2014 Weed Control Tactics – Alabama Vegetable Conference Stanley Culpepper UGA Tifton Campus

Weed Control Responsibilities

Weed Management At Its Best Mechanical Cultural Herbicide/ Fumigant

Agronomic Weed Control Mechanical Cultural Herbicide

Resistance Impacts Agronomic Crops

Changes in Herbicide Management 2002: $24/A2010: $63/A Roundup Burndown Roundup POST 1 Roundup POST 2 Roundup + diuron PD Roundup + Valor Burndown1 Gramoxone + Reflex + Direx PRE Roundup + Staple POST 1 Roundup + Dual POST 2 Direx + MSMA PD

Photo by A.C. York : 17% of growers hand-weeded 5% cotton acres at $2.40/A 2010: 92% of growers hand-weeded 52% cotton acres at $23.70/A

Tillage is now a common scene 2004: 13.1% of cotton acres cultivated 2010: 32.1% of cotton acres cultivated Herbicide incorporation: 264,266 A (26.7%)Deep turn: 256,075 A last 3 yr

Weed Management At Its Best Mechanical Cultural Herbicide/ Fumigant DIVERSIFICATION

Replacing Methyl Bromide – Great Progress Breakout session-this afternoon

Herbicides for Specialty Crops Many believe few options currently available with few products on the horizon!

New GA Veggie Labels Last 7 Yr 1. Chateau tomato RM 2. Chateau pepper RM 3. Chateau eggplant RM 4. Chateau watermelon RM 5. Chateau cantaloupe RM 6. Chateau cucumber RM 7. Chateau squash RM 8. Dual Magnum pepper topical 9. Dual Magnum broccoli topical 10. Dual Magnum cabbage topical 11. Dual Magnum collards topical 12. Dual Magnum cauliflower topical 13. Reflex tomato preplant 14. Reflex pepper preplant 15. Caparol in Okra 16. Sandea in Okra 17. Dual Mag. Carrot 18. Dual Mag. Watermelon 19. Dual Mag Cantaloupe 20. Dual Mag. Sweet Potato 21. Dual Mag. POST in Tomato 22. Dual Mag. POST in Beans 23. Dual Mag. POST in Kale 24. Dual Mag. POST in Collard 25. Reflex in Watermelon 26. Reflex in Squash 27. Reflex in Pumpkin 28. Treflan - Intercropping

Grower Standard + Future Product? Grower Standard (not a check!!) Notice pigweed

Herbicides More Available for GA Vegetable Growers 4 NEW HERBICIDE USES PER YEAR ON AVERAGE OVER LAST 7 YEARS

Why So Successful? University/Commodity Commission/Department of Ag

Why So Successful? University/Commodity Commission/Department of Ag Syngenta Indemnified Labels Valent 3 rd party registration

Why So Successful? University/Commodity Commission/Department of Ag Syngenta Indemnified Labels Valent 3 rd party registration IR-4

Limitations and Concerns 1.Limited number of scientists working in specialty crops. 2.Most growers scared to death of herbicides

Limitations and Concerns 1. Limited number of scientists working in specialty crops. - most of our labels studies - new corn label 550 studies

Dual PRE Dual POST

Herbicide Injury Greatly influenced by excess moisture, cold, and incorrect spray calibration.

Herbicides Can Only Be As Good As the Person Applying Them 1. Droplet Size –nozzle, pressure, speed

GreenLeaf TwinJetAir Induction There is a fine line between drift management and weed control!

Table 1. ASAE S Spray Tip Classification by Droplet Size 1. CategorySymbolColor Code Approximate VMD 2 (Microns) Extremely FineXFPURPLE~50 Very FineVFRED<136 FineFORANGE MediumMYELLOW CoarseCBLUE Very CoarseVCGREEN Extremely Coarse XCWHITE Ultra CoarseUCBLACK>622 1 Source: TeeJet Technologies Catalog 51, page VMD = Volume median diameter.

