Dissertation
The Effects and Economic Implications of Differing Phosphorus Fertilizer Sources, Application Techniques and Rates in the Columbia Basin
Washington State University
Doctor of Philosophy (PhD), Washington State University
01/2021
DOI:
https://doi.org/10.7273/000005435
Handle:
https://hdl.handle.net/2376/118940
Abstract
Phosphorus (P) is one of the most expensive inputs in commercial potato (Solanum tuberosum) production. Existing guidelines for P management are limited in the Columbia Basin and those that do exist have limited information for many of the new clones being grown for the frozen potato process market. During 2014-2016, two trials were conducted to assess the response of Umatilla Russet (R.) to varying sources of P fertilizer (MicroEssentials Sulfur and Zinc (MESZ), Avail, Accomplish, and industry standard ammonium polyphosphate (10-34-0)) rates (0, 128, 254, and 508 kg phosphorus pentoxide (P2O5) per hectare (ha)), and application techniques (band, broadcast, in-season, split application). All sources of P fertilizer increased yield over the untreated control (UTC), but only Accomplish and 10-34-0 provided a significant improvement in economic return. All application rates significantly increased yield compared to the UTC, but rates of 508 kg P2O5/ha reduced economic return of 3% compared to 254 kg P2O5/ha. All methods of application improved yield over the UTC, but only band and split applications significantly improved economic return. All sources of P fertilizer, application rates and techniques tended to reduce the yield of undersized tubers (<114 grams (g)) and increase the yield of tubers >227g. In conjunction to this work, a third study was conducted from 2013-2015 to assess the postharvest quality retention of seven clones (Alpine R., Alturas, Ranger R., R. Burbank, Sage R., Teton R., and Umatilla R.) when treated with high (508 kg P2O5/ha) and low (0 kg P2O5/ha) levels of P fertility. Five of the seven clones treated with high P fertility accumulated significantly more P content than the low P treated tubers. P fertility did not affect tuber specific gravity at final harvest. High P fertility significantly increased basal end photovolt reflectance as well as reducing sugar (RS) content, but a cultivar effect was noted. Our data suggests that standard sources of P fertility, banding and split applications of P, and rates of 254 kg P2O5/ha appear optimal for Umatilla R. P fertility also appears to play a role in postharvest quality retention of stored tubers.
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Details
- Title
- The Effects and Economic Implications of Differing Phosphorus Fertilizer Sources, Application Techniques and Rates in the Columbia Basin
- Creators
- Chandler James Dolezal
- Contributors
- Mark J Pavek (Advisor)Norman R Knowles (Committee Member)Carrie H Wohleb (Committee Member)Robert Thornton (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Department of Horticulture
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 101
- Identifiers
- 99900592055601842
- Language
- English
- Resource Type
- Dissertation