Allelopathic activity of water-soluble and volatile secretions of Crocus sativus L. (Iridaceae) flowers in the Northern Black Sea region

The introduction of new crops to agrophytocenoses, to which Crocus sativus belongs, should be preceded by research into their ecological safety and place in crop rotation. When harvesting raw materials for obtaining saffron, up to 90% of by-products remain, which during decomposition can have a negative effect on the soil and indirectly on the plants that are grown after saffron. Therefore, the aim of the research was to study the allelopathic activity of water-soluble and volatile secretions of Crocus sativus flowers in the agroclimatic conditions of the Northern Black Sea region. The research was conducted in 2021 according to the generally accepted methodology, freshly picked flowers were used, from which individual elements were extracted, and flowers of different stages of flowering. The following research methods were used: field, laboratory, computational and statistical. The results of the research established that the water-soluble secretions of Crocus sativus flowers and their parts stimulate the energy of germination and inhibit the growth of one-day seedlings of Lactuca sativum. Water-soluble secretions of Crocus sativus flowers have a negative allelopathic effect. The index of allelopathic activity under the action of water-soluble secretions of flowers ranges from -0.26 for a flower with all parts to -0.01 for petals. The highest stimulating effect of volatile secretions on the growth of Lactuca sativum roots and the allelopathic activity index value is characteristic of the flower that has just bloomed and the stamens, and the lowest - for the pistils. The allelopathic activity of the volatile secretions of Crocus sativus flower parts is set at the level of 6.4 (pistil) and 28.8% (stamens). Substances that inhibit the germination of Lactuca sativum roots are found mainly in the stamens. It was determined that the volatile secretions of Crocus sativus flower parts reduce the energy of seed germination of the test plant. The practical value of the research is that the results of the research can be used when determining the place of the crop in crop rotation and the duration of its cultivation in one field