Determining Environmental and Biological Conditions Influencing Lettuce Discoloration, Yield and Leaf Quality

Lettuce is a popular but perishable product, and up to 46 percent of head lettuce and 55 percent of fresh romaine and leaf lettuce is wasted. A major cause of rejection is the postharvest discoloration of leaves, which can reduce flavor, nutrition, consumer appeal and shelf life. While postharvest methods of preventing discoloration can be costly and short-term, controlling the environmental conditions in which lettuce is grown can lead to longer shelf life and accelerated growth.

In its first project, our Precision Indoor Plants Consortium is convening researchers to determine how biological and environmental conditions during growth can influence lettuce postharvest discoloration, yield and leaf quality. The research includes examining the effects of changes in the indoor growth environment on traits of interest, and screening cultivars to determine which ones are the best for controlled environment agriculture. In addition, genetic markers and metabolites associated with these traits of interest are being identified, and candidate genes edited to obtain lines with longer shelf life.

Lettuce has a wealth of resources available to researchers, and the results of the project will have implications for growing lettuce in any environment and growing other crops in indoor systems. A variety of stakeholders will benefit from this project.

Growers

• Gain new lettuce cultivars that are less susceptible to discoloration and grow more quickly
• Learn protocols for growing plants in indoor systems

Environment

• Less food waste
• Reduces most resources used in production of lettuce
• Reduced net loss of resources due to low quality produce

Consumers

• Access to high-quality produce
• Longer lettuce shelf-life and less leaf discoloration

Researchers

• Advance our understanding of the interaction between environment and genetics
• Obtain applicable knowledge of the phytochemicals affecting leaf discoloration