Greenhouse spinach production in a NFT system

Area of Science:

• Horticulture
• Plant Physiology
• Agricultural Engineering

Background:

• Controlled environment agriculture (CEA) is crucial for year-round crop production.
• Spinach (Spinacia oleracea L.) is a valuable crop for CEA systems.
• Optimizing light and managing root diseases are key challenges in NFT systems.

Purpose of the Study:

• To determine the relationship between light levels and spinach dry weight production in NFT systems.
• To identify potential toxic thresholds for chlorine in nutrient solutions.
• To assess the efficacy of various treatments against Fusarium root rot in spinach.

Main Methods:

• Spinach seedlings were grown in a controlled environment greenhouse using Nutrient Film Technique (NFT) systems.
• Different daily light integrals (mol m-2 d-1) were applied using HPS lamps.
• Dry weight was measured, and an expolinear growth equation was used for prediction.
• Nutrient solution chlorine levels and root health were monitored.

Main Results:

• Spinach dry weight production was predictable based on daily light levels using an expolinear growth equation.
• Chlorine residuals exceeding 1 ppm in the nutrient solution were toxic to spinach.
• Fusarium was identified as the causal agent of root rot, and tested remedies were unsuccessful.

Conclusions:

• Daily light integral is a critical factor for optimizing spinach yield in NFT systems.
• Maintaining low chlorine levels in nutrient solutions is essential to prevent toxicity.
• Effective management strategies for Fusarium root rot in spinach require further investigation.