Maize Light Interception and Grain Yield as Affectedby Precision Planting

Precision Planting of Corn (Zea mays L.) to Manipulate Leaf Geometry

Research Questions• Can corn leaf orientation be manipulated by controlling seed position at

planting?

• Which seed position can result in across-row leaf orientation and what is the effect on emergence?

• What is the effect of leaf orientation on light interception and grain

yield ?

With-rowLeaf orientation

Across-rowLeaf orientation

U.S. Maize Production

Source: http://usda.mannlib.cornell.edu/

1940

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2008

0

2,000

4,000

6,000

8,000

10,000

12,000

0

5

10

15

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25

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35

40

45

f(x) = 597.592910568347 x + 668.326079991409R² = 0.977089233076646

Corn Grain [kg/ha]

Gra

in Y

ield

(kg

ha-

1)

Sila

ge Y

ield

(M

g ha

-1)

Capturing Solar Radiation • Y= Q x I x E x H

• Crop growth is the product of IPAR and RUE†

• Plant population

• Row spacing

• Hybrid maturity

• Canopy architecture

†Andrade et al., 1993 and Gifford et al., 1984‡Figure from Gardner et al., 1985

Maize Seed Orientation

• Systematic leaf arrangement can maximize light interception and increase yield†

• Earlier and more complete emergence when maize seed was planted with the proximal end down‡

†Peters and Woolley, 1959; Peters ,1961 ‡Patten and Van Doren, 1970

Figure: (c) Adrian Koller

FlatUpright

Experiment• 5 Dekalb hybrids

• 8 treatments

• 4 leaf stage

• 400 seeds

Experiment # 3

Treatmentseed

position and orientation

description

1 Upright, on the side , parallel to the row

2Upright, caryopsis pointed up, parallel to

the row

3Upright, caryopsis pointed down, parallel

to the row

4 Laying flat embryo up, parallel to the row

5Laying flat embryo down, parallel to the

row

6Laying flat embryo up, perpendicular to

the row

7Laying flat embryo down, perpendicular

to the row

8 Random

(c) Adrian Koller

Seed Orientation and Leaf Azimuth• Leaf azimuth and emergence was affected

by seed orientation and hybrid

• Upright and flat - 76 and 86% of plants with leaf azimuth between 60 and 90°

• Mean leaf azimuth • Upright = 64°• Flat = 67 °

Torres et al., 2011

Seed-to-Leaf Correlation

Koller, 2012

Objectives

• Evaluate the effect of seed orientation / leaf azimuth,

plant population, canopy architecture, and row

configuration on light interception, radiation use

efficiency, and grain yield of maize.

• EFAW and LCB, 2010-2012

• RCBD, 12 treatments and 3 blocks

• Across-row, and random leaf azimuths

• Seed orientation - upright, flat, and random;

• Plant population (plants ha-1);• 37050, 49400, and 61750• 49400, 74100, and 98800

• Hybrid canopy architecture;• Planophile and erectophile

Row direction

Upright Flat

Flat = across row leaf azimuth

Measurements and Analysis• Light interception (IPAR, MJ m-2)

• fPAR x TU=daily fPAR • IPAR (MJ m-2) = daily fPAR x total incident PAR

• Cumulative IPAR (CIPAR, MJ m-2)

• Grain yield (Yield, kg ha-1)

• Radiation use efficiency (RUE, g MJ-1)• RUE= grain yield / CIPAR

• ANOVA, contrasts, regression, and correlation analysis

Light Interception

• Significant treatment effect on fPAR was observed between V10 and VT growth stages

200 300 400 500 600 700 800 9000.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Uprighty = -2E-06x2 + 0.0038x - 0.603; r² = 0.79Flaty = -2E-06x2 + 0.0033x - 0.473; r² = 0.85

Thermal Units, °C d

fPA

R

Across-row leaf azimuth

Cumulative IPAR at Maturity (Plant Population)

• At physiological maturity seed oriented treatments intercepted more light than random seed placement

Upright Flat Random560

570

580

590

600

610

620

aa

b

CIPAR

Seed Orientation

CIP

AR

, M

J m

-2

LSD=8.7 MJ m-2

Grain Yield (Plant Population)

• Upright and flat out-yielded random seed orientation by 6 and 9%• Toler et al. (1999) showed a 10% yield increase for across row

2010 2011 2012 2010 2012EFAW LCB

1000

2000

3000

4000

5000

6000

7000

8000

9000

NS

**

NS

**

*Upright Flat Random

Yie

ld,

kg h

a-1

Grain Yield (Hybrid)

• Upright and flat were 10 and 6% greater than random

2010 2011 2012 2010 2012EFAW LCB

1000

2000

3000

4000

5000

6000

7000

8000

9000

NS

*NS

**

Upright Flat RandomY

ield

, kg

ha

-1

Radiation Use Efficiency at Maturity (Hybrid)

Upright Flat Random0.80

0.85

0.90

0.95

1.00

1.05

1.10

1.15

1.20

1.25

a

a

a

RUE

Seed Orientation

RU

E,

g

MJ

-1

LSD=0.35 g MJ-

1

• RCBD and Split-block, 12 trts and 3 reps

• Across-row, random, and with-row leaf azimuths;• Seed orientation – flat (parallel and

perpendicular to the row), and random

• Plant population (plants ha-1); • 37050 and 61750• 83980 and 98800

• Row Configuration;• Single rows• Twin rows

0.20 m

0.20 m

0.76 m

With-rowAcross-row Random

Leaf Azimuth Effect on Light Interception

• Across-row > random > with-row

• Difference in fPAR between leaf

azimuths was usually greater at later vegetative stages at LCB

• No differences after V10 growth stage at Champaign

Orientation Performance

• release seeds as close to the ground as possible• cannot drop oriented seed 18" through seed tube

• relative velocity between seed and ground is a challenge• match ground speed?

0.6 GS 0.8 GS 1.0 GS 1.2 GS 1.4 GS

planting directing

Hybrid Dependence

• Performance dependent on seed shape (hybrid, grading)