08/12/2022
This past week I did a little product comparison, to show what crabgrass looks like as it is controlled by the most popular active ingredients in the market. These plants are all within 20 feet of eachother on the same property, and we’re sprayed at the same time. 4.5 days later, this is what has happened so far. All 3 products had Kinetic surfactant, a wetter/spreader/penetrant, added.
The top photo was treated with Tenacity (mesotrione). You can see leaf tissue turning bright white, this happens because mesotrione is an HPPD pigment inhibitor that stops chlorophyll production, which is what gives plants their green color. While control started to be visual after a couple days with the Tenacity, my previous experiences make me believe that without a second application this bleaching may only be temporary, and the plant may bounce back.
The bottom left photo was treated with Drive XLR8, which unlike mesotrione kills the plant by mimicking auxins and affecting growth, leading the plant to turn reddish-purple and die. You can also the whole lesions of head tissue appear and twisting and curling. In this experiment, I was very surprised that the Drive was significantly faster in providing visual control of the crabgrass. The big complaint with quinclorac is that while not does an excellent job killing immature crabgrass plants and very large crabgrass plants, in the 4-5 tiller, mid-life stage of the crabgrass plant it is not nearly as effective, and I certainly have seen that here as well.
Finally, the bottom right photo used Acclaim Extra (fenoxoprop). Acclaim is a lipid synthesis inhibitor, meaning it prevents the plant from utilizing fatty acids essential for cell development and leading to death of the plant. As shown in the photos, the effects of Acclaim are visible from the leaves turning yellow/tan/off white and wilting, finally leading to full necrosis. The benefit of using Acclaim is that it will control crabgrass even at the 4-5 tiller stage where Drive is ineffective. The downside to Acclaim, is you should not apply it within 2 weeks of an application of 2,4-D as they counteract eachother. For this reason, I’d also treating broadleaf w**ds you may need to change you broadleaf herbicide, or decide Acclaim isn’t best for you.
As for my opinion of the results in the first 4.5 days, the kne thing that struck me was how much quicker the Drive XLR8 was in providing control. While it may not have achieved 100% control, the results happens fast and did control most plants sprayed. I’d certainly say it’s better than Tenacity, which seems to always need a second app for most of the w**ds, and I guess when it comes to Drive vs Acclaim the jury is still out. In another 10 days we will know how thoroughly each controlled the plants, and be able to better judge if the increased kill potential of Acclaim is worth the extra wait!