Phenological Staging Schemes for Predicting Red Clover Quality
No phenological schemes are available for red clover (Trifolium pratense L.) in the USA, although it is the second most important forage legume grown there. We studied red clover growth and compared three phenological schemes; one modified by us (OW) but developed earlier by Kalu and Fick for alfalfa (Medicago sativa L.), one original (HH), and one modified (HH1) byHedlund Höglund for red clover. Comparisons were based on (i) detecting differences in phenological stage among the schemes; (ii) correlation between mean stage values (MSV) and four forage quality estimates: crude protein (CP), in vitro dry matter disappearance (IVDMD), neutral detergent fiber (NDF), and acid detergent lignin (ADL); (iii) the time required to assign a MSV to a sample. ‘Arlington’ and ‘Hermes II’ red clover were sampled weekly for 8 wk in 1985 and 1986. Mean stage by weight (MSW) and mean stage by count (MSC) were calculated. The MSW method resulted in higher R2 values (range of 0.78-0.93) than MSC (range of 0.37-0.91) when correlated with forage quality. No observable differences in R2 values resulted between the OW and HH schemes. More time was reqaired to use the HH than the OW scheme, 20 vs. 14 s stem−1. Both schemes work well over a wide range of cultivars and are easy to use. The OW method is preferable in farm management because it requires less time than the HH scheme. The HH scheme, however, may be preferable for research because more logical stage characteristics are used.
Copyright © 1989 by the Crop Science Society of America, Inc.