Bioactivating nutritional complex helps control Asian rust

The losses of productivity caused by diseases, combined with the low effectiveness of main chemical groups of fungicides currently used, can slow down the expansion of soybean cultivation in Brazil. In this way, in the last Over the years, interest in alternative management methods has grown. Like all methods have limitations, it is necessary to investigate the mode of action of nutritional complexes that bioactivate plant defense, among others, to compose integrated disease management. Annual losses caused by diseases in soybean cultivation are estimated between 15% and 20%, however, some diseases can cause losses of up to 90%. Due to the economic losses they cause, phytopathogenic agents must be controlled, and for the good performance of protective and curative activity of pesticides, some aspects must be considered. The architecture of the soybean plant and its broad overlapping leaves are characteristics unfavorable to the penetration of products, in addition, there are very little translocation of fungicides in plants, that is, these pesticides are translocated short distances within the leaf (circulation loco-systemic), for this reason they require good coverage and penetration into the target. Another limitation in management is related to the resistance of the species to conventional fungicides. The need to achieve sustainability, to reduce production costs and address difficult problems Phytosanitary issues requires the search for new strategies for managing phytopathogens. In this context, the use of intelligent resistance-inducing fertilizers constitutes an excellent tool to complement management, in addition to nourishing plants and increase the effectiveness of the application.

Goal

Evaluate the efficacy of Ultrazeb Inox in association with conventional fungicides in the management of Asian rust in soybean crops.

Material and methods

The experiment was installed in the experimental area of ​​Agro Carregal, in the municipality of Rio Verde, Goiás. The ST 797 soybean cultivar was used in the trial. Experimental used was randomized blocks, with four replications. You treatments consisted of Control (no application), Standard Fungicide (Aproach Prima + Fox + Fusion + oils in commercial doses) and Standard Fungicide + Ultrazeb Inox (0,30L/ha). The four applications were carried out when the culture was at stages V8, R4, R5.2 and R5.5. The volume of syrup used was 150L/ha. Among other variables, assessments of control (defoliation rate) and crop yield (grain mass and productivity). Partial data were subjected to analysis of variance and Tukey test (p < 0,05), using the SASM Agri software (Canteri et al., 2001).

Results

Ultrazeb Stainless demonstrated high synergism with fungicides, increasing effectiveness in management of Asian soybean rust. The association of Ultrazeb Inox with fungicides reduced the rate of plant defoliation. The defoliation rate in the control was 99%, for the standard treatment it was 81,2% and for the standard treatment associated with Ultrazeb Stainless steel was 61,5% (Figure 1). The reduction in defoliation is a reflection of greater effective control of Asian rust and is extremely important so that it does not there is a loss of the productive potential of the crop. In this context, with regard to productivity, the harvest in the control was 50,3, in the standard 64,3 and in the standard plus Ultrazeb Inox, 68,3 bags per hectare. The Ultrazeb Association Stainless steel to fungicides promoted an average increase in productivity of four bags per hectare in relation to the standard treatment (Figure 2). As most of conventional chemical fungicides presents limitations in control, the their association with Ultrazeb Inox proved to be an effective tool for ensure better management of Asian rust and, consequently, promote greater soybean crop productivity.

Conclusion

Ultrazeb Stainless, In addition to nourishing plants to maximize their productive potential, it is a promising alternative in the management of Asian soybean rust by inducing plant defense mechanisms, presenting high synergism with conventional fungicides.