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Fluid Journal : Late Spring 2012
Late Spring 2012 Figure 1. Grain yield (kg ha-1 ) and protein percentage results from Lahoma, OK location. Error bars represent standard error of each treatment. Treatment titles shown as: nitrogen rate in kg N ha-1 , nitrogen source, and application timing. 8 12 16 20 0 1000 2000 3000 4000 5000 6000 %ProteinGrainYieldkgha-1 Treatment Rate (kg N ha) Source Timing 1 Check Unfertilized Check 2 Rec Fert $ 3 6.7 UAN Flag Leaf 4 13.4 UAN Flag Leaf 5 26.8 UAN Flag Leaf 6 6.7 CoRoN Flag Leaf 7 13.4 CoRoN Flag Leaf 8 26.8 CoRoN Flag Leaf 9 6.7 UAN Post Anthesis 10 13.4 UAN Post Anthesis 11 26.8 UAN Post Anthesis 12 6.7 CoRoN Post Anthesis 13 13.4 CoRoN Post Anthesis 14 26.8 CoRoN Post Anthesis Table 1. Treatment structure for the impact of foliar N on baking and milling qualities of hard red winter wheat. Standard fertility quality is based on yield goal recommendations and soil test results. The yield goal N rates at Lahoma and LCB were 112 kg N ha-1 and 84 kg N ha-1 , respectively. 5,400 kg ha-1 . However, there was a great deal of variation across treatments so no significant difference was seen in yields. The coefficient of variation of the yields was 18. No main effects of interactions were significant. Protein. Analysis of protein showed no significant difference in protein values across treatments. The treatments receiving 13.4 kg N ha-1 post-anthesis achieved the highest protein values. There was a significant rate by time interaction at p of .095. Yield and protein results are shown in Figure 1. Mixing tolerance is a ranked value with a score from 0-6; values above 3 are preferred. The results from the Lahoma wheat samples showed significant differences across treatments. Three treatments fell below the industry preferences: 27 kg N ha-1 CoRoN post-anthesis, 13 kg N ha-1 CoRoN flag leaf, and check. The treatments receiving 13.4 kg N ha-1 post-anthesis and the 7 kg N ha-1 UAN at flag leaf had the highest mixing tolerance scores (Figure 2). Source was significant at .0013, with UAN at 3.67 and CoRoN at 2.94. Also rate by time interaction was significant at .0 091. Loaf volume. The hard winter wheat Quality Targets Committee gives a recommended target Loaf Volume of 850 cc or greater. At the Lahoma location only one treatment yielded a Loaf Volume sufficient to meet the committee’s recommendation of 13 kg N ha-1 CoRoN applied post anthesis (Figure 3). There was no significant main effect or interactions with the Loaf Volume data from Lahoma. LCB Yields. The Lake Carl Blackwell (LCB) location is near Stillwater and situated on a lower class of soils that will typically have lower yields than the Lahaoma site. The 2011 harvest resulted in yields ranging from 1,700 to 2,200 kg ha-1 . There was no significant difference in yields across treatments, however the check and standard fertility treatments did result in the lowest yields (Figure 4). Protein data from LCB showed results of which could be considered expected. Standard fertility significantly increased protein above 2012 Southwest Fertilizer Conference July 14-18, 2012 San Antonio, Texas For more information and to register, visit: www.swfertilizer.org
Early Spring 2012