Submitted to: Agronomy Journal
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/12/2012
Publication Date: 4/1/2012
Citation: Gitz, D.C., Xin, Z., Baker, J.T., Lascano, R.J., Burke, J.J. 2012. Effect of solar loading on greenhouse containers used in transpiration efficiency screening. Agronomy Journal. 104(2):388-392. Interpretive Summary: The crops we grow depend on irrigation to insure plentiful inexpensive food and fiber. But fresh water for drinking and for irrigating crops is becoming scarce in the United States and around the world. This could limit our food supply or make food much more expensive. We need crops that will produce more food with less water. Earlier we devised a simple method used in the greenhouse to test how efficiently plants use water. In this report we show how to make these tests even more reliably and with higher precision. We found that sunlight can make pots in the greenhouse get very hot. This heat can affect plant growth. We suggest that scientists should check container temperatures in the greenhouse and suggest how to avoid this problem.
Technical Abstract: Earlier we described a simple high throughput method of screening sorghum for transpiration efficiency (TE). Subsequently it was observed that while results were consistent between lines exhibiting high and low TE, ranking between lines with similar TE was variable. We hypothesized that variable micro-environmental conditions around individual plants introduced variation in soil temperature and influenced the TE. To test our hypothesis, two sorghum lines, TX-7078 and Liang Tang Ai, were grown in either conventional or in insulated containers and TE was determined as biomass/water transpired. Soil temperatures in sealed conventional thermoplastic containers exceeded 50° C. Plants grown in conventional containers developed more slowly than those grown in insulated containers. Our results showed that the effects of solar loading must be considered when designing TE screening tools or other physiological studies in greenhouses.