The Changing Face Of Ornamental Fungicides By A.R. Chase

Each year I face a challenge to think of enough topics for the articles, columns, newsletters and talks that I do. I have been doing the fungicide update for GPN off and on for about seven years, and sometimes I know what I want to write about months in advance. Other times, like this year, I am hard pressed to put a new spin on the topic. While there is quite a bit of activity in the arena of fungicide development on ornamentals, it is not necessarily different this year than it was last year and the year before. It takes a number of years for any product to reach the market, and updating what is going on each year with the same products can be tedious and frustrating when registrations are delayed.

So this time I thought I would review the industry’s development by highlighting some of the most important events historically as well as comparing the nature of our industry today to 30 or more years ago. Then I will try to relate the highlights in the ornamental fungicide industry this past year.

A Historical Overview

I started working in this field in 1979 at the University of Florida. At that time the newest products were Aliette (fosetyl-al), Chipco 26019 (iprodione), Subdue (mefenoxam) and Terraguard (triflumizole). In the foliage plant industry, fungicide standards included Banrot (thiophanate-methyl and etridiazole), Truban ç (etridiazole), Agri-Strep (streptomycin), Kocide (copper hydroxide) and Benlate (benomyl). Figure 1, page 20, shows some of these active ingredients, dates of their entries into the agricultural market and whether or not they are currently labeled for ornamentals, including some product names. Some of the products we use today were first introduced 30-40 years ago, including Dithane and Fore (mancozeb), 3336 and Fungo (thiophanate methyl), Daconil (chlorothalonil), and Terrazole and Truban (etridiazole).

More recently, we have seen Medallion (fludioxinil), Heritage (azoxystrobin), and PlantShield and Rhapsody (biological agents) enter the market. In 2006, Insignia (pyraclostrobin) and Fenstop (fenamidone) received their ornamental labels. Neither product was launched by its respective company at the time this article was written. It is interesting to see how many of our most important products have been around for more than 30 years. Very few have been lost since I started working in ornamentals, and many have been added.

Identifying Industry Trends

Since the early 1990s, we have seen a continuing process of company mergers. In the time frame, there were a number of new companies that formed to act as marketers to our specialty crop area. Most of them have special agreements with specific large companies. One example of this type of arrangement is between OHP and Bayer. In other cases, an agreement is made for specific products only.

Another trend that has occurred is the development of a large number of small companies with very limited product lines. Some of these companies are selling generic products such as phosphonates or active ingredients that are off patent like thiophanate methyl and chlorothalonil. Still others are bringing new active ingredients into the United States from other countries. Some of these companies will sell their partially developed product to an established U.S. company.

Some other trends we can expect to continue are pre-mixes, improved formulations and generics. We are also very fortunate that we will have new active ingredients (especially as part of a pre-mix) and new use patterns (drenches for leaf spot control). We will have a very long list of choices, and knowing the characteristics of each product will be a challenge. You may decide to choose a product based on its manufacturer, price, safety and spectrum of activity. I have listed some of the general activities of the companies we are working with this year (see Figure 2, left); I apologize to any company I inadvertently omitted from this figure.

In the July issue of GPN, I reviewed quite a bit of the testing we have been doing on pre-mixes like 26/36 (iprodione and thiophanate methyl), Clevis (myclobutanil and mancozeb), Concert (chlorothalonil and propiconazole), Hurricane (fludioxinil and mefenoxam) and Palladium (fludioxinil and cyprodinil). While we have seen some exciting results on some of the numbered or experimental products, we cannot discuss them at this time. So I have presented our most current summary of our trials on Insignia in Figure 3, above. We have been working with the product for five years and have done many trials in that time (more than 75). In most cases, we have tested the pathogen multiple times on a variety of crops.

The most effective uses of Insignia in our trials are leaf spots (Alternaria, Cercospora, scab and Anthracnose), downy mildew, powdery mildew and rust. Using the product for foliar diseases in general gives slightly better results than using it for root or soil-borne diseases. The use rates for Insignia are higher than those for Compass O (Trifloxystrobin) and Heritage (Azoxystrobin) mainly because the Insignia formulation is 20 percent active ingredient while Compass O and Heritage are each 50 percent. Be sure to read the label carefully when the product becomes available. The labeled rates for each target have been carefully worked out to reflect the entire knowledge base on Insignia, and I would not be surprised to find differences from those I might choose based on the limited trials we have completed.

Making Conclusions

In the next year, we may see a few new products registered, but more likely it will take a little longer. Information on some of these experimental compounds will be available as they move toward submission and registration. We are at the beginning of another growth phase in the fungicides labeled for use on ornamentals.

(Visited 6 times, 1 visits today)

A.R. Chase

A.R. Chase is plant pathologist at Chase Agricultural Consulting LLC and can be reached at [email protected]

Latest Photos see all »

GPN recognizes 40 industry professionals under the age of 40 who are helping to determine the future of the horticulture industry. These individuals are today’s movers and shakers who are already setting the pace for tomorrow.

75 Applewood Drive, Suite A
P.O. Box 128
Sparta, MI 49345

Get one year of Greenhouse Product News in both print and digital editions for free.
Preview our digital edition »

Interested in reading the print edition of GPN?

Subscribe Today »

Be sure to check
out our sister site.
website development by deyo designs