Competitive ability with weeds during the establishment of aries grass: morphological characteristics

Abstract

-The aim of this research was to evaluate interspecific competition in Panicum maximum cv. Aries during the establishment period, studying the factors of shading and nitrogen levels. The levels of shading caused by the weeds ranged from 0% and 40% to 70% and 60% with no nitrogen and in the presence of nitrogen. Analyses were made of plant height, tiller dynamics, leaf area index (IAF), dry matter, senescent leaf material and relative competition intensity (ICR) in P. maximum cv. Aries when with weeds. The data were submitted to tests for homogeneity of variance and residual normality; analysis of variance (ANOVA), Tukey's mean difference test at 5% probability, and regression analysis were then carried out. The morphological and yield characteristics of P. maximum cv. Aries responded better where there was no interference from the weeds. Nitrogen contributed to greater development in P. maximum cv. Aries, but when coexisting with the uncut weeds, the weeds dominated the P. maximum cv. Aries. Cutting the weeds caused a reduction in the intensity of interspecific competition. The variable conditions of shade over time express different morphological responses in comparison to a homogeneous situation, mainly interfering in the speed of establishment of P. maximum cv. Aries.

Morphogenic characteristics of black oat and vetch under different densities

“…Source: João de Assis Farias Leaf senescence rates were not significantly influenced by density (P > 0.05). Lower rates of leaf senescence may be connected to a lower rate of overall growth as observed by Szymczak et al (2016) in Guinea grass tillers subjected to different shade levels. Despite the differences obtained with respect to leaf appearance rate, the number of live leaves was not influenced by plant density (P > 0.05).…”