Effect of Application Timing on Turf Colorant Transfer and Quality.

Turf colorants are used to provide green color to turfgrasses during times of stress and dormancy. When used to treat dormant turfgrass, proper application and timing is imperative to accomplish a visually appealing and functional turfgrass surface. The primary objective of this field study was to evaluate the effect of air temperature on colorant transfer onto an absorbent material. Seven turfgrass colorants were applied to dormant ‘Tifway’ hybrid bermudagrass [Cynodon dactylon (L.) Pers. × Cynodon transvaalensis Burtt-Davy] and ‘El Toro’ zoysiagrass (Zoysia japonica Steud.) at three temperatures (-3.9, 4.4, and 12.8°C). Colorant transfer for each temperature treatment was sampled at 1, 2, 4, and 7 days after application (DAA) by dragging an absorbent cloth the length of treated turfgrass plots. When applied at -3.9°C, colorant transfer was 2.2 and 2.3 times greater than the amount removed from plots treated at 4.4 and 12.8°C, respectively. Furthermore, colorant transfer varied among products. A secondary objective was to examine the color and intensity of four turf colorants applied at 935 L ha^-1 following two levels of irrigation (irrigated vs. non-irrigated) immediately prior to colorant application. Both colorant color and intensity increased by 13% when applied after an irrigation event, suggesting that wetting the turfgrass leaf blade prior to colorant application can enhance measured color parameters. Results from this research show that timely applications can result in lower turf colorant transfer as well as greater paint quality.