Determination of Seed Physiological Maturity of Kangkong (Ipomoea reptans Poir.) Based on Phenology, Seed Quality, and Heat Unit Accumulation Neny Priska Yuliandira, Okti Syah Isyani Permatasari, Satriyas Ilyas*
Department of Agronomy and Horticulture, Faculty of Agriculture, IPB University, Jl. Meranti IPB Darmaga Campus, Bogor 16680, Indonesia. Email: satriyas_ilyas[at]apps.ipb.ac.id
Abstract
This study aimed to obtain information about the phenology of flowers, fruits, seeds, and to determine the appropriate heat unit accumulation to reach the seed physiological maturity of kangkong (Ipomoea reptans Poir.) when the maximum seed quality is achieved. The experiment was arranged in a randomized completely block design with one factor. The experimental factor was the seed harvest age consisted of 15 levels, starting from 16 days after anthesis (DAA) or 79 days after planting (DAP) to 30 DAA. The anthesis occurred at 63 DAP. The results showed that the seed physiological maturity of kangkong cv KK02 was achieved at 25 DAA with the characteristics of brownish fruit color, white seeds, and the seeds turned dark brown after drying. At 25 DAA, the seed moisture content was the lowest (9%) while the seed dry weight (4.55 g), seed viability (87% germination), and seed vigor (79% vigor index, 84% simultaneity of germination, and seedling growth rate of 118.11 mg normal seedling-1) reached their maximum. The heat unit of kangkong cv KK02 at the seed physiological maturity was 1,668.50 degrees Cd.
Keywords: Days after anthesis, Harvest age- Seed dry weight- Seed viability- Seed vigor
