Population dynamics and structural characteristics of 'Survenola' digit grass subjected to intermittent defoliation strategies

Abstract

The objective of this work was to evaluate the effect of defoliation strategies and insolation periods on the population dynamics and structural characteristics of Digitaria eriantha 'Survenola'. The following four defoliation strategies (DSs) were evaluated: 40/10, 40/20, 50/10, and 50/20 cm (that is, 40 and 50 cm pre-defoliation height, and 10 and 20 cm post-defoliation height), under high- (September to March) and low- (April to August) insolation periods. An experimental randomized complete block design was carried out with five replicates. The accumulation of forage and leaf blade was higher when using the DS 40/20 cm in the higher insolation period. DSs 40/10, 50/10, and 50/20 cm resulted in a higher stem accumulation than DS 40/20 cm. 'Survenola' grass showed a higher appearance rate for basal and aerial tillers using the 40/10 and 40/20 cm strategies, respectively, during the lower insolation period. Greater tiller densities (basal, aerial, and total) were observed in the DS 40/20 cm in the higher insolation period. DS 40/20 cm resulted in a greater tiller renewal. In the DS 40/20 cm, 'Survenola' grass shows the greatest number of defoliation cycles, the highest density of tillers, and the greatest accumulation of forage and leaf blade.

Fatores que afetam as características morfogênicas e estruturais de plantas forrageiras

“…, as variações climáticas alteram a sua arquitetura através das modificações nas características morfogênicas da planta. Neste sentido,Sousa et al (2019) eFontes et al (2020) avaliaram a influência de períodos de insolação (quantidade de luz solar irradiada, em horas) nas características morfogênicas do capim-survenola, e relataram que no período de maior insolação houve maior densidade e taxa de sobrevivência de perfilhos, bem como acúmulo de forragem, resultado da disponibilidade de luz e temperatura para o crescimento da planta, uma vez que não houve limitação hídrica no sistema de avaliação. Ademais, o aumento da intensidade de sombreamento, houve aumento na taxa de alongamento de folhas e colmo (Tabela 4).…”