Herbicides Can Only Be As Good As the Person Applying Them 1.Droplet Size –nozzle, pressure, speed 2.Adjuvants – some products need

Photo credit: Webster

Herbicides Can Only Be As Good As the Person Applying Them 1.Droplet Size –nozzle, pressure, speed 2.Adjuvants – some products need 3.Persistence

No ReflexReflex 1 pt/A applied 205 days before transplanting

Herbicides Can Only Be As Good As the Person Applying Them 1.Droplet Size –nozzle, pressure, speed 2.Adjuvants – some products need 3.Persistence 4.Relationship with mulch

Roundup PreplantNo Roundup

Sandea Dissipation on Mulch 65% 6%

Herbicides Can Only Be As Good As the Person Applying Them 1.Droplet Size –nozzle, pressure, speed 2.Adjuvants – some products need 3.Persistence 4.Relationship with mulch 5.Labels – 6.Extension/Manufacture/Dealer

Weed Management At Its Best Mechanical Cultural Herbicide/ Fumigant DIVERSIFICATION Mechanical Tillage – Pre-plant – cultivation – after harvest

No Deep TillageDeep Turn No Herbicide Treatment Number of Palmer Amaranth Plants During Early Season. Macon Co., Georgia 2008.*

Influence of burial depth on Palmer amaranth emergence Keeley et al. (1987) reported 36-44% emergence at 0-1”, 7% at 2”, and 2% at 3”.

Deep TurnDrilled

Nutsedge Number 1 Problem in Plastic

Don’t plow unless you have to!!!!!!!!!!

Weed Management At Its Best Mechanical Cultural Herbicide/ Fumigant DIVERSIFICATION Cultural Crop rotation Plant population Row spacing Planting date Cover crops

Rolling Creates a Mulch that is Critical in Reducing Palmer amaranth Emergence

After Cover is Terminated and it Rains; Planting will be Ideal for a Significant Amount of Time

70 to 95% control in middle Rye Mulch Reduces Palmer Emergence

Rye/Mulch System

7830 b 88,015 d 30,350 c no herbicide no rye 2465 a Palmer amaranth plants per acre as influenced by herbicide, rye cover crop, and fumigant. no herbicide rye herbicides no rye herbicides rye

1740 b c 2030 b no herbicide no rye 435 a Annual grass plants per acre as influenced by herbicide, rye cover crop, and fumigant. no herbicide rye herbicides no rye herbicides rye

8845 c 44,805 d 5945 b no herbicide no rye 2900 a Yellow nutsedge plants per acre as influenced by herbicide, rye cover crop, and fumigant. no herbicide rye herbicides no rye herbicides rye

Rye/Mulch System Fumigant under mulch if wanted

Rye/Mulch System Two Biggest Challenges: 1.Time required to get rye established 2.Delay in maturity

BIOLOGY Integrated to remain sustainable Management programs Diversity and Integration = Survival

Rapid Growth Becoming Extremely Large

230 K K 309 K Giant ragweed 450 K Number of Seed Produced per Plant Ragweed = Harrison et al. 2001; johnsongrass = Warwick and Black (1983); horseweed = Regehr and Bazzaz (1979); waterhemp = Nordby and Hartzler (2004); Palmer amaranth = Macrae et al (2009). Johnson -grass HorseweedWaterhempPalmer amaranth

Palmer amaranth seed production allows for rapid field domination Year 1Year 3 to 4

Weakness of Pigweeds 1. Emergence depth! 2. Seed life longevity? 3. Light requirement for emergence.

Nutsedge Tuber Production: The Key YEAR 1: 10 plants (tuber) survive fumigation 35,000 plants ready for year 2 YEAR 2: control = 95% control (1750 plants survive) 6,125,000 plants ready for year 3 YEAR 3: control = 95% control (306,250 plants survive) 1,071,875,000 plants ready for year 4

About 3 wk after emergence = tubers

ROTATE DISKING WITH ROUNDUP EVERY 3 WKS. ADD SANDEA IN WITH ROUNDUP ONCE IF NOT CARRYOVER PROBLEMS

Non-treated control Hoelon 2X rate

Non-treated control PowerFlex 3X rate or Osprey at 3X rate

Non-treated control Axial XL 2X rate

Non-treated control Was A Future Product

EPA will have great influence 1.Regulatory 2.More difficult to get new tools 3.Loss of old tools 4.Media sensitivity 5.More paperwork 6.Required training

INDUSTRY Georgia Department of Agriculture Commissioner Gary Black

Questions/Comments Culpepper, University of Georgia, Tifton Campus

Cotton/Melon Intercropping Melons planted as normal Cotton generally planted about 3 week later. GA acreage exceed 3000 during 2013

Cotton/Cucurbit Intercropping Cantaloupe SquashWatermelon 30 days after transplant

Cantaloupe-Cotton Intercropping CantaloupeCotton YieldNo reduction0-12% reduction Crop value17% increase>1,000 increase

Watermelon-Cotton Intercropping WatermelonCotton YieldNo reduction12-18% reduction Crop Value14% increase>1,000 increase

Cucurbit crop WatermelonCantaloupeSquash Row crop Soybean Peanut Cotton

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