The University of Georgia College of Agricultural & Environmental Sciences
Cooperative Extension Service

Applying Contacts and Systemics for Sucker Control

Paul E. Sumner

Care should be taken when applying contacts and systemics to obtain effective control. When applying contacts, be sure the spray mixture flows down the stalk and into the leaf axils. Use three solid cone nozzles spaced 9 to 12 inches apart over each row. Direct the two outside the nozzles toward the upper one third of the tobacco plant. It is suggested that a larger nozzle be used in the center. Application speed commonly used 3-nozzle arrangement (TG3-TG5-TG3) is limited to 2.5 to 3 mph in order to concentrate the appropriate spray volume over the center of the row. Growers who wish to apply suckercides at faster speeds need uniform row widths, good application equipment and relatively level land that will allow the nozzles to remain over the row and the boom stable at the speed used. When applying contacts sprayers should be calibrated to deliver approximately 50 gallons of mixture per acre at 20 - 25 psi.

Apply systemics to the active growing parts of the tobacco plant. Use solid cone nozzles, spaced 9 to 12 inches apart, over each row. Direct the two outside the nozzles toward the upper one third of the tobacco plant. DO NOT USE DROP NOZZLES. Apply spray mixture to the top surface of leaves. Calibrate sprayers to apply 30 to 50 gallons of mixture per acre at 25 - 35 psi. Do not apply MH materials with less than 30 gallons of water. There have been cases of plant burn with low rates of water.



Table 3. Suggested spray nozzles for application of contacts and systemics

Type of Material Nozzle Arrangement Pressure
(PSI)		 Speed
(MPH)		 Row Spacing (inches)
42 44 46 48
Contacts, Localized TG2-TG3-TG21 20 2.5 55 52 50 48
(Offshoot T, Prime+, 20 3 46 44 42 40
Butralin) TG2-TG4-TG2 20 3 52 50 48 46
20 3.5 45 43 41 39
TG3-TG5-TG3 20 3.5 61 58 56 53
20 4 53 51 49 48
20 4.5 47 45 43 41
TG4-TG6-TG4 20 4 68 65 62 59
20 4.5 60 58 55 53
20 5 54 52 50 47
TG5-TG8-TG5 20 5 70 67 64 61
Systemics TG3-TG3-TG3 20 3.5 50 47 45 43
(MH Alone) 20 4 43 41 39 38
20 4.5 38 37 35 34
TG4-TG4-TG4 20 4 58 56 53 51
20 4.5 52 49 47 45
20 5 47 45 43 41
TG5-TG5-TG5 20 5 59 56 53 51
20 5.5 53 50 49 47

1 - TG is the designation for Spraying Systems nozzles. Other nozzle systems are available that may be used.

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Issued in furtherance of Cooperative Extension work, Acts of May 18 and June 30, 1914, The University of Georgia College of Agricultural and Environmental Sciences and the U.S. Department of Agriculture cooperating.

Gale A. Buchanan, Dean and Director