Vertical layer distribution of leaves, stems and dry matter yield of Pennisetum purpureum cv. Cuba CT-115 after grazing during the dry season

Resumen

In order to study the performance of some morpho-agronomic indicators in strata of Pennisetum purpureum cv. Cuba CT-115, a completely randomized design was used with 15 repetitions. The treatments consisted of five strata: 0-30 cm, 30-60 cm, 60-90 cm, 90-120 cm and more than 120 cm. The results indicated that in the rejected material (immediately after grazing) the residue yield was stabilized up to the upper strata (P < 0.05), whereas there were no differences at 30 and 60 d of regrowth. At 90 d of regrowth it appeared plant material in the stratum of more than120 cm, with values of 0.64 kg DM/tuft, differing from the rest of the strata (P < 0.001), except the basal stratum (0-30 cm). The percentages of leaves from the residue for all regrowth ages were increased up to the upper strata, with maximum values of 18.67, 19.45, 21.66, and 46.51 % for the rejected material, 30, 60, and 90 d of regrowth, respectively. However, the percentages of stems and dead material were reduced. The basal tillers emerged since 60 d of regrowth, not showing differences so as to their yield between strata. The percentage of leaves in the basal tillers was increased (P < 0.001) up to the stratum of 30-60 cm, with values of 60.37 and 63.33 %, for 60 y 90 d, respectively. The stems had an inverse performance. It was concluded that the upper strata had the highest percentages of leaves, the lowest of stems and dead material, in the basal tillers as in the residue, for all the regrowth ages, favoring the nutritive value of the forage. Using this information for designing other management choices is recommended.
Key words: strata, Pennisetum, yield, grazing.