Determination of harvesting indices and harvesting stage of Annona muricata L. (soursop) based on fruit growth

Harvesting time plays a decisive role in ripening, storage and table quality of soursop (Annona muricata L.) fruits. This study was conducted with the objective of developing a harvesting index based on the change of selected physical and biochemical parameters at different growth stages of fruits. Growth curves for 3 accessions of A. muricata were developed by using weekly changes of fruit length and circumference. Physical, physiological, biochemical and chronological parameters of the fruit were tested at 5 identified stages. Growth curve was identified as double sigmoid with long and highly variable quiescent phase. As harvesting indices fruit skin color (L*= 42.45, b*=25.72, and h*=100.4, Yellow green group -YG 144A of Royal horticulture color chart) and number of spurs per 2.5 cm² (1 sq. inch) (3-4) were identified at stage 6 with high total soluble content (17.4 Brix⁰) with longer shelf life (5.2 days) compared to stage 7 (1.7 days).