Seed Physiological Maturity of 3 Varieties of Nakhon Phanom Local Chili

Abstract

Chili pepper is an important vegetable worldwide including Thailand. Local crop varieties have some good agronomic and horticultural traits, i.e., disease resistance and environmental stress tolerance. Therefore, to improve local chili production, the investigation of seed physiology and quality is necessary to enhance chili yield. This study aimed to evaluate the relationship between fruit ripening stages and seed quality in Prik-Pi, Prik-Phee and Prik-Khee-Noo-Suan. All of the chili varieties were evaluated at the Nakhon Phanom University during October 2020–March 2021. A Completely Randomized Design (CRD) was used with 3 replications and 50 seeds of each variety per replication. The results clearly showed that colour parameters and the seed qualities were cultivar and fruit ripening-dependent. At 45 days after anthesis (DAA) for Prik-Pi, Prik-Phee and 41 DAA for Prik-Khee-Noo-Suan were suitable for seed harvesting as the seeds had reached physical and physiological maturity and gave the highest values for seed qualities (%germination, %normal seedling, seedling fresh weight, seedling dry weight and biomass). Moreover, days after anthesis could be used as an indicator of harvesting time. That is following certain days after anthesis, depending on cultivar, chili fruits displayed a colour transition from orange to red while remaining firm.