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MISSISSIPPI SOYBEAN PROMOTION BOARD

PROJECT 58-2014 (YEAR 2)

2014 Annual Report

TITLE: Impact of Planting Date and Maturity Group on Management Strategies for

Insect Pests in Soybean

INVESTIGATORS: Angus Catchot, Associate Professor of Extension, Mississippi State

University, 662 418-8163, acatchot@ext.msstate.edu; Jeff Gore, Assistant Research Professor,

Mississippi State University, 662 820-9969, jgore@drec.msstate.edu; Trent Irby, Assistant

Professor of Extension, Mississippi State University, 662 418-7842, tirby@pss.msstate.edu; Don

Cook, Assistant Research Professor, Mississippi State University, 662 255-1899,

dcook@drec.msstate.edu

BACKGROUND AND OBJECTIVES

The Early Soybean Production System (ESPS) is the program that armed growers with the ability

to achieve much higher yields and avoid many of the devastating late-season insect pests that

robbed soybean yields across the South. Currently, growers are trending toward later planting

dates, and in many cases have forgotten the benefits of early planting. Because of this pests such

as corn earworm and soybean looper are being observed infesting more and more acres, and

many are also pondering the use of Bt soybean technologies for the South.

This project will answer critical questions around insect infestation timings based on planting

dates and maturity groups, as well as strong agronomic data based on planting dates in the Hills

and Delta region of the state.

Graduate Student Masters Project

Objective One: Identify the seasonal periods in MG IV and V soybeans in the Hills and Delta

region of Mississippi where the greatest threat of insect pest loss is likely to occur.

Activities: Data have been analyzed and reports are in review.

Objective Two: To evaluate the benefits of season-long control of caterpillars in MG IV and

MG V Soybeans in the Hills and Delta region of Mississippi at various planting dates.

Activities: Data have been analyzed and reports are in review.

Objective Three: Document the potential risk of flaring caterpillar pests by use of disruptive

pyrethroid sprays targeting other pests or their potential economic benefit at various planting

dates and maturity groups in the Hill and Delta regions of MS.

Activities: Data have been analyzed and reports are in review.

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Materials and Methods

To determine the seasonal periods where the greatest threat of insect pest loss is likely to occur

in Mississippi, an experiment was conducted at the R.R. Foil Experiment Station in Starkville,

Mississippi, as well as the Delta Research and Experiment Center in Stoneville, Mississippi.

Experimental design was a randomized complete block with a factorial arrangement of

treatments with four replications, with factor 1 being planting date and factor 2 being treatment.

Plots were four rows 65 feet long, with 10-foot-wide alleys and four border rows in between

planting dates. There were seven planting dates with two maturity groups at each location spaced

out every 15 days from the third week of March through the second week of July.

The two cultivars were Asgrow 4632 and Asgrow 5332, which are MG IV and V, respectively.

There were four spray regimes in each planting date by maturity group combination. Foliar

applications were initiated at the R1 stage, or at first sign of caterpillar pest, or if economic

threshold was reached before the R1 stage.

Spray Regimes were 1) Untreated Check, 2) Simulated Bt soybeans (Prevathon at 20 oz/acre

every 2 weeks), 3) Bug only/Disruptive Sprays (Dimethoate 16 oz/acre) @ R1, R3, and R5, and

4) Threshold.

Sampling for insect pest was done with a standard 38-cm sweep net at 25 sweeps per plot.

Samples were placed into one-gallon Ziploc bags and placed into a freezer for 24 hours and then

counted in the lab to determine all beneficial and pest insects per sample.

Samples were taken weekly starting at the R1 growth stage and carried out through the R7

growth stage. Stand counts were taken at the V1 to V2 growth stage to determine plant

populations and uniformity of plots. Plant heights were taken at the V1, R1, and R6 growth

stages, as well as a canopy closure measurement at the R6 growth stage. Soil temperature was

also recorded at planting. Plots were harvested at the end of the season (middle two rows of each

plot). All data were analyzed in PROC GLIMMIX from SAS with a Poisson distribution and a

0.05 alpha level.

Report of Progress/Activity

Due to the extremely large volume of data associated with this project, the student is

transitioning from a M.S. program directly into a PhD program to allow for large plot

implementation of his findings in 2015 and 2016.

The student has summarized 2013-14 results for publication. The publications are in review and

will be available after all revisions are made.

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The publications are:

Effects of Planting Date and Maturity Group on Soybean Agronomics

N.R. Bateman1, A.L. Catchot

1, J. Gore

2, D.R. Cook

2, F.R. Musser

1, and J.T. Irby

1

1 Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology,

Mississippi State University, 100 Old Highway 12 Mississippi State, MS 39762, USA 2

Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi

State University, Delta Research and Extension Center, 82 Stoneville Rd P.O. Box 197,

Stoneville, MS 38776, USA

Effects of Planting Date and Maturity Group on the Occurrence of Soybean Insect Pest

N.R. Bateman1, A.L. Catchot

1, J. Gore

2, D.R. Cook

2, F.R. Musser

1, and J.T. Irby

1

1 Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology,

Mississippi State University, 100 Old Highway 12 Mississippi State, MS 39762, USA 2

Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi

State University, Delta Research and Extension Center, 82 Stoneville Rd P.O. Box 197,

Stoneville, MS 38776, USA

A summary version of a Power Point presentation of the results from this study follows.

