Shallot growth and production responses to application of microorganisms based-biostimulant and NPK fertilizer combinations on acid soil

Abstract

Abstract Shallot plants require attention because the demand for this high-value commodity is increasing, especially as Indonesia expands its cultivation over a large area of land. This study aimed to assess the potential of microorganism-based biostimulant formula doses and NPK combinations in promoting shallot growth and production in acidic soil. The experiment used an RCD with four treatments: P=control; P1=standard NPK (600 kg· ha1 urea, 250 kg·ha1 SP-36, and 175 kg·ha1 KCl); P2=3 ml L1 biostimulant + 3/4 standard NPK; and P3=5 ml L1 biostimulant + 3/4 standard NPK with four replications. The observed parameters were plant height, number of leaves and bulbs, as well as bulb fresh and bulb dry weights. The results showed that all treatments gave significantly different effects on all observed parameters. Treatment of P1, P2 and P3 showed a higher bulb’s number and dry weight than control. The P3 is an optimal treatment with a bulb number of 10.0 ± 2.2 per clump. This biostimulant formula is an eco-friendly, renewable, and promising technology for improving the growth and production of shallots in acidic soil.