Assess the impact of preharvest silicon application on the postharvest quality of tomatoes

Project Description

Partially burnt rice hull is a rich source of Silicon which enhances plant growth in nutrient-less soil and overall plant health and Productivity. Hence main objectives of this study are to recommend an optimum dosage of partially burnt rice hull application for tomato plants; to distinguish quality improvement by the application; and to distinguish postharvest quality and shelf life of the treated fruits with other handling practices

Key Findings

No Significant difference in treated and non-treated tomatoes in terms of Average fruit weight, TSS and fruit diameter.

Higher L* and b* values in R1 & R2 → Redness is low and lightness is high (Less ripening)

Significantly higher (p<0.05) firmness with and without peel (Treatment R2)

Significantly higher shelf life in R2 (More than 13 days)

R2 → After drop test, Comparatively lower weight loss upon 3 days of storage

Si treated tomatoes - Significantly higher firmness even after the drop test

Even though the Si treated tomatoes are dropped from 1m and 0.5m distances – longer shelf life (More than 9 days)

R2 – Marketable tomato % was higher after the drop test

After 14 days of storage at room temperature conditions, Treatment R2;

• Significantly lower weight loss and Comparatively higher peel firmness

After 14 days of storage at refrigerated conditions, Si treated tomatoes;

• Significantly lower weight loss and Comparatively higher peel firmness
• Cold storage – Quality is higher than ambient temperature conditions

Policy Implications

  1. Best Si treatment → R2
    • Higher peel firmness
    • Longer shelf life
    • Higher keeping quality in storage (Lower weight loss and high peel firmness)
    • Resistant to the adverse conditions during transportation and postharvest handling
  2. Additional cost for a farmer for growing tomatoes 50m2 land area by applying PBRH is around LKR 1,200
  3. Si treatment;
    • Increase the marketability compared to non- Si treated tomatoes
    • Delays the ripening of tomatoes – ideal for postharvest handling and improve the visual quality too
    • Si helps strengthen fruit cell walls and improves the outer cuticle thickness of the fruits – Increase the peel firmness
    • Helps to Retain firmness after 14 days of ambient and cold storage and have a longer shelf-life → Suitable for exports
    • Reduce the postharvest losses and cost effective

Publication

Weerahewa, D., Liyanage, J. and Rajapakse, S. (2024). “Food For the Future: Putting an old-fashioned ingredient in Rice Husks – silicon – to produce high quality tomatoes. FLM Briefing No. 6. ACIAR Food Loss Mitigation Project. Institute of Policy Studies of Sri Lanka. Colombo.