Plant residues and litter may affect the plant growth. The objective of this study was to evaluate the allelopathic effects of aqueous extracts of pine (Pinus sp.), millet [Pennisetum americanum (L.) Leeke] and velvet bean (Stizolobium aterrimum Piper & Tracy) on germination, mycorrhizal colonization and initial growth of corn (Zea mays L.), soybean (Glycine max L.) and bean (Phaseolus vulgaris L.). Extracts of ground leaves were prepared. For the in vitro seven day- germination test, pH - neutral paper was previously wetted with the aqueous extracts or distilled water. The greenhouse experiment was arranged in a 3 x 3 x 4 factorial design, with four replications: three plant species (soybean, corn and bean), three aqueous extracts (Pinus, millet and velvet bean) and four extract doses (0.0; 0.5; 1.0 and 2.0 kg L-1). A Red Latossol (Oxisol) collected in Selvíria, state of Mato Grosso do Sul, in the Cerrado biome was used as substrate. After sowing in pots, 50 mL of the aqueous extracts was applied every 5 days, during 45 days. Opposite to pine, extracts of velvet bean and millet reduced the hypocotyl and root length in soybean. In common bean, pine extract reduced hypocotyl and root length, contrasting to velvet bean and millet. Millet extract decreased the germination percentage and germination rate of beans. All plant extracts reduced mycorrhization and the number of spores of arbuscular mycorrhizal fungi on soybean, maize and common bean.
arbuscular mycorrhizal fungi; millet; Pinus; velvet bean; savannah; allelopathy; plant extracts
