Download - Weed Control Without Methyl Bromide
Weed Control Without Methyl Bromide
Drs. Stanley Culpepper and Ted Webster
University of Georgia and USDA-ARS
Tifton, Georgia
Methyl Bromide
Phasing out of the marketplace 1999 = 25% reduction
2001 = 25% reduction
2003 = 20% reduction
2005 = gone
(reduce methyl bromide ai over time)
Global Methyl Bromide Use
Preplant
Durable
Perishable
Commodity
Structural
Chemical interm
66%
Countries Using Methyl Bromide U.S.ItalyJapanSpainFranceMexicoBrazilTurkeyBelgiumMoroccoGreeceSouth AfricaChinaCosta Rica
37%
Replacing Methyl Bromide
A multi-tactic approach is needed and should include the following:
– application of weed biology
– cultural practices
– fumigants
– herbicides
Yellow Nutsedge:Yellow Nutsedge: - Yellow florets- Yellow florets - All tubers attached to - All tubers attached to mother tubermother tuber - Suppressed by bentazon - Suppressed by bentazon and metolachlorand metolachlor - Leaves: long drawn-out tip- Leaves: long drawn-out tip
Purple Nutsedge:Purple Nutsedge: - Dark red/purple florets- Dark red/purple florets - Forms chains of tubers- Forms chains of tubers - Not suppressed with - Not suppressed with bentazon or metolachlorbentazon or metolachlor - Leaves: short, abrupt tip- Leaves: short, abrupt tip
Chain of Purple Nutsedge TubersChain of Purple Nutsedge Tubers
Yellow NutsedgeYellow NutsedgePurple NutsedgePurple Nutsedge
Objective: Evaluate the Spatial Dynamics of Yellow Objective: Evaluate the Spatial Dynamics of Yellow and Purple Nutsedge and Purple Nutsedge
Expansion After 3 Months Expansion After 3 Months (From a Single Planted Tuber)(From a Single Planted Tuber)
Purple and Yellow Nutsedge Density: 3 and 6 Months of Growth
Following Planting of 1 Tuber
3 Months of Growth
Nu
tsed
ge D
ensi
ty (
Sh
oots
per
Pat
ch)
0
50
100
150
200
250
300
350
6 Months of Growth
Purple Nutsedge
Yellow Nutsedge
Purple Nutsedge
Yellow Nutsedge
29 22
323
135
Alternatives to Methyl Bromide Alternatives to Methyl Bromide for Weed Management?for Weed Management?
1 Soil Solarization/Organic AmendmentsSoil Solarization/Organic Amendments– Requires a hot and cloudless climateRequires a hot and cloudless climate– Studies have shown that:Studies have shown that:
• solarization can reduce pests prior to plantingsolarization can reduce pests prior to planting
• crop yields can be increasedcrop yields can be increased
• effects can be extended through several seasons effects can be extended through several seasons
– Research has focused on pathogens and Research has focused on pathogens and nematodes - only a handful of studies on nematodes - only a handful of studies on weedsweeds
How hot does the soil temperature get underneath plastic?
Is it hot enough to kill nutsedge?
• Yellow Nutsedge:Yellow Nutsedge:• 113 F for 8 hours = 113 F for 8 hours = >> 90% Tuber Viability 90% Tuber Viability• 122122+ + F for 15 minutes = F for 15 minutes = << 50% Tuber Viability 50% Tuber Viability
• Purple Nutsedge:Purple Nutsedge:• 122 F for 8 hours = > 70% Tuber Viability122 F for 8 hours = > 70% Tuber Viability• 131 F for 4 hours = 131 F for 4 hours = << 20% Tuber Viability 20% Tuber Viability• 140 F for 1 hour = < 5% Tuber Viability140 F for 1 hour = < 5% Tuber Viability
• How hot can we get our soils? How hot can we get our soils?
• How long can they stay this hot?How long can they stay this hot?
Preliminary ConclusionsPreliminary ConclusionsLethal Temperature/Duration of Exposure:Lethal Temperature/Duration of Exposure:
Alternatives to Methyl Bromide Alternatives to Methyl Bromide for Weed Management?for Weed Management?
