Aplicação de fungicidas em associação com diferentes adjuvantes no controle da ferrugem asiática da soja

Abstract

The asian soybean rust control was studied in field and laboratory conditions. In 2008/09, 2009/10 and 2010/11 crop season , were carried out experiments about the application time of picoxystrobin + cyproconazole. In all crop seasons, fungicide application at the detecting, or at 4, 8, 12 and 16 days after detection provided disease control at the lower and middle canopy. In 2010/11 crop season, fungicide application in the detection of the disease, provided a production increase. Association to picoxystrobin + cyproconazole fungicide with adjuvants of different chemical natures (mineral, vegetable oil and silicon), in one or two sprays, were evaluated in 2009/10 and 2010/11 crop season. In 2010/2011, treatment with Silwet ® Nimbus ® and generally resulted in higher volumetric median diameter, coefficient of variation drops, number median diameter, volume recovered and percentage of area covered. All adjuvants associated with the fungicide, independently of the number of applications, provided reduction in the AUDPC and increased yields. Besides the field work, spore germination was evaluated with the objective of evaluate the adjuvant effects on the in vitro germination of Phakopsora pachyrhizi and Puccinia kuehnii urediniospore. The adjuvants Assist®, Veget Oil®, Natur Oil®, Break Thru®, Aureo®, Silwet® e Nimbus® inhibited germination of both pathogens.