ABSTRACT.- Two tall fescue seed production fields (A and B) with some similarities but with important differences on the technology used were contrasted. Similarities: same cultivar (Rizar), an early, rhizomatous, with good seed potential production; new crops (two- and three-years old field
areas); grazed from January to June; free of pests; 100 kg/ha of nitrogen in August/September and windrowed at the middle of November. Differences: 185 (A) vs 80 (B) kg/ha of nitrogen during fall and winter; rainfed (A) vs 165 mm of irrigation in 14 times form middle of August
to windrowing (B), and harvest five days after windrowing with 15% seed humidity and artificial drying (A) vs harvest 14 days after windrowing with less than 9% seed humidity (B).