New Disease Control Products for Y2K

The 1999-2000 growing season offers some significant developments in the area of greenhouse chemical and biological disease control. This article attempts to bring the reader up to date on the disease control front with regards to chemical and biological products.

Let's first cover newly labeled products. The SePro corporation has released it's newest fungicide Decree. This fungicide is based on some new chemistry; the product provides excellent control of Botrytis on a wide variety of ornamentals. Decree has a 4-hour REI and should be an integral part of any rotation for control of the "Big B."

Novartis' newest product is Compass. It is a strobilurin fungicide. Strobilurin fungicides have been derived from products found in wood decay fungi. Strobilurin chemistry is relatively new and exciting. Compass is labeled for the control of a wide variety of foliar fungal diseases in a wide variety of bedding plants, perennials, and woody ornamentals. It is also labeled for the control of Rhizoctonia damping-off in seedlings. It has an REI of 12 hours. The label is still pending in some states including California , New York, and should be labeled in all states by the May of 2000. Another relatively new strobilurin-based fungicide is Heritage manufactured by Zeneca Professional Products. Like Compass, this product is labeled for foliar diseases on a large list of ornamental plants. Heritage is also labeled for some soil-borne diseases caused by Fusarium, Rhizoctonia, and Sclerotium. It's REI is 12 hours. As plant pathologists we are very excited about the strobilurins because they appear to be highly effective. Since they are natural product derivatives, they should help reduce the possibility pathogen resistance.

Uniroyal Chemical has introduced Quell (not new chemistry). The active ingredient is mefenoxam, the same active ingredient in Subdue MAXX. However, unlike Subdue MAXX, Quell is formulated much like the old Subdue 2E and it is labeled for the control of Pythium and Phytophthora root rots in a wide variety of ornamental plants. Its REI is 12 hrs.

Spectro 90 is a relatively new product from the Cleary Chemical. Spectro 90 is a combination product made up of chlorothalonil and thiophanate methyl. Both of these products are good fungicides when used as individuals, however, as a combination product Spectro 90 is an excellent fungicide registered for a long list of foliar and stem diseases on a long list of ornamentals. The REI for this product is 48 hours (Cleary has applied with EPA to reduce this REI to 12 hours). Since this is a combination product, it contains two types of chemistry with differing modes of action toward the target fungus. This should help increase control efficiency and reduce resistance in the target fungus.

Although not a new product, the REI on Daconil has been reduced from 48 hours to 12 hours. This is a significant change in the label of this chlorothalonil-based product.

RootShield continues to be the most widely used of all the biologicals in the United States and recent research studies have shown that this product can be an effective control of both Pythium and Rhizoctonia root and stem rot on Poinsettia. Another biological product called AtEze has been released. It proved to be a good to excellent control agent against Pythium and Rhizoctonia on Poinsettia, as well as good to excellent control of Fusarium wilt or corm rot of Cyclamen.