Initiation of Flowering and Bulbils in Shallot with Various Treatments in Tropical Regions

Background: Shallots are one of the horticultural commodities with low production growth value in Indonesia. Shallots production in Indonesia is limited by the quality of planting material and the climate, especially temperature. The flowering of shallots is a significant obstacle to the regulation of tuber development and bulbils. This study aimed to examine the effect of treatment on the initiation of flowering and the formation of bulbils. Methods: The method used was a complete randomized block design with six treatments: without treatment, vernalization at 5oC, Immersion GA3 100 ppm, Immersion IAA 100 ppm, Immersion NAA 100 ppm, injury to the flower stalk and three replications. Result: The treatment of flowering initiation and the formation of bulbils had a significant effect on the flowering day, the number of flower stalks, the percentage of flowering plants, number weight of bulbils and weight of bulbils. GA3 and vernalization can speed up the appearance of flowers and increase the percentage of flowering plants. GA3 and the opening of the flower stalks can encourage the formation of bulbils with a higher weight and diameter of the tubers. The flowering day had a negative correlation with the number of bulbils formed. Bulbils formation requires a higher content of endogenous GA3. GA3 can initiate the flowering and formation of shallot bulbils.