Root Growth and Phosphorus Responses Among Clones of Creeping Bentgrass at Low Temperatures1
- William R. Kneebone and
- Gordon V. Johnson
Some creeping bentgrasses (Agrostis palustris Huds.) often tum reddish-purple and grow slowly while others maintain good color and some growth when night temperatures range from 0 to 5 C. Increasing available P tends to keep the bentgrass turf greener. These studies were initiated to determine if bentgrass genotypes differed in P needs or uptake at low temperatures.
Twenty-seven clones selected from ‘Seaside’ plus ‘Penncross’ , Seaside, and ‘Eldorado’ creeping bentgrasses grown in field plots in Tucson, Ariz., USA, were fertilied differentially with P. Foliage color and root length were evaluated periodically from 1973 to 1976.
Selected genotypes grown in cool environmental growth chambers were also differentially fertilized with P. Color and shoot growth were rated and the foliage was analyzed for P. Additional experiments were conducted with selected genotypes under constant root temperatures. Phosphorus uptake was measured with 32P.
Color differences among creeping bentgrass clones at low temperatures were related to P nutrition. There were significant differences among clones in 32P uptake at 5, 15, and 25 C. More 32P was recovered in roots than in shoots, especially at 5 C. Color response differences among clones were not related to 32P uptake rate differences, nor were uptake rate differences associated with significant clonal root length differences. Results indicate that clones subject to P deficiency symptoms at low temperatures have higher P requirement thresholds at those temperatures than clones which remain green.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © 1980. . Copyright © 1980 by the American Society of Agronomy, Crop Science Society of America, Soil Science Society of America, and International Turfgrass Society, 5585 Guilford Rd., Madison, WI 53711 USA