The aim of the work was to study accessions of Dactylis glomerata L. of different origin for breeding in the Leningrad region. The work was carried out at the Leningrad Agricultural Research Institute. The study involved 15 accessions. The nursery was founded in 2016 and included two replications for green yield and two – for seed production. Cutting and sampling for biochemical studies were conducted in May-June 2018, seeds were collected in July. The amount of ascorbic acid, carotenoids and chlorophylls and crude protein were determined. Statistical analysis included the calculation of the parameters of variation, ANOVA and correlation analysis. Three groups were identified by the degree of ripeness: a small group of early maturing – 31 days, a group of late maturing (single accession from Karelia) – 51 days, a large group of middle maturing – 34–37 days. For the late maturing accession the mechanism of regulation of the beginning of heading is due to the sensitivity to photoperiod. The adaptive potential of widely zoned varieties is wider than for localized. Their productivity is higher. The content of pigments in the green mass is closely correlated. The system of pigments in the complex of characters is separate, but is positively associated with the seed productivity and negatively – with the content of ascorbic acid. The seed productivity of the accessions is related to the total pigment content and power of the generative shoots (length and mass).

In order to identify the quality of natural Silver birch stands in Latvia, fifteen sample plots covering all country's regions were established. Stem quality affecting morphological traits - stem straightness, branch angle, branching thickness and branching patterns were measured and assessed to all birches in sample plots. To compare the stand's quality, the integral quality indicator was introduced. According to results obtained in plots, most quality birch stands in Latvia are located in East and North parts of Latvia. The best stands proved to be in Aluksne and Smiltene. Birch stands in West part of Latvia had stems of substantially lower quality. The best quality stand in this region was birch stand located in Tukuma's head forestry.