Potencial alelopático de extratos aquosos de trigo sobre germinação de soja (Glycine max L.) e buva (Conyza spp.)

Abstract

The wheat (Triticum aestivum L.) crop stands out in southern Brazil because of its economic importance, food, and also can be used as an alternative, so that the soil does not become unprotected during the winter. This remaining coverage can act directly or indirectly on the germination of weed seeds and thus favor the control of these plants for the next crop. Wheat can be regarded as a plant that has allelopathic potential, because it has certain compounds which are able to inhibit the germination and growth of other plants. Therefore the objective of this study was to evaluate the allelopathic potential of aqueous extracts of twenty wheat cultivars and their influence on the germination of soybean and horseweed. The composition of the extracts were obtained by mixing 0, 7, 14 and 21 g of crushed material of the dry mass of shoots of each cultivar, dissolved in 100 mL of distilled water. The experiment was conducted in a completely randomized design with four replications in factorial design 20 x 4 x 2 (cultivars and species concentrations) in the BOD incubator with controlled temperature and photoperiod. The results showed that significant differences (p <0.05) so much to isolated factors, as well as to doubles and triples interactions indicating that there allelopathic effect of aqueous extracts of wheat on the germination of horseweed. The Mirante, BRS Pardela, BRS Parrudo, CD 1550, BRS Gralha Azul, BRS Tangará, IPR 144 and TBIO Sinuelo cultivars were the most efficient in the control of horseweed, with control of over 80% germination. Cultivars that most affected the germination of soybean were the IPR 144, BRS 327, CD 1550 and BRS Gralha Azul with 5.4; 13.5; 13.5 and 18.9% inhibition respectively.