Thesis
Defining in-season nitrogen needs for maximum economic yields and quality for Alturas and Premier Russet
Washington State University
Master of Science (MS), Washington State University
2010
Handle:
https://hdl.handle.net/2376/102940
Abstract
Proper nitrogen (N) management is a crucial component of potato cropping systems. Rapid adoption of two new cultivars, Alturas and Premier Russet, has necessitated the development of appropriate in-season N fertilizer recommendations tailored to each cultivar. A three year study was performed at the WSU Research Station in Othello, Washington to determine an in-season N rate that would maximize grower revenue and optimize field performance for each cultivar. Five in-season N rates were applied: 0, 25, 50, 100, and 150% of typical Russet Burbank fertilizer rates. Petiole and soil N values from each treatment were distinctly different from each other. Typically, higher N rates produced higher petiole and soil N values. Vine senescence at 141 days after planting (DAP) was hastened as in-season N rate decreased. As in-season N rates increased, total yield typically increased. Alturas total yield peaked at the 150% treatment (355 lbs in-season N/A) while Premier peaked at 125% (300 lbs in-season N/A). As N rate increased, specific gravity decreased significantly. In Alturas, revenue was optimized at 108% of the typical in-season N rate (259 lbs in-season N/A) for Russet Burbank, while Premier revenue was highest at 100% (240 lbs in-season N/A) of the standard rate. An additional component of the study was to establish the efficacy of a chlorophyll meter for in situ determination of current crop N status. SPAD readings were recorded in Premier once per week throughout the growing season and results regressed against corresponding petiole NO3-N concentrations as well as leaf and petiole total N (2008 data not included). The relationship between SPAD and petiole NO3-N, leaf total N, and petiole total N were strong in 2007, but poor relationships were found in 2009. In general, SPAD correlated well with petiole NO3-N concentrations of approximately 0.5 to 2.0%, but was not as responsive or precise to reflect treatment variations as was traditional petiole NO3-N analysis. At petiole NO3-N % above 2.0, the plant canopy was too green for SPAD to reliably predict crop N.
Metrics
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Details
- Title
- Defining in-season nitrogen needs for maximum economic yields and quality for Alturas and Premier Russet
- Creators
- Christopher D. Hiles
- Contributors
- Mark J. Pavek (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Horticulture, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; Pullman, Wash. :
- Identifiers
- 99900525055901842
- Language
- English
- Resource Type
- Thesis