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Looking Ahead

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Keep more dollars in your pocket by topping with precision, controlling suckers and curing properly.

Rocky Womack

You want to provide your customers with the highest-quality product, but at the same time, rising harvest and curing costs are putting the squeeze on profits. So as harvest approaches, it pays to think ahead. Follow these best practices to please your customers and boost your bottom line.

Topping and sucker control
As growers know, controlling sucker growth keeps the weight in the plant versus in the sucker. Weight equals profit per pound. However, because many growers in the future will be raising more tobacco under contract, their management of suckers also must improve as their crop size increases.

“Growers can continue to improve the job that they do with sucker control,” says University of Georgia Extension Agronomist J. Michael Moore.

One way to efficiently increase quality and yield is to top at the button stage, according to recommendations by the North Carolina Cooperative Extension Service. Yields decline by 20 to 25 pounds per acre per day if growers wait three weeks after the tops reach the button stage. Topping early also decreases the chances of strong winds blowing the tobacco to the ground.

To better control suckers, establish a uniform crop early in the seeding process. A uniform crop is essential and often starts in the greenhouse. “This increases the potential for fewer trips for application of suckercides and once-over topping,” says Bryant Spivey, an Extension agent in Onslow County, N.C.

Moore says, “Uniformity encourages workers not to overharvest and stick to stalk position. When they have a lot of missing plants or poor stand, there’s often a tendency to harvest higher on the stalk.”

Automation can also help tobacco growers with better sucker control. “Many of our growers have shown us that they can minimize the number of hand-labor hours used for pulling tops and suckers,” Moore says. “They substitute the cost of chemicals. They substitute multiple trips across the fields with a sprayer combination topper, where they top and spray at the same time, and they minimize the amount of hand labor that is required to handle that crop.”

Spivey says most growers in Onslow County use automatic toppers as a prior trip to a “clean-out” by a hand crew. “However, even when used in this manner it reduces the amount of labor required to top and sucker.”

He advises growers to make timely applications of suckercides, especially contacts before or after topping. “If done correctly, this limits the number of man hours per acre for topping and suckering,” he says. “It has been a common mistake for growers to start too late with fatty alcohol contacts.”

Spivey adds that the overuse of nitrogen can increase sucker growth, so he advises growers to use only what they need.

In some instances, uniformity and effective sucker control may not exist when storms blow through, making topping and suckering challenging at best. “Sucker control is limited in this situation due to the fact that the full benefits of gravity on stalk rundown do not occur,” says Mitch Smith, the Extension director in Pitt County in Greenville, N.C. “Localized systemics (Prime Plus and Flupro) are also affected, because these chemicals are not able to touch all suckers, which [is] necessary for their use in tobacco.”

A good first step in controlling suckers is to mix the proper amount of contact materials, which burn suckers, with the right amount of water. Follow label directions carefully for better control. If the contacts don’t chemically top 5 to 10 percent of the small and late plants in the first application, then the solution may be too weak for good sucker control, according to the North Carolina Cooperative Extension Service.

Pull any suckers that have grown more than 1 inch, because the contact material may not burn the sucker enough to stop growth. It is recommended to top when 50 to 60 percent of the tops reach the button stage and when leaf axils are open. Of course, droughts can cause these leaf axils to close, so a more precise application is then necessary.

Smith advises growers who use multiple contacts not to exceed a 4 percent solution until they reach their last application, when a 5 percent solution is recommended. He says at least a 4 percent solution is needed to kill the small suckers in each leaf axil. Smith warns to halt application of contacts when temperatures exceed 90 degrees Fahrenheit and when the plants wilt. He also suggests not applying suckercides when the tobacco is wet, as this reduces effectiveness. In addition, he advises growers to use only a 3 percent solution when applying the contacts Antak, Fair-Tac, Royaltac or Tentac.

Set up tobacco, often with its crooks and turns, can cause suckercides to miss some leaf axils. Smith recommends that growers slow down their sprayers or tractors so they can be more precise in application. The latest Extension recommendation is to use two TG-3 nozzles and one TG-5 nozzle at a sprayer or tractor speed of 3 miles per hour. “This will apply 50 gallons per acre at a pressure of 20 psi,” Smith says.

Growers considering the use of four nozzles instead of three over the row may want to rethink their options. “In our tobacco research trials, using four nozzles over the row compared to three nozzles did not improve sucker control,” Smith says. “More importantly, the position of the boom over the row was found to be more of a factor in obtaining good sucker control.
So … if your rows are not regular or if you are dealing with severe wind damage, even 10 nozzles per row will not improve sucker control!”

As most growers know, windblown tobacco means setting up plants, suckering and applying suckercides using hand labor instead of mechanical toppers. Besides hand labor, growers can apply maleic hydrazide (MH), because this chemical’s effectiveness isn’t affected as much by windblown tobacco. “Under these conditions, growers are advised to apply MH as soon as the upper leaves reach maturity,” Smith says. “This may require a program which uses one contact followed by Prime Plus or Flupro and then MH. An additional contact may also be needed later in the season.”

Smith reminds growers that if rains occur within two hours of applying Prime Plus or Flupro, growers should not reapply. He says reapplying could contribute to the stunting of planted crops in the fall or spring. Additionally, growers do not need to reapply the full rate of MH unless a substantial rain pours within four hours after the first application. MH slows the growth of suckers for about seven weeks.

“Only a half rate (0.75 gallon of MH per acre) is needed if rain occurs between four and 10 hours after the first application,” Smith says. “No application is needed if rain occurs more than 10 to 12 hours after the first application. Following these important guidelines will ensure good sucker control with only minimal increases in MH residues.”

Curing tips
Loading the same amount of tobacco uniformly in each curing box ensures an efficient cure, Spivey says.

Growers can use wet-bulb thermometers to set proper ventilation on barns during curing, Spivey says. “If growers give the barn too much air, it results in higher fuel consumption,” he says. “Without the use of a wet bulb, growers tend to over-ventilate.”

To save fuel, Spivey suggests growers check their heat exchangers for proper burner tuning. They can check these using a combustion analyzer.