Analysis of Drought Tolerance and Water Use Efficiency in Castor, Cotton, and Sorghum.

Water management and water use efficiency have become real issues amid agriculture production throughout the country.  In water limiting conditions, it is imperative to better understand crop water use efficiency.  The objective of this study was to establish a base line for irrigation among castor, cotton, and sorghum.  There were thirteen irrigation levels beginning with non-irrigated increasing at a .02” rate, the highest rate being .24”.  Crop growth rates were monitored with a LI-COR light bar.  Water use patterns were monitored using a Troxler 4301 neutron probe.  Relationships between soil water and water potential and leaf water potential were measured using thermocouple phsychomotors and the LI-COR 6400 portable photosynthesis system.  These results could possibly provide useful information for deficit irrigation and the most profitable irrigation levels for crop combinations.