Developing a Standard test for Lodging Resistance in Alfalfa for North America

Developing a Standard test for Lodging Resistance in Alfalfa for North America

Debra Sharpee, Gary Hoard, Mark Smith, Dave Miller

Pioneer Hi-Bred International Inc.

Introduction

• Lodging resistance (LR) or standability is an important trait in many crops.

• Improved LR often results in increased harvestable yield and crop quality.

Introduction

• Alfalfa has been improved for LR primarily in germplasm adapted to France.

• French varieties must meet minimum standards for LR to be eligible for inscription.

• Testing for LR in France is based on observations prior to cutting, and on stubble after cutting.

Introduction

• Varieties with improved LR are beginning to be marketed in North America.

• There is a need to describe LR in North American adapted varieties for purposes of variety description.

Objectives

• Examine the relationship between LR in solid-seeded plots vs. spaced planted alfalfa.

• Develop criteria for evaluating individual plants for lodging resistance.

• Take the first step in developing a standard test for LR in North America.

Experimental Procedure

• Establish solid seeded yield plots (~1m x 4m) with LR varieties and commercial varieties in spring 2001.

• Transplant 100 plants (4 reps, 25 plants/rep) of same varieties in spring 2001.

• Allow both trials to grow until commercial varieties are obviously lodged and score in Johnston, IA and Arlington, WI in spring 2002.

Experimental Procedure

• Score plots on a 1-9 scale where 9 = no lodging and 1 = completely lodged.

• Score each plant in transplanted test and determine a Percent Resistant Plants (PRP) to lodging.

Experimental Procedure

• Spaced plant scoring criteria:– 9=Erect, plants instantly spring back

to vertical.

– 7=Mostly erect, but leans some.

– 5=Plant leans ~45 degrees.

– 3=Plant leans more than 45 degrees.

– 1=Plant flat on ground.

Spaced Plant rated a “9”.

Johnston, IA

LRLR

LS LS

Lodging Resistant vs Lodging Susceptible plots

Results

Variety Plots-IA Plots-WI

PRP-JH PRP-WI

Europe 9.0 7.5 50 44Exp A 6.3 7.0 65 76Exp B 5.8 4.0 30 2354H91 4.3 2.5 0 454V54 1.8 1.5 1 7Geneva 1.0 1.0 1 4LSD(.05) 1.6 1.8 14 14

Plots= whole plot scores; PRP based on classes 7-9

Discussion

• There is a clear relationship for LR between solid-seeded and spaced planted tests.

• The spaced plant scoring criteria was useful for describing solid-seeded performance.

Discussion

• Progress on developing a standard test:– Good “first-step” in developing

scoring criteria.

– Europe (French variety) is a candidate for an HR check.

– Several candidates for lodging susceptible check (eg. 54V54, Geneva).

Discussion

• Additional data has shown that LR in seeded plots is very consistent across cuts, locations, and years.

Future work

• Generate additional spaced plant data to determine appropriate level of LR for resistant check (likely Europe).

• Run cooperative trials to determine consistency across organizations for checks and scoring criteria.