Festuca Rubra Research Articles

Mycorrhizal Maps as a Tool to Explore Colonization Patterns and Fungal Strategies in the Roots of Festuca rubra and Zea mays.

Arbuscular mycorrhizal fungi are symbionts in the roots of plants. Their role is to sustain host development and maintain the nutritional equilibrium in the ecosystems. The colonization process is dependent on several factors like soil ecology, the genetic diversity of the fungi and host, and agronomic practices. Their synchronized action leads to the development of a complex hyphal network and leads to the secondary development of vesicles and arbuscules in the root cells. The aim of this research was to analyze the efficiency of the mycorrhizal patterns (MycoPatt) method for the positioning of fungal structures in the roots of Festuca rubra and Zea mays. Another objective was to explore the fungal colonization strategy as revealed by mycorrhizal maps of each species. The acquisition and assemblage of multiple microscopic images allow mycorrhizal colonization assessment in both corn and red fescue plants to provide information on the realistic position of the developed structures. The observed mycorrhizal patterns highlight the variable efficiency of each plant in terms of developing connections with soil symbiotic fungi, caused by applied treatments and growth stage. Mycorrhizal detailed maps obtained through the MycoPatt method are useful for the early detection of plant efficiency in symbiotic acquisition from the soil.

Soil Pollution and Plant Efficiency Indices for Phytoremediation of Heavy Metal(loid)s: Two-Decade Study (2002–2021)

This paper reviews research on phytoremediation (2002–2021), particularly for the estimation of plant efficiency and soil pollution indices, examining the extraction of metals from soil and plants growing under both artificial (spiked with specific metal) and natural conditions. From the analysis of >200 published experimental results, it was found that contamination factor and geo-accumulation index as well as translocation and bioconcentration factors are the most important soil pollution and plant efficiency metrices, respectively, which are gaining importance to assess the level of metal pollution and its transfer from soil to plant to find a better metal clean-up strategy for phytoremediation. To access the metal concentration, it was found that the most widely accepted extractants to dissolve and extract the metals from the soil and plant were HNO3 and HClO4 (mainly in 5:1; v/v or 4:1; v/v), which are used both in natural and artificial metal contamination studies. Moreover, plants such as Pteris vittata, Monochoria korsakowi, Lolium perenne, Festuca rubra, Poa pratensis, Ricinus communis, and Siegesbeckia orientalis can act as hyperaccumulators under both natural and artificial experiments and can be directly implemented into the fields without checking their further efficiency in phytoremediation.

Peyzaj uygulamalarında kullanılan bazı çim çeşitlerinde farklı tuz yoğunluklarının çimlenme üzerine etkileri

This study was conducted in laboratory conditions to determine the response of some cool season turf grass species (Lolium perenne Caddieshack, Lolium multiflorum Jivet, Poa pratensis Evora, Festuca rubra Rassinante, Festuca arundinacea Starlet, Festuca ovina Ridu) to different salt doses during the germination period. In the study, 8 different NaCl doses, 0, 30, 60, 90, 120, 150, 180, 210 mM, were applied, germination rate (%), germination time (%), plumula length (cm), radicula length (cm) and vigor index values were examined. Because of the research, it was observed that the germination rate, plumula and radicula lengths increased at 30 mM concentrations and in general, significant damage occurred after the dose of 90 mM. Lolium perenne Caddieshack and Lolium multiflorum Jivet species showed the highest mean values and were less affected by increasing salt doses in all properties examined.

Self-renewing legume-grass stands on drained lands of the Central District of the Non-Chernozem Zone

Studies to study the adaptive responses of self-renewing legume-grass stands were carried out in 2018-2021 at the agroecological station VNIIMZ (Tver region). The object of research was pasture herbage with the participation of rhizomatous grasses: giant bentgrass variety VIK-2, meadow bluegrass variety Balin and red fescue variety Maxima, their productivity was studied under conditions of uneven precipitation. It was revealed that the most adaptive conditions for the growth, development and formation of the productivity of the studied herbs were formed in the first and second years of use with a hydrothermal coefficient of 1.16 and 1.33, respectively. A high adaptive potential was established in grass stands with the participation of red fescue, which were the most resistant to the conservation of sown species and the introduction of forbs. It is shown that grass stands with bentgrass showed the most adaptive reactions to mineral fertilization. The increase in their yield was 2.3-6.5 t/ha of green mass, which is 1.3-2.3 t/ha more than the increase in other grass stands. The advantage in terms of productivity, both in terms of the background of fertilizers and the natural background, was in grass stands with red fescue. Meadow bluegrass mixtures had the lowest collection of pasture fodder - 19.9-22.5 t/ha of green mass. The resulting feed with a content of 18.3-22.1 % of crude protein, 23.5-28.1 % of crude fiber and with a dry matter concentration of 9.91-10.9 MJ of metabolizable energy per 1 kg is of high quality. It has been established that for the sustainable development of grassland farming in a changing climate on drained lands, it is necessary to use legume-grass stands with the participation of rhizomatous grasses, which provide a high opportunity for a more complete use of habitat resources and resistance to agro-climatic stresses of the growing season, form productivity at level 3.94-5.02 t/ha of dry matter and 3.2-4.2 thousand fodder units in a natural place of growth and 4.7-6.1 t / ha of dry weight and 3.9-5.0 thousand fodder units on the background of fertilizers.

