These large crabgrass seedlings show the effect of preemergence application of manuka oil. Control is on the right. Concentrations of manuka oil increase toward the left. Large crabgrass was completely controlled with 1% of oil in water in the leftmost pot. Bleaching to the foliage in that pot is due to the mechanism of action of leptospermone that blocks the synthesis of carotenoids in plants Photo by J’Lynn Howell, USDA Scientists of the U.S. Department of Agriculture have found a natural product that might in the future provide growers with an important tool that’s been missing from the organic weed […]