Group Title: Central Florida Experiment Station mimeo report - Central Florida Research & Education Center ; CFES-68-1
Title: Weed control in caladiums
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 Material Information
Title: Weed control in caladiums
Series Title: Central Florida Experiment Station mimeo report - Central Florida Research & Education Center ; CFES-68-1
Physical Description: Book
Language: English
Creator: Scudder, W. T.
Affiliation: University of Florida -- Central Florida Experiment Station
Publisher: Central Florida Experiment Station, University of Florida
Publication Date: 1968
 Record Information
Bibliographic ID: UF00075849
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 123192644

Full Text


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source

site maintained by the Florida
Cooperative Extension Service.

Copyright 2005, Board of Trustees, University
of Florida

Sanford, Florida

Mimeo Report CFES 68-1 February 16, 1968


W. T. Scudder, Associate Horticulturist

Chemical weed control experiments with caladiums were begun in 1958 at the
Central Florida Experiment Station. Each year, trials have been conducted on
the Everglades mucky peat soil at Zellwood. A few experiments have also been
conducted on Leon fine sand at Sanford. Detailed experimental data from all of
these trials are recorded in the annual Progress Reports of the Station. Copies
of these are available on request. The information given below summarizes these
experimental results in terms of practical recommendations for the grower. The
final selection of specific treatments to be used will depend upon the grower's
past experience on his own farm and on the particular weed problem facing him.

Treatment rates are specified in terms of pounds of active chemical ingredient
per acre, on a broadcast basis. If any treatments are applied as narrow bands,
the actual amount of herbicide formulation used should be reduced proportionately.
Company trade names and formulation rates are given in parenthesis.

A. Pre-plant treatment for the control of nutsedge (nutgrass).

EPTC at 6 pounds

Use 1 gallon of Eptam (6 EC)

Nutsedge in heavily infested areas can be controlled for one growing
season by spot treatment with EPTC. The chemical should be sprayed on the soil
before planting and then incorporated to a depth of 2 to 3 inches by multiple
disking or rotary tilling. Shallow subsurface blade application is also satis-
factory. This treatment does not eradicate nutsedge, but instead keeps the nuts
in a state of dormancy for several months. In our trials, EPTC has been harmless
to caladiums.

B. Pre-emergence control of annual weeds (applied soon after planting).

1. CDAA + CDEC, 3 pounds of each mixed

Use 3 quarts each of Randox (4 EC) and Vegadex (4 EC).

2. Atrazine at 3 pounds

Use 3.75 pounds of Atrazine (80 WP).

3. Simazine at 3 pounds MAR 12 *9

Use 3.75 pounds of Simazine (80 WP).

200 copies

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Any of these pre-emergence chemical treatments will give good control of
annual broadleaf weeds and grasses if applied soon after planting before the weeds
have germinated. Results are better if the treatment is followed by a light rain
or overhead irrigation. The application may be made following a rain provided the
weeds have not emerged. Under dry conditions, CDAA is much more effective than
atrazine or simazine. The latter are effective longer during rainy periods.

C. Early post-emergence control of annual weeds (caladiums in the spike stage).

1. Paraquat at 0.75 pound

Use 1.5 quarts of Ortho Paraquat (2 SC).

2. DNBP at 3 pounds + diesel oil, 5 gallons

For 3 pounds of DNBP, use 2.4 quarts of either Dow General (5 EC) or
Sinox W (5 EC); or use 1 gallon of either Dow Premerge (3 SC) or Sinox PE (3 SC) +
1 quart of any good surfactant per 100 gallons of spray mixture.

3. Linuron at 3 pounds

Use 6 pounds of Lorox (50 WP).

4. Prometryne at 3 pounds

Use 3.75 pounds of Caparol (80 WP).

These herbicides are all effective contact weed killers. Although they
usually kill weeds that are up to 3 inches tall, better results are obtained if
the weeds are smaller. Sprouted caladiums in the spike stage are not injured by
these sprays. All opened leaves are burned, but where only a few of these are
present, there is no permanent injury.

These contact herbicides may be mixed with the residual herbicides listed
under B to give longer lasting weed control. If either linuron or prometryne,
which have considerable residual as well as contact activity, are used in a mix
with simazine or atrazine, the rates of the latter should be reduced to 2 pounds
per acre (2.5 pounds of the 80 WP formulations).

D. Late post-emergence weed control (caladiums with full foliage).

1. CDAA + CDEC, 3 pounds of each mixed

Use 3 quarts each of Randox (4 EC) and Vegadex (4 EC).

2. Simazine at 3 pounds

Use 3.75 pounds of Simazine (80 WP).

These chemicals are not toxic to caladium leaves. The sprays should be
directed from above to cover all of the soil. This is best done by using two
flat-fan nozzles on each boom drop. With one nozzle angled slightly forward
and one to the rear, better soil coverage is obtained than when the sprays are
directedd from each side of the row.


Since these chemicals, being pre-emergence herbicides, are not effective
against established weeds, they must be applied while there is still residual
control from the previous treatment, or else after cultivation. Cultivations
needed for weed control or after fertilizer applications should be timed so that
they are done just as weed seedlings start to emerge. The residual activity from
CDAA and CDEC usually lasts 3 to 5 weeks, depending upon the rainfall. Generally,
the weed control from atrazine or simazine does not break for 4 to 6 weeks after
application. Atrazine is toxic to the foliage and should not be used on caladiums
after the leaves have unfurled.

Post-emergence treatments with CDAA + CDEC or with simazine may be repeated
as needed throughout the growing season. In Experiment Station trials, as many as
four applications at approximately four-week intervals have been used, giving
complete season-long weed control and yields of tubers exceeding those from the
cultivated check plots.

E. Suggested weed control program (where annual broadleaf weeds and grasses

1. With caladiums at spike stage and weeds 1 to 1.5 inches tall, apply
herbicide spray containing:
1 gallon Dow Premerge (3 SC)
1 pint Triton X-100 surfactant (or liquid detergent)
5 gallons Diesel oil
Mix these thoroughly before adding to the water. Then add:
3 quarts Randox (4 EC)
3 quarts Vegadox (4 EC)

2. After 4 weeks, or when the weed control starts to break, apply a
pray over the foliage containing:
3.75 pounds Simazine (80 WP)

3. Fertilize, cultivate, and repeat this simazine application again
ifter approximately 5 weeks.

F. Several new herbicides are currently under study for caladiums, but are
lot yet recommended for grower use. Some of these chemicals may prove superior
;o some of those given above, but further trials are necessary. Among these are
imetryne, propachlor (Monsanto Ramrod), and an atrazine + oil emulsion mixture.

All of the above suggestions for weed control in caladiums are intended only
'or trial use by growers, since none of the herbicides listed have been registered
specificallyy for use with this ornamental crop. The grower, therefore, must
assume full responsibility whenever these treatments are used.

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