ASSESSMENT OF FLAX POPULATION PRODUCTIVITY UNDER VARIABLE ECOLOGICAL FACTORS DURING ONTOGENESIS

The limiting factor that affects flax development often is different abiotic and biotic stress. Most crucially ecological adaptation of plants is dependent on the genetically determined productivity of flax and variation in yields in the agroecosystems. The aim of this study was to analyze the flax population of the important agronomic trait productivity under variable agro- ecological conditions and the incidence of fungal diseases at different flax growth stages. Field investigations were carried out from 2014 to 2017 for agronomically important traits of flax and from 2015 to 2017 for the incidence of fungal diseases at the growth stages of flax. In the study was evaluated flax population with Latvian origin in 24 fibre flax genotypes and ‘Vega 2’ (ST) as the standard variety of Lithuanian origin under Latvian meteorological conditions. According to the results obtained from analysis of variance between flax population agrono- mically important yield traits and years the significant higher plants stem yield, total plant height, technical plant height, number of seed vessels per plant, and oil content were measured in the growing seasons with high humidity. However, the higher seed yield and 1000 seed weight were measured in the driest year. The lowest lodging rate of flax population was found in years with higher humid level and rapid rainfall. Statistically significant higher average diseases incidence was detected during early yellow ripening stage for all diseases, except flax wilt. The incidence of flax wilt was detected during vegetative stages, anthracnose, stem break, browning of flax and fusarium browning during all growth stages, but pasmo and powdery mildew were found during the reproductive stages of flax population.