Growth and yield of different leaf-type lettuce cultivars grown in protected and open field cultivation

Leafy vegetable production in the Philippines is less diversified than many other countries, especially those used in salads. As a result, Filipino farmers are less familiar with production of leaf-type lettuce that is increasing in popularity with consumers. Therefore, two separate experiments were conducted simultaneously in open field and under bamboo house-type protective structures roofed with plastic to evaluate the performance and profitability of different leaf-type lettuce cultivars. Each study was carried out in randomized complete block design with five treatment cultivars and three replications. Most cultivars grown under protective structures had higher marketable yields than those grown in the open field. Despite plants grown under protective structures incurring higher production costs compared to the open field, higher marketable yields under protective structures resulted in higher net returns. Among the five cultivars, Green Span gave the highest return in the open field and Green Tower under the protective structure. Smaller lettuce cultivars produced lower yields than bigger cultivars.