I0. 71-a AGRICULTURAL RESEARCH AND EDUCATION CENTER
Ses Quincy, Florida
Quincy AREC Mimeo Report NF-1972-2
REDUCING PESTICIDE RESIDUES ON FLUE-CURED TOBACCO IN THE FIELD
William B. Tappan and Donald P. Driggers1
Pesticide residues on tobacco of all types have become a major concern of tobacco
growers in all the tobacco producing areas of the World. West Germany has taken action to
make effective as of January 1, 1973, stringent pesticide residue restrictions on all
tobacco leaf and products imported into the country. Other countries, particularly those
of the European Common Market, are expected to follow West Germany's lead in passing
residue legislation of some type in the near future. With that prospect in mind, the
countries exporting tobacco to European markets will have to insure that their tobacco leaf
and products meet the residue requirements.
In view of current residue data, the flue-cured tobacco grower in the United States is
apparently in a good position with respect to pesticide residues on that particular tobacco
type. However, it is evident that some growers may exceed the established tolerances by
using excessive amounts of pesticides during the growing season. Therefore, the growers
must be ever aware of reducing or keeping pesticide residues on the crop to a low level.
With the advancement of insect control technology over the past 20 years, the reduction
of pesticide residues on flue-cured tobacco without jeopardizing insect control is within
the realm of possibility.
A program of reducing pesticide residues on flue-cured tobacco in Florida is outlined
in the following table. If the grower plans to transplant the crop on or about March 25, he
should broadcast Diazinon, 14% granules on the soil surface and incorporate the material to
a depth of 4 to 6 inches about March 11 for wireworm control. As soon as the Diazinon has
been applied, an application of Dylox, 5% bait should be broadcast on the soil surface and
left undisturbed for about 2 weeks before transplanting for cutworm control. The day before
or the same day as transplanting, an application of Di-Syston, 15% granules should be
broadcast on the soil surface and incorporated to a depth of 2 to 4 inches for aphid and
flea beetle control. The Di-Syston treatment will give protection to the tobacco foliage
against aphids and flea beetles for about 6 weeks after transplanting. No other appli-
cations of an aphicide should be needed during that period of time. Approximately 2 to 3
weeks after transplanting, foliage applications of Bacillus thuringiensis should begin and
continue on a 2-week schedule for the remainder of the growing season to control budworms,
cabbage loopers, and hornworms. If any of the worm pests or aphids become a problem later
in the season, the grower could use an application of Thiodan or Lannate as a spot-treatment
to effect needed control. The Bacillus treatments will leave no chemical residue on the
leaf. If Thiodan or .Lannate applications are needed, it would be advisable to limit the
number of applications of either material to 2 each. In a season of moderate insect infes-
tations, late applications of Thiodan or Lannate may not be needed.
The grower must remember that if this program is to be effective, the 2-week schedule
of Bacillus applications must be adhered to strictly.
......____HUMF I IRRARY
1Associate Entomologist, AREC, Quincy, Florida, and Assoc ate in Extension Entomol
Cooperative Extension Service, Gainesville. APR 72
I.F.A.S. Univ. of Florida cc
AGRICULTURAL RESEARCH AND EDUCATION CENTER
Bi-Weekly-2 to 3
14% G, 15-20 lbs.
5% B, 20-30 Ibs.
15% G, 15-26 Ibs.
ASC, S, 1-2 qts.
WP, S, 1-3 Ibs.
2.5-5.0% D, 20-30 ibs.
50% WP, S, 1-2 lbs.
25% EC, S, 2-3 pts.
4% D, 15-30 lbs.
90% SP, S, 0.33-0.55 lb.
2.5% D, 25-30 lbs.
Aphid and Flea Beetles
Cabbage Loopers, and
Cabbage Loopers, and
B = Bait, D = Dust, G = Granule, ASC = Aqueous Suspension Concentrate, WP = Wettable Powder,
EC = Emulsifiable Concentrate, SP = Soluble Powder, and S = Spray.
2As Needed When these materials are applied, Bacillus applications are not needed.
3One application of Thiodan and Lannate may be applied for aphid control in late season, e.g.,
Thiodan on May 20 and Lannate on June 3.
4An additional application of Lannate may be necessary on July 1 for aphid control.