FORAGE YIELD OF SEVEN ASSOCIATION AND TWO PURE SWARDS OF GRASSES AND LEGUMES UNDER GRAZING CONDITIONS

To find the best association for maximizing dry matter yield, seven associations of two grasses (Dactylis glomerata L. and Lolium perenne L.) and one legume (Trifolium repens L.) were studied under grazing conditions at Texcoco, State of Mexico. The associations of white clover (WC), orchard grass (O), and perennial ryegrass (PR) were (in %): 30:20:50 (WC:O:PR); 10:70:20 (WC:O:PR); 40:60 (WC:PR); 30:50:20 (WC:O:PR); 20:40:40 (WC:O:PR); 40:60 (WC:O); and 10:20:70 (WC:O:PR. Additionally, two pure swards with 100 (PR) and 100 (O) were included. The nine treatments were distributed in a totally random block design with four replications. The evaluated variables were dry matter yield and botanical composition. Swards were defoliated by sheep every four weeks in the Spring-Summer, and every six weeks in the Fall-Winter. The 10:20:70 (WC:O:PR) association showed the highest annual dry matter yield, 66 % more than the 10:70:20 (WC:O:PR) association and the pure orchard grass sward (P < 0.05). Among seasons, the highest seasonal dry matter yield was recorded in the Spring-Summer, and the lowest in the Fall-Winter, with 69 and 31 % of the annual herbage yield. On average, perennial ryegrass, orchard grass, and white clover accounted for 47, 21, and 13 % respectively, to total dry matter yield. Based on annual herbage yield and seasonal distribution, the best association was 10:20:70 (WC:O:PR).