Establishment and stress tolerance of buffalograss

Buffalograss (Buchloe dactyloides (Nutt.) Engelm.) is an adapted, drought tolerant grass, native to the semiarid Southern Great Plains of North America. Successful establishment of this species using burrs or caryopses has been limited by lack of information on planting date, planting rate or type of seed used in planting. Buffalograss responds to drought stress by becoming dormant and initiating very rapid regrowth when water becomes available. Further enhancement of drought tolerance in this species has been limited by lack of a suitable drought stress tolerance screening test. This dissertation presents the results of several studies conducted at the Texas Tech University Plant Stress Laboratory in Lubbock, Texas to determine the optimal planting dates, optimal seeding rates, and the impact of planting caryopses vs. burrs in buffalograss. A modified tray screening system was developed to select buffalograss seedlings at two drought tolerance levels.; Optimal establishment dates for the cultivars 'Comanche' and 'Texoka' were shown to be mid-May to mid-July. Planting caryopses always produced better stands two and four weeks after planting than planting treated burrs.; Optimal seeding rates of Comanche buffalograss were 1125 to 1875 caryopses {dollar}rm msp{lcub}2-1{rcub}{dollar}. Caryopses had faster emergence and had less seedling mortality than burrs. However, density and turf quality at the end of the growing season were not affected by either the type of seed or planting rate.; Drought tolerance of buffalograss seedlings were assessed using a modified tray screening system based on a test previously used to screen for drought tolerance in forage grasses. This modified test used variable day/night temperatures and constant air movement across the seedlings. Tests were performed on over 1000 seedlings of four populations and no significant differences were detected between either drought stress levels ({dollar}-{dollar}4.0 and {dollar}-{dollar}6.7 Mpa) or the populations evaluated. Seedling survival ranged from 0.6 to 1.5 percent. This system proved to be useful for screening buffalograss seedlings for drought tolerance under highly controlled conditions. These studies should enhance utilization of buffalograss as a turfgrass across this region.