Efeito Fisiológico Do Inseticida Thiamethoxam Na Cultura Da Cana-De-Açúcar

Abstract

RESUMO Com a finalidade de avaliar o efeito fisiológico de thiamethoxam no desenvolvimento inicial de plantas de cana-de-açúcar, foram realizados dois experimentos. O primeiro conduzido em caixas plásticas do tipo gerbox (3,5 x 11 x 11 cm) contendo substrato, aplicou-se thiamethoxam em toletes de cana-de-açúcar, nas doses: 0, 100, 150 e 200 g de ingrediente ativo (i.a.).ha-1. O segundo experimento foi realizado em tubos de PVC (0,2 x 1,20 m), preenchido com solo, utilizaram-se seis doses de thiamethoxam (0, 50, 100, 150, 200 e 250 g i.a.ha-1) em mudas de duas variedades (RB867515 e SP80-1816). Avaliou-se a parte área e o sistema radicular das plantas aos 30 dias após a aplicação do inseticida, no primeiro experimento e aos 130 dias no segundo. Observou-se que no primeiro experimento as características altura, diâmetro e massa seca da parte área não foram alterados em razão da aplicação do inseticida nos toletes de cana-de-açúcar, porém, nos tratamentos com thiamethoxam houve um incremento na massa seca das raízes de até 3,7 vezes mais. No segundo experimento, thiamethoxam proporcionou aumento no diâmetro das plantas e incremento na massa seca das raízes da variedade RB867515 de até 72,69%. No entanto, o comprimento do sistema radicular e a massa seca da parte aérea não foram alterados pela aplicação do inseticida nas mudas.

The effects of thiamethoxam on coffee seedling morphophysiology and Neotropical leaf miner (Leucoptera coffeella) infestations

“…However, Castro's findings were not observed in the present study, where higher thiamethoxam concentrations compromised plant development. Thiamethoxam produced a deleterious effect on the coffee plants studied, which is consistent with the results of several previous studies 29,43,44,47–49 …”

“…Thiamethoxam produced a deleterious effect on the coffee plants studied, which is consistent with the results of several previous studies. 29,43,44,[47][48][49] Thiamethoxam protects coffee plants against leaf miner infestation up to 150 days after application, 25 which was also verified by the present study. Coffee leaf damage caused by leaf miners reduces leaf area and causes leaf fall, thereby decreasing photosynthetic activity and productivity.…”

“…23,24 In coffee, there were morphological changes 25 resembling the effects of the plant regulators used during the initial growth stage. [26][27][28] However, studies on the plant-stimulating properties of thiamethoxam and its relationship with insects are generally lacking, 29 as researchers usually emphasize the morphophysiological changes observed in plants treated with thiamethoxam. [30][31][32][33] Thus, this article will focus on thiamethoxam's potential as a bioactivator for such plants as coffee.…”

Equine allergic skin diseases: Clinical consensus guidelines of the World Association for Veterinary Dermatology

“…The authors concluded that filarial larvae could elicit a response and only in animals with some predisposing susceptibility. 16 At least part of the controversy and mystery of what caused this pruritic skin disease in horses was eventually resolved by Riek who did not find microfilaria in Australian horses suffering from 'Queensland Itch'. 17 Building on the observations of Bancroft 5 that Queensland itch was associated with biting flies, Riek demonstrated positive allergic reactions to intradermal skin tests with Culicoides robertsi antigens, and went on to show that sensitivity could be transferred passively to the skin of unaffected horses by a heat labile serum antibody.…”