Population dynamics of stems in Urochloa hybrids with different harvest intensity

Abstract

The stability of the stem population allows analyzing the variations in the rates of appearance, death and survival, so the objective of this research was to determine the effect of harvest intensity (15 and 25 cm) on the stability of the population of stems of hybrid Urochloa Mulato II, Cayman and Mavuno. The study was conducted from March 2020 to February 2021 in Güémez, Tamaulipas, Mexico. In established meadows, 18 experimental plots of 3 x 3 m were delimited. In each experimental unit, two areas of 100 cm2 were placed to select the initial population of stems and count the dead stems and tillers present every four weeks. Differences were found between the intensities and sampling dates for the variables stem density, tillering rate, and stability index (p< 0.05). The cutting intensity of 15 cm generated the highest density of stems with 2 545, 2 996 and 2 200 stems m2 in Mulato II, Cayman and Mavuno, respectively, as a result of tillering rates greater than 12% without showing differences in death rates and survival percentage. The cutting intensity of 15 cm averaged stability indices of 0.98 and 0.96 in Mulato II and Mavuno, while negative stability (0.93) occurred in Cayman. The cutting intensity of 15 cm allowed maintaining the stability of the population of stems of the Urochloa hybrids Mulato II and Mavuno over time.