The experiment was conducted to estimate morphogenic and structural characteristics and dry matter accumulation rate of leaf blades in a pasture of Cynodon dactylon cv. coast-cross grass intermittently grazed by lactating cows. The evaluations were performed in Spring (October-November), in Summer (February-March) and in Fall (May-June). The study was conducted observing a completely randomized design. with six replications. Leaf length, appearance and senescence in marked tillers were registered over the rest period of the paddock. Tillers in sampling areas of 0.09 m2 were counted for estimation of the tiller population density. The net DM accumulation rate of leaf blades was obtained by multiplying the dry matter accumulation rate by the number of tillers/area. Leaf elongation rate was higher in the Summer; while leaf appearance rate and the number of leaves/tiller were higher in Spring. Tiller population did not vary with season, averaging 2,770 tillers/m². The senescence rate averaged 2.44 mm/day in the Spring and no leaf senescence was observed over the Summer and Fall. Dry matter accumulation rate of leaf blades was higher in the Summer and showed a close relationship with leaf elongation rate and leaf size. Leaf blade accumulation rate was overestimated when calculated from leaf elongation rate and tiller density data.
leaf elongation; dry matter; tiller; senescence
