Study of breaking dormancy and after-ripening period of Gorontalo’s upland rice cultivars

Abstract

This research was designed to study persistence of seed dormancy from Gorontalo’s upland rice cultivars and to find the most effective method for breaking dormancy. Upland rice seed were harvested at 125 days after planting. The seeds were stored in a plastic seal for up to 11 weeks, observation conducted every week. Persistence of seed dormancy in each cultivars was determined based on the time needed to reach a minimum of 80% germination capacity. This research used 6 cultivars i.e Ponelo Merah, Maraya, Buruno, Jorone, Pulo and Ponelo Putih. The methods of breaking dormancy were applied : untreated, soaking in water for 48 h, soaking in 3% KNO3 and heating 500C for 48 h. The result of this research were found that viability and vigor of upland rice seeds were increased after storage. Persistence of seed dormancy was different in each cultivars i.e. 5.9 weeks in Maraya, 6.5 weeks in Ponelo Putih, 7.1 weeks in Buruno, 7.7 weeks in Jorone, 9.9 weeks in Ponelo Merah and 10.6 weeks in Pulo. Soaking the seeds in water for 48 h and soaking the seeds in 3% KNO3 for 48 h were effective method for breaking dormancy. The most responsive to breaking dormancy is Jorone at 0-week harvest time. Pulo and Ponelo Merah have long persistence of dormancy. Soaking the seeds in water for 48 h and soaking the seeds in 3% KNO3 for 48 h can’t break dormancy of Pulo before 3 weeks and Ponelo Merah before 4 weeks. Soaking in KNO3 able to break dormancy Ponelo Putih at 1 week, Maraya and Buruno at 3 weeks. Soaking in water able to break dormancy Buruno at 0-week harvest time, Maraya at 1 week, and Ponelo Putih at 3 weeks. Heating the seeds in 500C for 48 h less effective breaking dormancy for all of cultivars.

Kendala yang menghambat kelancaran penyediaan benih padi diantaranya sifat benih itu sendiri. Benih padi memiliki sifat dormansi yang bervariasi dan menyebabkan beberapa varietas padi yang baru dipanen tidak dapat tumbuh jika ditanam meskipun pada kondisi yang optimum. Penelitian dormansi sangat penting untuk mengatasi kendala penyediaan benih padi agar tanaman tumbuh serempak. Tujuan penelitian ini adalah (1) mengetahui persistensi dormansi beberapa kultivar padi gogo lokal Gorontalo, (2) mendapatkan metode yang efektif dalam pematahan dormansi beberapa kultivar padi gogo lokal Gorontalo dan (3) mempelajari korelasi antara intensitas dormansi dan persistensi dormansi.