Interference of shading on the performance of <em>Stylosanthes guianensis </em>genotypes

Abstract

The objective of this research was to analyze the interference of three levels of shading (without shading, 30% and 50%) on the values of nine plant growth characteristics of five Stylosanthes guianensis genotypes. A randomized complete block design with four replications was used. At 60 days after the beginning of the experiment these traits were measured: plant height, number of branches, number of leaves and nodules, leaf area, root length, dry mass of branches, leaves and roots. The genotypes vulgaris var. Cook, vulgaris var. Pucallpa, canescens CPAC 4227 and vulgaris CPAC 4323 showed the highest values for the characters studied in comparison with vulgaris var. Mineirăo, whose better performance in was found to occur at 30% of shading. The genotypes responded differentially to shading.. The significant phenotypic correlations (P≤0.05) were always positive, regardless of levels of shading, except between the number of nodules and plant height. The coefficients of correlation between the characteristics ranged in magnitude as shading conditions changed.

Additional keywords: Stylosanthes; forage legume; light incidence; plant breeding.