RESPONSE OF RED ONION GROWTH AND YIELD TO TRICHODERMA ASPERELLUM AND COW MANURE UNDER FUSARIUM DISEASE PRESSURE

Fusarium solani is one of the soil-borne pathogens that can reduce the growth and yield of red onions. Biological control using Trichoderma asperellum combined with organic matter has the potential to be an alternative to improve plant growth under pathogen pressure. This study aims to evaluate the effects of various doses of T. asperellum and cow manure on the growth and yield of three red onion varieties inoculated with F. solani. The research used a factorial design with five application treatments and three red onion varieties. The treatments consisted of P0 (no application), P1 (F. solani inoculation), P2 (0.5 kg T. asperellum + 5 kg cow manure), P3 (0.25 kg T. asperellum + 5 kg cow manure), and P4 (0.167 kg T. asperellum + 5 kg cow manure). The varieties used were Batu Ijo, Bima Brebes, and Tajuk. The results showed an interaction between treatment and variety on several growth and yield parameters. The combination P2V1 produced the highest fresh bulb weight of 67.36 g and dry bulb weight of 46.18 g, while P3V1 resulted in the highest number of leaves at 37.13 leaves. These findings indicate that the response of red onion varieties to T. asperellum and cow manure differs. The combination of T. asperellum and cow manure, especially P2, can enhance the growth and yield of red onions under F. solani pressure.