Study of the effect of allychemical compounds of Hoary Cress (Lepidium draba L.) field and root extract on the characteristics of germination and oat (Avena sativa L.) growth

In order to evaluate the effects of aqueous extract of various organs of Hoary Cress on germination and seedling growth of oat crop a factorial experiment was conducted in a randomized complete block design with 3 replications in 2015 and 2017 in Seed Research Laboratory of Mohaghegh Ardebil University. The treatments were concluded of aqueous extracts of the air and underground parts of the Hoary Cress and a mixture of these organs in equal proportions and at five concentrations of 5, 10, 20, 40 and 80% volumetric. Distilled water was used for control treatment. Based on the results, the aqueous extracts of various organs of Hoary Cress in different concentrations were able to significantly affect on germination and seedling growth of oat (p <0.01) as a result of increasing the concentration of aqueous extract of the Hoary Cress plant, were significantly decreased the germination percentage, germination rate, radicle length, coleoptile length and radicle and coleoptile weight, as well as number of oat derivative roots. In this experiment, the most rate of traits were observed in control and then at 5% concentration of different extracts of Hoary Cress organs and the least traits were observed in 80 and 40% of the extracts of various Hoary Cress organs. Concentration of 80% of the extract of organs aerial, underground and their mixture could reduce almost the total traits of the examined to zero. Based on the results of the threeparameter logistic equation and also based on X50 values, the highest effect of the aqueous extract was belong to Hoary Cress aerial parts and the least effect on the studied traits belonged to the aqueous extracts of underground organs. The results showed that plant debris of Hoary Cress could have inhibitory effects on germination characteristics as well as oat crop growth and development. Then soil should be investigated, in the conditions of field cultivation and at the time of preparation of the seedbed, in terms of the amount of Hoary Cress residues.