Eric C. Miller Jeremiah L. Mullock , Jacob T. Bushong , and William R. Raun

1. Evaluation of NUE and WUE on Corn Hybrids With and Without Drought Tolerance in Irrigated and DrylandProduction Systems Eric C. Miller Jeremiah L. Mullock, Jacob T. Bushong, and William R. Raun ASA, CSSA, & SSSA Annual MeetingsTampa, FL November 5st, 2013

2. Drought • The 2012 drought, 597 counties in 14 states primary natural disaster areas (USDA, 2013). • $14 billion in crop insurance indemnity payments (Congressional Budget Office, 2013).

3. Drought effects on corn

4. Transgenic trait/GMO • Cold shock protein B gene • Called ‘cspB’ • Bacillus subtilisbacterium • Cold shock proteins accumulate • Act as RNA chaperones • Bind and unfold tangled RNA molecules to promote normal function(Castiglioni et al., 2008) http://www.lhsc.on.ca/_images/Genetics/centraldogma.jpg

5. Conventional breeding • Express native drought tolerant traits using marker assisted selection (Butzen and Schussler, 2009)

6. WUE x NUE interaction • Dry soil = poor nutrient uptake • Drought alters the root:shoot ratio • Increased root respiration, increases nutrient solubility • More root respiration, has the potential to increase nutrient uptake (Liu et al., 2004) http://www.monsanto.com/newsviews/pages/bt-corn-performance-in-us-corn-belt.aspx

7. Objective • Evaluate N use efficiency (NUE) and water use efficiency (WUE) • Drought tolerant and less drought tolerant corn hybrids • Irrigated and rainfedproduction systems

8. Experiment sites • Established in 2013 and will continue in 2014 • 3 replicates • 4 row plots, 6.1 m long • Soils: • Efaw • Norge: Fine-silty, mixed, active, thermic UdicPaleustolls • Lake Carl Blackwell (LCB) • Port: Fine-silty, mixed, superactive, thermic CumulicHaplustolls, Oscar: Fine-silty, mixed, superactive, thermic, TypicNatrustalfs Efaw LCB

9. Experimental design: GxExM • Genetics • Drought tolerant • Pioneer P1498: Optimum AQUAmax • Monsanto63-55: Droughtgard • Less drought tolerant • Pioneer P1395 • Monsanto 62-09 • Environment xManagement Photo Courtesy of Jacob Bushong • Rainfedproduction system • Preplant N rates • 0, 67, and 134 kg ha-1 • Seeding rate • 53,800 seeds ha-1 • Irrigated production system • Preplant N rates • 0, 101, and 202 kg ha-1 • Seeding rate • 75,650 seeds ha-1

10. Statistical analysis • Treatment Structure • Two way factorial with • 4 levels of hybrid • 3 levels of N rate • Randomized complete block design • Nested withinproduction system • SAS PROC GLM • Analysis conducted by site and year

11. Grain yield and nitrogen use efficiency (NUE) • Grain yield (Mg ha-1) • Center two rows per plot • Adjusted to 155 g kg-1 moisture • NUE(kg kg-1) • Grain yield kg ha-1/ kg ha-1applied N fertilizer http://web.extension.illinois.edu/nwiardc/eb270/20121015_6040.html

12. Water use efficiency (WUE) • Cumulative WUE (kg m-1) • Grain yield kg ha-1 / Evapotranspiration (ET; m) • ET = +∆SWC + R + I – D • Soil Water Content (SWC) • Preplant and postharvest • 1 m soil profile • Rainfall (R) • Mesonet • Irrigation (I) • Drainage (D) • negligible Photo Courtesy of Tracy Wilson

13. Rainfall

14. Analysis of variance

15. Grain Yield

16. Hybrid differences: Efaw

17. Hybrid differences: LCB

18. NUE x WUE: Efaw

19. NUE x WUE: LCB

20. Conclusions • Irrigation significantly increased grain yield, WUE, and NUE at both sites • Increased N rates resulted in higher yields for the irrigated production systems • Regardless of hybrid, improvements in WUE resulted in increased NUE • The Monsanto Droughtgard hybrid yielded ~1 Mg ha-1 more than the Pioneer AQUAmax hybrid at both sites (~$70) • Lack of drought tolerant hybrid differences in 2013 could have been from an unseasonably wet growing season

21. Questions?