C. Mendoza F., A. Celis F., M.E. Pachón S.
For a long time, Colombian agriculture was part of the green revolution process, which has created several problems of environmental contamination, deterioration of soil quality and health of producers who handle the products of chemical synthesis. The use of plant extracts of the genus Piper can be an alternative weed management to reduce the indiscriminate use of herbicides, because these plant extracts contain secondary metabolites that can cause allelopathic effects in inhibiting germination and seedling development of weeds, contributing to generate cleaner production and lower cost. Greenhouse experiments under semi-controlled conditions were conducted at the University of Cundinamarca (Fusagasugá, Colombia) in order to evaluate the possible effect as pre-emergent and post-emergent herbicide of five extracts of the genus Piper on weeds present in the seed bank of a University farm. Application effect of Piper aduncum (wood), P. aduncum (leaves), P. hispidum (leaves), P. eriopodon (leaves) and P. holtonii (leaves) extracts was evaluated. In each type of evaluation (pre-emergence and post-emergence) we used a completely randomized design with A×B factorial arrangement with three replications. Factor A was the extract type and factor B was the applied concentration (0, 1000, 2000 and 3000 mg L-1). In pre-emergence, the germination percentage in different groups of weeds (dicot, monocot and Cyperaceae) was evaluated. In post-emergence, the effect of damage according to the EWRS (European Weed Research Society) scale was estimated. In pre-emergence, the highest inhibitory effect on germination of dicot weeds was presented by application of P. aduncum (leaves) extract (with a control of 59.6% inhibition of germination). In monocot weeds, the lowest percentages of germination were presented with application of extracts of P. holtonii, P. eriopodon and P. aduncum. In post-emergence, application of P. holtonii extracts produced greater phytotoxic effects in dicot weeds, while in monocot weeds, all extracts applications showed a statistically similar phytotoxic effect that was greater than the control (without extract application). Applying Piper extracts generated a pre-emergence and post-emergence bio-herbicide effect on weeds, which was evident but not as strong as that obtained with a commercial herbicide. There were differences in percentage of weed control according to extract and its concentration, type of weed (dicot, monocot, Cyperaceae) and time of application (pre-emergence and post-emergence). It highlighted the effect exerted by pre-emergence application of 3000 mg L-1 of P. aduncum leaf extract in dicot weeds.
Mendoza F., C., Celis F., A. and Pachón S., M.E. (2014). HERBICIDE EFFECTS OF PIPER EXTRACTS ON A SEED BANK IN FUSAGASUGA (COLOMBIA). Acta Hortic. 1030, 77-82
DOI: 10.17660/ActaHortic.2014.1030.9
pre-emergent effect, post-emergent effect, Piper aduncum (wood), Piper aduncum (leaves), Piper hispidum (leaves), Piper eriopodon (leaves), Piper holtonii (leaves)

Acta Horticulturae