Jeremiah L. Mullock, Jacob T. Bushong, and William R. Raun
ASA, CSSA, & SSSA Annual Meetings
Tampa, FL
November 5 st , 2013

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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)
.

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Cold shock protein B gene
◦
◦ Called ‘cspB’
Bacillus subtilis bacterium
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


Express native drought tolerant traits using marker assisted selection
(Butzen and Schussler,
2009)

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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

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Evaluate N use efficiency (NUE) and water use efficiency (WUE)
◦ Drought tolerant and less drought tolerant corn hybrids
◦ Irrigated and rainfed production systems

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Established in
2013 and will continue in 2014
3 replicates
LCB
4 row plots, 6.1 m long
Soils:
◦ Efaw
 Norge: Fine-silty, mixed, active, thermic Udic
Paleustolls
◦ Lake Carl Blackwell (LCB)
 Port: Fine-silty, mixed, superactive, thermic
Cumulic Haplustolls ,
Oscar: Fine-silty, mixed, superactive, thermic,
Typic Natrustalfs
Efaw

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G enetics
◦ Drought tolerant
 Pioneer P1498: Optimum AQUAmax
 Monsanto 63-55: Droughtgard
◦ Less drought tolerant
 Pioneer P1395
 Monsanto 62-09
E nvironment x M anagement
◦ Irrigated production system
 Preplant N rates
 0, 101, and 202 kg ha -1
 Seeding rate
 75,650 seeds ha -1
Photo Courtesy of Jacob Bushong
◦ Rainfed production system
 Preplant N rates
 0, 67, and 134 kg ha -1
 Seeding rate
 53,800 seeds ha -1

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Treatment Structure
◦ Two way factorial with
 4 levels of hybrid
 3 levels of N rate
◦ Randomized complete block design
◦ Nested within production system
SAS PROC GLM
◦ Analysis conducted by site and year

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

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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

30
25
20
15
10
5
0
Long Term
2013

Main effects and interaction effects for grain yield, water use efficiency
(WUE), and nitrogen use efficiency (NUE) at Efaw and Lake Carl Blackwell
(LCB), 2013.
Efaw LCB
Grain
Yield WUE NUE
Grain
Yield WUE NUE
Irrigation
Hybrid
N Rate
Irrigation x Hybrid
Irrigation x N Rate
Hybrid x N Rate
------------------- Pr > F -------------------
0.002
0.008
0.006
0.001
0.001
0.005
0.297
0.248
0.301
0.292
0.351
0.566
0.722
0.529
0.700
0.507
0.004
0.897
0.017
0.705
0.016
0.765
0.007
0.962
0.503
0.570
0.231
0.027
0.026
0.012
0.795
0.810
0.531
0.684
0.664
0.844
Irrigation x Hybrid x N Rate 0.084
0.074
0.367
0.548
0.501
0.698

12
10
8
6
4
2
0
Efaw -
Irrigated
Efaw -
Rainfed
LCB -
Irrigated
LCB -
Rainfed
Low N
Med N
High N

Single degree of freedom contrasts and differences of the means for grain yield (Mg ha -1 ), water use efficiency (kg m -1 ; WUE), and nitrogen use efficiency (kg kg -1 ; NUE) at Efaw, 2013.
Grain Yield
(Mg ha -1 )
WUE
(kg m -1 )
NUE
(kg kg -1 )
P > F Diff.
P > F Diff.
P > F Diff.
Drought tolerant vs.
Less drought tolerant
Monsanto vs.
Pioneer
Droughtgard vs.
AQUAmax
0.416 -0.485 0.503 0.314 0.361 -5.44
0.110
0.116
0.994 0.085 0.582 0.204
1.38
0.079 1.06
0.100
7.69
14.4

Single degree of freedom contrasts and differences of the means for grain yield (Mg ha -1 ), water use efficiency (kg m -1 ; WUE), and nitrogen use efficiency (kg kg -1 ; NUE) at Lake Carl Blackwell (LCB), 2013.
Grain Yield
(Mg ha -1 )
WUE
(kg m -1 )
NUE
(kg kg -1 )
P > F Diff.
P > F Diff.
P > F Diff.
Drought tolerant vs.
Less drought tolerant
Monsanto vs.
Pioneer
Droughtgard vs.
AQUAmax
0.928
0.065
0.139
0.084 0.837 0.012 0.839
0.832 0.084 0.107 0.179
0.916 0.170 0.116 0.275
1.10
7.58
8.58

Irrigated - High N
Rainfed - High N
2,5
2
1,5
1
0,5
0
0 20 40 60 80
NUE (kg kg -1 )
100 120 140

Irrigated - High N
Rainfed - High N
2,5
2
1,5
1
0,5
0
0 20 40 60 80
NUE (kg kg -1 )
100 120 140

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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