Effect of Various Pre-sowing Treatments on Germination and Seedling Performance of Bixa orellana L. at Low Seed Moisture Content

Natural plant-based substances are becoming more and more popular in today's society for a variety of uses. Bixin (vibrant red-orange dye) is one such compound derived from Bixa orellana L., commonly known as annatto. This plant is primarily propagated through seeds for commercial cultivation. However, there is very little information available on germination combined with the seedling performance of this species. Hence, to fill this research gap, the present study evaluated seed morphological characteristics and various pre-sowing treatments to enhance seed germination and its vigour at a low seed moisture content of 10%. This study used Completely Randomized Design (CRD), and seeds were subjected to six pre-sowing treatments with four replications. The study showed the highest germination (52%) and highest mean daily germination (4.6) in 24hrs Water-soaked seeds, whereas mechanical scarification in combination with 24hrs water-soaking increased the germination percentage from 19% to 47%. In addition, the highest seed vigour index (411.25) was also observed in mechanical scarification combined with 24-hour water soaking. These findings of germination and vigour at low seed moisture content will certainly help in the formation of desiccation and storage protocols for medium to long-term conservation of Bixa orellana L. seeds.