Influence of substrate and mycorrhizal fungus on the root and shoot architecture of coffee-shading walnut (cordia alliodora [ruiz et pav.] oken)

Abstract

Cordia alliodora (coffee-shading walnut) is a species of economic importance to Colombia because of its multiple uses for farmers and for reforestation as a timber and industrial resources, mainly in the central coffee region of the country. The aim of this research was to study parameters of C. alliodora shoot and root system architecture over the first year of development. Plants were established in Pacho municipality (Cundinamarca) at an 2,150 m a.s.l. A split plot design with a randomized complete block and three replicates was applied. Within the main plot, we evaluated the substrates (soil, husk and compost 2:1:1; soil and husk 3:2; soil and husk 3:1), and withing the subplot, the mycorrhizal fungus (without fungus, Kuklospora colombiana, Glomus manihotis and Acaulospora lacunosa). Substrate type affected C. alliodora root and shoot architectural parameters. Plants transplanted into soil, husk and compost 2:1:1 had the best responses in architectural parameters: diameter of the base of the root (7.82 mm), number of secondary roots (48.4), root dry weight (5.38 g), number of leaves (47.33), dry weight of shoots (7.71 g), shoot length (72.64 g) and leaf dry weight (6.28 g) at 384 days after transplant. Since no fertilizer was applied to coffee-shading walnut plants, we conclude that the mycorrhizal fungi facilitated a better use and development of mineral elements present in the substrates