2012: Changes in Cotton Weed M anagement Practices in Georgia - - PowerPoint PPT Presentation

2012: Changes in Cotton Weed M anagement Practices in Georgia Following the Development of Glyphosate-Resistant Palmer Amaranth

Lynn M . Sosnoskie1,2 and A. Stanley Culpepper1

1University of Georgia - Tifton 2University of California - Davis

Distribution of GR Palmer amaranth

Map credit: R. L. Nichols

Cotton producing regions in US

Map credit: http://www.cottonusa.org/

Glyphosate-resistant cotton: Changes in weed management

• Shaner (2000) Pest M anage. Sci. 56:320-326.

– Glyphosate use increasing in cotton – Concomitant decrease in:

• PS II inhibitors – diuron, fluometuron, prometryn
• DNAs – pendimethalin, trifluralin
• Arsenates – M SM A
• Carotenoid biosynthesis inhibitors - clomazone

Glyphosate-resistant cotton: Changes in weed management

• Young (2006) Weed Technol. 20:301-307.

– Increase in glyphosate applications:

• 1/ crop (1996) to 1.8/ crop (2001)

– Decreased use of fluometuron and trifluralin:

• Fluometuron - 27-44% (1992-1998) to 20-27% (1999-2001)
• Trifluralin – 52-67% (1992-1999) to 30-39% (2000-2001)
• Glyphosate – 30-36% (1998-1999) to 56-57% (2000-2001)

Objective:

To determine if cotton weed management practices in Georgia have changed following the development of glyphosate-resistant Palmer amaranth

Survey development and administration

• Two surveys (growers and extension agents)
• Surveys were designed by the authors and reviewed by an

expert committee consisting of: extension agents, University (UGA and other) research scientists, UGA rural sociologist, industry personnel

• Surveys were ‘identical’ except for the fact that the growers

were asked (anonymously) about their individual farming practices and agents provided 3rd party information about county-wide activities

Survey development and administration

• Final survey was 8 pages long, contained 19

questions, and was administered in person

• Survey sections:

– Commodities/ acreage – Herbicide use – Additional weed management practices

• Tillage, cultivation, hand-weeding

– Weed problems

• Including the presence and severity of

glyphosate-resistant Palmer amaranth

BEFORE 2000-2005 AFTER 2006-2010

Survey development and administration

• E-mail was sent to all Georgia extension agents with cotton

responsibilities (2010) describing the survey and requesting that they and 3-5 ‘representative’ growers in their county participate in the process

• Grower qualifications:

– Cotton production – Responsible for making (agricultural) decisions on their

property

– Did not work for a chemical manufacturer, distributor, of

retailer, nor a seed company

County Data

2009 Georgia Farm Gate Value Report (AR-10-01)

County * Cotton acres Value (M illions) Cotton rank Total commodity rank Berrien 21,804 $14.3 18 41 Candler 9,000 $6.5 35 79 Grady 22,403 $17.0 14 16 Irwin 28,269 $20.5 10 43 M acon 9,781 $6.4 36 11 M iller 28,366 $21.6 8 47 Randolph 7,229 $6.0 40 73 Seminole 24,369 $14.1 20 56 Screven 12,822 $12.1 24 62 Sumter 17,697 $11.5 25 26 Taylor 452 $0.2 77 88 Terrell 15,466 $9.5 16 75 Tift 18,820 $12.2 23 19 Thomas 25,858 $17.3 13 37 Turner 20,879 $15.1 16 54 Worth 49,185 $37.8 4 21 * Extension agent from Colquitt County also returned a survey (54,010 acres, $42.1 M illion, Rank = 2).

Total grower (n = 65) acres = 129,615 (12.6% of GA cotton) Total agent county (n = 10) acres = 246,034 (24% of GA cotton)

Commodities - example

Grower Question 4: How many acres do you farm?____________________ Grower Question 5: What types of agricultural commodity groups do you produce on your farm? Yes No Approximate number of acres

• r number of heads, houses or

ponds Row and forage crops ___ ___ _____________________ Poultry and eggs ___ ___ _____________________ Livestock and aquaculture ___ ___ _____________________ Forestry products ___ ___ _____________________ Vegetables ___ ___ _____________________ Ornamental horticulture ___ ___ _____________________ Other (Please describe) (Continued on next page)

100.0 3.1 36.9 35.4 18.5 3.1 3.1

0.0 20.0 40.0 60.0 80.0 100.0 120.0

Row and forage Poultry and eggs Livestock and aquaculture Forestry Vegetables Ornamentals and turf Other

