Cotton Production Workshop A. Stanley Culpepper
Breakout Session Objectives 1. New labels or uses 2. RR cotton tolerance to glyphosate 3. Managing weeds that are difficult to control in RR cotton 4. Glyphosate/tank mixes 5. Replacing Bladex 6. Cadre carryover 7. DNA application timing in strip-till 8. Layby applications in liquid N
New Labels or Uses 1. Paraquat formulations: Boa (2.5 lb ai) Gramoxone Extra (2.5 lb ai) Gramoxone Max (3.0 lb ai) 2. Glyphosate formulations:
Glyphosate Formulations* Acquire Credit DuPont Glyphosate Gly-Flo Glyfos Glyfos X-TRA Glyphomax Glyphomax Plus Glyphosate Original Rattler Roundup D-Pak Roundup Original Roundup Ultra Roundup UltraDry Roundup UltraMax Touchdown *Products in orange may be applied overtop of RR cotton according to label.
Roundup Ready Cotton Tolerance to Roundup, Touchdown, and Touchdown 5. Clayton, NC. 2000.* % injury 1 application 2 applications Roundup Ultra 0 0 Touchdown 0 0 Touchdown 5 39 63 *Glyphosate applied at 1 lb ai/A. ACY
Morningglory Control in RR Cotton by Harvade Mixtures. Attapulgus, GA. 2000.* Smallflower morningglory Roundup Ultra 84 Roundup + Harvade 92 Roundup + Harvade + COC 99 Harvade + MSMA + COC 99 *Roundup Ultra 2 pt/A; Harvade 6 oz/A when mixed with RU and 10 oz/A when mixed with MSMA; MSMA 2.67 pt/A
Breakout Session Objectives 1. New labels or uses 2. RR cotton tolerance to glyphosate
Transgenic Cotton Acreage in Georgia 64 % 32 32
Lint Cotton Yields in RR Cotton when Treated Topically with Glyphosate at Various Growth Stages a a a b 1) Ten plants per plot were hand harvested on October 10, 1999 in Moultrie, GA. 2) Roundup Ultra applied at 1 qt/A broadcast over-the-top. Conventional plots treated with standard herbicide system.
Glyphosate Overtop After 4th Leaf Stage • Can cause boll shed, delay maturity Salvage treatment only
Is Stem Absorption of Glyphosate Directed in RR Cotton a Concern? No noted concerns with precision applications in field trials Lab data from North Carolina, Georgia, and Mississippi? What about sloppy directed applications?
Cotton Yield After Various Glyphosate Applications. Moultrie, 2000.* a a a b b Lint yield (Lb/A) Topical 1- & 4-lf Standard system Topical 1-, 4-, & 12-lf Topical 4-lf PD 8- & 12-lf Topical 4-lf SD 8- & 12-lf *Glyphosate applied at 1.0 lb ai/A. PD = precision directed at cotyledons; SD = sloppy directed 33 to 40% up the plant. Standard system = Prowl + Cotoran fb Staple fb Caparol + MSMA. LSD = 55
Directing Glyphosate in RR Cotton? • Precision PD or hooded sprayers
Directing Glyphosate in RR Cotton? • Precision PD or hooded sprayers • Direct spray to the base of the cotton plants
Directing Glyphosate in RR Cotton? • Precision PD or hooded sprayers • Direct spray to the base of the cotton plants • Contact of spray with cotton leaves should be avoided to the maximum extent possible
Directing Glyphosate in RR Cotton? • Precision PD or hooded sprayers • Direct spray to the base of the cotton plants • Contact of spray with cotton leaves should be avoided to the maximum extent possible • Place nozzles in low position directing a horizontal spray pattern under the cotton leaves to contact weeds in the row
Breakout Session Objectives 1. New labels or uses 2. RR cotton tolerance to glyphosate 3. Managing weeds that are difficult to control in RR cotton
Cutleaf Eveningprimrose Response to Burndown Herbicides Treatment Rating Gramoxone F Gramoxone + Direx G Glyphosate F Glyphosate + Direx G Glyphosate + Harmony Extra F-G Glyphosate + Clarity G Glyphosate + 2,4-D E
Cutleaf Eveningprimrose Control by Glyphosate and 2,4-D. Tifton, 2000.* % control glyphosate 2,4-D *Roundup Ultra applied at 1 qt/A. Ratings 24 days after treatment.
