USA: Study evaluates pink rib disorder tolerance in lettuce germplasm in humid subtropical environments

Lettuce (Lactuca sativa) is primarily produced in the United States in California, Arizona, and Florida, with a production value of $2.7 billion (USDA-NASS 2021). Florida produces an estimated 3% of the total lettuce in the United States (USDA-NASS 2019), primarily in the Everglades Agricultural Area, which is a humid subtropical region in southern Florida. Despite this relatively low proportion of the industry in the United States, lettuce grown in Florida has significant market demand because it is harvested during winter and spring months.The expected shelf life of lettuce is 2 to 3 weeks when promptly cooled and held at 1 °C and 95% to 100% relative humidity. Shelf life is limited by several postharvest factors, including physiological disorders such as russet spotting, brown stain, and pink rib or pinking. Maintaining recommended field and postharvest conditions reduces its incidence but does not eliminate these disorders.During the past decade, research has identified ...