Natural ecological phenomenon of relationship between organisms that can be used for weed control in all annual and perennial crops is called allelophaty. In the future, as a natural phenomenon it can represent one of the mechanisms in biological weed control measures. During 2011 and 2012, in laboratory conditions allelophatic effect of cold aqueous extracts made of underground and above ground parts of Amaranthus retroflexus L. and Abuthilon theophrasti Med. was studied on germination capability of seeds and beginning growth phases of maize and soybean seed. Laboratory tests were set up in randomized block design in four replications. Tests were set up in four concentration ranges of 25, 50, 75 and 100 g/l of aqueous extractions from underground part, i.e. root and aboveground parts, i.e. stem and leaf of weed species A. retroflexus L. and A. theophrasti Med. In control variant maize and soybean seeds were sprayed by distilled water. After germination of crop seeds and subsequent treatment by cold aqueous extract made of these weed species, in next five days followed measurements of epicotyls and hypocotyls length of maize and soybean seeds on a daily basis. Before setting up of the test, studies of germination capability of seeds of the chosen maize and soybean crops were performed in climatic chamber under controlled conditions. Inhibiting effect of the applied aqueous extract from underground part of A. theophrasti Med. proved statistically insignificant on soybean hypocotyls growth in all four studied concentrations. Studied cold extract from above ground A. theophrasti Med. showed high inhibiting effect on soybean epicotyls length in all four tested concentrations. Application of cold extract made from underground part of A. retroflexus L. resulted in high allelophatic effect on germination capability of maize seed, as well as in reduction of maize seed hypocotyls length. On the other hand, treatment of maize seed by cold extract from above ground parts resulted in statistically significant effect in the highest concentration, whereas in the remaining three concentrations significant effect to the growth of maize seed epicotyls was not established.

allelophaty, Amaranthus retroflexus L., Abuthilon theophrasti Med., maize, soybean

Presentation: oral