Effect of Preharvest Application of Alginate Oligosaccharides on Postharvest Quality and Shelf Life of Tomato

Alginate oligosaccharide (AOS) is a water-soluble non-toxic compound and act as plant biostimulator. In order to know the preharvest spraying effect of AOS on postharvest quality and shelf life of tomato, an experiment was conducted. Two varieties of tomato namely Roma VF and BARI tomato 14, and different preharvest treatments viz., control, AOS 25 mg/L, AOS 50 mg/L, AOS 100 mg/L and AOS 250 mg/L were used for this study. The field experiment was carried out in a Randomized Complete Block Design (RCBD) and Lab experiment will be conducted in a Completely Randomized Design (CRD) with three replications. Results displayed that most of the studied parameters were significantly influenced by the varieties and preharvest application of AOS. The maximum number of fruits per plant (67.0), fruit weight per plot (1.67 kg) and yield (75.55 t/ha) were obtained from BARI tomato 14 when treated with AOS 100 mg/L. AOS 100 mg/L treated BARI tomato 14 fruits showed minimum weight loss (9.02%) during storage, while untreated Roma VF tomato fruits exhibited maximum weight loss (10.42%). The maximum firmness (4.407) and titratable acidity (0.0.48%) was recorded from BARI tomato 14 when treated with AOS 100 mg/L whereas the highest total sugar (4.89), vitamin C content (17.90 mg 100 g¹) and shelf life (9.40 days) were recorded from the combined effect of 'Roma VF' variety treated by AOS 100 mg/L. The lowest percentage of disease incidence (9.11%) and disease severity (66.51%) were also found in Roma VF tomato' treated by AOS 100 mg/L. The findings of this study suggests that pre-harvest application of AOS is very useful for increasing yield, enhancing quality and shelf life of tomato.