Tobacco Curing with our Generators

The generator converts Ethy-Gen® II Concentrate into ethylene, a powerful natural plant hormone which acts as a stimulant to accelerate the curing of tobacco leaves. The ethylene produced is discharged into the air of the curing unit during the first (yellowing) stage of the cure, usually for 24 hours. The generator leaves no residue on the cured leaves. Lower stalk tobacco can be helped as much as upper stalk leaf.

The generator can be effectively used on an easy-curing or normal crop as well as on difficult to cure crops. (For curing wet, drought-stressed, or over-fertilized crops, see section on weather and crop conditions).

Ethylene produced by the generator accelerates the entire curing process, including yellowing, wilting (flopping) and leaf and stem drying. It is very important when using the generator to take care not to over-color or to allow temperatures to remain too long at high temperatures before completing the cure. Darkened or reddish tobacco may result if the necessary adjustments are not in the curing schedule. (See section “Tips on getting the most out of your generator”).

Tobacco properly cured with Ethy-Gen® II has fewer green butts, green fibers, and other off-colors. Ethy-Gen® II treated tobacco generally grades higher and brings a higher price. The use of Ethy-Gen® II can cut up to 32 hours of curing time, reducing energy costs and allowing earlier re-use of curing system.

When it is necessary to cure ripe, yellow, and mature-green tobacco (or separate varieties with different curing characteristics) together, the generator helps insure a more uniform color throughout the cure.

Note: Harvest Only Mature Leaves
Installation of the Generator for Bulk Curing (see diagram on right)Placement of Generator and ethylene hose

a. FURNACE IN END: Drill a 5/8″ – 3/4” hole through the furnace room floor near furnace. Screw tube into generator and place generator on furnace room floor next to hole. Bend end of tube and insert tip through hole into airflow. Position tube so the tip points with airflow.

b. FURNACE IN CENTER: Drill a 5/8″ – 3/4” hole in floor or air duct at a point where the airflow is split evenly between rooms. Screw tube into generator and place generator on furnace room floor next to hole. Allow tube to bend downward with air flow.

c. UP-DRAFT FAN UNITS: Drill a 5/8″ – 3/4” hole through the floor near furnace. Screw tube into generator and place generator on furnace room floor next to hole. Insert tip of tube through hole into air flow. Position tube so the tip points with air flow.



  1. If the tobacco has surface water on the leaves from dew or rain remove before using generator.
  2. When ready to use generator tightly close all doors and vents in order to hold the ethylene as long as possible. The curing unit must be closed tight.
  3. For best results, leave burners off or set a very low temperature. If possible, maintain a dry bulb temperature of 70° to 90° F. Turn on fan (if equipped) to circulate air.
  4. Place generator and tube, if used, in proper position. Plug into proper grounded 120 VAC electrical outlet. Fill generator reservoir with Ethy-Gen® II, close lid (do not overfill; reservoir capacity is 2.7 quarts). Turn generator switch to “ON” position and select flow rate (2 – 4 quarts per 24 hours) relative to your tobacco and condition of curing unit.NOTE: DO NOT INVERT A BOTTLE of Ethy-Gen® II on top of generator!
  5. At the end of the treatment period, remove generator and complete the yellowing process, setting burner temperature and dampers as usual.
  6. It is important to check the cure regularly after treatment. All stages of the cure are normally accelerated, and it is necessary almost always to go up on curing temperatures faster than on an untreated leaf. When temperatures on treated tobacco are not increased at the correct rate over- colored, brown or reddish cured leaf may result.
  7. Respiration rates in the leaves will increase; more water than usual may drip from the leaf during yellowing and leaf drying. This is normal.


  1. Follow the basic suggested instructions.
  2. Watch coloring, wilting and all conditions during the cure more carefully than when not using the generator
  3. Adjust your curing schedule as required to keep up with, or even anticipate, changes in the leaf as the cure progresses.
  4. Curing tobacco is an art more than an exact science: use your own good judgment and common sense.

Properly used, the generator is effective on any kind of crop under a variety of weather conditions.

  1. Dry Year (Drought) Tobacco: hard-to-yellow, low moisture content — use one to four additional quarts of Ethy-Gen® II or a total of five to eight quarts to improve the color and quality of the cure and to shorten the total time of the cure.
  2. Wet Year Tobacco: full of moisture, sometimes under-fertilized because of leaching; thin, easy to yellow. Ethy-Gen® II removes moisture more quickly, causing the leaf to wilt more quickly; shortens curing time. Only two to four quarts are usually required.
  3. Over-Fertilized, Green, “Rank” Tobacco: When this type of tobacco cannot be left in the field to ripen properly, use four to eight quarts of Ethy-Gen® II being careful, as usual, not to over-color.

Do not pour any liquid other than Ethy-Gen® II into the generator.
Damage to the generator and the creation of dangerous gases may result. The customer is responsible for the cost of any repairs due to damage to leased generator. Ethy-Gen® II is registered with the Environmental Protection Agency (EPA) as a pesticide (plant growth regulator), EPA #37433-1, and must be used according to directions under penalty of Federal Law. Only plant growth regulators like Ethy-Gen® II and ethylene that are registered with the EPA are legal for use on tobacco.