Hobbyists have successfully grown plants upside down for more than twenty years, but few scientific studies have reported plant growth and development using inverted (upside down) horticulture. Despite high yields, many hobbyists have noted that some inverted plants appear “leggy”, with elongated stems. Plants exposed to different light recipes often have slightly varied morphology, so exposing the inverted plants to various light recipes will allow me to examine whether the light recipe will reduce the elongated stems of inverted “Outredgeous” lettuce plants. I will grow upright and inverted plants under four light quality treatments of white LEDs with or without additional blue light (25, 50, 75%).
NASA is considering several space-efficient plant growth chamber designs for weightless (microgravity) conditions, including growth chambers which hold plants upside down. This is no problem for the plants in space transit, since there is no “up” or “down” in microgravity. However, as NASA moves forward with its long-term goal of crewed expeditions to the surface of Mars, they will need those growth chambers to function well in conditions with Mars-like gravity. By characterizing the effects of light recipe on lettuce growth, morphology, and physiology, this experiment will help us understand how we can best grow plants upside down on Earth, the Moon, and Mars.