Agricultural and Forestry Experiment Station

Strawberry and bell pepper production and plant growth under LEDs are just some of the research projects in the AFES Westridge greenhouse attached to the Arctic Health Building. Meriam Karlsson, a professor of horticulture and a specialist in greenhouse crop production, indoor farming and controlled environment production, leads these projects. Her focus is improving methods of greenhouse food production for Alaskan commercial growers.

There is a high interest in commercial greenhouse strawberry production in Alaska. Karlsson found that strawberry plants grow so well in the AFES greenhouse that they flowered over winter, and Karlsson was flooded with fresh strawberries in February! Two varieties of strawberries are grown in the greenhouse: Albion, an everbearing variety and Cabota, a June-bearing variety.

Bell peppers have been grown in the AFES greenhouse for almost a decade. Research focuses on the best methods for growing peppers, local peppers' nutritional value compared to imported peppers, and their viability as a commercial crop. Currently, Karlsson is investigating how well peppers grow with inter-canopy lights hung at different heights.

Karlsson experiments with different colors of LEDs (light-emitting diodes) for the best growth response in plants. She walls off her study plants to prevent light pollution from sunlight or overhead lighting. Blue, red and violet colored lights help plants achieve different goals. Blue light, for example, tends to suppress or delay flowering in spinach, which means a leafier plant and more food. Red light will prevent flowering in short-day plants and the opposite in long-day plants. Understanding how different plants respond to different lights allows researchers to increase crop yield and maximize plant growth, flowering, or fruit production.