Integrated Management of Bramble Diseases

Organic Fungicides for Bramble Disease Control

Liquid Lime Sulfur

Lime sulfur is recommended for use on brambles as a delayed-dormant application in early spring (when buds show 1/4 inch green). It is used at the rate of 10-20 gal per acre.  If applied at this rate later in the season (after ¼ inch green) it can cause severe damage to leaves and young canes.  Lime sulfur is recommended for control of the cane infecting fungi (anthracnose, cane blight and spur blight). The delayed dormant application in spring is intended to eliminate or reduce the overwintering inoculum for these diseases on canes. Where cane diseases are a problem, this spray is very important. Where good sanitation is used, (old fruited and infected canes are removed from the field) and cane diseases are not a problem, the need for this spray may not be necessary, or at least it would probably be safe to use the lower rate, especially on red raspberries.

Lime sulfur has a bad smell (rotten eggs) so there can be a problem spraying it around your neighbors. Some growers have received complaints from neighbors after applying lime sulfur. In addition, lime sulfur is very caustic. It is harmful to machine parts, paint (especially on cars) and sprayers. Special care should be taken to avoid drift to nontarget objects and proper protective clothing should be worn by the applicator.

Copper Fungicides

If a dormant application of fungicide is required, and lime sulfur cannot be used, Bordeaux mixture or a fixed copper fungicide can be used in its place. Although lime sulfur is the proven material, dormant sprays of copper should provide some level of control. The use of copper in the growing season (after leaves are present), could result in significant plant damage.

Sulfur

Sulfur is available as a wettable powder or in flowable formulations. Sulfur is registered for control of powdery mildew.  Sulfur has little or no activity against the other bramble diseases caused by fungi. Because powdery mildew is generally not a serious problem in the Midwest, sulfur is of little importance within the bramble disease management program.

There are several biocontrol products available for control of Botrytis fruit rot.  Their efficacy under moderate to severe disease pressure needs to be determined.