Seascape strawberries are day-neutral, meaning they aren't sensitive to the length of available daylight to flower. Seascape was tested with as much as 20 hours of daylight and as little as 10 hours. While there were fewer strawberries with less light, each berry was larger and the volume of the yields was statistically the same.
The findings are detailed in Advances in Space Research.
It almost looks like they're floating
(Photo Credit: Purdue Agricultural Communication photo/Tom Campbell)
Strawberry plants are relatively small, meeting mass and volume restrictions. Since Seascape provides fewer, but larger, berries under short days, there is less labor required of crew members who would have to pollinate and harvest the plants by hand. Needing less light cuts down energy requirements not only for lamps, but also for systems that would have to remove heat created by those lights.
"We're trying to think of the whole system -- growing food, preparing it and getting rid of the waste," said Gioia Massa, a horticulture research scientist at Purdue. "Strawberries are easy to prepare and there's little waste."
Seascape also had less cycling, meaning it steadily supplied fruit throughout the test period. Massa said the plants kept producing fruit for about six months after starting to flower.
The earliest space crops will likely be part of a "salad machine," a small growth unit that will provide fresh produce that can supplement traditional space meals. Crops being considered include lettuces, radishes and tomatoes. Strawberries may be the only sweet fruit being considered.
Researchers say they next plan to test Seascape strawberries using LED lighting, hydroponics and different temperature ranges.
Gioia D. Massa, Judith B. Santini, Cary A. Mitchell, 'Minimizing energy utilization for growing strawberries during long-duration space habitation', Advances In Space Research, February 2010; doi:10.1016/j.asr.2010.02.025