Biocompost Application Trichoderma spp. and NPK Fertilization on the Growth and Yield of Shallots (Allium ascalonicum L.)

Shallots (Allium ascalonicum L.) are plants that are needed as a kitchen spice. Production decreases along with decreasing planting area and land fertility levels, so a solution is required to increase land fertility using biocompost. They should also require large amounts of N, P and K for their growth and development. This research aims to determine the effect of Trichoderma spp. biocompost application and NPK fertilization on the growth and yield of shallot plants. The experiment used a completely randomized factorial design consisting of two factors, namely biocompost dosage (b), which consists of four levels: 1) without biocompost (b0), 2) 1.25 t/ha (b1), 3) 2.50 t/ha (b2), 4) 3.75 t/ha (b3), and the NPK dose factor (n) has four levels, namely: 1) 400 kg/ha (n1), 2) 300 kg/ha (n2), 3) 200 kg/ha (n3), 4).100 kg/ha (n4). The research results show the following. Application of Trichoderma spp. biocompost had a significant effect on the number of tillers at 6 WAP, number of tubers per hill, wet tuber weight, dry tuber weight, tissue P and K nutrient uptake values and had no significant effect on plant height, number of leaves and tissue N nutrient uptake values. Various doses of NPK fertilizer substantially affected the number of tillers at 6 WAP, number of tubers per hill, wet weight of tubers per hill, dry weight of tubers and tissue N, P and K nutrient uptake values. It had no significant effect on plant height and number of leaves. Secondly, there is an interaction effect of the two treatments on tissue N and P nutrient uptake values, with the highest N uptake value obtained in a combination of 2.50 t/ha (b2) of biocompost with a 300 kg/ha (n2) (b2n2) NPK fertilizer dose. In contrast, the highest P uptake value was obtained in a combination of 3.75 t/ha (b3) of biocompost with an NPK fertilizer dose of 200 kg/ha (n3). The best yield tendency was obtained in a combination of 2.5 tons/ha (b2) of biocompost with a 300 kg/ha (n2) NPK fertilizer dose (b2n2).