Growth chamber studies showed that a relationship exists between transpiration and dry matter production of spring wheat (Tritiaum Aestivum L. var . Thatcher). A temperature of 27 C for a 16-hour day,and 21 C at night were used throughout the experiment. Relative humidities (RH) of 12, 25, 71, and 83 percent and matric suctions of 1, 3, and 9 bars were used a l ong with six fertility levels and a 20-day growing period. An equation was developed from previous equations by De Wit and Arkley to describe the transpiration ratio (Tr = mass of water transpired/mass of dry matter produced) as it relates to evaporative demand conditions measured by humidity and pan evaporation. Time and fertility effects were not included because of insufficient data.
As humidity both increases and decreases from 25 percent, the transpiration ratio decreases. Increasing levels of matric suction had an effect on Tr only at 25 percent RH. As fertility increased, Tr decreased toward some minimum level. Tr seems to reach a stable maximum as plants mature under steady state conditions.
| Identifer | oai:union.ndltd.org:UTAHS/oai:digitalcommons.usu.edu:etd-4668 |
| Date | 01 May 1970 |
| Creators | Warrington, Gordon Edgar |
| Publisher | DigitalCommons@USU |
| Source Sets | Utah State University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | All Graduate Theses and Dissertations |
| Rights | Copyright for this work is held by the author. Transmission or reproduction of materials protected by copyright beyond that allowed by fair use requires the written permission of the copyright owners. Works not in the public domain cannot be commercially exploited without permission of the copyright owner. Responsibility for any use rests exclusively with the user. For more information contact Andrew Wesolek (andrew.wesolek@usu.edu). |
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