualidade de Dickson. ABSTRACTSoil contamination with copper has become common in the mining and agricultural regions by the use of copper-based-fungicide and application of liquid swine slurry to the soil, causing a reduction in plant productivity. Therefore, a study was undertaken to determine the effect of copper doses in growth and quality of Barbatimão (Stryphnodendron polyphyllum Mart.) and Cassia (Cassia multijuga Rich.) seedlings. The experimental design was completely randomized in a factorial (2 x 4) being the two forest species and four doses of copper: 0, 150, 300 and 450 mg kg -1 , with 10 repetitions. It was evaluated plant height, stem diameter, dry weight of shoot and root length and specific root surface area, and the quality indexes 1 Engenheiro Agrônomo, Dr., Professor
ABSTRACT:Euschistus heros is one the most important pest insect in soybean fields in Brazil. Therefore, site-specific management applied for controlling E. heros can result in economic and environmental benefits. However, sampling protocols for assessing spatialtemporal variability of this soybean pest and, then, for guiding a more sustainable pest management, were still unknown. Thus, the
During the application of pesticides on soybean fields, a vertical deposition gradient of the product can occur throughout the canopy, resulting in difficulties for controlling stink bugs that are in the middle and lower thirds of plants. This study aimed at evaluating the systemicity of thiamethoxam insecticide in different soybean phenological stages, using brown stink bugs as bioindicators of the pesticide efficacy. The study combined product application sites (lower, middle and upper third) and stink bugs infestation areas at five soybean phenological stages (R2, R3, R4, R5.2 and R6). For the R2 and R5.2 stages, plants presented acropetal translocation of the product, being the effect more evident in the R2 stage. For the R3, R4 and R6 stages, the product translocation was not sufficient for controlling the stink bugs. In all stages, for treatments with direct exposure (same infestation and spraying place), stink bugs were satisfactorily controlled.
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