Influence of Environmental Conditions and Crop Competition on Morphological and Biological Diversity of Avena Fatua L. and Solanum Nigrum L.

This study investigated the effects of climate/soil conditions and crop competition on selected morphological traits, biomass productivity and some other biological aspects of the weedy species Avena fatua L. and Solanum nigrum L. The species examined came from arable fields differing with respect to soil type and crop species according to the following pattern: A. fatua (in maize – brown soil, in spring wheat – podsolic soil), S. nigrum (in maize – brown soil, in potatoes – podsolic soil). The investigations included measurements in their original habitats and in a controlled environment. Plants grown on fields with brown soil reached higher values of the evaluated traits as compared to those recorded for plants grown on a podsolic soil. The height of A. fatua was similar in both habitats because competitive ability of the crop balanced the soil effect. There were no differences in plant morphology and biomass productivity within the two species when plants were grown in the same soil/climate conditions but on different soils S. nigrum exhibited variation in plant height and biomass productivity. Both species similarly responded to reduced light that revealed differences between them in chlorophyll content. Seeds of A. fatua and S. nigrum, regardless of their origin, germinated better in darkness than in the light and seeds of both species were more able to germinate when they were collected from plants grown in the light conditions from above the crop canopy. All seeds of S. nigrum also germinated better under warm conditions (20°C).