A: Generally, the current price is about $250/quart. In the old days, Alamo was used at the rate of 2 to 3 mL/diameter inch of tree. Now Alamo is used at the rate of 10 to 20 mL/ diameter inch. One quart of Alamo treats a tree (or trees totaling) about 50 diameter inches. If a contractor treats your trees, it will cost about $15/diameter inch, or $150 to treat a 10 inch diameter tree. (Note: Oak Wilt Specialists of Texas in Wimberly, TX has treated trees in Tierra Linda for $11/ diameter inch.)
Robert Edmonson recommends using the maximum allowable Alamo treatment rate of 20 mL/diameter inch. If you are going to the trouble and expense of treatment, you want the best likelihood of success.
The old Alamo was gold colored. The active ingredient in Alamo is propiconazole, which does not dissolve in water. The old gold Alamo used a petroleum-based carrier, including benzene, xylene etc.. The current Alamo formulation contains micro-encapsulated propiconazole which can be suspended in water. This new technology is a bit more expensive, but it is safer water-based formulation, which permits the higher, more effective dosage rates in the trees. If you are going to inject a fungicide into an oak tree, it should say “Alamo” on the bottle and it should be a blue liquid. The Texas Forest Service does not recommend using any other product.