Crescimento diurno e noturno dos capins Paiaguás e Xaraés

Abstract

This work was conducted in three seasons of the year (late spring, early summer and late summer) with the objective of knowing, by the evaluation of morphogenesis, in which period (diurnal or nocturnal) the highest foliar and leaf growth rates occur. Of two cultivars of Brachiaria brizantha (paiaguás and xaráes). The design was completely randomized, with three replications, and the plot scheme subdivided in time. The plots corresponded to the cultivars and the periods of the day were the subplots. The evaluations took place in three seasons: late spring, early and late summer. In the three seasons, the two cultivars of Brachiaria brizantha (paiaguás, xaráes) were similar in relation to the diurnal and nocturnal periods. The leaf elongation rate was influenced only by the cultivar, with a higher value for the Xaraés cultivar than for the paiaguás cultivar, regardless of how it was expressed, if in mg.perfilho-1.hour-1 or in cm².perfilho-1 .hours-1. Only at the end of the summer, the leaf senescence rate was higher in paiaguás cultivar, in relation to cultivar xaraés. Leaf growth and senescence of Xaraés and Paiaguá grasses do not vary between diurnal and nocturnal periods. The Xaraés grass has higher leaf growth than the paiaguás grass.