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New Method for Comparing Cultivars

There is a method to compare yield and digestibility of entries in the spring cut on the same day by adjusting yield and digestibility to a date with similar NDF level. This can be accomplished by determining the linear rate of change of yield and quality over time. While rates of change vary slightly among cultivars, an average rate of change over time for yield or quality adequately represents all cultivars in a trial. Ranking grass cultivars for milk/acre is virtually identical to ranking them for dry matter yield/acre. This system, however, places more emphasis on quality and results in significantly different varietal rankings, compared to unadjusted yield and digestibility. The single best quality comparison under this system is to compare fiber digestibilities adjusted to a common neutral detergent fiber (NDF). The best comparison to combine yield and quality into one term is to rank dry matter yields of cultivars that are adjusted to a common NDF. [GIS-24]

Reference: Cherney, J.H., D. Parsons, and D.J.R. Cherney. 2011. A method for forage yield and quality assessment of tall fescue cultivars in the spring. Crop Sci. 51:2878-2885.