EVALUATION OF MH FREE CHEMICALS FOR SUCKER CONTROL Gary Palmer, Bob Pearce & Andy Bailey University of Kentucky

MH Free Tobacco Trials were conducted in Jessamine County to study the mechanical application of sucker control chemicals that do not contain Maleic Hydrazide. Control has been well documented with methods that run Butralin, Flupro or Prime+ down the stalk. However, such methods are slower and labor intensive and not likely to be adopted by larger growers.

Spraying with Coarse Nozzles

Location Day Chemical BoomNozzleDrought Sucker ControlComments Home16Prime +StraightTG-3Low Fair- Poor Two - Three 4-7" suckers in 1/2 of plants in top Dodd16ButralinStraightTG-3ModerateGoodOccasional 4-7" sucker Dodd16Prime +StraightTG-3ModerateGoodOccasional 4-7" sucker Dodd16Butralin 3 nozzle TG-3& TG-5 Low- ModerateExcellentFew suckers Dodd16Prime +StraightTG-3ModerateGoodOccasional 4-7" sucker MH Free Tobacco Trial

Location DayChemicalBoomNozzleDrought Sucker ControlComments Creek* 9Prime +StraightTG-5 Moderate - HighGood Occasional 4-7" sucker By- Pass15 FA+ FluproStraightTG-50-LowPoor Two 5-9" in tops of most plants By- Pass15Prime +StraightTG-50-LowPoor Three or more suckers in tops of most plants Shop14Prime +StraightTG-50-LowFair Two - Three 5-9" suckers in 1/3 of plants in top MH Free Tobacco Trial

Summary Although initial results were encouraging, none of the treatments provide acceptable control in the end.

MH Free Tobacco )Chemicals Trial 2)Topping Study No1stRate2 nd 7 daysRate3 rd 14 daysRate 1Butralin1 galButralin*1 gal 2Royaltac-M2 galButralin1 gal 3Royaltac-M2 galRoyal MH gal 4Royaltac-M2 galRoyaltac-M2 gal 5Royaltac-M2 gal Royaltac-M + Butralin 2 gal 1 gal TreatmentInitial3 days 1Normal Topping 2High Top (8-10 leaf)Retop to Normal 3Not ToppedTop to Normal * Not applied due to weather

MH Free Tobacco )Nozzle Study No. SizePSIMPH All treatments were applied with a CO 2 backpack with an over- the –shoulder two row boom. Plots were 40 ft by 2 rows (40” rows) in a randomized complete block design with four replications.

Comparison of Sucker Control Treatments on Degree of Control Harrison Co. - Ricci Rowland Farm RTM=Royal Tac M, But=Butralin, MH= Royal MH-30, fb=followed by at 7 days

Comparison of Sucker Control Treatments on Yield of Burley Tobacco Harrison Co. - Ricci Rowland Farm RTM=Royal Tac M, But=Butralin, MH= Royal MH-30, fb=followed by at 7 days

MH Free Topping Study Harrison Co. - Ricci Rowland Farm TR TFirst TopRe-top Sucker Control Rating 1Normal ToppingNoneFair4.75 2High Top (8-10" leaf)Re-top to Normal 3 days Moderate4.5 3Not ToppedTop to Normal 3 daysPoor3.25

MH Free Nozzle Study Harrison Co. - Ricci Rowland Farm TRTNozzle typePSISpeed Rating (0-10 best) 1TG-3 – TG-4 – TG-3302 mph5 2TG-5 – TG-5 – TG-5254 mph3 3TG-5 – TG-6 – TG-5254 mph3

Summary Although initial results were encouraging, none of the treatments provide acceptable control in the end except for the one containing MH.

Sucker Control Trials The Regional Sucker Control Trials are conducted under the auspices of the Regional Growth Regulator Committee of the Tobacco Worker’s Conference. Treatments proposed by the committee were treatments 1-7. Treatment 8 was added for this study only.

Regional Sucker Control Treatments* 1 st Treatment (Elongated Bud)2 nd Treatment (At topping – 10-25% bloom) 1Untreated Check 2Royal MH-30 (2 gal/a) 3Royal MH-30 (1.5 gal/a) 4Royal MH-30 (1.5 gal/a + Flupro 0.5 gal/a) 5Royal MH-30 (1.5 gal/a + Butralin 0.5 gal/a) 6Off-shoot T (3%)Off-shoot T (4%) + Butralin (0.5 gal/a) 7Butralin (1 gal/a) 8Off-shoot T (3%)Off-shoot T (4%) +Butralin (1 gal/a) * 60 gal/a at 2.4 mph and 30 psi using a West Texas Lee high clearance sprayer Treatments were scheduled for 5 days apart but were applied 7 days apart due to weather. Treatment 8 was added to the RSC treatments.

