Variability in strawberry tunnels impacts fruit quality and limits melatonin effects

Area of Science:

• Agricultural Science
• Horticultural Science
• Plant Physiology

Background:

• Environmental fluctuations and crop performance variability significantly impact agricultural production and quality standards, especially for producers with tight profit margins.
• These challenges are often amplified at the end of the crop season when conditions are less than optimal.
• This study investigates strawberry (Fragaria × ananassa) nutritional quality under varying end-of-season conditions.

Purpose of the Study:

• To assess the impact of harvest timing, tunnel microclimate, and inter-individual plant variability on strawberry nutritional quality.
• To evaluate the effectiveness of sprayed melatonin in mitigating end-of-season quality declines.
• To understand the factors contributing to fruit quality variation in commercial strawberry production.

Main Methods:

• Two harvests were conducted three weeks apart in a Mediterranean production tunnel divided into blocks.
• Environmental factors, including light radiation within the tunnel, were monitored.
• Inter-individual plant variability in nutrient content was assessed.
• Fruit hydration, antioxidant capacity, and ripening-related hormones were analyzed.
• The effects of melatonin application were evaluated.

Main Results:

• End-season harvesting negatively affected fruit hydration, antioxidant capacity, and ripening hormones.
• Tunnel microclimate, particularly light radiation, influenced nutritional quality and antioxidant content.
• Inter-individual plant variability accounted for 20% of nutrient variation and correlated with fruit hydration and hormones.
• Melatonin application did not significantly impact fruit production or nutritional parameters, with effects masked by inherent plant variability.

Conclusions:

• Fruit quality variation in strawberries is driven by a combination of environmental factors and inherent inter-individual plant variability.
• The application of regulatory molecules like melatonin may have limited success in heterogeneous field conditions.
• Reducing microclimate variability within production fields is crucial for maintaining consistent fruit quality and advancing agricultural practices.