Natural plant defense reinforced against Asian rust

Bioactivating nutritional complex shows high synergism when associated with the use of conventional fungicides and potential to assist in the management of Asian rust by inducing the plant's defense mechanisms against the disease.

Cubo IR associated with conventional fungicides increased control efficacy by 16,4% and increased productivity by 6,2 bags per hectare, in relation to standard treatment. Since the emergence of Asian Rust (Phakopsora pachyrhizi) in Brazil at the end of the 2001/02 harvest, productivity losses of up to 90% were reported in all regions of the country. The difficulties in managing this disease are great, as all control methods have limitations, and with each harvest there is a loss in the effectiveness of the chemical pesticides used. Thus, in recent years, interest in alternative management methods has grown. In this context, Spraytec developed the IR Cube, which stands for nutrition, greater plant natural defense and better application quality. High-tech and biodegradable product that acts in the fertilization of flowers, the formation and weight of grains and the transport of carbohydrates, with positive impacts on productivity. Another differentiating characteristic of the product is related to the increased resistance of plants to biotic factors. In response to the application of Cubo IR, defense mechanisms are activated, inducing the plant to synthesize high concentrations of secondary metabolites, which act as true physical and chemical barriers, hindering the entry and development of pathogens, such as the fungus that causes Asian Rust. . The use of cultivars with high genetic potential associated with sustainable development requires innovative products such as Cubo IR.

Goal

To evaluate the efficiency of the bioactivating nutritional complex Cubo IR in association with conventional fungicides in the management of Asian Rust in soybean crops.

Material and methods

The experiment was conducted at the experimental station of FAPA - Fundação Agrária de Pesquisa Agropecuária, located in the district of Entre-Rios, Colônia Vitória, municipality of Guarapuava, PR. The Roos Camino RR soybean cultivar was used in the test. The experimental design used was randomized blocks, with four replications. The treatments consisted of Control (no application), FAPA Standard (three fungicide applications) and FAPA + Spraytec Standard (three fungicide applications associated with Cubo IR 0,30 L ha-1). Applications were performed when the culture was at stage V8, R3 and R5.3, respectively. The volume of spray used was 200 L/ha. Evaluation of the product's efficiency in controlling Asian Rust and crop yield was carried out. The data were subjected to analysis of variance and the Tukey test (p < 0,05), using the SASM Agri software (Canteri et al..

Results

Cubo IR demonstrated high synergism with fungicides, increasing the effectiveness of controlling Asian Soybean Rust. The association of Cubo IR with fungicides increased control efficacy by 16,4%, compared to standard treatment. The control for the standard treatment was 80,4% and for the standard associated with the IR Cube it was 96,8% (Figure 1). Increasing the effectiveness of controlling Asian Rust is extremely important so that there is no loss of the crop's productive potential. In this context, in relation to productivity, the harvest in the control was 70,3, in the standard 76,1 and in the standard plus Cubo IR 82,2 bags per hectare. The association of Cubo IR with fungicides promoted an average increase in productivity of 11,9 bags per hectare in relation to the control and 6,2 bags in relation to the standard treatment (Figure 2). As most chemical fungicides have limitations in control, their association with Cubo IR proved to be an effective tool to ensure better control of Asian Rust and consequently, promote greater productivity of soybean crops.

Conclusion

The IR Cube, in addition to nourishing the plants aiming for the maximum expression of their productive potential, is a promising alternative in the management of Asian Soybean Rust by inducing the plants' defense mechanisms, presenting high synergism with conventional fungicides.

Heraldo R. Feksa, Agricultural Research Foundation (Fapa)