Cutleaf Eveningprimrose Fresh Weights After Treating with Burndown Herbicides. Tifton, 2000.* Grams/plot *Fresh weights taken from 12 plants per plot. Roundup Ultra applied at 2 pt/A and 2,4-D at 1 pt/A.
2,4-D Burndown for Cotton(from fallow land section of labels) • No specific language concerning cotton • Do not plant any crop in treated fallow land until 3 months after treatment or until chemical has disappeared from soil
Current Recommendations -- 2,4-D Burndown for Cotton • 1 pt/acre • Alone or mixed with glyphosate • Applied 45 days before planting • Research to date shows effectiveness and crop safety
Cotton Injury from 2.1 mls Per Acre of 2,4-D. Tifton, 2000.
Florida Pusley Control with Glyphosate and Glyphosate Tank Mixtures. Tifton, 2000.* 99 a 92 ab 87 bc 81 bc % control *Florida pusley 2 inches. Roundup UltraMAX applied at 1.25 pt; 2,4-D at 1 pt; Direx or Caparol at 1.5 pt.
Controlling Yellow and Purple Nutsedge? Nutsedge Control Programs: 1) 2 applications of glyphosate prior to 5th leaf followed by conventional chemistry including 2 lb ai MSMA directed 2) 1 application of glyphosate prior to 5th leaf followed by conventional chemistry including 2 lb ai MSMA directed 3) 2 applications of glyphosate 4) Zorial or Staple?????
Yellow and Purple Nutsedge Control by Glyphosate. Greenhouse. 98 90 * 81 * 82 77 * 70 % control 42 42 Glyphosate (lb) *Purple nutsedge controlled significantly greater than yellow nutsedge. LSD=10
Yellow and Purple Nutsedge Control by MSMA. Greenhouse. 82 * 69 61 % control 48 49 * 42 MSMA (lb) *Yellow nutsedge controlled significantly greater than purple nutsedge. LSD=10
Mid-Season Morningglory Control by Glyphosate & Glyphosate/Staple Mixtures. Moultrie, 2000. Pitted Smallflower morningglory morningglory Glyphosate 73 89 Glyphosate + Staple 93 97 Things to consider? 1. Morningglory size at time of application (5 inches here). 2. Will you post-direct with conventional chemistry or glyphosate?
Glyphosate/Staple Tank Mixtures • DuPont label allows tank mix of 1.5 pt of Roundup Ultra plus 0.6 oz of Staple per acre broadcast • DuPont’s Staple Plus
Smallflower Morningglory Control by Glyphosate Alone and Mixed with Residual Herbicides; Attapulgus, 2000. a a % control a a b Smallflower mg 4 to 5 inches; irrigated environment Roundup (2 pt/A), Bladex (1.5 pt/A), Caparol (1.5 pt/A), Direx (1.5 pt/A), Valor (2 oz/A)
Asiatic Dayflower Control by Glyphosate & Glyphosate/Staple Mixtures. Grady Co., 2000.* 90 % control 67 Glyphosate + Staple Glyphosate *Dayflower 1 to 5 inches. Ratings 30 days after treatment. Roundup Ultra applied at 1.5 pt/A and Staple at 0.6 oz/A.
Asiatic Dayflower Control by Glyphosate Mixtures at Layby. Grady Co., 2000.* 86 85 81 80 76 67 % control LSD = 10 *Dayflower 1 to 5 inches. Ratings taken 30 days after directing in 8 to 10 inch cotton. Roundup Ultra, Caparol, and Direx applied at 1.5 pt/A. Cobra, Harvade, and Valor applied at 8 oz/A, 8 oz/A, and 2 oz/A, respectively.
Asiatic Dayflower Control by Conventional Layby Herbicides. Grady Co., 2000.* 91 90 90 85 84 82 80 78 78 % control LSD = 9 *Dayflower 1 to 5 inches. Ratings taken 30 days after directing in 8 to 10 inch cotton. Bladex, Caparol, Cotoran, and Direx applied at 2 pt/A. Cobra, Harvade, Linex, MSMA, and Valor applied at 9.6 oz/A, 9 oz/A, 1.5 pt/A, 2.67 pt/A, and 2 oz/A, respectively.