ASHS 2015 Annual Conference

Tomatoes are the leading greenhouse vegetable grown in North America and the world. Grape, cherry and plum varieties are gaining popularity as a healthy snack food and are becoming more commonly grown in greenhouse production. Almost all greenhouse tomatoes are produced hydroponically using computerized production systems and grown in media such as rock-wool or coconut fiber. In the US and Canada, growers normally transplant new plants into their greenhouses in December and the first ripe tomatoes are produced in late March. A greenhouse experiment at the Dr. James S. Craigie Research Center in Cornwallis, Nova Scotia was designed to test the effects of Acadian^® extract (a derivative from Ascophyllum nodosum) in the production of hydroponically grown greenhouse grape tomatoes (Lycopersicon esculentum Mill. var. Amsterdam). Ascophyllum nodosum seaweed extract (ASE) treatments in combination with a standard hydroponic fertilizer were applied to the root systems of grape tomato plants through the irrigation system. Fruit production and quality of the ASE-treated plants was compared to fertilizer-only treated plants. With the inclusion of ASE into the fertilizer program, the average number of fruit produced per plant increased by 9.5% and the total weight of fruit per plant by 8.1%. An increase of 13.4% in fruit wall thickness and a 10.9% increase in skin firmness were observed in the ASE treatments as well. Both of these parameters may lead to improved shelf-life. These results indicated that ASE applications increased yields and improved the quality of hydroponically grown grape tomatoes which ultimately improves the economic return for the user.