Manuel J. Reigosa1, Alejo Carballeira Ocaña2
1 Departamento de Bioloxía Vexetal e Ciencia do Solo, Facultade de Bioloxía, Universidade de Vigo, Spain.
2 Departamento de Bioloxía Fundamental, Facultade de Bioloxía, Universidade de Santiago de Compostela, Spain.
Topsoils were collected 41 times along one year under the vegetal cover of Acacia dealbata, and their phytotoxicity was assessed using Lactuca sativa var. Great Lakes bioassays.
The results show that toxicity is not so pronounced as when other kinds of assays are carried out (decomposition of vegetal residues in the laboratory, artificial and natural washes) so being confirmed that the soil can act either by soaking up or by inactivating the allelopathic agents by means of microbial action. The maximum toxicity appears after that flowers have fallen down on the soil and their decomposition has begun what means that decomposition of vegetal residues is probably the most important release way of allelochemicals. The importance of the phenological gap between the blooming of A. dealbata, exotic species and the germination periods of the autochthonous herbaceous species is discussed.
Keywords: Allelopathy, Acacia dealbata Link, Lactuca sativa L., Soil Toxicity.
RECEIVED: May 2, 2016
ACCEPTED: December 21, 2016