Pesticide Sprays

by Frank Van Lenten

Consulting Rosarian - Staunton, VA.

            Even as a chemist, I get confused over the myriad of names with which we are confronted as rosarians for our pesticide spray possibilities.  “Propiconazole”, the common chemical name for the active ingredient in Banner Maxx is also known by many different product names by different companies:  Banner, Benit, Desmel, Orbit, Radar, Tilt, Fidis, Alamo, Spire, Practis, Bumper, Mantis, Restore, Banner Maxx, Taspa, Juno, Novel and Break.  Formulations come as an emulsifiable concentrates and wettable powders.  It is also formulated with other pesticides and in several different dosages or concentrations.  We won’t even talk about the official chemical name, since it would take a full line of text and wouldn’t help us understand what it’s for.

            Companies sometimes even change the name of well-known pesticides to names which they think will be more descriptive to us; for instance, Ortho recently changed the name of its familiar “Funginex” to “Ortho Rose Pride Rose & Shrub Disease Control”.  There are several great internet web-sites that can help us sort out the mess.  You can type in the company product name or common chemical name for pesticides and many other household chemicals is: http://householdproducts.nlm.nih.gov.  If you find yourself without this website reference, you can often get to several other good web sites by using your favorite search engine like www.google.com and then typing in what product or chemical name you want to find.

            Sometimes companies seem to want to fool us into thinking we have bought something that we have not.  The one that comes to mind is Bonide’s “Bonomyl” fungicide which sounds a lot like the banned fungicide “Benomyl” which was the same as DuPont’s “Benlate”. Bonomyl is a pretty good fungicide, since some searching as I have described above, finds that it is really the same as “Clearys 3337”.  Phew!!!

            As mentioned, dosage is also very important in how much chemical is needed in your spray, several of the Banner Maxx type chemicals come in different concentrations, i.e.:  instead of the normal 14.3%, it might be 5% and require perhaps 1 tablespoon instead of one teaspoon.  In any case, the best advice is to read the label carefully!  And know the common conversions of amounts:

3 teaspoons = 1 Tablespoon = ½ fluid oz.

            One of the best references on pesticides is found on the Tri-State Rose Society of Chattanooga www.chattanoogarose.org which articles “Modes of Action” (MOA) on pesticides and a great chart which includes the MOA as a easy-to-reference number system.  In short, in order to have the best effective spray program you need to mix your modes of action so that you are not constantly using the same mode (i.e.: 1 only).  So, spraying Funginex and Immunox, both mode 1 fungicides can lead to decreasing effectiveness due to build up resistance by the fungus (like using penicillin too much causes bacteria to increase their resistance to human medicines).  It would be better to alternate Immunox (1) with Mancozeb (6).  The same thing goes for alternating insecticides.  One of the great things about Mancozeb is that the mode 6 fugicides often do not suffer from resistance build up by fungus/mildew and they can be used every spraying.

            Please see the enclosed chart from www.chattanoogarose.org which contains articles on "modes of Action".