Soybean grain yield in response to herbicide and fungicides

With the introduction of the resistant soybeans to the glyphosate changed the management of the culture, mainly for management of the weed. This work was developed with the objective of evaluate the effect of the different management systems of herbicides and fungicides in grain yield and yield components of the soybean. The experiment was carried in the agricultural year of 2006/2007, at the Experimental Area of Department of Phytotecny of the Santa Maria Federal University. It was used, four soybean cultivars Roundup Ready (TM) ('NK Mireya 4.2 RR', 'Fundacep 55 RR'. 'NK Magica 7.3 RR' and 'A 8100 RG'), two herbicide management (Clethodim + Bentazon and with glyphosate) and two fungicides management with application (Tebuconazole + Tiofanato Metilico) and without treatment. The experiment design was randomized blocks with splitsplitplot plot, with four replications. It was evaluated the grain yield and components of yield. The cultivars showed different responses to the management of herbicide and fungicides, for grain yield, cultivars that were affected by the herbicide management showed higher productivity with the application of glyphosate. The effect also was observed with the application of fungicide. The cultivars more and less productive presented the highest and lowest grain weight respectively Fungicide application increased the harvest index.