Morphogenesis in pastures of Coastcross-1 and Tifton 85 mixed with forage peanut, submitted to cutting management

Abstract

The objective of this study was to evaluate the effect of the presence of forage peanut (Arachis pintoi Krap. and Greg.) on the morphogenesis characteristics of two cultivars of Cynodon (Tifton 85 and Coastcross-1). The experimental design was factorial (three factors), in randomized blocks, having as factors the cultivars (2), the occupancy area of forage peanut (4) and the seasons (3), with three replications, established in plots. There were three assessments during the study, in spring, summer and autumn, in which the total number of tillers, the culm and leaf elongation, the senescence rate and leaf emergence, the phyllochron, the leaf lifespan, the leaf number and the height of culm and canopy were evaluated. The number of green leaves, number of elongating leaves and senescence rate were similar among cultivars, but cv. Coastcross-1 showed higher number of expanded leaves and leaf emergence rate, and lower phyllochron and leaf lifespan. We observed lower rates of senescence and higher leaf emergence in spring, and lower rates of leaf elongation in autumn. The increasing participation of forage peanut in the pastures did not affect the calculated morphogenetic variables, but decreased the number of grass tillers. A lower average daily thermal accumulation decreased the development of both grasses in this study, with a more pronounced effect in cv. Tifton 85. The Coastcross-1 cultivar has higher elongation rate and leaf emergence, coupled with lower phyllochron and leaf lifespan, indicating a need for shorter rest periods when compared to cv. Tifton 85.