Synopsis The rate of growth of individual roots and total root production of creeping bentgrass was significantly reduced at 90° F. Cessation of growth of individual roots occurred more rapidly as temperature was increased from 60° to 90° F., but the rate of root growth on a per day basis was similar in the 60 to 80° F. range.

Temperature was found to be the most consistent environmental factor in accounting for variation in root number and color of irrigated creeping bentgrass. Soil temperature at the 6‐inch depth was most highly correlated with root growth. Light intensity ranked second in accounting for variation in root activity while soil moisture was quite low. There were only two times when new roots were produced. In both cases, this new root growth occurred right after a very sharp drop in temperature suggesting that lower temperatures either initiate root elongation or are required for the elongation of new roots from bentgrass crowns.

Fifteen seed sources (accessions) of Kentucky bluegrass (Poa pratensis L.) constituting a rather broad based, random sample of bluegrass turf types, were grown to study several turf characteristics. Individual plants were transplanted into pots on two dates and ultimately space planted to the field.Measurements on six characteristics were made: (1) leaf width, (2) growth habit, (3) leaf angle, (4) rust resistance, (5) total spread and (6) sod spread. All characters were found to be highly significant for the accessions genetic mean square.Broad sense heritability and genetic coefficients of variation were calculated as estimates of the genetic variability among these accessions. Phenotypic and genotypic correlation coefficients were also computed, and indicated that simultaneous selection may be possible for important characters in the development of superior turf types.

No abstract

No abstract