Tillering dynamics of digit grass subjected to different defoliation frequencies

Abstract

The objective of this work was to evaluate the tillering dynamics of 'Suvernola' digit grass (Digitaria eriantha) when subjected to different defoliation frequencies. Four defoliation frequencies (interval among harvests) were evaluated – very high, when the grass reached 25 cm in height; high, 35 cm; medium, 45 cm; and low, 55 cm – in two seasons of the year, with higher and lower insolation, from January 2015 to January 2016. A randomized complete block design with four replicates was used. The increase in defoliation frequency increased the number of generations and the appearance, mortality, and density rates of tillers, besides decreasing their survival rate, without changing population stability. At the time of lower insolation, tiller appearance and mortality rates were higher, while tiller survival rate, balance, and density were lower. The evaluated defoliation frequencies and seasons of the year do not change the persistence of digit grass when irrigated. Higher defoliation frequencies result in a greater renewal of digit grass tillers.