The effect of increased temperature and CO2 air enrichment on the nutritive value of orchard grass (Dactylis glomerata) in permanent grassland

High yielding ruminant livestock require high nutritive value in forage for maintenance, growth and production. Climate change has been documented as impacting on the nutritive value of forage plants. Therefore, the aim of this study was to investigate the impact of increased temperature in combination with CO2-enhancement on the nutritive value of orchard grass (cocksfoot; Dactylis glomerata L.), as a C3 model plant, widespread in mountainous permanent grassland plant communities. Functional traits and forage quality of orchard grass were investigated both under ambient (C0T0) and under simulated, future climate conditions (C2T2) with increased temperature (+3°C) and enhanced CO2 concentration (+300 ppm) under field conditions. Plant samples were taken from each of the three growths over a period of three consecutive years and numerous functional properties and forage quality parameters were determined. Special attention was paid to the determination of water-soluble carbohydrates (WSC), crude protein (CP), non-protein N (NPN) and metabolizable energy (ME) as possible indicators for different climatic conditions. It is hypothesized that (i) functional traits and (ii) forage quality of orchard grass are altered by increased temperature and higher CO2 concentration. The results showed a negative impact of C2T2 compared to C0T0 on tiller height (54.4 v. 70.6 cm) and weight (2.42 v. 3.22 g) as average over cuts and years. The NPN content was lower in C2T2 (312 g/kg CP) compared to C0T0 (339 g/kg CP). In contrast, the WSC content was higher in C2T2 (90.3 g/kg DM) compared to C0T0 (82.5 g/kg DM). Both ME content and digestibility were increased in C2T2 (9.18 ME/kg DM and 68.2%) compared to C0T0 (8.86 ME/kg DM and 65.4%). Concluding, under increased temperature and enhanced CO2, both functional traits and certain nutrients and their fractions appear to change in orchard grass.

Peculiarities of growth and development of alfalfa-grasses mixtures depending on species composition and fertilizing

The results of research on the influence of grass species composition, fertilizer level, and Fumar growth stimulator on plant density and botanical composition are presented. The experimental part of the work was performed in the scientific laboratories of the Department of Forage Production, Land Reclamation and Meteorology in the production unit of the National University of Life and Environmental Sciences of Ukraine "Agronomic Research Station". The territory of the research station is located in the Right-Bank Forest-Steppe and is a part of Bila Tserkva agro-soil district. The experimental plots were laid on typical low-humus chernozems, coarse-grained light loam in terms of mechanical composition, which are characterized by a high content of gross and mobile forms of nutrients. The climate of the region is characterized by unstable humidity and moderate temperatures. The average annual air temperature is 6-8 ° C. The annual amount of precipitation reaches 562 mm, during the growing season - 354-394 mm (63-70% of the annual norm), which fall unevenly throughout the year. Based on the research, it was found that sown grasses was formed with a density of 686–1250 shoots per 1 m2 and a height of 58–148 cm. Alfalfa-grasses and grasses are denser than alfalfa. During the period from the 1st to the 3rd year of grassland use, the density of alfalfa shoots decreases, while orchard grass and smooth brome grass increase, moreover, and more significant on the backgrounds of N60 application. During the first three years of use, grasslands are formed with the dominance of sown components with the share of alfalfa in single-species sowing 85–98%, in alfalfa-grasses mixtures - 30–58%. During the period from the 1st to the 3rd year of alfalfa-grasses stands using, the share of alfalfa decreases by 11–24%, and more significantly on backgrounds with N60 application. Also between the two kinds of grass components, there is a change of co-dominant - from meadow fescue to reed fescue, reed fescue to orchard grass, English bluegrass to smooth brome grass, while, as in grasses, reed fescue to smooth brome grass. English bluegrass in the 3rd year of use is much liquefied, reducing the share of participation to 5-14%.

Does ectoin affect release of allergens from pollen of wind-blown plants?

The effect of ectoin on the release of allergens from pollen grain of wind-blown plants was studied. The birch, alder, hazel, timothy, and orchard grass pollen grains were used for this experiment. Enzyme-linked immunosorbent assay (ELISA) and morphological examination of birch pollen grains utilizing the light microscope were used. The findings indicated that ectoin does not promote the allergen release from pollen. Thus, ectoin not only improves the barrier function of the nasal mucosa and washes pollen from the nasal cavity, but also does not disturb their integrity and does not affect the release of allergens.

POPULATION OF ORCHARD GRASS HYBRID SAMPLES (DACTYLIS GLOMERTA L.) IN THE CONDITIONS OF THE PRIMORSKY KRAI

The data obtained as a result of breeding work with perennial grasses in the Primorsky Krai in 2018 - 2020 is presented. In the F1 breeding nurseries, 2 hybrid specimens of the orchard grass were studied: Dikorastuschaya♀ x Aukshtuole♂, Pushkinskaya♀ x Dikorastuschaya ♂, which in terms of green mass yield exceeded the standard by 32 - 22%.