Petryshyna A. Harm of weed species and weed control optimization in pea agrophytocenosis at the right-bank Forest-Steppe of Ukraine

The thesis is devoted to combine methods and tools' working out and implementation with the purpose of decrease the potential soil weediness as well as regulation of actual infestation level in pea sowings and yield increase achievement on this base. It is established the harm of the most abundant weed species, herbocritical period of competitive relationships between cultivated plants and weeds. It is revealed the antiweed effectivness of different agricultural systems and tillage systems. It is worked out the pea sowings defend system against weeds. It is shown the research results of agricultural systems and tillage systems' influence on pea sowings infestation, dynamics of shoots appearance of problematic weed species and crop competitive ability. It is established the seed productivity of problematic weeds species of different terms of their appearance and viable seeds amount entering the soil depending on agricultural systems and tillage systems. Key words: weed, infestation, tillage, agricultural systems, seeds, productivity, yield, pea, agrophytocenosis, optical density.