Allelopathic potential of Eucalyptus spp plantations on germination and early growth of annual crops Espinosa-García F.J.1,*, Martínez-Hernández E., Quiroz-Flores A.2 Instituto de Ecología, Universidad Nacional Autónoma de México, Circuito exterior S/N, Ciudad Universitaria, 04510, México, D.F. * Correspondence Autor, E-Mail: espinosa@oikos.unam.mx.
1Ctro de Investigaciones en Ecosistemas, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro No. 8701, Morelia, Mich, 58089, México 2Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México, Circuito exterior S/N, Ciudad Universitaria, 04510, México, D.F. Abstract We investigated the allelopathic potential of soil from Eucalyptus species (E. grandis, E. urophylla and E. grandis × urophylla) plantations on the germination and early growth of 4 crops [maize (Zea mays), bean (Phaseolus vulgaris), watermelon (Cucurbita pepo) and squash (Citrullus vulgaris)]. Soil samples were collected from different soil horizons (A0, A1 and B) and at varying distances from eucalyptus trees and used for growth studies. These soils had variable effects (inhibitory to slightly stimulatory) on test crops. Inhibitory effect was minimum on maize and maximum on black bean. Among the three Eucalyptus species, E. grandis × urophylla was most inhibitory against maize, bean and watermelon growth, whereas, E. grandis adversely affected the squash. The soils from Eucalyptus species contained water soluble phenolics and their amount varied with soil horizons. The soil from A0 horizon was most inhibitory, suggesting the accumulation of bioactive allelochemicals in this horizon. The study concluded that soil from eucalyptus spp contains inhibitory principles that affected the germination and early growth of crop plants. Top Key words Allelopathy, Citrullus vulgaris, Cucurbita pepo, Eucalyptus sp., germination, growth inhibition, Phaseolus vulgaris, phenolics, Zea mays. Top |