Effect of ‘Monument’ herbicide on overseeded turf grass

To solve the issue of appropriate transitioning from cool-season turfgrass to warm-season turfgrass during spring in an overseeded turf in Hunan area, different concentrations of ‘Monument’ were foliar sprayed on a Zoysia japonica ‘Lantai No. 3’ lawn that was overseeded with ryegrass to inhibit its overgrowth and to create suitable conditions for the regrowth of zoysia grass. The results showed the NDVI and green index to decrease initially and then increase after foliar application of ‘Monument’ in the overseeded turf. The MDA content and electrolyte leakage gradually increased while the turf density declined for ryegrass and increased for zoysia grass after foliar application of ‘Monument’ in the overseeded turf. The most suitable spraying concentration was recorded to be 3×10-2 mL·m-2 for the two ryegrass cultivars. According to our results here, it takes 45 days to completely transition for ‘Panterra’ and 60 days to completely transition for ‘Monterey’ under this spraying concentration. This concentration of ‘Monument’ can effectively inhibit the overgrowth of ryegrass and accelerate the proper transitioning of ryegrass to zoysia grass in an overseeded turf during spring. This study provides theoretical and technical guidance for the extension and application of techniques for overseeding turf.