2 Fumigants:Fumigants:• ChloropicrinChloropicrin• Metam SodiumMetam Sodium• Methyl IodideMethyl Iodide• Telone, Telone IITelone, Telone II• Telone C17/C35Telone C17/C35
Methyl Bromide
chickweed crabgrass goosegrass crowfootgrass pigweed morningglory? purslane nutgrass
Telone II, Telone C-17/35, Chloropicrin
No mention of specific weeds controlled
Non-treated Telone Broadcast Telone In Bed
25 GPA 35 GPA
Photos taken from Florida Field Day. Bill Stall, 2000.
Metam Sodium
chickweed dandelion ragweed lambsquarters pigweed nightshades purslane nutsedge, morningglory - suppression
Metam Sodium
Nutsedge –
1) May be suppressed if actively growing and a high use rate is applied (75 gal/A).
2) More often roots and shoots will be controlled, but the tuber will remain viable and re-grow at a later time.
METHYL BROMIDE: 400 LBS (98%)METHYL BROMIDE: 400 LBS (98%)
NONTREATED CONTROLNONTREATED CONTROL
Purple Nutsedge Through Plastic in Purple Nutsedge Through Plastic in Squash: Shoots/PlotSquash: Shoots/Plot
• Methyl Bromide (392 Lbs/A - Fumigated):Methyl Bromide (392 Lbs/A - Fumigated):– 1998: 99% lower than UTC (*)1998: 99% lower than UTC (*)– 1999: 99% lower than UTC (*)1999: 99% lower than UTC (*)
• Telone C-35 EC (12 Gal/A) - Drip:Telone C-35 EC (12 Gal/A) - Drip:– 1998: 81% lower than UTC (*)1998: 81% lower than UTC (*)– 1999: 40% greater than UTC (NS)1999: 40% greater than UTC (NS)
Purple Nutsedge Through Plastic in Purple Nutsedge Through Plastic in Squash: Shoots/PlotSquash: Shoots/Plot
• Methyl Bromide (392 Lbs/A - Fumigated):Methyl Bromide (392 Lbs/A - Fumigated):– 1998: 99% lower than UTC (*)1998: 99% lower than UTC (*)– 1999: 99% lower than UTC (*)1999: 99% lower than UTC (*)
• Telone C-35 EC (12 Gal/A) - Drip:Telone C-35 EC (12 Gal/A) - Drip:– 1998: 81% lower than UTC (*)1998: 81% lower than UTC (*)– 1999: 40% greater than UTC (NS)1999: 40% greater than UTC (NS)
Purple Nutsedge Through Plastic in Purple Nutsedge Through Plastic in Squash: Shoots/PlotSquash: Shoots/Plot
• Methyl Bromide (392 Lbs/A - Fumigated):Methyl Bromide (392 Lbs/A - Fumigated):– 1998: 99% lower than UTC (*)1998: 99% lower than UTC (*)– 1999: 99% lower than UTC (*)1999: 99% lower than UTC (*)
• Telone II + Chloropicrin + Vapam Telone II + Chloropicrin + Vapam (12 Gal/A - Chisel ) and (6.6 + 50 Gal/A - Drip)(12 Gal/A - Chisel ) and (6.6 + 50 Gal/A - Drip)::– 1999 Early Season: 76% lower than UTC (*)1999 Early Season: 76% lower than UTC (*)– 1999 Late Season: 22% greater than UTC (NS)1999 Late Season: 22% greater than UTC (NS)
Nontreated ControlNontreated ControlTelone II + Chloropicrin + VapamTelone II + Chloropicrin + Vapam (12 Gal/A - Chisel ) and (6.6 + 50 Gal/A - Drip)(12 Gal/A - Chisel ) and (6.6 + 50 Gal/A - Drip)
13 Days After Treatment13 Days After Treatment
• Methyl Iodide (392 Lbs/A - Drip):Methyl Iodide (392 Lbs/A - Drip):– 1998: 81% lower than UTC (*)1998: 81% lower than UTC (*)– 1999: 21% greater than UTC (NS)1999: 21% greater than UTC (NS)
Purple Nutsedge Through Plastic: Purple Nutsedge Through Plastic: Shoots/PlotShoots/Plot
Alternatives to Methyl Bromide Alternatives to Methyl Bromide for Weed Management?for Weed Management?
