Abstract
Cuphea (Cuphea viscosissima Jacq. X C. lanceolata W.T. Aiton; PSR23) is a new oilseed crop adapted to temperate climates that provides a rich source of medium-chain triglycerides. Although prior research indicated cuphea seed yield is not greatly affected by row spacing due to its indeterminate growth, little is known about optimum seeding rate. The present study was designed to test effects of varying seeding rate with row spacing on seed yield. Seed was sown at rates of 4.5, 9.0, and 13.4 kg ha−1 in 380, 560, and 740 mm spaced rows in west central Minnesota during 2002 and 2003. Seeding rate did have a significant effect on seed yield and harvest index in 2002, but not in 2003. In 2002, yield under the 9.0 kg ha−1 rate was 47 and 19% greater than the highest and lowest seeding rates, respectively. The interaction of row spacing and seeding rate was generally not significant. Cuphea does have good yield plasticity over a range of row spacing and seeding rates. However, results generally indicated that a seeding rate of around 9.0 kg ha−1 is near optimum for PSR23 cuphea production and that row spacing less than 740 mm tended to favor greater seed and biomass yields.
Research highlights
Cuphea is a new oilseed crop that grows well in temperate climates and produces oil rich in medium-chain fatty acids. A field experiment was designed and conducted to determine the effects of seeding rate and row spacing on cuphea seed and biomass yield. Results showed that cuphea has good yield compensation or plasticity over a range of row spacing and seeding rates. However, results generally indicated that a seeding rate of around 9.0 kg ha−1 is near optimum for PSR23 cuphea production and that row spacing less than 740 mm tended to favor greater seed and biomass yields.
Keywords
Cuphea; Seed yield; Planting rate; Row spacing