General Information


Quali-Pro Chlorothalonil DF, a dry flowable product containing chlorothalonil, is recommended for use as a spray for the control of many important plant diseases.


To avoid the development of tolerant or resistant strains of fungi, Quali-Pro Chlorothalonil DF should always be tank mixed with a fungicide of different chemistry, and/or a fungicide of different chemistry should be alternated with Quali-Pro Chlorothalonil DF at each application. If after using Quali-Pro Chlorothalonil DF as recommended and the treatment is not effective, a tolerant or resistant strain of fungi may be present. Discontinue the use of Quali-Pro Chlorothalonil DF for at least one season.

Quali-Pro Chlorothalonil DF is effective for use in programs that attempt to minimize disease resistance to fungicides. Quali-Pro Chlorothalonil DF has a multi-site mode of action and may be used to delay or prevent the development of resistance to single-site fungicides. Consult with your Federal or State Cooperative Extension Service representatives for guidance on the proper use of Quali-Pro Chlorothalonil DF in programs that seek to minimize the occurrence of disease resistance to other fungicides.


Quali-Pro Chlorothalonil DF can be used effectively in dilute or concentrate sprays. Thorough, uniform coverage is essential for disease control.

Do not combine Quali-Pro Chlorothalonil DF in a spray tank with pesticides, surfactants, or fertilizers, unless prior use has shown the combination to be physically compatible, effective, and noninjurious under conditions of use. Do not combine Quali-Pro Chlorothalonil DF with DiPel 4L, Foil, Triton AG-98, Triton B-1956 and Latron B-1956 as phytotoxicity may result from the combination when applied to crops listed on the label.

The required amount of Quali-Pro Chlorothalonil DF should be added slowly into the spray tank during filling. With concentrate sprays, premix the required amount of Quali-Pro Chlorothalonil DF in a clean container and add to the spray tank as it is being filled. Keep agitator running when filling spray tank and during spray operations.

Dosage rates on the label indicate pounds of Quali-Pro Chlorothalonil DF per acre, unless specified otherwise. Under conditions favoring disease development, the high rate specified and shortest application interval should be used.


This product must not be applied within 150 feet for aerial and air-blast applications, or 25 feet for ground applications of marine/estuarine water bodies unless there is an untreated buffer area of that width between the area to be treated and the water body.

Limitations, Restrictions, and Exceptions

Algal Scum:

For prevention of algal scum on turfgrasses caused by cyanobacteria of the genus Lyngbia, apply Quali-Pro Chlorothalonil DF at the rate of 5 to 8.8 pounds per acre of turf on a 7 to 14 day schedule. When algal scum is well established, every attempt should be made to dry out the afflicted area. Once dry, spiking or verticutting should be done to enhance turfgrass recovery in conjunction with an Quali-Pro Chlorothalonil DF application at the rate of 13.6 pounds per acre with a 7 day retreatment at the 5 to 8.8 pounds per acre rate. Several applications of Quali-Pro Chlorothalonil DF at the high 8.8 pounds per acre rate may be necessary for turfgrass recovery. Only a preventative spray program with Quali-Pro Chlorothalonil DF will prevent a recurrence of the algae when environmental conditions are favorable for algal growth. The maximum seasonal application limits are 88.4 pounds per acre for greens, 63 pounds per acre for tees, and 31.5 pounds per acre for general turf and fairways.

Restricted Entry Interval

12 hours