3 HerbicidesHerbicides– Limited # of Registered CompoundsLimited # of Registered Compounds
• Cucurbits (3-5) - no nutsedge materialsCucurbits (3-5) - no nutsedge materials
• Eggplant (4) - no nutsedge materialsEggplant (4) - no nutsedge materials
• Pepper (5) - no nutsedge materialsPepper (5) - no nutsedge materials
• Squash (4) - no nutsedge materialsSquash (4) - no nutsedge materials
• Tomato (7) - Tillam for nutsedge suppressionTomato (7) - Tillam for nutsedge suppression
– IR-4 is working to increase this listIR-4 is working to increase this list
Sandea
Gowan
Halosulfuron-methyl
75% active ingredient
MAY be labeled in FL in 2001
Ever labeled in GA????
Rate unknown -- probably 0.024 lb ai/A
Sandea for Vegetable Weed Control
1-3 inch 1-9 inch
passionflower cocklebur
redroot pigweed ragweed
pokeweed velvetleaf
yellow nutsedge - suppression purple nutsedge - suppression
2 to 3 weeks residual weed control
Yellow Nutsedge Control with Sandea Applied PRE in Watermelon.*
0
20
40
60
80
100
0.5 oz
0.75 oz
1.0 oz
*In cooperation with Ken Lewis, Crisp County, 2000. Rating 21 days after treatment.
% c
ontr
ol
Yellow Nutsedge Control with Sandea Applied POST in Watermelon.*
0
20
40
60
80
100
0.5 oz
0.75 oz
1.0 oz% c
ontr
ol
*In cooperation with Ken Lewis, Crisp County, 2000. Rating 21 days after treatment.
Nontreated Sandea (0.024 lb ai/A)
Sandea
Potential Crops (in order of crop tolerance?)
tomato
0
200
400
600
800
1000
medium large X-large
none
0.5 oz/A
1.0 oz/A
*In cooperation with Joel Hudgins, Decatur County, 2000.
Number of Tomato Boxes Per Acre After Sandea Treatments. Spring, 2000.*
0
500
1000
1500
2000
2500
3000
total number of boxes
none
0.5 oz/A
1.0 oz/A
*In cooperation with Joel Hudgins, Decatur County, 2000.
Number of Tomato Boxes Per Acre After Sandea Treatments. Spring, 2000.*
0
200
400
600
800
1000
medium large X-large
none
0.5 oz/A
1.0 oz/A
*In cooperation with Joel Hudgins, Decatur County, 2000.
Number of Tomato Boxes Per Acre After Sandea Treatments. Fall, 2000.*
Sandea
Potential Crops (in order of crop tolerance?)
tomato
cucumber
pumpkin
cantaloupe
watermelon
Nontreated Sandea (0.024 lb ai/A)
Watermelon farm in Crisp County, May 2000. Treatment at 1-leaf.
Watermelon Injury with Sandea Applied PRE in Watermelon.*
0
20
40
60
80
100
0.5 oz
0.75 oz
1.0 oz
*In cooperation with Ken Lewis, Crisp County, 2000. Rating 21 days after treatment.
% in
jury
0
20
40
60
80
100
0.5 oz
0.75 oz
1.0 oz
Watermelon Injury with Sandea Applied POST to 3-inch Watermelon.*
*In cooperation with Ken Lewis, Crisp County, 2000. Rating 5 days after treatment.
% in
jury
0
20
40
60
80
100
0.5 oz
0.75 oz
1.0 oz
Watermelon Injury with Sandea Applied POST to 14-inch Watermelon.*
*In cooperation with Ken Lewis, Crisp County, 2000. Rating 5 days after treatment.
% in
jury