KARAKTERISTIK FISIOLOGI TOLERANSI TANAMAN BAWANG MERAH TERHADAP CEKAMAN KEKERINGAN DI TANAH PASIR PANT

Abstract

Drought stress in crop is affected by imbalance between water suply and demand that its in natural condition tightly controlled by the crop. Crop responses to drought stress are influenced by the varieties differently. This research was aimed to investigate the threshold of available soil moisture capacity that affected on drought stress and also known several varieties of shallot that it was tolerance and sensitive varieties on drought stress in coastal sandy soil, as well as its was investigate the physiological characters . This research was conducted in Green House of BPTPH DIY and its arranged in two experiments, i.e : (1) The study about threshold of available soil moisture capacity that affected in drought stress on shallot, (2) Study about the character of physiological tolerance in drought stress on several varieties of shallot grown in coastal sandy soil. Completely randomize design was used in factorial experiment with three replications. The result showed that : (1) Drought stress on shallot in coastal sandy soil is caused by decrease at 60% of available soil moisture capacity, (2) These several varieties of shallot that its limited investigate have found tolerance varieties on drought stress, i.e : Ampenan variety, Biru variety, Kuning variety, Timor variety and Kuning Tablet variety; moderate varieties, i.e.: Bima NTB variety, Probolinggo variety and Siam variety; sensitive verieties, i.e. : Bima Brebes variety, Bima Juna variety and Tiron variety, (3) Drought stress pressed the growth of root that its decreased the water and nutrient uptake, (4) Drought stress was affected significantly different on several physiological characters between tolerance and sensitive varieties of shallot, i.e.: leaf relative water content, stomatal conductance and content of proline in shoot.
Key Words : Shallot, physiological tolerance, drought stress, coastal sandy soil