The response of shallot (Allium ascalonicum L.) growth and yield to gibberelline concentration and the interval of NASA liquid organic fertilizer

This study was aimed at determining the effect of gibberellin concentration and the interval of Natural Nusantara (NASA) liquid organic fertilizer, as well as their interactions to influence growth and yield of shallots. This study was conducted from April to July 2019 in Experimental Field and Horticulture Laboratory of the Faculty of Agriculture, Universitas Syiah Kuala. The experiment used a Randomized Block Design with a Factorial pattern of 4x3. Gibberellin concentrations were observed at 4 levels (control, 100, 150, and 200 ppm) and the interval of NASA liquid organic fertilizer was observed at 3 levels (controlled, every 7, and 14 days DAP). The results showed that the highest shallot plant was found of 14 DAP, and the largest number of bulbs was found at 100 ppm of gibberellins concentration. The highest of fresh biomass per clump and the largest bulb diameter were found at 150 ppm gibberellins concentration. The growth and yield of the highest shallots were found at the interval of control treatment of NASA liquid organic fertilizer. The highest number of bulbs was found in the combination of gibberellins control with the interval of NASA liquid organic fertilizer every 14 days.