PERAN KOMBINASI BIOFRESH PLUS DAN DOSIS NPK DALAM MENEKAN PENYAKIT PUSTUL BAKTERI PADA TANAMAN KEDELAI DI LAHAN ULTISOL

Abstract

Soybean (Glycine max L.) is an important commodity in supporting national food security. However, its productivity in Indonesia, especially in the ultisol lands of Southeast Sulawesi, is still low due to limited soil fertility and bacterial pustule disease attacks. This study aims to determine the effectiveness of the combination of Biofresh plus biofertilizer and NPK inorganic fertilizer doses in suppressing the intensity of bacterial pustule disease in several soybean varieties on ultisol soil. The study applied a split plot design within a BRD framework, consisting of 16 treatment combinations and replications three times. The variables measured included disease severity, area under the disease development curve (AUDPC), and the level of effectiveness of disease control. The results showed that the Dena-1 (F4) variety was the most resistant to bacterial pustule, with the lowest AUDPC (247.80%-day) and the lowest disease severity at all stages. The combination of Biofresh plus with or without low NPK (25–50%), is more effective in suppressing disease than full inorganic fertilizer, with the highest effectiveness of 32.91% (F1R2). Control effectiveness is highly dependent on the combination of varieties and fertilizers, where F4 is most effective with R1, F1 with R2, and F3 with R3.