Occurrence and some morphological features of Bromus secalinus L. in agrocenoses of the Podlaski Przełom Bugu mesoregion.
Occurrence analysis of Bromus secalinus in the area of the Podlaski Przełom Bugu mesoregion as well as some biological features of the species, depending on the cultivated plant are presented in the paper. Studies on distribution Bromus secalinus stands were carried out between 2004 and 2009. Afterwards 30 specimens were randomly selected from various cereal cultivations and subjected to biometric analysis. The following biometric parameters were measured: height of tuft, number of blades in one tuft, length of generative shoots, length of blade up to flag leaf, length of panicle, number of panicle branches, number of spikelets in one inflorescence and in tuft, number of kernels in one spikelet, panicle and tuft. Bromus secalinus frequently occur in cereal cultivations of the Podlaski Przełom Bugu mesoregion and is considered to be in expansion. The species was noted in 75 plots, situated in the area of 31 localities. It was noted on all soil types and in all soil-agricultural complexes. The species was the most frequently recorded in winter cereals on compact soils, with pH ranging from 5 to 7.5. The highest Bromus secalinus cover was noted in winter wheat on compact soils. Biometric features of Bromus secalinus individuals were diversified depending on the cultivated plant. Fertility was the most diverse and variable parameter. The most fertile individuals were recorded in spring cereal mixture. They were also characteristic for the largest number of blades in one tuft. The highest specimens, significantly differing from the others were observed in winter rye and wheat cultivations. Such parameters, as: number of blades in one tuft, number of spikelets in one tuft, length of panicle, and number of branches and kernels in panicle favourably affected Bromus secalinus fertility, whereas increase of length of generative shoots and length of blade up to flag leaf had a opposite effect.