A field experiment was conducted on a Pima clay loam at the Safford Agricultural Center to: 1) determine the optimum rates of late season N needed to achieve optimum yield and quality of irrigated durum wheat in conjunction with varying rates of early season N; and 2) evaluate the usefulness of stern NO₃-N analysis in predicting the late season N rates which optimize grain production but minimize the potential for nitrate pollution of groundwater. The application of 75, 175 and 350 lbs. N/a during vegetative growth resulted in wheat with deficient, sufficient and excessive N status at the boot stage, as indicated by stem NO₃-N analysis. The application of 60 lbs. N/a at heading to N- deficient wheat and 15-20 lbs. N/a to N-sufficient wheat resulted in grain protein levels above 14 %, but the applications had little effecton grain yield. Applications of N at heading to wheat which had previously received excessive N did not affect grain yield or quality. The use of stein NO₃-N analysis appears to be a useful tool in predicting the minimum N rate to be applied during the early reproductive period to insure acceptable levels of grain protein at harvest.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/201074 |
| Date | 09 1900 |
| Creators | Doerge, T. A., Knowles, T. C., Clark, L., Carpenter, E. |
| Contributors | Ottman, Michael, Kingdon, Lorraine |
| Publisher | College of Agriculture, University of Arizona (Tucson, AZ) |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | text, Article |
| Relation | 370079, Series P-79 |
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