Comparison of Sucker Control Treatments at Two Weeks after Application UK Spindletop Farm (MH= Royal MH-30, F=Flupro, B=Butralin,) in (gal) O=Off-Shoot-T in (%), UTC=untreated check, fb=followed by at 7 days. *=Sprayer malfunctioned

The Effects of Sucker Treatment on Sucker Number per Plant UK Spindletop Farm (MH= Royal MH-30, F=Flupro, B=Butralin,) in (gal) O=Off-Shoot-T in (%), UTC=untreated check fb=followed by at 7 days. *=Sprayer malfunctioned

The Effects of Sucker Treatment on Sucker Weight UK Spindletop Farm (MH= Royal MH-30, F=Flupro, B=Butralin,) in (gal) O=Off-Shoot-T in (%), UTC=untreated check, fb=followed by at 7 days. *=Sprayer malfunctioned

The Effects of Sucker Treatment on Yield UK Spindletop Farm

Summary A sprayer malfunction produced results that were not characteristic of the past performance of MH at 2 gal/a. Treatments 3 (MH at 1.5 gal/a), 4 (MH at 1.5 gal/a + Flupro at 0.5 gal/a), & 5 (MH at 1.5 gal/a + Butralin at 0.5 gal/a) were all excellent treatments. Both the Off-shoot T followed by Off-shoot T + Butralin at 0.5 gal/a & Off-shoot T followed by Off-shoot T + Butralin at 1 gal/a were acceptable, but not as clean as MH containing treatments 3-5. Butralin at 1 gal/a by itself was as good as when Off-shoot T was added.

MH Free Trials All Treatments were made with a West Texas Lee high clearance sprayer using a three nozzle arrangement in a TG-3 – TG-5 – TG-3 configuration and an application volume of 60 gal/a. Applicator speed was 2.4 mph at 30 psi. Plots were 30 ft by 2 rows (42” rows) in a randomized complete block design with four replications.

MH Free Trails Treatments 1 st Treatment (Elongated Bud) 2 nd Treatment At topping ( 10-25% bloom) 3 rd Treatment 5 days post top 1Off-Shoot T 3%Off-Shoot T 4%Butralin 1 2Off-Shoot T 4% Butralin 1 3Off-Shoot T 4%Butralin 1 4Off-Shoot T 4%Off-Shoot T 4%+Butralin 1 5Off-Shoot T 4%Off-Shoot T 4%+Butralin 1Butralin 1 6Off-Shoot T 4%Flupro 1Butralin 1 7Off-Shoot T 4%Butralin 1 8Off-Shoot T 4%Royal MH 1.5 9Off-Shoot T 4%Butralin 0.5+Royal MH1.5 10Untreated Check * 60 gal/a at 2.4 mph and 30 psi using a West Texas Lee high clearance sprayer Treatments were applied 5 days apart

MH Free Trials Comparison of Sucker Control Treatments UK Coldstream Farm (MH= Royal MH-30, F=Flupro, B=Butralin,) in (gal) O=Off-Shoot-T in (%), UTC=untreated check (-) followed by at 5 days.

MH Free Trials The Effects of Sucker Treatment on Sucker Number per Plant UK Coldstream Farm (MH= Royal MH-30, F=Flupro, B=Butralin,) in (gal) UTC=untreated check O=Off-Shoot-T in (%), (-) followed by at 5 days

MH Free Trials The Effects of Sucker Treatment on Sucker Weight UK Coldstream Farm (MH= Royal MH-30, F=Flupro, B=Butralin,) in (gal) O=Off-Shoot-T in (%), UTC=untreated check, (-) followed by at 5 days.

MH Free Trials: The Effects of Sucker Treatment on Sucker Weight UK Coldstream Farm (MH= Royal MH-30, F=Flupro, B=Butralin,) in (gal) O=Off-Shoot-T in (%), UTC=untreated check, (-) followed by at 5 days.

Summary Treatments with MH produced 100% control Results from Off-shoot T at 4% followed by a tank mix of Off-shoot T + Butralin at 1 gal/a followed by Butralin at 1 gal/a were close to those containing MH. Results from the above treatment were not statistically better than – Off-shoot T at 4% fb Off-shoot T 4% fb Butralin 1 –Off-shoot T at 4% fb Off-shoot T 4% + Butralin 1 –Off-shoot T at 4% fb Flupro 1 fb Butralin 1 –Off-shoot T at 4% fb Butralin 1 fb Butralin 1 A 3% concentration of Off-shoot T applied before topping did not perform as well as a 4% concentration.

MH-Free Nozzle Study Application technique changed a MH-Free sucker control program from unsuccessful to successful. Nozzle size was studied as part of the overall application technique trial. While a rundown method is known to work successfully, mechanical application has proven difficult to achieve acceptable results. All treatments were applied with a CO 2 backpack with an over-the –shoulder two row boom with a TG-(3-5-3) arrangement. Plots were 40 ft by 2 rows (42” rows) in a randomized complete block design with four replications. Treatments consisted of 4% Off-shoot T at elongated bud followed by a combination of Off-shoot T at 4 % plus Butralin at 1 gal /a.

MH-Free Nozzle Study Treatments Nozzles ArrangementPSIMPHGal 1TG-3 - TG-5 - TG TG-3 - TG-5 - TG TG-5 - TG-5 - TG TG-5 - TG-6 - TG All treatments were applied with a CO 2 backpack with an over-the –shoulder two row boom. Plots were 40 ft by 2 rows (42” rows) in a randomized complete block design with four replications. Treatments consisted of 4% Off-shoot T at elongated bud followed by a combination of Off-shoot T at 4 % plus Butralin at 1 gal /a.

Effects of Nozzle Size on Sucker Control All Nozzles were TG full cone nozzles

Effects of Nozzle Size on Sucker per Plant All Nozzles were TG full cone nozzles

Summary Yields are not yet available Percent control and suckers per plant were not significantly different

Acknowledgement Financial Support –Chemtura Corporation Establishment, Plot Maintenance, Data Collection –Dr. Bob Pearce & Edwin Ritchie Treatments –Interns: Austin Perkins & Keith Johnson Equipment –Dr. Kenny Seebold