Poa annua at Penn State
Research green facility/ demonstration plots
A 3,500 sq. ft. research green was constructed in 1996. This green was designed to mimic an old push-up green with a long history of topdressing. The top 4 inches was composed of 60% sand, 20% O.M., and 20% top soil. The middle 4 inches was composed of 30% sand, 10% O.M., and 60% topsoil. The bottom 4 inches was 100% topsoil. To ensure adequate drainage, drain lines were placed underneath the green and the green was slightly crowned.
Research plots were established in spring 1996 and have been utilized as demonstration plots at the 1996 PSU Fields Days. Thirty-eight strains of greens-type Poa annua and 6 cultivars of creeping bentgrass (Penncross, Providence, A-1, A-4, G-2, and G-6) were planted as a randomized complete block design with six blocks. Plot size was approximately 1 ft x 2 ft. All 252 plots were initially established in the greenhouse and planted as solid sod on the experimental green. All 42 entries were randomized within each block. Quality ratings will continue to be recorded in 1997. Preliminary observations suggest that creeping bentgrass requires daily mowing to maintain a constant height of cut whereas many Poas could maintain a constant greens height of cut even if mowing were performed every other or every third day. Most Poas seem to required more nitrogen than the bents in order to produce an acceptable color. This may be an inherent nutritional requirement difference between the two species or may it be a function of the enormous tiller density difference between the two species (Poa tiller density >> bent tiller density). A leaf spot disease was observed on several Poa strains that has not been previously reported in the state of Pennsylvania; although this disease has been reported to occur in Michigan (J. Vargas pers. com.). The lack of any report of this disease (likely a Bipolaris sp.) in the central PA region seems most likely due to a lack of observation rather than a new or newly arrived pathogenic organism. Observations of this disease will continue in 1997.