Three genetically diverse Kentucky bluegrasses (Poa pratensis L. cvs. Kenblue, Vantage, and Adelphi) and 6 other turfgrasses were evaluated for susceptibility to the greenbug, Schizaphis graminum Rondani. Nine common lawn weed species were also tested as potential alternative hosts. Heavy greenbug populations and feeding damage occurred on all 3 bluegrasses and on tall fescue (Festuca arundinacea Schreb. cv. Kentucky 31) and chewings fescue (Festuca rubra var. cummutata Guad. cv. Jamestown). Creeping bentgrass (Agrostis palustris Huds. cv. Penncross), bermudagrass (Cynodon dactylon L. cv. Midiron), perennial ryegrass (Lolium perenne L. cv. Derby), and zoysia grass (Zoysia japonica Steud. cv. Meyer) were not suitable hosts. No greenbugs survived on the 9 weed species tested.
A method was devised to use honey bees and cages For controlled interpollinalion of numerous planl introduction accessions grown for seed increase. Honey bees (Aphismellifera L.) were maintained for 4 months (June-September) in small nuclei (min-ihive) for use in pollinating various crops grown under cages for seed increase. The nuclei remained as effective pollinating units without dwindling, swarming, overcrowding, starvation, or any of the other problems associated with extended maintenance of small pollinating nuclei. Cages used were easily assembled and stored, and were practical Tor caging large numbers of plantings for controlled pollination. Seed vields were excellent and of good quality.
An inexpensive chamber for controlled freezing of large container-grown plants up to 2 m in height was constructed using liquid nitrogen as a refrigerant. A microcomputer-based system was developed to control the cooling sequence and to collect data on tissue temperature, air temperature, and exotherms. Versatile software was written that allowed the programmed rate of temperature drop to be based on either tissue temperature or air temperature.