Abstract

SILVA JUNIOR, Jorge da et al. Effect of protectant and systemic fungicides applied at different growth stages on the control of soybean asian rust. Ciênc. agrotec. [online]. 2009, vol.33, n.3, pp. 705-712. ISSN 1413-7054.  http://dx.doi.org/10.1590/S1413-70542009000300007.

The aim of this work was to verify the effect of the fungicides dicopper chloride trihydroxide, thiophanate methyl, chlorothalonil+thiophanate methyl, chlorothalonil, and pyraclostrobin+epoxiconazole applied at the stages V₆, R₁, R₅, V₆+R₁, V₆+R₅, R₁+R₅ on the control of the Asian rust and on the agronomic characteristics of the soybean. The experiment was carried out at the experimental area of the Agriculture Department, Federal University of Lavras, Lavras MG, Brazil. Significant effects were observed for all fungicides on Asian rust control, in comparison with the control. The treatments with fungicide sprays pyraclostrobin + epoxiconazole at the growth stage R₁ provided the effective control of the disease, no significant differences were observed between V₆ + R₁ and R₁ + R₅. The sprays at R₅ and V₆ + R₅ showed high disease severity however, with grain yield similar to the applications of the same fungicide at the stages R₁, V₆ + R₁ and R₁ + R₅.

Keywords : Frequency of applications; Phakopsora pachyrhizi; Glycine max.