Percent (%) of surveyed growers

Commodity composition of growers' farms

Herbicides - example

Grower Question 9: What herbicides have you relied on for weed control in cotton before (2000- 2005) and after (2006-2010) the development of glyphosate-resistant Palmer amaranth (pigweed)? On what percent of you row crop acreage have you used each product? PREPLANT and PREEMERGENCE (burndown (including early), applications made at or prior to planting, and applications made prior to cotton emergence):

Before (2000-2005): After (2006-2010): Yes No Average % of Acres Yes No Average % of Acres Roundup, Glyphomax, Touchdown, others ___ ___ _________________ ___ ___ _________________ 2,4-D ___ ___ _________________ ___ ___ _________________ Aim ___ ___ _________________ ___ ___ _________________ Clarity ___ ___ _________________ ___ ___ _________________ Valor SX ___ ___ _________________ ___ ___ _________________ Direx, others ___ ___ _________________ ___ ___ _________________ Firestorm, Parazone, Gramoxone Inteon ___ ___ _________________ ___ ___ _________________ (Continued on next page)

Herbicides - example

Herbicides are not divided up/grouped by MOA, activity, selectivity Grouped by timing of application as expressed in Georgia Pest Management handbook (http://www.ent.uga.edu/pmh/).

• 1. PREPLANT and PREEMERGENCE (burndown (including early),

applications made at or prior to planting, and applications made prior to cotton emergence):

• 2. POSTEMERGENCE OVER-THE-TOP (following cotton emergence):
• 3. POSTEMERGENCE DIRECTED:

Growers: Pre-plant herbicides applied Percent (%) of acres treated

86.1 73.7 34.2 38.6 14.9 29.4 0.5 24.7

10 20 30 40 50 60 70 80 90 100 2000-2005 2006-2010 2000-2005 2006-2010 2000-2005 2006-2010 2000-2005 2006-2010 Glyphosate 2,4-D Paraquat Glufosinate

Percent (%) of acres treated

* * *

Agents: Pre-plant herbicides applied Percent (%) of acres treated

87.5 74.3 23.3 58.9 23 37.5 0.3 11.8

10 20 30 40 50 60 70 80 90 100

2000-2005 2006-2010 2000-2005 2006-2010 2000-2005 2006-2010 2000-2005 2006-2010 Glyphosate 2,4-D Paraquat Glufosinate

Percent (%) of acres treated

* * *

Growers: Pre-plant* / PRE herbicides applied Percent (%) of acres treated

37.8 45.8 26.9 15.1 25.1 24.7 2.8 26.9 8.1 81

10 20 30 40 50 60 70 80 90 100

2000-2005 2006-2010 2000-2005 2006-2010 2000-2005 2006-2010 2000-2005 2006-2010 2000-2005 2006-2010 Diuron Fluometuron Pyrithiobac Flumioxazin Fomesafen

Percent (%) of acres treated

*

* * *

Agents: Pre-plant* / PRE herbicides applied Percent (%) of acres treated

3.4 25.5 6.7 8.1 11.2 11.7 2.7 29.1 11.2 58

10 20 30 40 50 60 70 80 90 100

2000-2005 2006-2010 2000-2005 2006-2010 2000-2005 2006-2010 2000-2005 2006-2010 2000-2005 2006-2010 Diuron Fluometuron Pyrithiobac Flumioxazin Fomesafen

Percent (%) of acres treated

*

* * *

PPI herbicides applied Percent (%) of acres treated

69.9 75.9 29.6 25.2 37 68.5 11 16.9

10 20 30 40 50 60 70 80 90 100 2000-2005 2006-2010 2000-2005 2006-2010 2000-2005 2006-2010 2000-2005 2006-2010 Pendimethalin Trifluralin Pendimethalin Trifluralin Growers Agents

Percent (%) of acres treated

GROWERS AGENTS

*

Growers: POST herbicides applied Percent (%) of acres treated

94.4 88.4 0.6 29.7 40.8 45.7 16.3 54.4

10 20 30 40 50 60 70 80 90 100 2000-2005 2006-2010 2000-2005 2006-2010 2000-2005 2006-2010 2000-2005 2006-2010 Glyphosate Glufosinate Pyrithiobac S-metolachlor

Percent (%) of acres treated

* * *

Agents: POST herbicides applied Percent (%) of acres treated

95 74.7 0.5 33.5 38.3 40.3 11.9 42

10 20 30 40 50 60 70 80 90 100 2000-2005 2006-2010 2000-2005 2006-2010 2000-2005 2006-2010 2000-2005 2006-2010 Glyphosate Glufosinate Pyrithiobac S-metolachlor

