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Irradiance and Nitrogen to Potassium Ratio Influences Sweetpotato Yield in Nutrient Film Technique
Author(s) -
Mortley Desmond G.,
Bonsi C. K.,
Hill Walter A.,
Loretan P. A.,
Morris C. E.
Publication year - 1993
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1993.0011183x003300040030x
Subject(s) - ipomoea , nutrient , shading , vine , yield (engineering) , biology , cutting , cultivar , photosynthesis , nitrogen , horticulture , potassium , herbaceous plant , agronomy , botany , chemistry , materials science , ecology , art , organic chemistry , metallurgy , visual arts
Sweet potato [ Ipomoea batatas (L.) Lam] is being grown with the nutrient film technique as part of the National Aeronautics and Space Administration's Controlled Ecological Life Support System (CELSS) program for long‐termed manned space missions. Our objective was to evaluated the effects of two levels of photosynthetic photon flux (480 and 960 μmols m −2 s −1 PPF) and three N/K ratios (1:1.1, 1:2.4, and 1:3.6) on yield of sweetpotato when grown using this technique. Vine cuttings (15‐cm length) of ‘Georgia Jet’ and T1‐155 were grown in each treatment for 90 or 120d, respectively, in controlled‐environment growth chambers. Storage root growth for Georgia Jet and T1‐155 increased with light intensity, while foliage growth decreased with high K levels. The number of storage roots produced by each plant increased with intensity only for Georgia Jet but was not significantly influenced by higher K levels for either cultivar. Light by N/K interactions were not significant. The level of PPF exerted a greater effect in enhancing sweetpotato storage root yield in nutrient film than did N/K ratio.