Abstract

Warm-season grasses that are used for turf are primarily in the genera Axonopus, Cynodon, Eremochloa, Paspalum, Stenotaphrum, and Zoysia.   People in subtropical areas benefit from the recreation, aesthetic, sanitation, and conservation features which those grasses provide.  The most widely used warm-season turfgrasses are cultivars selected by public plant breeders, although private efforts have been notable in development and marketing.  Breeding has created warm-season turfgrass cultivars that are more utilitarian and less costly to maintain, compared with unselected common strains.  Successes of breeding include selection for finer texture (e.g., 'Tifgreen' bermudagrass, Cynodon X magenissii Hurcombe); for insect resistance [e.g., 'Floratam' St. Augustinegrass, Stenotaphrum secundatum (Walt.) Kuntze]; and for higher apparent density (e.g., 'Argentine' bahiagrass, Paspalum notatum Flügge).  Most progress in breeding warm-season turfgrasses has been based on serendipitous creation, and skillful discovery.  Further stepwise improvement from past successes is difficult, because there is generally no source germplasm available.  Scientists have broadened the knowledge of warm-season grass genetics, but knowledge is still fragmentary in other critical areas.  The accurate description and identification of cultivars and their wild relatives are almost nonexistent.  Shade tolerance and acceptability under reduced irrigation are of the utmost importance, but have been vexing research problems.  Pest resistance, while desirable, must be understood in the context of generalized (horizontal) adaptation to the stress environment.  Not enough work has been done to correlate laboratory observed resistance with field level resistance.  Future progress will depend upon better knowledge of taxonomy and genetic resources, selection method, and the basis of cultivar adaptation.