The Effects of Vernalization and Photoperiod on Flowering of Shallot (Allium cepa var. ascalonicum Baker) in Lowland Area

Abstract

Flower development is a key element of seed production in plants. In Allium genera, this process strongly influenced by photoperiod and temperature. Photoperiod has been reported as important factor on shal lot flowering in highland area, however the effect on lowland area has not been reported. This research was aimed to analyze the effects of vernalization and photoperiode on shallot flowering in lowland area. This experiment was carried out using local shallot varieties i.e: bulbs of Bima Brebes and Sumenep cultivars. The experiment was arranged in split plot design with 3 replication. The main plot was photoperiod with 3 treatments i.e: natural light (control), 2 hours night break, 4 hours extension using additional light while the subplot was vernalization of bulb seedlings with ambient (room temperature) and cold temperature (10°C) for one month. Vernalization increased the shallot flowering up to 11 .68% in Bima Brebes cu1tivar and 2.85% in Sumenep cultivar. Photoperiod slightly decreased the percentage of flowering, but increased the bulbing ratio significantly. Both vernalization and photoperiod treatments decreased leaf biomass, leaf number and plant height. Vernalization effectively induced shallot flowering in lowland area, while photoperiod effectively induced shallot bulbs formation.