Abstract
ABSTRACT The evolution of the reduction in Asian soybean rust (caused by Phakopsora pachyrhizi) control by site-specific fungicides has been reported season after season. In a field experiment, the effect of prothioconazole solo and added to multisite mancozeb was evaluated for rust control. Treatments were evaluated in a factorial design of four prothioconazole doses and three mancozeb doses. In a set of treatments, three applications were performed in one soybean cycle and four applications in another one. The first applications were performed at GS V8, 11 days before rust detection, with 2.56% leaflet incidence, while the other applications were at 12 to 14-day interval. Rust severity was quantified, control was calculated in relation to the unsprayed treatment, and soybean grain yield was estimated as kg/ha. Fifty-one to 61% control was obtained with three sprayings and 68% to 70% control with four sprayings of prothioconazole alone. Over 80% control was obtained with at least 0.3 L/ha prothioconazole + 2.0 kg/ha mancozeb, corresponding to 75 g a.i./ha prothioconazole + 1500 g a.i./ha mancozeb. Reduction in P. pachyrhizi control by the use of the site-specific fungicide alone was confirmed, while the addition of mancozeb can recover the efficacy of the site-specific fungicide.
Highlights
Tem sido relatada a evolução da redução do controle da ferrugem asiática da soja causada por Phakopsora pachyrhizi pelos fungicidas sítio-específicos safra após safra
After five seasons of use of site-specific chemicals alone, such as demethylation inhibitors (DMIs), a reduction has been reported in P. pachyrhizi sensitivity to these chemicals [6, 7, 10]
Among the three groups (DMI, quinone outside inhibitors (QoIs) and succinate dehydrogenase inhibitor (SDHI)) of site-specific fungicides, prothioconazole (Prot), a DMI released to the market in the 2012/13 season in combination with trifloxystrobin, has been the most efficient and the most used fungicide for rust control in the 2016/17 season [7]
Summary
Tem sido relatada a evolução da redução do controle da ferrugem asiática da soja causada por Phakopsora pachyrhizi pelos fungicidas sítio-específicos safra após safra. Among the three groups (DMI, QoI and SDHI) of site-specific fungicides, prothioconazole (Prot), a DMI released to the market in the 2012/13 season in combination with trifloxystrobin, has been the most efficient and the most used fungicide for rust control in the 2016/17 season [7]. 345-347, 2020 prothioconazole, a site-specific fungicide, solo and added to mancozeb, in the control of P. pachyrhizi in the soybean crop.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
