Partial Submergence Tolerance in Rice ( L.) Cultivated in North Sulawesi at the Vegetative Phase.

Background And Objective: The partial-submergence-tolerant crop plants, including rice are required for fulfilling food needs when a flooding disaster occurs in Indonesia. The information of effective selection method for obtaining submergence tolerant rice is required for increasing the North Sulawesi capacity as a pillar of national food security. This study evaluated the partial-submergence-tolerance in 10 rice cultivars that are cultivated in North Sulawesi Province based on the morphological characters (plant height, shoot dry mass, shoot length, root dry mass, root length, root volume, shoot:root ratio and leaf number) at the vegetative phase.

Material And Methods: This experiment was conducted in the greenhouse using 10 rice cultivars (cv. Cigeulis, Seruni, Mekongga, Ciherang, TB, Ombong, Inpari 13, Burungan, Temo and Superwin). These cultivars were grown at the vegetative phase in partial submergence condition (the entire root system and 30 cm of above-ground shoot was under water) for 20 days, with 8 replicates, in a randomized block design.

Results: The longer duration of partial-submergence treatment resulted in the decrease of leaf number, the increase of plant height and the increase of shoot elongation. There were three categories of partial-submergence tolerance, i.e., tolerant for Cigeulis and TB, semi tolerant for Seruni, Mekongga, Inpari 13, Burungan, Temo and Superwin and non-tolerant for Ciherang and Ombong.

Conclusion: Rice cv. TB as tolerant cultivar showed better growth response under partial submergence rather than other rice cultivars at the vegetative phase.