Evaluation of Several Lettuce (Latuca sativaL.) Cultivars Grown Inside a Greenhouse Using Nutrient Film Technique

Abstract

Small greenhouse and outdoor hydroponic growers in Florida have recently shown an increased interest in growing a wide variety of vegetables for local direct to consumer sales. These markets typically demand a diversity of vegetables to be offered and even diversity within a particular crop. This demand would include leafy vegetables such as lettuce (Latuca sativaL.) and would also likely include many different types, cultivars, and colors of lettuce. Very few lettuce cultivar trials have been conducted in Florida to provide recommendations on the best types or cultivars within various types of lettuce that are suitable for greenhouse production. A randomized complete-block design trial replicated three times was conducted at the Suwannee Valley Agricultural Extension Center in Live Oak, FL, during the winter and spring of 2012. The trial was conducted using the nutrient film technique in channels 4 inches wide and 10 ft long. Fifteen cultivars of various types of lettuce were evaluated for yield, color, susceptibility to tip burn, and overall quality
appearance. Lettuce types included romaine, bibb, butterhead, and lollo. Several cultivars performed well in yield and quality during the first trial in January when temperatures were moderate. However, during the subsequent trials, temperatures were unusually high and several cultivars showed susceptibility to leaf tip burn, a common calcium-related disorder in lettuces grown in warm greenhouses. The trial results showed the best adapted cultivars for Florida greenhouse production using nutrient film technique culture and also showed varieties that are not appropriate in Florida due to size, quality, or leaf tip burn concerns.