Objectives

The objectives of the meeting are to: (i) examine the current physiological understanding of the

mechanisms underlying leaf-area expansion and its response to abiotic factors

(ii) compare methodologies used in current maize models to model leaf-area expansion and senescence.

Abiotic factors that require special attention in modeling leaf-area expansion and senescence are:

– Water stress– N stress– Temperature – Plant density– Soil compaction

AgendaTime Description

00:00 – 00:10 Introduction

00:10 – 00:40 Physiology of leaf-area expansion – François Tardieu

00:40 – 00:50 Questions and discussion

00:50 – 01:05 Modeling leaf-area expansion and senescence at the canopy level – Armen Kemanian & Claudio Stöckle

01:05 – 01:10 Questions and discussion on how other canopy-level models differ

01:10 – 01:25 Modeling leaf-area expansion and senescence at the leaf level – Jon Lizaso

01:25 – 01:30 Questions and discussion on how other leaf-level models differ

01:30 – 01:50 Available data sets to evaluate leaf-area expansion and senescence routines and evaluation methodologies.

01:50 – 02:00 Next steps…

Participation Last Name First Name Institute/company Andrade Fernando INTA, Balcarce, Argentina

x Boote Ken Univ. of Florida, Gainesville, FL Cairns Jill CIMMYT, Harare, Zimbabwe

x Castiglioni Paolo Dow AgroSciences, Davis, CA Edmeades Greg New Zealand

x Hammer Graeme Univ. of Queensland, Brisbane, Australiax Hatfield Jerry USDA-ARS, Ames, IAx Holland Jim USDA-ARS, NC State Univ., Raleigh, NC

Hoogenboom Gerrit Washington State Univ., Prosser, WAx Jones Jim Univ. of Florida, Gainesville, FLx Kemanian Armen PennState, University Park, PAx Kim Soo Univ. of Washington, Seattle, WA

Kiniry Jim USDA-ARS, Temple, TXx Kumudini Saratha Monsanto Co., RTP, NCx Lizaso Jon Univ. of Madrid, Madrid, Spain

Nendel Claas Leibniz, Germany Otegui Maria Univ. of Buenos Aires, Buenos Aires, Argentina.

x Sala Rodrigo Monsanto, Jerseyville, IL Singh Upendra IFDC, Muscle Shoals, AL

x Stöckle Claudio Washington State Univ., Pullman, WAx Tardieu François INRA, Toulouse, Francex Timlin Dennis USDA-ARS, Beltsville, MDx Tollenaar Thijs Monsanto Co., RTP, NCx Vyn Tony Purdue Univ., West Lafayette, IN

Wallach Daniel INRA, Toulouse, France Westgate Mark Iowa State Univ., Ames, IA

x Yang Haishun Univ. of Nebraska, Lincoln, NE

Next Steps

1. Evaluation of leaf area routines (how?)

Data Source Genetic material Year(s) Publication

USDA, Collins, DE Pioneer 33B53 2006-2007 Kim et al., 2012

USDA, Wye, MD Pioneer 34M91 and Pioneer 37Y14

2006-2008 Kim et al., 2012

Grignon, France DEA (Pioneer hybrid) 1994-1995 Lizaso et al., 2011

East Lansing, MI GL 420 1991 Lizaso and Ritchie, 1997

Manchester, IA Pioneer 33P67 2002 Yang et al., 2004

Lincoln, NE Pioneer 33A14 and Pioneer 33P67

1999-2001 Yang et al., 2004

Urbana-Champaign, IL Pioneer and Dekalb 2007-2008 Dohleman and Long, 2009

Gainesville, FL McCurdy 1982 Bennett et al., 1986

Guelph, Ontario, Canada

Pioneer 3902, Pioneer 3851, and Pride 5

1999-2001 Valentinuz and Tollenaar, 2004

Leaf Area Evaluation Data sets

Leaf Area Expansion and Senescence – Plant Density Effect

Data from Yang et al., 2004

Next Steps

Evaluation of leaf area routines

- Evaluate leaf area routines in various models similar to AgMIP maize pilot project?

Next Steps

1. Evaluation of leaf area routines (how?)

2. Report on analyses of the temperature response for anthesis/silking and GFP

3. Photoperiod response to time to anthesis/silking and duration of the GFP

Data Source Description Year Publication

Balcarce, Argentina • many hybrids (Monsanto/Pioneer)• multiple planting dates (Sept. to Jan.)• various plant densities

1989-2012 Andrade et al. (many)

Paysandu, Uruguay • 2 hybrids• 3 planting dates ( Nov. to Jan)

2009-2010 Kemanian and Mazilli

Indiana and Ohio • 3 Pioneer hybrids• 3 planting dates (April to June)• 4 locations

1994-1994 Nielsen et al. , 2002

IA •2 hybrids 2010-2012 Hatfield

Missouri • 3 hybrids• 2 planting dates• 2 locations

1978-1979 Kiniry and Keener, 1982

NE and IA • 2 hybrids• 3 plant densities•2 locations

1999-2002 Yang et al., 2004

Monsanto • >3,000 hybrids (RM75 – RM120)• 1 location

2007-2012

Monsanto • various hybrids (RM75 – RM120)• 45 locations

2007-2011

Phenology Data Sets

TLU 4 TLU 8 TLU 12 TLU 220

0.1

0.2

0.3

0.4

0.5

0.6ALL DKC

Argentina

IN and OH

MO

Leaf-tip stage (TLU)

Corr

elati

on c

oeffi

cien

t (R2

)

N

N

N N

NN N

Association between planting-anthesis interval and photoperiod at four leaf-tip stages in four data sets (N = slope is negative)

Association between duration of GFP and photoperiod at four leaf-tip stages in four data sets (N = slope is negative)

TLU4 TLU8 TLU12 TLU220

0.1

0.2

0.3

0.4

0.5

0.6

0.7

All DKC

Argentina

IN andOH

MO

Leaf stage (TLU)

Corr

elati

on c

oeffi

cien

t (R2

)

N

N

N N NN

N

Next Steps

1. Evaluation of leaf area routines (how?)2. Report on analyses of the temperature

response for anthesis/silking and GFP3. Photoperiod response to time to

anthesis/silking and duration of the GFP4. Leaf and canopy photosynthesis routine

Model Evaluation with Public Data: Leaf Appearance and Leaf Area Expansion and

Senescence