Seasonal Occurrence Of

Caterpillar Pests Of

SoybeansNick Bateman, Angus Catchot,

Jeff Gore, Fred Musser, Don Cook,

Trent Irby

Introduction

• Early Soybean Production System (ESPS)

– Ability to achieve higher yields

– Potential to avoid damaging late season pest

a) Corn Earworm

b) Soybean Looper

c) Stink Bugs

– Now growers are trending back toward later planting

dates, and in some cases have completely forgotten

about the ESPS

Justification

• 2014 Insect Control + Losses > $34,500,000

– Stink Bugs, Soybean Loopers, and Corn Earworms

• Corn Earworms Loss + Cost = $11,009,548

– Infested 16.9% of total soybean acres

– 688,455 Bushels lost

• Soybean Loopers Loss + Cost = $11,101,041

– Infested 33.8% of total soybean acres

– 690,104 Bushels lost

Caterpillar Pests Infesting Soybean in Mississippi

0

500,000

1,000,000

1,500,000

2,000,000

2,500,000

2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014

Acres Treated

$38,988,282

Mississippi Soybean

• In 2004 65% of MS soybeans were planted by April

25th

• In 2012 it was less than 40%

• As cotton acres drop, producers are beginning to

plant more Group V soybeans over several planting

dates to manage harvest

Acreage Shifts Mississippi (2014)

400,000

2,225,000

540,000

400,000100,000

Cotton Soybean Corn Wheat Sorghum

60%

Objectives

• Identify the seasonal periods where the greatest threat of insect pest loss is likely to occur.

• To evaluate the benefits of season-long control of caterpillars (Simulated Bt) and the potential risk of flaring caterpillar pests

• Determine the agronomic benefits of planting date for soybean

Overall Materials and Methods

• RCB Design

– Factorial trt arrangement

– Factor A Planting Date

– Factor B Treatment

• Treatments

– Prevathon 20oz (Simulated Bt)

– Threshold

– Dimethoate 16 oz (Bug Only)

– UTC

• 2 Locations

– Hills (Starkville North Farm)

– Delta (Stoneville DREC)

• 2 Maturity Groups

– Asgrow 4632 (Group IV)

– Asgrow 5332 (Group V)

• Samples taken once a week

– Samples were bagged in Ziploc bags and

frozen then counted in the lab

• All pest and beneficial insects where counted

• Data Analyzed with SAS 9.3

– Alpha = 0.05

– Poisson Distribution

Mississippi Soybean Planting

5 15 25 25 20 5 3 2

0 10 20 30 40 50 60 70 80 90 100

% Planted

14-Mar/1-Apr 1-Apr/15-Apr 15-Apr/1-May 1-May/15-May

15-May/1-June 1-June/15-June 15-June/1-July 1-July/15-July

Materials and Methods Cont.

• Hills 2013

– Planting Dates

– 3/28, 4/17, 5/9, 5/30, 6/13, 7/1,

7/15

• Hills 2014

– Planting Dates

– 3/21, 4/1, 5/8, 6/4, 6/16, 6/30,

7/16

• Delta 2013

– Planting Dates

– 4/8, 4/15, 5/8, 5/30, 6/13, 7/1,

7/15

• Delta 2014

– Planting Dates

– 3/25, 4/16, 5/12, 6/3, 6/13, 6/30,

7/16

Results

• Canopy closure was maximized before Julian Day 147 (May 27)

– Loss of 1% of canopy closure a day after 5/27

• Plant height was maximized on Julian Date 153 (June 2)

– Loss of .4426 IN/day after June 2

• Yield was maximized on Julian day 110 (April 20)

– Loss of .396 bu/day (2.77 bu/week) after April 20

Summary

• With yield decreasing daily after April 20 it is important to save what yield potential is left for plantings later than April 20 through extensive Management

• Also after May 27 canopy closure starts to decrease leaving later planted soybean more vulnerable to higher egg lays by caterpillar pest

• When plant heights were maximized there was more lodging that occurred

Results

• Soybean Looper peaked between 8/20-10/8

– Planting dates 4-7(5/30-7/16) vulnerable to soybean looper

• Stink Bugs had the same peak and vulnerable planting dates as Soybean Looper

• Bean Leaf Beetle peaked between 8/10-9/27

– Planting dates 3-5 (5/8-6-16) fell in this peak

– Planting dates 6 and 7 (6/30-7/16) also vulnerable to this peak

Table of Caterpillar Threshold Sprays

Threshold Sprays

Location and

Planting Date Spray Date Insect Pest Chemical

Hills 2013

4 29-August Soybean Loopers Belt 2 oz/a

5 29-August Soybean Loopers Belt 2 oz/a

6 29-August Soybean Loopers Belt 2 oz/a

Delta 2013

5 17-September Soybean Loopers Belt 2 oz/a

6 17-September Soybean Loopers Belt 2 oz/a

Soybean Loopers By Treatments

0

5

10

15

20

25

30

35

40

45

Prevathon 20 oz Threshold UTC Disruptive

Me

an

of

the

se

as

on

to

tal

a

bb

ab

P<0.0001

Yield for treatments

44.3 42.2 40.9 39.5

0

5

10

15

20

25

30

35

40

45

Prevathon 20 oz Threshold UTC Disruptive

Bu

sh

els

/Ac

re

a bbab

P=0.0057

Results

• Prevathon (Simulated Bt) significantly lowered caterpillar pest compared to all other treatments

• When looking only at planting dates that reached economic threshold, Prevathon (Simulated Bt) yield statistically higher than the UTC.

• The potential for Bt beans through these two years of research only fall in the last 30% of the planting window, but more work is needed to define the actual window for Bt beans

Questions?