Percent (%) of acres treated

* * *

Growers: PD herbicides applied Percent (%) of acres treated

61.6 46.3 63.3 60 59.3 67.9 23.1 9.6 25.5

10 20 30 40 50 60 70 80 90 100 2

• 2

5 2 6

• 2

1 2

• 2

5 2 6

• 2

1 2

• 2

5 2 6

• 2

1 2

• 2

5 2 6

• 2

1 2

• 2

5 2 6

• 2

1 Glyphosate MSMA Diuron Flumioxazin S-metolachlor

P e r c e n t ( % )

• f

a c r e s t r e a t e d

* * *

Agents: PD herbicides applied Percent (%) of acres treated

68.5 40 41 70 34 74 3.5 9.2 5.4 29.5

10 20 30 40 50 60 70 80 90 100 2

• 2

5 2 6

• 2

1 2

• 2

5 2 6

• 2

1 2

• 2

5 2 6

• 2

1 2

• 2

5 2 6

• 2

1 2

• 2

5 2 6

• 2

1 Glyphosate MSMA Diuron Flumioxazin S

• metolachlor

P e r c e n t ( % )

• f

a c r e s t r e a t e d

* * * * *

Growers: Changes in glyphosate and glufosinate applications from 2000-2005 to 2006-2010

2.3 2.4 0.0 1.5

0.0 0.5 1.0 1.5 2.0 2.5 3.0 2000-2005 2006-2010 2000-2005 2006-2010 Glyphosate applications Glufosinate applicatons

Number of applications / year

*

Agents: Changes in glyphosate and glufosinate applications from 2000-2005 to 2006-2010

2.2 1.8 0.2 2.0

0.0 0.5 1.0 1.5 2.0 2.5 2000-2005 2006-2010 2000-2005 2006-2010 Glyphosate applications Glufosinate applicatons

Number of applications / year

*

Growers 2000-2005: Herbicide costs = $32.30/ A 2006-2010: Herbicide costs = $62.50/ A

Agents 2000-2005: Herbicide costs = $27.80/ A 2006-2010: Herbicide costs = $68.00/ A

Additional practices - example

Grower Question 13: Have you ever hand-weeded cotton due to insufficient chemical

• r mechanical weed control before (2000-2005) and after (2006-2010) the development
• f glyphosate-resistant Palmer amaranth (pigweed)?

Before (2000-2005): After (2006-2010): Yes No Average % of Acres Yes No Average % of Acres ___ ___ ___________________ ___ ___ ___________________ Grower Question 14: Please estimate the cost of hand-weeding in cotton before (2000- 2005) and after (2006-2010) the development of glyphosate-resistant Palmer amaranth (pigweed). Before (2000-2005): After (2006-2010): ____________________________$/Acre ___________________________$/Acre (Continued on next page)

Photo by A.C. York 2010

2000-2005: 17% of growers hand-weeded 5% cotton acres at $2.40/ A 2006-2010: 92% of growers hand-weeded 52% cotton acres at $23.70/ A

Photo by A.C. York 2010

2000-2005: According to agents, growers hand-weeded 3% cotton acres at $3.50/ A 2006-2010: According to agents, growers hand-weeded 66% cotton acres at $21.70/ A

Growers: Changes in tillage/ planting practices from 2000-2005 to 2006-2010

28.0 21.4 36.3 35.2 36.1 43.0

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0 2000-2005 2006-2010 2000-2005 2006-2010 2000-2005 2006-2010 Strip into weeds Strip into cover crops Conventional

Percent (%) of acres

Agents: Changes in tillage/ planting practices from 2000-2005 to 2006-2010

35.0 29.0 24.1 27.8 40.9 43.2

0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0 2000-2005 2006-2010 2000-2005 2006-2010 2000-2005 2006-2010 Strip into weeds Strip into cover crops Conventional

Percent (%) of acres

In-row cultivation

• Growers:

2000-2005: 34.3% of cotton acres cultivated 2006-2010: 43.9% of cotton acres cultivated

• Agents:

2000-2005: 13.1% of cotton acres cultivated 2006-2010: 32.1% of cotton acres cultivated

Growers: M ost troublesome weed*

20 40 60 80 100 120

Percent (%) of growers surveyed

2000-2005 2006-2010

* Summed averages are greater than 100% because of multiple votes for most troublesome species/ grower

Growers: 2nd M ost troublesome weed*

* Summed averages are greater than 100% because of multiple votes for most troublesome species/ grower

10 20 30 40 50 60 70 80 90 100

Percent (%) of growers surveyed

2000-2005 2006-2010

Agents: M ost troublesome weed

20 40 60 80 100 120

Percent (%) of agents surveyed

2000-2005 2006-2010

Agents: 2nd M ost troublesome weed

10 20 30 40 50 60 70 80 90 100

Percent (%) of agents surveyed

2000-2005 2006-2010