Submitted to: American Oil Chemists' Society Meeting
Publication Type: Abstract Only
Publication Acceptance Date: May 16, 2001
Publication Date: May 16, 2001
Citation: SHARRATT, B.S., GESCH, R.W., FORCELLA, F., VOORHEES, W.B. WATER USE AND WATER USE EFFICIENCY OF CUPHEA. AMERICAN OIL CHEMISTS' SOCIETY. 2001. P. S72. Technical Abstract: Seed oil of Cuphea contains saturated fatty acids that are only commercially available through import of coconut and palm kernel oils. The potential value of Cuphea for American agriculture thereby demands a thorough understanding of physiological processes that will improve domestication and production of Cuphea. This study evaluated water use of Cuphea sown on various dates and at different plant densities in the northern Corn Belt. Cuphea was sown biweekly beginning May 3 at a population of 328000, 164000, and 82000 seeds ha**-1. Row spacing was 0.6 m within 4 row by 2 m plots. Crop water use was determined by assessing changes in soil water content to a depth of 1.5 m using neutron attenuation. Precipitation data was available from a weather station located within 200 m of the experimental plots. Cuphea was hand harvested when the bottom pods began to shatter. Seasonal water use appeared to diminish as sowing was delayed, ranging from 33 cm for the early sowing to 26 cm for the late sowing. Plant population had no influence on water use. Total above ground biomass and grain yield was greatest for the middle sowing date and least for the late sowing date. Biomass and yield decreased with a decrease in plant population. Water-use efficiency ranged from about 15 kg ha**-1 cm**-1 for the middle sowing date to 10 kg ha**-1 cm**-1 for the late sowing date. Water-use efficiency also declined with a decrease in plant population. Water stress was observed near the time of harvest, but only for the late sowing. This study indicates that Cuphea production diminishes as sowing date is delayed beyond mid-May in the northern Corn Belt due to increased water stress later in the growing season.