Growth of Sweetpotato in Lunar and Mars Simulants

Sweetpotato [Ipomoea batatas (L) Lam] cv ’TU-82-155’ was grown in Lunar or Mars simulants to evaluate growth and yield responses. Stem cuttings (15 cm long) were grown in Lunar (LS) or Mars (MS) simulants, or Turface (TF3; three cuttings) or (TF4; 4 cuttings). Plants were supplied with nutrient solutions through a microporous tube buried in the media. Plants were harvested 120 days after planting. The number of storage roots per unit area was greater among plants grown in MS and similar for plants grown in LS, TF3, and TF4. Storage root fresh and dry mass and percent dry mass were similar among media treatments. Foliage fresh mass and harvest index were also similar regardless of media used, while foliage dry mass was lowest among plants grown in LS. Nutrient solution pH remained close to the set point of 6.0 for the first 60 days but declined thereafter while EC was most stable among plants grown in MS. Total leaf area and number were greatest for plants in TF3 while stomatal conductance was greatest for plants in TF4. These results indicate that sweetpotato can be successfully grown in both Lunar and Mars simulants and would probably grow well in true planetary substrates.