Stable bromine isotopic composition of methyl bromide - DiVA Portal
Weed Control Without Methyl Bromide
description
Transcript of 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