Tropical Grasslands (2001) Volume 35, 114123
Leaf appearance, death and detachment in a bahia grass (Paspalum notatum) pasture under cattle grazing
W. PAKIDING and M. HIRATA
Grassland and Animal Production Division, Faculty of Agriculture, Miyazaki University, Miyazaki, Japan
Number of leaves, rates of leaf appearance, death and detachment, and leaf longevity were measured for 2 years in a bahia grass (Paspalum notatum) pasture under cattle grazing, in an endeavour to characterise the leaf dynamics variables and examine their contribution to the persistence of the sward. The number of live leaves (range = 3.1–8.2 leaves/tiller) was high in summer and autumn, and low in winter. The number of dead leaves (3.1–8.1 leaves/tiller) was high in winter and spring, and low in summer and autumn. Leaf appearance rate (0.005–0.145 leaves/tiller/d) increased in spring, maintained high values until early autumn, and decreased thereafter. The rates of leaf death and detachment ranged from 0.016–0.152 leaves/ tiller/d and from 0.006–0.250 leaves/tiller/d, respectively, with similar seasonal patterns. Leaf appearance rate was positively related to air temperature, and leaf death rate and leaf detachment rate to the number of live and dead leaves, respectively. Leaves appearing in October and November (mid- and late autumn) survived longer (half-life = 3.6–5.4 months) than those appearing in April–September (mid-spring to early autumn) (half-life = 1.3–2.3 months). This high longevity of leaves appearing in mid- and late autumn and the high leaf detachment rate during the growing season (late spring to mid-autumn) are crucial factors in the persistence of bahia grass as well as the long life of tillers.