Morphogenic responses of two Brachiaria genotypes to clipping frequency

Abstract

Tropical grasslands represent an important resource for the Brazilian cattle industry, which is heavily dependent on grazed pastures. Total pasture area in the country totals 196 Mha (23% of the country’s land area) (FAO 2013). The genus Brachiaria represents around 85% of cultivated pastures in Brazil (Moreira et al. 2009), 40% of which are established with B. brizantha cv. Marandu (Barbosa 2006). Mulato II is a new hybrid brachiariagrass cultivar, which has been developed to improve agronomic characteristics, broaden the range of adaptation, and ensure high forage production and nutritive value. It has also been viewed as a means of reducing the dependence on the Marandu palisadegrass monoculture (Argel et al. 2007). The use of new cultivars should be based on adequate understanding of physiological processes and growth potential under a range of management practices. Morphogenic characteristics allow for accessing herbage accumulation potential through the measurement of tissue synthesis and senescence in forage plants. Management practices such as defoliation frequency can modify assimilate partitioning in the forage plant, affecting morphogenic characteristics related to growth rate and forage nutritive value. The objective of this research was to describe and explain morphogenic differences between Marandu palisadegrass and Mulato II brachiariagrass as affected by harvest frequency.