Bitterness and composition of lettuce varieties grown in the southeastern United States

Abstract

Lettuce (Lactuca sativa) production historically has been limited in the southeastern United States because of the risk of early bolting and unacceptable bitterness. Small-scale vegetable growers may be able to include lettuce in their production through selection of bolt tolerant and nonbitter varieties. The objectives of this research were to evaluate earliness, bitterness, vitamin E, ascorbic acid, folate, β-carotene, and lutein content in 17 lettuce varieties. Significant difference were found among varieties for days to harvest (DTH) (47 DTH for 'Epic' to 37 DTH for 'Big Curly'). Observed DTH in this study was consistently 7 to 10 days less than commercial descriptions of the lettuce varieties, due to the use of transplants. Only 'Slobolt' and 'Greengo' bolted before reaching marketable size. Panelists found that the bitterness was acceptable for most varieties, but not for 'Nancy,' 'Big Curly,' and 'Slobolt'. Significant differences among varieties were also found in vitamin E, ascorbic acid, folate, β-carotene, and lutein. 'Redprize' and 'Nevada' were the best varieties overall, while 'Salinas 88 Supreme,' 'Epic,' 'Legacy,' 'Big Curly,' 'Slobolt,' and 'Greengo' were unacceptable.