Vol. 15—1961 - NorthEastern Weed Science Society

416.
application. Atrazine has a water solubility of 70 ppm, compared to
Simazine which has a water solubility of .5ppm. The herbicidal
action of Atrazine is considerably faster than Simazine. Unlike
Simazine, Atrazine will bum foliage. Its basic mode of herbicidal
action is primarily by absorption through the plant's root system.
Atrazine is effective in controlling a wide range of annual and
perennial broadlea,f weeds and grasses at dosage rates ranging from
10 - 20 lbs. per acre. . When runoff or lateral leaching is undesirable
such -as on slopes or adjacent to desirable trees and shrubs, Atrazine
is not recommended. S1nijlzine is the preferred herbicide for this
type of 8i tuation.
THE USE OF THETRIAZINEHERBICIDES
IN COMBINATIW.WITHOTHERHERBICIDES
The primary reason for using combinations of Atrazine or
Simazine with other herbicides is to effectively and economically
control weed species not controlled by the triazine herbicides
alone. Conversely, it may be stated that the addition of Simazine
or Atrazine to systemic, hormone or "knockdown" type herbicides
will increase the herbicidal effectiveness of these materials by
providing residual action, particularly after the systemic, hormone
pr knockdown herbicides have lost their effectiveness. Where the
practice of later post-emer gence application of herbicides is
followed, especia.lly where a large variety of woody and non-woody
plants are present in the population, a combination of Atrazine
with other· types of herbieidesprovides excellent weed control.
In certain instances where difficult-to-control plant
species are present in the weed population, additional applications
of a specific herbicide or combination of herbicides will be
necessary to control the problem species.
Simazine or Atrazine, when used in combination with one
or two of the following herbicides, has given excellent weed
control when applied post-e:nergence:
1. Radapon
2. Aminotriazole
3. Sodium chlorate formulations
4. Sodium Arsenite
.5. Pentachlorophenol formulations
6. 2,4 D
7•. 2,4.5T
8. TCA
9. Kuron