Monday, November 5, 2007 - 2:00 PM
73-5
Salinity Tolerance of Greens-Type Poa annua L.
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Salt tolerant turfgrasses are valuable in areas afflicted with saline soils and/or salt-rich irrigation water. Greens-type Poa annua L. (annual bluegrass), possessing desirable turf traits such as high shoot density and tolerance to close mowing, is being developed into a commercial turfgrass at The Pennsylvania State University. Current literature suggests Poa annua is intolerant to salinity stress. Research shows that under a 6.4-mm mowing height, greens-type Poa annua was more salt tolerant and more adjustable in root structure than turf-type Poa annua. Growth response of 33 greens-type Poa annua experimental lines to chronic salinity stress (12 wks at 8.0 dS m-1) was examined in greenhouse studies. A wide range of variability in salinity tolerance was detected among lines as significant differences in relative percent cover and relative clipping yield were observed. Salinity tolerance of greens-type Poa annua relative to other cool-season turfgrass species was evaluated in seed germination and hydroponic studies. On the basis of final germination percentage, germination rate, shoot mass, root mass, and the longest root length, greens-type Poa annua was generally intermediate among the species rankings of salinity tolerance. However, some lines exhibited nearly equal salinity tolerance to that of creeping bentgrass (Agrostis stolonifera L.) ‘Mariner’ and perennial ryegrass (Lolium perenne L.) ‘Charger II’. We thus conclude that greens-type Poa annua possesses moderate to good salinity tolerance and particular lines have potential to be used on golf courses with moderate salt problems.
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