1. Irrigation and Nitrogen Management Systems for Enhancing Hard Spring Wheat Protein J. Stark, E. Souza, B. Brown, and J. Windes University of Idaho

2. Factors Affecting Grain Protein Concentration and Quality Fertility Water Temperature ? Variety

4. 906-R 1986 Grain Protein (%)

5. 1989 - Pondera Grain Protein (%) Preplant Nitrogen (kg N/ha)

7. Increase in Flag Leaf Nitrogen Resulting From Topdress Nitrogen at Heading Increase in Flag Leaf N at Milk Stage (%) Flag Leaf Nitrogen at Heading (%) 3.2 3.4 3.6 3.8 4.0 4.2 4.4 4.6 20 lbs N/acre y =1.65-0.37x r 2 = 0.83 y =1.65-0.37x r 2 = 0.83 40 lbs N/acre y =2.48-0.55x r 2 =0.90 y =2.48-0.55x r 2 =0.90

8. Flag Leaf Nitrogen vs Protein, Aberdeen, 1989 - 1991 Flag Leaf Nitrogen at Milk Stage (%) Grain Protein (%) Pondera y = 7.47+1.79x r 2 =0.85 Copper y = 6.15+1.88x r 2 =0.85

9. Increase in Grain Protein (%) as Related to Topdress Nitrogen and Flag Leaf Nitrogen at Heading Increase in Grain Protein (%) Flag Leaf Nitrogen at Heading (%) 20 lbs N/acre y =1.81-0.40x r 2 = 0.86 y =1.81-0.40x r 2 = 0.86 40 lbs N/acre y =2.52-0.56x r 2 =0.88 y =2.52-0.56x r 2 =0.88 3.2 3.4 3.6 3.8 4.0 4.2 4.4 4.6

10. 2000-2001 Nitrogen Timing – Protein Quality Variety – Iona HRS Preplant N – 0, 60 lbs N / acre Topdress N – 0, 20, 40 lbs N / acre Topdress timings – tillering boot, and flowering

11. 2000 ANOVA NSNSNSNSNSNS Topdress x Timing (RxT) ****NS***** Topdress N Rate ( R) NSNSNSNSNSNS Topdress N Timing (T) NSNSNS*NSNS Preplant x Timing (PxT) ***NS***NS Preplant N (P) LoafVolSedValuesFlourYieldFlourProtGrainProt Test Wt Source NS = Not significant *, ** = Significant at 0.05 and 0.01, respectively

12. Grain Protein as Influenced by Topdress Nitrogen Grain Protein (%) 2001 2000 Std.err. = 0.35 Std.err. = 0.19

13. Loaf Volume as Influenced by Topdress Nitrogen Loaf Volume (mL) 2001 2000 Std.err. = 23.4 Std.err. = 20.9

14. Loaf Volume to Grain Protein Ratios 2001 2000 Loaf Volume (mL) Grain Protein (%) tiller boot flower Growth Stage at Topdress N Application:

15. Flour Yield to Grain Protein Ratios 2001 2000 Flour Yield (%) Grain Protein (%) tiller boot flower Growth Stage at Topdress N Application:

16. N Rate x Irrigation Cut-off Timing (1999-2000) 4 Cultivars: IDO 377s (HWS), Lolo (HWS), 4 Cultivars: IDO 377s (HWS), Lolo (HWS), IDO 523 (HWS), Westbred 936 (HRS) IDO 523 (HWS), Westbred 936 (HRS) 4 N Rates (soil and fertilizer N): 112, 202, 4 N Rates (soil and fertilizer N): 112, 202, 291, 381 kg N ha -1 291, 381 kg N ha -1 3 Irrigation Cut-off Timings: milk (Z75), 3 Irrigation Cut-off Timings: milk (Z75), early dough (Z83), soft dough (Z86) early dough (Z83), soft dough (Z86)

17. Irrigation Effects on Yield Components Irrigation SpikeKernelKernelGrain cut-offdensityweightnumber yield cut-offdensityweightnumber yield spikes m -1 mg kernel -1 kernels spike -1 kg ha -1 Milk 94 36.9 55 6722 Soft dough 105 41.7 53 8843 Early dough 96 40.2 53 7512 Std.err.22 1.64 1439

