Effect of substrate and arbuscular mycorrhiza on the root system and nutritional status of Swietenia mahagoni L. Jacq.

Abstract

The study was developed with the objective of evaluating the influence of substrate factors and strains of arbuscular mycorrhizal fungi (AMF) on the root system and nutritional status of Swietenia mahagoni L. Jacq. The factors tested were: factor 1 substrate: cocoa husk, coconut fiber and composted pine sawdust in proportions 6:2:2 and 2:6:2 and a control composed of 100 % soil; factor 2 mycorrhizal strains: Glomus cubense, Rhizoglomus irregulare and Funneliformis mosseae. The nine treatments resulting from the 3x3 factorial arrangements were established under a completely randomized experimental design. Variables related to the root system (length of the main root, number of primary and secondary roots, mycorrhizal colonization) and accumulation of nitrogen, phosphorus and potassium were measured by vector graphic analysis. The results obtained showed that there was a differentiated effect of mycorrhizae on the growth of S. mahagoni. Inoculation with mycorrhizal strains improved plant nutrition. The best substrate for the establishment of the mycorrhizal association was S2, composed of 20 % coconut husk + 60 % coconut fiber + 20 % pine sawdust, but the best treatments for the growth and nutrition of the seedlings were the combination of substrate S2 and the strains Glomus cubense and Rhizophagus irregulare.

Keywords

• análisis de vectores
• colonización micorrízica
• nutrición forestal
• sistema radical.