ISHS Acta Horticulturae 783: II International Conference on Turfgrass Science and Management for Sports Fields
MULTI-WAY KENTUCKY BLUEGRASS BLENDS AND THEIR EFFECT ON TURFGRASS QUALITY |
| Author: | A.D. Brede |
| Keywords: | grass seed, mixtures, competition, Poa pratensis, smooth-stalked meadowgrass, population dynamics |
| Abstract:
Kentucky bluegrass (Poa pratensis L.) cultivars are generally sown as blends of two or more cultivars. This study was initiated to examine multi-way bluegrass blends on turfgrass quality (TQ) throughout the year at two US locations. Five improved cultivars ('Award,' 'Liberator,' 'Chicago II,' 'Rambo,' 'NuBlue') with a range of documented TQ performance levels were used to study all possible blend combinations (monostands, 2-, 3-, 4-, and 5-way blends in equal proportions by seed weight). TQ ratings were taken monthly at duplicate trials in Maryland and Idaho over 2 and 3 years, respectively. Stepwise regression showed higher R2 values in Idaho, probably resulting from consistent irrigation; the Maryland site was unirrigated. Regression revealed a complicated cultivar effect, with all five cultivars participating in performance. There were 10 instances of cultivar × cultivar interactions on TQ, a positive slope of which suggests that two cultivars acted synergistically to enhance quality. A categorical ANOVA was used to explore criteria for ejecting a cultivar from a potential blend, and for testing the suitability of a monostand of a high performing cultivar in place of blending. In 76 out of 221 possibilities, 'NuBlue' (a low performing cultivar) decreased TQ of a blend by its presence and increased it in 3 examples, all related to spring greenup. A given blend candidate should be expected to contribute at least an equal number of positive and negative attributes to a blend, and thus 'NuBlue' would be rejected. Out of 403 combinations, the 'Award' monostand outperformed 98 blend combinations and underperformed 9, suggesting that planting a top performing bluegrass monostand might be a valid agronomic practice. | |
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