Effectiveness of the Antagonistic Microbe Trichoderma spp. Applied via Encapsulation to Control Moler Disease in Shallots on Peatland

Abstract

Shallot (Allium cepa) is a high-value vegetable crop consistently cultivated due to high demand; however, production has declined due to outbreaks of moler disease caused by the fungus Fusarium oxysporum. Environmentally friendly control innovations for moler disease include the use of Trichoderma spp., which are known to suppress plant pathogens and stimulate plant growth. This study aimed to evaluate the effectiveness of applying encapsulated Trichoderma spp. (an antagonistic microbe) to control moler disease in shallots grown on peat soil. A Completely Randomized Design (CRD) was employed. The experimental factor was the dosage of encapsulated Trichoderma spp., comprising six treatments replicated three times: a healthy control, a diseased control, and dosages of 1 g, 1.5 g, 2 g, and 2.5 g of encapsulated Trichoderma spp. per plant. The best result was achieved with the 2.5 g/plant dosage (t5); this treatment prevented the onset of F. oxysporum symptoms (no incubation period observed) and resulted in zero disease incidence. Furthermore, the 2.5 g dosage increased fresh bulb weight, bulb diameter, and the number of bulbs, achieving a yield of 12.97 tons/ha. This differed significantly from the diseased control (t1), where F. oxysporum symptoms appeared on day 11, disease incidence reached 30%, and the yield was only 6.27 tons/ha.