Submitted to: Research Day Abstracts: Regional Universities Research Day
Publication Type: Abstract only
Publication Acceptance Date: 11/26/2006
Publication Date: 12/1/2006
Citation: Muniz, M., Dalbow, D., Mackown, C.T. 2006. Effects of water stress on cotton fiber quality and price [abstract]. Research Day Abstracts: Regional Universities Research Day, Dec. 1, 2006, Oklahoma City, OK. Available on-line: http://broncho2.uco.edu/facres/forms_downloads/Abstracts-06.pdf Interpretive Summary: ABSTRACT ONLY
Technical Abstract: Wheat is considered good forage, but excessive nitrate accumulation can pose risks to ruminants. This research contrasted two wheat cultivars (cv) for total N and nitrate in a hay crop. Winter wheat cv. 2174 and Endurance were planted late September 2005 in a strip-plot experimental design with four reps and received one of six N fertilizer treatments (0-448 kg N/ha). Hay samples from mid April at Feekes growth stage 10.5 were divided into stem and leaf blades for analysis of total N and nitrate. Hay yields of both cv were similar and differed due to N fertilizer treatments. Distribution of dry matter between stem and leaf blades was unaffected by cv and only the stems differed significantly among the N treatments. As N fertilizer increased, stem total N of both cv increased linearly from 103 to 159 g/kg crude protein (CP). In contrast, the response of leaf blade total N for both cv was quadratic and ranged from 179 to 268 g/kg CP between 0 and 224 kg N/ha. Stem nitrate for both cv were similar and the nitrate levels of leaf blades and stems of Endurance were similar while that of 2174 leaf blades was 50% less than the stem nitrate. For both cv, stem and leaf blade nitrate levels increased in direct proportion to increasing N fertilizer. Only at the highest N fertilizer application to Endurance did forage nitrate exceed a level considered safe for ruminants. These results demonstrate that nitrate level and partitioning can be managed by cv selection and amount of fertilizer N used.