The research team led by Prof. Antonio Elia at University of Foggia (Italy) has concluded the deliverable N. 4.21 of the Quafety project. The aim of the work was to strategically manage the nutrient solution (NS) and the soilless cultivation system (SS) in several "model" leafy vegetables for obtaining a raw material with high attitude for fresh-cut processing.
The Research Unit (RU) focused on the definition of an innovative growing protocol for leafy vegetables to produce raw material suitable for fresh-cut production in terms of safety, nutritional quality and shelf-life.The innovative protocols were based on soilless cultivation systems, considered the most intensive production method in today's horticulture industry.
The RU studied:
1) several model-species: lettuce, endive, escarole, and rocket salad;
2) different Electrical Conductivity (EC) levels of NS: EC1 ≈1.5 dS m-1, EC2 ≈2.5 dS m-1, EC3 ≈3.5 dS m-1, and EC4 ≈4.5 dS m-1;
3) two soilless systems: a modified Ebb and Flow (EF) system and a Floating System (FS) system.
The RU concluded the study with following recommendations for the best NS management in soilless system:
1. irrespective of the soilless system and genotype, EC level of NS should be close to 3.5 dS m-1. This level gives the best performance in terms of low nitrates, high antioxidant compounds and high dry matter contents as well as high shelf life of raw material;
2. among the SS systems, the modified Ebb and Flow (EF) system appears to be more suitable for lollo’ lettuce, while the Floating System (FS) performed the best with rocket salad, endive and escarole. EF requires a lower input of water and minerals, but the NS supply must not be lower than 3 applications per day;
3. nitrate content can be successfully lowered by using the abatement strategy of the substitution of the NS with water, but the strategy must not be used longer than the last 3 days before harvest.
For further info: http://www.freshplaza.com/article/131994/QUAFETY-Scientists-test-the-soilless-cultivation-systems-to-produce-leafy-vegetables-for-fresh-cut-industry