This work evaluated the morphogenic response of pearl millet (Pennisetum americanum) to two heights of pasture management. Marked tillers were used to check the variables being studied. Proposed treatments were average heights of 20-30 and 40-50cm. The variables evaluated were: phyllochron; average numbers of elongated leaves and of green leaves per tiller; appearance, defoliation, elongation and leaf senescence rates. The treatment with average height of 20-30cm presented greater senescence rate and greater number of elongating leaves, respectively, in the first and second periods of evaluation. In the treatment with height of 40-50cm a greater number of senescent leaves, greater final leaf length and phyllochron was observed, respectively in the first and second periods. The rate of leaf defoliation differed between treatments, being higher in the lower height of plants, in both periods. The rate of leaf appearance was higher in the second period in the lower height of plants, influenced by the lower height of the tiller in this period. The morphogenic responses can be assigned to changes in pasture structure imposed by the treatments. The use of a grazing height around 20-30cm maintained a higher proportion of leaves in the pasture.
phyllochron; leaf appearance rate; leaf elongation rate; leaf senescence rate; defoliation frequency
