Evaluation of breeding material of awnless rump (Bromus inermis Leyss.) For productivity in agrophytocenoses mixed with alfalfa

In recent decades, the tendency of climate aridization has been increasing in the main agricultural regions. This has a negative impact on the productivity of agricultural crops. In this regard, an important task is to identify the most tolerant to changing conditions species and varieties of forage grasses with the most adaptive potential, the cultivation of which will make it possible to compensate for extreme manifestations of climatic changes. Awless rump (Bromus inermis Leyss) is one of the most widespread and long-term forage perennial grasses that grow in almost all areas where grasses are possible. This crop can be used in fodder production for hay and pasture use, as well as hay and bulky canned fodder. However, the forage productivity of awnless rump has increased insignificantly over the past 50 years, which is explained by insufficient selection. Traditionally, the breeding and evaluation of new varieties of rump was previously carried out in its single-species crops. To increase the efficiency of the economic use of herbs, it is necessary to reorient breeding programs to develop new highly productive varieties with increased resistance to a complex of factors of biotic, abiotic and operational stress. Phytocenotic breeding is an important aspect of the biogeocenotic approach to the breeding of awnless rump. Creation of a new starting material of rump, with increased phytocenotic plasticity, will significantly increase the productivity of grass mixtures based on this culture. As a result of selection work, samples with high complementarity were obtained in grass mixtures with alfalfa varia (Martyn) Arcang.)

Responses of Seed Yield Components to the Field Practices for Regulating Seed Yield of Smooth Bromegrass (Bromus inermis Leyss.)

Agronomic practices improve seed yield by regulating seed yield components, and the relationship between seed yield and seed yield components is still unclear in smooth bromegrass (Bromus inermis). To optimize seed production and yield in smooth bromegrass, a five-year field trial was designed with split-split-plot to study the combined effects of row spacing (30, 45, 60, and 75 cm), phosphorus (0, 60, 90, and 120 kg P ha−1) and nitrogen (0 and 100 kg N ha−1) on seed yield and seed yield components including fertile tillers m−2 (FTs), spikelets per fertile tiller (SFT), florets per spikelet (FS), and seeds per spikelet (SS). The results showed that FTs as a key factor had a positive effect to seed yield with the biggest pathway coefficient, while SS had a negative effect. Meanwhile, an interaction effect between FTs and SS was observed. FS and SS were increased with phosphorus application under the condition of sufficient nitrogen. In addition, sufficient precipitation at the non-growing season resulted in more FTs in the next year in rain-fed regions. Therefore, the optimum seed yield of smooth bromegrass can be obtained with row spacing (45 cm), nitrogen (100 kg N ha−1), and phosphorus application (60 kg P ha−1).

Effects of post oak Quercus Stellata and Smooth Brome Bromus Inermis Competition on Water Uptake and Root Partitioning of Eastern Redcedar Juniperus Virginiana

Water availability may alter species competitive interactions, resulting in different outcomes as plants compete for available water. Eastern redcedar Juniperus virginiana (hereafter ERC) will likely continue to encroach into new habitats, which will affect soil and water budgets. We designed a greenhouse experiment to investigate changes in water uptake and rooting depths of two-year old ERC saplings in the presence of an invasive grass (Bromus inermis) and a native tree (Quercus stellata). We measured soil moisture content over two growing seasons. When grown together, ERC took up water from the deeper layers (21–40 cm) whereas B. inermis used water from the top layers of the soil (0–20 cm). Similarly, when ERC grew with Q. stellata, ERC took up water from the deeper layers and Q. stellata used water mostly from the top layers. This root partitioning can allow the co-existence of ERC, grasses, and other trees, which can facilitate ERC encroachment into grasslands and woodlands. However, when the three species grew together, we found root overlap between the ERC and Q. stellata. This overlap can affect ERC establishment and encroachment in habitats where grasses and trees co-occur. A major factor that affected ERC performance was higher mortality in treatments with B. inermis than in the ERC-alone or with Q. stellata. This indicates that competition with grasses is a major factor affecting ERC sapling establishment.

Levels of acid detergent insoluble protein in grasses and feeds made from them

The purpose of this research is to assess the level of thermal damage by determining the content of acid detergent insoluble crude protein (ADICP) in perennial cereal forage grasses Bromus inermis, Festuca pratensis, Phleum, depending on the phase of their vegetation (at the beginning of shooting, during the earing and flowering phases), as well as in silage and haylage prepared from them during the same phases. Samples for analyzes were dried at the temperature of 60-65 °C. Nitrogen of ADICP was determined in the residue of ADF (acid detergent fiber) obtained by filtering a solution of acid detergent through a paper filter. With the growth of grasses, an increase in the content of ADF in them was observed, followed by an increase in ADICP in Phleum and especially in Festuca pratensis which was characterized by higher rates of ADF accumulation. In Bromus inermis, the increase in ADF did not lead to an increase in the concentration of ADICP in the grass due to a decrease of its portion in ADF. The content of ADICP in green grass ranged from 0.85 to 1.58 % in dry matter, ADF ‒ from 27.0 to 45.8 %, no correlation was found between them. Conservation of grasses in all phases of their growth caused an increase in the content of ADF compared to the original grass, but the mass fraction of ADICP in the dry matter of silage and haylage was not higher than in the original grass, due to a lower mass fraction of ADICP in the ADF compared to grasses. In this regard, it is noted that if the technology of harvesting silage and haylage is observed, there is no increase in the level of thermal damage to these feeds. In this regard, it is noted, that when the preparation of silage and haylage is carried out according to the required technology, there is no increase in the level of thermal damage to these feeds. There is close correlation between the percentage of ADICP in CP (crude protein) and the contents of CP. The correlation coefficients were -0.83; -0.88 and -0.92 for grasses, silage and haylage, respectively. The lowest percentage of ADICP in CP was observed in the early phases of grass growth. In this regard, there is a need to harvest them in earlier growth phases, since the content of CP decreases with growth and the proportion of indigestible protein in it increases. If there are organoleptic signs of thermal damage to feeds given in the article, it is recommended to make an amendment to CP content on the basis of the result of the analysis for the content of ADICP.

Spatial structure of Globularia bisnagarica L. (Plantaginaceae, Magnoliopsida) coenopopulations

The paper presents the results of the spatial distribution analysis of 18 Globularia bisnagarica L. coenopopulations in the Saratov, Samara, Ulyanovsk and Orenburg regions and the Republic of Tatarstan. The analysis was carried out with the Spatstat package of the R environment for statistical computing. The research reveals an aggregation tendency for the G. bisnagarica coenopopulations. It is suggested that this tendency may be attributed to the prevalence of seed reproduction and certain peculiarities of dissemination (barochory) in the studied coenopopulations as well as to the confinement of the species to eroded landforms (slopes of watersheds, gullies, runoff hollows, etc.) characterized by high heterogeneity of environmental conditions. It has been established that the majority of G. bisnagarica coenopopulations grow in heavily or moderately sodded habitats. Nevertheless, in the studied communities, G. bisnagarica occurs abundantly and dominates along with Stipa pennata, Bromus inermis, Salvia nutans, Elytrigia repens, Poa compressa, etc. Finally, the spatial structure of G. bisnagarica coenopopulations is impacted by the interspecific competition in calciphilous phytocenoses under the invasion of eurybiontic steppe grasses.