The Evaluation of Production, Chlorophyll Content and Number of Flower of Samosir Local Shallots through Application of Gibberellin and Boron in the Highlands

Shallot is a leading horticultural commodity with good seasoning and medicinal properties prospects. In increasing local Samosir shallot production, growth regulators and micronutrients are needed. Gibberellin (GA₃) is a plant growth-stimulating hormone that can simultaneously trigger the appearance of flowers and flowering when applied as an exogenous hormone. Applying boron on shallots could increase the quality of seeds and the number of flowers. The study's objective was to evaluate the production and quality of Samosir local shallots by applying gibberellin and boron in the highlands. The research was conducted at Humbang Hasundutan, North Sumatera Province, Indonesia, from August to October 2022. A factorial randomized block design was used with two-factor and three replications. The first factor is the application of Gibberellin (0, 100, 200, and 300 ppm), and the second is Boron (0, 3, and 6 kg/ha). The result showed that applying gibberellin until 200 ppm increased the content of chlorophyll a, chlorophyll b total chlorophyll, bulb wet weight, and number of flowers of Samosir local shallots. The application of boron until 3 kg/ha increased plant length 2-8 weeks after planting (WAP), leaf number 4-8 WAP, number of tillers 4-8 WAP, the content of chlorophyll a, chlorophyll b and total chlorophyll of Samosir local shallot. The combination treatment of 100 ppm gibberellin and boron 6 kg increased bulb wet weight and bulb dry weight of Samosir local shallots.