Adaptability of Cuphea, a New Oil Seed Crop, to Climate and Soil Environments.

Cuphea, a new oilseed crop rich in medium-chain fatty acids (C8:0 to C14:0), may serve as a renewable, biodegradable source of oil for lubricants, motor oil, and aircraft fuel. Impacts of climate and soil environment on cuphea growth and development are not well understood. The objective of this study was to evaluate influences of climate and soil characteristics on growth, yield, and seed oil of several cuphea genotypes differing in their fatty acid profiles and agronomic characteristics. Six genotypes [PSR23 (Cuphea viscosissima x C. lanceolata), HC-10, blizzard, Cuphea wrightii, C. lutea, and VS-6 (C. lanceolata)] were grown at experimental sites in ND, MN, IA, and IL. Air temperature, precipitation, and soil-water content were monitored at each site and soil samples (0-15 and 15-60 cm) were taken before planting and after harvest for chemical and physical analysis. Seed oil and medium-chain fatty acid (MCFA) profile were analyzed. Growing season air temperatures and precipitation increased from north to south (ND< MN< IA< IL). PSR23, HC10, and blizzard appeared to be more regionally adapted than VS-6, wrightii, and lutea. Regardless of genotype, high temperatures affected seed yield. Seed yields were as much as 3-4 times greater in MN and ND than at IA and IL sites. Oil content for PSR23 was 5-6% higher in the MN and ND than in the IA and IL sites. Although oil content was greater at the northerly sites, but the content of key fatty acids such as C10, C12, and C8 for various genotypes increased with more southerly latitude. These results will aid in develop specific regional cuphea genotype management based on site-specific climate changes and temporal and spatial soil environment as welll as identify ky plant characteristics for future improvement.