Effect of trichoderma formulated with cultivated oyster mushroom waste toward the growth and yield of shallot (Allium ascalonicum L.)

The utilization of oyster mushroom waste as an organic fertilizer for onion cultivation in former rice fields frequently encounters soil acidity problems. This experiment aims to determine the effect of administering Trichoderma biofertilizer, formulated with Oyster Mushroom Waste (OMW) on the growth and yield of shallots. The experiment was carried out in a greenhouse setting and a completely randomized design with four replications was employed, each experimental unit having six plants. Seeds were planted in a 5 kg capacity polybag containing sterile planting media soil of pH 4.85. The experimental treatments consisted of three types of Trichoderma biofertilizers, each containing a different isolate of the fungi (Tc-Jjr-02, Tc-Pjn-01, and Tc-Clk-02), oyster mushrooms waste fertilizer and the only soil. Each isolates formulated in oyster mushrooms waste through the biofertilizer treatment contained a uniform spore population of 0.375x106 CFU.g-1. Data were collected on plant height, number of leaves per plant, fresh and dry mass of stover, number of tillers per plant, tuber weight, tuber diameter, soil pH, and the population of each Trichoderma isolate at harvest time. The data were analyzed using a one-way analysis of variance (ANOVA). The significant differences between treatments were determined using the Honest Significant Difference test at the 5% level. Based on the growth and yield, the amount of increase for each treatment was calculated compared to the treatment of oyster mushrooms waste fertilizer. Subsequently, the types of isolate and their phylogenetic classes were determined. The results showed that the Trichoderma biofertilizer formulated in OMW affected plant height and number of leaves at 7-28 DAP (p<0.05), fresh weight and dry weight of stover, number of tuber shoot, and tuber weight (p<0.01), tuber diameter (p<0.05), soil pH at six weeks after planting and one week before harvest (p<0.05), and also Trichoderma population (p<0.05). These three types of this biofertilizer can increase stover fresh weight of shallot between 13.97-52.05%, dry stover weight 67.76-151.42%, number of tillers 44.75-47.00%, heavy fresh tuber 20.31-28.13%, and tuber diameter 3.13-10.97%. The three isolates of the biofertilizer agent were identical to Trichoderma asperellum, where the Tc-Jjr-02 isolate showed the best performance in assisting the growth and production of shallot plants in acidic soils. Key words: acid soil, growth, oyster mushroom waste, shallots, Trichoderma isolates, yield