The adaptive potential of 20 forage cultivars was evaluated by using a simulated grazing technique (cutting at 21 - and 28-day intervals during long-day and short-day season, respectively) over a 1 1/2-year period at Corozal, Most of the 12 Cynodon cultivars were susceptible to fungi during a very rainy period. With the exception of C. nlemfuensis PRPI 2341 and C. plectostachyus PRPI 12949, none of the eight Hemarthria altissima cultivars presented this problem. Cynodon cultivars suffered moderate to severe insect damage; H. altissima cultivars slight to moderate damage. Eleven Cynodon cultivars presented a poor to medium resistance. Four of the H. altissima cultivars (PRPI 13202 and 13178, and USDAPI 379617 and 364873) excelled in terms of dry matter production both seasons in development qualities (plant height and soil cover) and disease as well as insect and weed tolerance. The simulated grazing technique in combination with agronomic evaluation was effective for screening many grass accessions within a short time.