Agronomic and Economic Evaluation of Sequential Spray of Silicon and Fungicides for a Sustainable Soybean Crop

Abstract

This study was carried out to determine whether the yield of soybean cultivars and the severity of Asian Soybean Rust (ASR) are influenced by foliar spray of silicon exclusively or along with a fungicide mixture, as well as the economic viability of their use for a sustainable crop. The experiment was performed in randomized-block design, five replicates, two soybean cultivars and (2×6) + 2 factorial arrangements: S1 (AlSi at R1 + R4); S2 (AlSi at R1 + R5.1); S3 (AlSi at R1 + FM at R4); S4 (FM at R1 + AlSi at R4); S5 (AlSi at R1 + FM at R5.1); S6 (FM at R1 + AlSi at R5.1); NC and PC (negative and positive control). The economic evaluation and sensitivity analysis were undertaken for Anta 82 RR. There was no interaction effect between the factors, and cultivar CD 2737 had a higher yield. ASR was less severe in CD 2737, and S3 and S5 provided the lowest disease severity. Exclusive spray of aluminum silicate was able to reduce the number of lesions with uredinia, open uredinia and uredinia per lesion. S3 increased grain yield, resulting in higher revenues and a 66.1% gross margin. Sensitivity analysis revealed that S3 was profitable in all scenarios.