Seletividade do herbicida saflufenacil a Eucalyptus urograndis

Abstract

RESUMO -As áreas com plantios florestais estão constantemente em expansão, e a interferência das plantas daninhas alteram o crescimento e desenvolvimento de plantas de eucalipto, pois estas competem por água, nutrientes, espaço e luz. Objetivou-se com este estudo avaliar a seletividade do herbicida saflufenacil, aplicado com e sem óleo mineral Dash, em plantas de Eucalyptus urograndis, em diferentes locais de aplicação (planta, solo e solo + planta). O delineamento experimental adotado foi o inteiramente casualizado, com quatro repetições, constituído de um fatorial 3 x 11, sendo três locais de aplicação do herbicida na planta e 11doses do herbicida saflufenacil combinadas ou não com o adjuvante Dash. Cada parcela constou de um vaso com uma planta. Os tratamentos usados foram: 0, 25, 25+Dash (0,5% v/v), 50, 50+Dash (0,5% v/v), 75, 100, 125, 150, 175 e 200 g i.a. ha -1 . Foram realizadas avaliações visuais de fitointoxicação durante 56 dias após aplicação (DAA). Avaliouse, ainda, a altura, o diâmetro de caule e a biomassa seca das plantas. Todas as doses testadas de saflufenacil sem adjuvante mostraram-se seletivas às plantas de E. urograndis, independentemente do local de aplicação. A adição de Dash aos tratamentos proporcionou injúrias severas às plantas nas avaliações iniciais, quando aplicado sobre as plantas, com a recuperação total destas no fim do ensaio, aos 56 DAA. A aplicação do herbicida em mistura com adjuvante somente no solo não causou intoxicação às plantas de eucalipto.Palavras-chave: controle químico, eucalipto, fitotoxicidade, local de aplicação.ABSTRACT -Forest plantation areas are constantly expanding. However, weed interference affects the growth and development of eucalyptus plants, as they compete for water, nutrients, space, and light. The objective of this study was to evaluate the selectivity of the herbicide saflufenacil, applied with or without the mineral oil Dash, on Eucalyptus urograndis at different application sites (plant, soil and soil + plant). The experimental design was completely randomized, with four replications, consisting of a 3 x 11 factorial, with three sites for herbicide application on the plant and eleven saflufenacil doses combined or not with the adjuvant Dash. Each plot consisted of a vase with a plant. Treatments were 0, 25, 25 + Dash (0.5% v/v), 50, 50 + Dash (0.5% v/v), 75, 100, 125, 150, 175 and 200 g a.i. ha -1 . Visual evaluations of plant intoxication were carried out for 56 days after application (DAA). Height, stem diameter, and dry biomass of the plants were also evaluated. The saflufenacil doses tested without adjuvant proved to be selective for the plants of E. urograndis, independent of the application site. The addition of Dash to the treatments caused severe injuries to the plants at the initial assessments, when applied on the plants, with full recovery at the end of the test at 56 DAA. Herbicide application combined with the adjuvant only in the soil did not cause plant toxicity to the eucalyptus plants.

DESENVOLVIMENTO INICIAL DE MUDAS DE Euterpe ssp. APÓS A APLICAÇÃO DE HERBICIDAS

“…os estudos de seletividade de herbicidas em espécies perenes costumam ser realizados inicialmente sobre mudas, pois plantas resistentes nas fases iniciais de desenvolvimento em viveiro podem ser também na etapa adulta do pomar no campo (bRanCalion et al, 2009;PeReiRa et al, 2011). na implantação de áreas de produção de culturas com crescimento lento, como as do gênero Euterpe ssp., faz-se necessário ter o conhecimento e a identificação de herbicidas seletivos à cultura para que se tenha uma ferramenta a mais no manejo de plantas daninhas.…”

Herbicide Selectivity In Eucalyptus Influenced By Spraying Nozzles

“…The results obtained in this study with clone VC865 in relation to saflufenacil resemble those of Pereira et al (2011), who evaluated the intoxication of Eucalyptus urograndis in relation to saflufenacil Averages followed by the same uppercase letter in the rows and lowercase in the columns do not differ statistically by Tukey's test (p ≥ 0.05); * phytotoxicity data were transformed using X . applications with and without adjuvant.…”

Phytotoxic Effects of African Mahogany Seedlings to Herbicides

“…Isoxaflutole and clomazone have the same mechanism of action, but they presented opposite effects on volume increments: the first presented the smallest differences when compared to the control treatment; and the latter presented the smallest volumetric gain during the experiment. One of the explanations is the fact that isoxaflutole is considered a pro-herbicide and its performance depends on the conversion of the molecule into diketonitrile (Oliveira, 2011). There were no significant differences between treatments and control treatment.…”

“…One of the factors that interfere with the productivity of any agricultural or forestry crop is the presence of insects, diseases or weeds. In this sense, weeds compete with forest species for water, light, nutrients, and may also have allelopathic effects and serve as alternative hosts for insects and diseases, not to mention their contribution to forest fire incidence and negative interference in silvicultural operations (Cantarelli et al, 2006;Pereira et al, 2011). Weed interference is more severe in the period of establishment of forest crops, especially during their first year (Pitelli & Marchi, 1998).…”