The signaling and identification of phytotoxic substances in soil is a very difficult problem. The main cause of this difficulty is that many of these phytotoxic substances, especially the organic ones, are ephemeral, transform rapidly and this changes the character of their physiological action on plants. As germination is the main characteristic of sowing seeds, the phytotoxicity of extracts on the plant growth and development can be followed through the effects they produce on seed germination. A characteristic that can be followed is the way the radical system develops. The radicals in particular are especially sensitive to the action exerted by the phytotoxic substances. Thus, the region of the root apical meristem develops abnormally, exteriorizing by their discoloration and then their complete mortification. In most cases, the effect of the phytotoxic extracts on the apical meristem is very quick. The root necrosis is observed an hour after the exposure of the roots to the phytotoxic solution. The paper presents the possible phytotoxic effects on the seed germination that extracts from different indigenous plants and invertebrates could produce, as it is well known that these can be used to fight certain pests in the ecological agricultural crops. The experiment was done within the Phytotechny Laboratory of the Faculty for Natural and Agricultural Sciences – the Agriculture Department. Wheat seeds (Flamura 85 variety) were set to germinate, with aqueous extracts of celandine, wormwood, oily extract of Allium with 10 g sodium-free soap and extract of Coccinella diluted in ethanol. These extracts, used for the ecological fight against pests, were monitored to see if they have phytotoxic effect in the soil.

the phytotoxicity, phytotoxic extracts, the germination

Presentation: oral