Seed Germination and Seedling Growth of Triticum Aestivum L. And Hordeum Vulgare L. Under Allelopathic Effects of Brassica Napus L. - Aqueous Extract

The expansion of energy crop acreage, such as oilseed rape, and the increasing demand for cereals have led to a reduction in the biodiversity of agricultural crops. The cultivation of many crop plants is abandoned, which leads to the shortening of a plant's return time in the same field. Agricultural practice has shown that the replacement of a 5-6-year crop rotation with a 2-3-year rotation causes at least a reduction in crop productivity in very favourable years. In recent years, the importance of this phenomenon has been increasing - despite significant countermeasures such as the use of chemical fertilizers, pesticides, mechanization or irrigation. Many researches have attributed these crop losses to allelopathic phenomena in agroecosystems but the problem needs to be addressed more thoroughly. More than 10,000 secondary metabolites are known from the plant kingdom which displays important more or less plant-specific allelopathic effects. They can lead to alterations in water and nutrient uptake, stomatal conductivity and photosynthesis. This paper presents some aspects regarding the allelopathic effect of oilseed rape on seed germination and seedling growth of wheat cv. Boema1, Dropia, Izvor and barley cv. Flavia, Gabriela, Laura. We have observed that the physiological reactions of the plants exposed to the treatments with aqueous rapeseed extract are strongly dependent on the cultivar investigated. The inhibitory allelopathic effect was expressed as a change in germination phenology in the range of 05 to 09, according to the BBCH scale. Notably a reduction in seedling growth and effects on the biosynthesis of chlorophyll have been recorded, which could contribute to the reduction of crop production.