Abstract
The objective of this research was to assess morphogenetic and structural characteristics of tillers of guinea grass cv. Tanzania at different ages. The pastures of guinea grass were managed in six pasture conditions related to the combination of three frequencies (90, 95, and 99% light interception) and two post-grazing heights (25 and 50 cm). In these six pastures conditions, three tiller ages were evaluated (young, mature, and old). The design was of completely randomized block with three replications. Young tillers exhibited higher leaf appearance rate and leaf elongation rate and, consequently, higher final leaf length and number of live leaves than mature and old tillers, regardless of the pasture condition. On pastures managed with 90 or 95% light interception associated with a post-grazing height of 25 cm, old tillers presented longer leaf lifespan than young and mature ones. There is a progressive reduction in the vigor of growth of pastures of guinea grass cv. Tanzania with advancing tiller age.
Highlights
Concerning the tiller, the forage production in pastures from tropical climate can be described in terms of the leaf appearance rate, leaf elongation rate, life lifespan (Lemaire & Chapman, 1996), and stem elongation rate (Sbrissia & Da Silva, 2001)
Young tillers presented higher leaf appearance rate (P0.10) between young and mature tillers (Table 1)
In the pasture condition of 90/25, 95/20 and 90/50, higher leaf elongation rates were obtained in young tillers, intermediate rates were observed in mature tillers, and lower rates were obtained in old tillers
Summary
Concerning the tiller, the forage production in pastures from tropical climate can be described in terms of the leaf appearance rate, leaf elongation rate, life lifespan (Lemaire & Chapman, 1996), and stem elongation rate (Sbrissia & Da Silva, 2001). In adequate environmental conditions (day length, temperature, humidity and soil fertility), plants increase their leaf appearance and elongation rates (Marcelino et al, 2006) and tiller appearance rate (Mazzanti et al, 1994; Difante et al, 2008) during regrowth. This pattern makes the forage accumulation be basically composed of leaves (Da Silva & Nascimento Júnior, 2007). There is increase in the leaf senescence (Hodgson et al, 1981) and decrease in the leaf lifespan as a way of keeping the number of live leaves per tiller relatively stable (Davies, 1988)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
