This work was done in order to evaluated the fungicides effect on the control of soybean rust caused by Phakopsora pachyrhizi, as well as their effect on yield. The fungicides were sprayed when the plants were at the growth stage R4. The cultivar used was Fepagro-RS 10. The experimental design used was a randomized blocks replicated four times and with ten treatments. The disease severity evaluation was done 30 days after spraying using a scale of notes (0 to 5), measuring the infected leaf area. The treatments with the fungicides azoxystrobin, difenoconazole + propiconazole, fluquinconazole, myclobutanil, pyraclostrobin + epoxiconazole, tebuconazole and trifloxystrobina + propiconazole controlled the pathogen when compared with the control, showing severity average notes equal or lower then 2, without difference among them. The treatment with difenoconazole (note 3.05) controlled the pathogen, with lower note than the carbendazin treatment (note 3.85) and non-treated plants (note 4.5). All fungicides treatments showed higher yield than non-treated plants varying from 14.5% to 27.3%. The weight of 100 seeds was higher than the control (11.8% to 14.4%), except for carbendazin (5.2%).
Glycine max; chemical control; severity