18. Nitrogen Effects on Yield Components SpikeKernelKernelGrain SpikeKernelKernelGrain N ratedensityweightnumber yield kg N ha -1 spikes m -1 mg kernel -1 kernels spike -1 kg ha -1 112 8641.8 526812 381 11036.7 557868 291 10738.4 558176 202 9141.6 537976 Std.err.21 1.64 1434

19. Flour Protein Irrigation Cut-off N Rate MilkEarly doughSoft dough Kg N ha -1 % 11211.0 11.4 11.3 20211.6 12.0 11.5 29112.4 12.3 11.5 38112.9 12.6 11.8 Std. Err. 0.5

20. Change in Test Weight With Timing of Irrigation Cut-off Nitrogen Rate (kg N ha -1 ) Test Weight (kg hL -1 ) Std.err. = 0.5

21. Change in Kernel Weight With Timing of Irrigation Cut-off Nitrogen Rate (kg N ha -1 ) Kernel Weight (mg) Std.err. = 1.7

22. Change in Flour Yield With Timing of Irrigation Cut-off Flour Yield (%) Nitrogen Rate (kg N ha -1 ) Std.err. = 1.0

23. Flour Yield to Protein Ratios Over Three Irrigation Treatments Flour Yield (g kg -1 ) Flour Protein (%) early moderate optimal

24. Change in Loaf Volume With Timing of Irrigation Cut-off Nitrogen Rate (kg N ha -1 ) Loaf Volume (mL) Std.err. = 32

25. Loaf Volume to Protein Ratios Over Three Irrigation Treatments Loaf Volume (mL) Flour Protein (%) early moderate optimal

26. HRS Response to Late Season N as Affected by Moisture During Grain Fill 1995, 1996, 1997, 1998 Treatments Early Season N: 67, 134 kg/ha Mid Season N: 0, 44, 88 kg/ha Late Season Water: 0, 0.5, 1.0 x ET RCB - Four Replications

29. 04590 Protein (%) 12 13 14 15 16 17 18 N at Heading (kg ha -1 ) 0459004590 04590 I I I I Early Season N 67 kg ha -1 135 kg ha -1 1995 199619971998

30. 12 13 14 15 16 17 18 I I Water Added 0 % ET 0.5 % ET 1.0 % ET 1995 1996 1997 1998

31. 04590 Bake Volume (cm3) 900 1000 1100 1200 1300 Late Season N at Heading (kg ha -1 ) 0459004590 I I I Water Added 0 % ET 0.5 % ET 1.0 % ET 04590 I 1995199619971998

32. Late Season N Rate (kg/ha) Volume/Protein Ratio

33. Fraction of ET Applied Volume/Protein Ratio

34. Conclusions Additional nitrogen applied from boot stage to heading will increase flag leaf nitrogen, grain protein and flour protein when nitrogen levels are less than optimal. Additional nitrogen applied from boot stage to heading will increase flag leaf nitrogen, grain protein and flour protein when nitrogen levels are less than optimal. There is a greater response in grain protein to late-applied nitrogen with larger deficits of plant nitrogen. There is a greater response in grain protein to late-applied nitrogen with larger deficits of plant nitrogen.

35. Conclusions Loaf volume is directly related to protein concentration within years. Loaf volume is directly related to protein concentration within years. The loaf volume to grain protein ratios are not affected by topdress timing and only slightly by late season N. The loaf volume to grain protein ratios are not affected by topdress timing and only slightly by late season N. Early termination of irrigation increases grain protein, but decreases kernel weight, grain yield, test weight, and flour yield. Early termination of irrigation increases grain protein, but decreases kernel weight, grain yield, test weight, and flour yield. Early termination of irrigation did not change loaf volume to flour protein ratios but moisture deficit throughout grain filling reduced the ratio. Early termination of irrigation did not change loaf volume to flour protein ratios but moisture deficit throughout grain filling reduced the ratio.

36. Conclusion Inducing late season moisture stress to enhance protein concentration or quality is a poor strategy. Inducing late season moisture stress to enhance protein concentration or quality is a poor strategy. Late season N enhanced protein concentration and protein increases were associated with improved baking quality. Late season N enhanced protein concentration and protein increases were associated with improved baking quality.