Thursday, November 16, 2006 - 8:15 AM

Interactive Effects of Salinity and Mowing Heights on the Growth of Various Inland Saltgrass Clones.

Mohammad Pessarakli, Univ. of Arizona, Dept of Plant Sci, "Forbes Bldg, Room 303", "Forbes Bldg, Room 303", Tucson, AZ 85721, United States of America, David Kopec, University of Arizona, Room 303 Bldg 36 Plant sci Dept, Tucson, AZ 85721, J.J. Gilbert, "Univ. of Arizona, Dept of Plant Sci", "Forbes Bldg, Room 303", "Forbes Bldg, Room 303", Tucson, AZ 85721, United States of America, and A.J. Koski, Colorado State University, Dept. Hort. & Landscape Arch., Dept. Hort. & Landscape Arch., Fort Collins, CO 80523-1173, United States of America.

Twelve inland saltgrass (Distichlis spicata L.) clones (A37, A49, A50, A60, 72, A86, A107, A126, A136, A138, 239, & 240) collected from several western states of the US were studied in a greenhouse, using hydroponics technique to evaluate their growth responses in terms of shoot & root lengths, shoot (clippings) & root DM, & general grass quality under various mowing heights and salinity. Grasses were grown vegetatively in 1/2 strength Hoagland solution for 90 d prior to exposure to salt stress. Then, a combination of 6 treatments [2 salinity levels (EC of 6, control & 20 dSm-1 NaCl, Sodium Chloride) and 3 mowing heights (0, 2.5, & 5 cm)] were replicated 3 times in a RCB design experiment. Grasses were grown under these conditions for 12 weeks. During this period, shoots were clipped bi-weekly, clippings were oven dried at 60o C & DM recorded, & shoot & root lengths were also measured. At the last harvest, roots were also harvested, oven dried, & DM determined. General grass quality was weekly evaluated & recorded. Overall, all the grasses showed a linear reduction in growth responses as the mowing height decreased and the salinity level increased. All the evaluated growth parameters were more severely affected by reduction in mowing height compared to increase in salinity level. However, there was a wide range of variations observed in grass responses under the studied conditions. Among the 12 clones, 239 & 240 which have the finest texture & generally are more turf type grasses were more tolerance to the mowing and salinity. These clones had the best recovery among all the clones when transferred into the normal 1/2 strength Hoagland solution.