Herbicidas aplicados na soja e produtividade do milho em sucessão

Abstract

Resumo -O objetivo deste trabalho foi avaliar o efeito residual de herbicidas aplicados na cultura da soja sobre a produtividade do milho em semeadura subseqüente. Foram instalados cinco experimentos na safra agrícola 2002/2003, com delineamento em blocos ao acaso e quatro repetições. Cada experimento correspondeu ao período decorrido entre a aplicação dos herbicidas e a semeadura do milho: zero (semeadura no mesmo dia da aplicação), 30, 60, 90 e 120 dias após aplicação (daa). Os experimentos foram compostos por oito tratamentos (herbicidas diclosulan, sulfentrazone, imazaquin, imazethapyr, fomesafen, lactofen, e chlorimuron-ethyl e um tratamento testemunha), e o efeito dos herbicidas sobre a cultura do milho foi avaliado pela fitotoxicidade e a produtividade. O efeito da fitotoxicidade foi acentuado a zero e 30 daa, e apresentou correlação direta com a redução da produtividade de milho, principalmente quanto aos herbicidas diclosulan e imazaquin. Aos 60 daa não houve correlação direta entre a fitotoxicidade e a produtividade, demonstrando que a cultura do milho apresentou boa capacidade de recuperação. Aos 90 e 120 daa não ocorreram sintomas de fitotoxicidade em nenhum dos tratamentos. Os produtos utilizados apresentaram efeito residual sobre a cultura do milho, principalmente quando foi semeado até 60 dias após aplicação dos herbicidas.Termos para indexação: Glycine max, Zea mays, fitotoxicidade, cultivo sucessivo. Herbicides applied in soybean and the productivity of corn in successionAbstract -The objective of this work was to assess the residual effect of herbicides applied in soybean cultures on the productivity of corn planted in succession. Five experiment units were installed in the crop year 2002/2003 in random blocks, with four replications. Each experiment corresponded to the period between the application of the herbicides and the planting of the corn: zero (planting on the same day of application) 30, 60, 90 and 120 days after application (daa). Experiments were made up of eight treatments (herbicides diclosulan, sulfentrazone, imazaquin, imazethapyr, fomesafen, lactofen, and chlorimuron-ethyl, and control treatment), and the effect of the herbicides on the corn was evaluated by means of fitotoxicity and productivity. The effect of fitotoxicity was significant at zero and 30 daa, and was directly correlated to the reduction of the corn productivity, especially for the herbicides diclosulan and imazaquin. At 60 daa there was no direct correlation between fitotoxicity and productivity, showing that the culture of corn presented capacity to recover. At 90 and 120 daa no symptoms of fitotoxicity were found in any treatment. The products had an effect on the culture of corn, especially when it was planted up to 60 days after the application of the herbicides.Index terms: Glycine max, Zea mays, phytotoxicity, successive crop. IntroduçãoEm espécies cultivadas de maneira intensiva, como as culturas da soja e do milho, a utilização de herbicidas para controle de plantas daninhas é uma técnica indispensável....

Volunteer RR® corn management in roundup ready® soybean-corn succession system

“…These data are similar to those obtained by Artuzi & Contiero (2006), who also found no effect of imazethapyr and imazaquin in soybeans. The absence of graminicidal effects was expected, since they are totally selective herbicides for soybean crops.…”

“…DAE -days after soybean emergence. imazaquin up to 60 days after application on maize plants were also verified by Artuzi & Contiero (2006). However, these researchers did not find any effect on corn when it was planted after 60 DAA.…”

“…In general, researches (Artuzi & Contiero, 2006;Dan et al, 2012;Souto et al, 2013) show an absence of imazethapyr residual effects from 90 DAA. Based on these results, maize cultivation in the off-season after application Table 7 -Control of maize in desiccation under cover crops and herbicides in desiccation management.…”

“…Some herbicides, as diclosulam, that could play a preventively role in the control of volunteer corn may have phytotoxic effect on maize in the off-season when applied in desiccation management for soybean plantation (Artuzi & Contiero, 2006;Dan et al, 2011). …”

Microbial activity of soil with sulfentrazone associated with phytoremediator species and inoculation with a bacterial consortium

“…Due to its persistence, it can cause injury of sensitive crops grown in succession (Artuzi and Contiero 2006) as well as increase the risk of leaching and environmental contamination. To decontaminate soils with a history of application of this herbicide, bio-remediation techniques involving phytoremediator plants and microorganisms with remedial potential can be used.…”