Abstract

Marlina, Lukman Hakim, Alfizar, Sufardi.

Soybean (Glycine max, L Merr) is one of the food crops that has long been cultivated by the people of Indonesia. Constraints that are often found in the cultivation of soybean plants, among others, are disease infection factors. One of the harmful diseases is stem rot that is caused by the fungus Sclerotium rolfsii Sacc. Therefore an alternative must be sought to control this pathogen by utilizing mycorrhizal biological agents that can be symbiotic with plant roots. The study used a completely randomized design (CRD) factorial pattern of 2 factors. The first factor is mycorrhizal fungi, consisting of 4 dose levels, namely 0 gram per plant, 5 gram per plant, 10 gram per plant, and 15 gram per plant. The second factor was soybean cultivar, consisting of 2 namely Anjasmoro and Kipas Merah. Thus there are 8 treatment combinations. Each treatment was repeated 3 times and each experimental unit consisted of 4 experimental pots, so that the total number of pots was 8x3x4 = 96 pots. The observation variable is the incubation period (days), the length of the lesio at the base of the stem. The intensity of the attack, calculated by the formula: P = a / b x 100%. P = intensity of disease attack, a = number of plants attacked, b = total number of plants. The results showed that the Kipas Merah cultivar soybean was more resistant to stem rot disease caused by Sclerotium rolfsii Sacc than Anjasmoro cultivars. Inoculation with mycorrhizal fungi of 10 to 15 g per plant decreases the percentage of soybean plants affected by stem rot, prolongs the incubation period, and inhibits the development of lesions. This shows that mycorrhiza can suppress soil-borne pathogens or can control Sclerotium rolfsii Sacc which causes stem rot disease in soybeans.