Citrus Experiment Station Mimeo Series No. 60-11
SUGGESTIONS FOR PERENNIAL GRASS ERADICATION IN
CITRUS PLANTING SITES
Dale W. Ktetchman
Citrus Experiment Station
Lake Alfred, Florida
Bermudagrass, pangolagrass, paragrass, maidencane, guineagrass, napiergrass,
and bahiagrass have been satisfactorily eliminated from citrus planting sites
with chemical herbicides.
The following treatment has been successful:
Two applications of dalapon at 5 to 7.5 lb/A per application of the com-
mercial product, "Dowpon", with a 5- to 14-day interval should be applied to
the foliage of the grass prior to seed-head formation. This is followed by
plowing 6 to 8 inches deep, 4 weeks after the second application. Discing is
not as favorable as plowing. The use of a wetting agent may be necessary to
obtain good coverage of the grass foliage.
Spot-spraying may be necessary to control the regrowth that may occur in
areas that did not receive the initial treatment. One pound of dalapon in 20
gallons of water can be used for retreatment of isolated spots. The grass foli-
age should be sprayed until wet with this solution.
Under certain conditions, the first series of treatments may not be effec-
tive, necessitating another series of applications. This second series should
be delayed 3 to 4 months after the first set to allow all the grass that may be
viable to grow and produce foliage to absorb the chemical.
Although, herbicides can be used to eliminate an original infestation of
grass, subsequent spot treatments may be necessary for several months or years
to eradicate a species from an area, particularly, if the species seeds profusely.
If broadleaf weeds or brush are present in the planting site, 2,4-D and/or
2,4,5-T at rates of 2 to 4 Ib/A can be included in the initial dalapon applica-
tion for their control.
Citrus can be planted on the site 2 months after the last application of
dalapon or 2,4-D and 2,4,5-T, if used at the suggested rates.
NOTE: No practical means of eliminating torpedograss from a citrus planting
site is known at the present time. --
CES # 944 DWK 10/20/59
Do not apply dalapon on desirable plants or near their rooting area.
Spray equipment used to apply dalapon should be rinsed thoroughly several
times with clean water to remove any residue and to prevent corrosion of
Do not allow a dalapon spray solution to stand in the tank for more than
1 to 2 days prior to use because it may lose effectiveness on long standing.
If 2,4-D or 2,4,5-T is used with dalapon, precautions should be taken to
prevent the 2,4-D or 2,4,5-T vapors from drifting to desirable plants. The amine
salt formulations are generally less hazardous than the ester forms of these
chemicals. It is nearly impossible to remove all traces of 2,4-D or 2,4,5-T from
spray equipment. Therefore, equipment contaminated with 2,4-D or 2,4,5-T should
not be used for applying pesticides to desirable plants.
CES # 944a DWK 10/20/59