Evaluating cool‐season grass species as potential perennial groundcover for maize production

AbstractRemoval of crop residue poses negative consequences for soil health, nutrient leaching, and runoff. Perennial groundcovers (PGC) provide a method of maintaining soil health while allowing the sustainable intensification of maize (Zea mays L.) systems for biofuel production by providing groundcover for several years. However, previous studies have only evaluated a few varieties of PGC. We conducted a 2‐yr study to evaluate the compatibility of cool‐season turfgrass PGCs under maize. Maize was interplanted into 20 accessions of Kentucky bluegrass (Poa pratensis L.), Sandberg bluegrass (Poa secunda J. Presl), and red fescue (Festuca rubra L.) in a randomized complete block design in Boone, IA. Data on maize grain yield, maize grain quality, and ground coverage of PGC were collected. There were no differences in maize grain yield across species in 2017. In 2018, maize grain yield under red fescue was 1.0, 1.8, and 2.1 Mg ha–1 less than Kentucky bluegrass, Sandberg bluegrass, or the no‐grass control, respectively. Maize under red fescue produced 2.3, 4.8, and 3.9 g kg–1 more protein than Kentucky bluegrass, Sandberg bluegrass, and the no‐grass control, but produced 878 L ha–1 and 758 L ha–1 less ethanol than the no‐grass control and Sandberg bluegrass, respectively. In both years, Kentucky bluegrass groundcover declined approximately 22%, while Sandberg bluegrass groundcover remained below 10%. Red fescue maintained groundcover over 22% in 2017 and 34% in 2018. These results indicate that maize under Kentucky bluegrass and Sandberg bluegrass can perform similarly to conventional maize.

АНАЛИЗ СОСТОЯНИЯ ТРАВЯНИСТОЙ РАСТИТЕЛЬНОСТИ ПРИВОКЗАЛЬНЫХ ТЕРРИТОРИЙ ГОРОДОВ КОЛЬСКОЙ СУБАРКТИКИ

The study of species diversity and the state of grassy ground cover in the station territories of 5 cities of the Murmansk region (Murmansk, Apatity, Olenegorsk, Polyarnye Zori, Kandalaksha) have been carried out. It has shown that the floristic composition of herbaceous plants was monot-onous, poor and was represented by species characterized by a wide range of ecological tolerance. Common species found in all cities were Taraxacum officinale Taraxacum officinale Wigg. s. l., Trifolium repens L., Achillea millefolium L., Equisetum arvense L., E. Palustre L., Rumex confer-tus L. and cereals (Dactylis glomerata L., Deschampsia cespitosa (L)., Festuca rubra L., Festuca pratensis Huds., Poa annua L., Poa pratensis L., Phleum pratense L.). The greatest species diver-sity was found in Apatity and Polyarnye Zori. The plant state was satisfactory, no pests and dis-eases were found, no damage in the form of necrotic spots was noted. Of the ornamental flower plants, 20 species were found, Aconite firmum Reichenb., Primula elatior (L.) Hill var. tatrica Domin, Primula amoena Bieb. were widely distributed. The analysis of the projective cover of herbaceous vegetation showed the presence of a different number of areas with disturbed ground cover. The highest percentage of wastelands (56%, due to trampling and other types of anthropo-genic impact) was found in Olenegorsk, the least – in Kandalaksha (84%).

Phytoremediation potential of flowering plants in relation to copper under the conditions of a model laboratory experiment

This paper describes the results of studying the phytoremediation potential of flowering plants in relation to copper ions in laboratory experiment conditions. The test crops were tansy-leaved phacelia, white mustard, small-flowered marigolds and a mixture of grasses consisting of red fescue, pasture ryegrass and meadow bluegrass in a ratio of 40%, 50%, 10% respectively. Under experimental conditions copper ions in concentrations of 2 and 10 MPC were introduced into the soil selected from the territory of agricultural lands (leached medium-sized heavy loamy chernozem with a high content of humus, mobile phosphorus and exchangeable potassium and a low content of nitrate nitrogen, gross and mobile forms of copper). It has been found that all the selected crops accumulated copper ions from the soil to varying degrees, which makes them suitable for phytoremediation of agricultural lands planned for organic farming. The ability to accumulate copper ions increases in a row: white mustard small-flowered marigolds tansy-leaved phacelia a mixture of grasses. The maximum effect of phytoremediation of the soil in relation to copper ions has been revealed in the variant with a cereal mixture: the content of copper ions in the soil decreases by 38,8% when applying 2 MPC, by 47,8% when applying 10 MPC.

A Diaporthe Fungal Endophyte From a Wild Grass Improves Growth and Salinity Tolerance of Tritordeum and Perennial Ryegrass.

Some microbiome components can provide functions that extend the capabilities of plants, increasing the environmental adaptability and performance of holobionts. Festuca rubra subsp. pruinosa is a perennial grass adapted to rocky sea cliffs, where soil and nutrients are very limited, and exposure to salinity is continuous. This study aimed to investigate if a Diaporthe fungal endophyte belonging to the core microbiome of Festuca rubra roots could improve the performance of two agricultural grasses. In a greenhouse experiment, plants of tritordeum (Triticum durum x Hordeum chilense) and perennial ryegrass (Lolium perenne) were inoculated with Diaporthe strain EB4 and subjected to two salinity conditions (0 and 200 mM NaCl). Biomass production, mineral elements, proline, hormone profiles, antioxidant capacity, and total phenolic compounds were examined in plants, and fungal functions potentially related to the promotion of plant growth were determined. The inoculation with Diaporthe promoted plant growth of both grasses, increasing leaf biomass (84% in tritordeum and 29% in perennial ryegrass), root biomass, nutrient content (N, Ca, Mg, and Fe), and the production of indole 3-acetic acid, regardless of the salinity treatment. Improved growth and nutrient uptake might occur because Diaporthe produces several extracellular enzymes capable of recycling organic nutrient pools. In addition, the fungus produced indole 3-acetic acid in vitro and modulated the production of this phytohormone in the plant. Under salinity, the activity of Diaporthe ameliorated the stress, increasing proline, nutrient uptake in roots, gibberellins, and indole 3-acetic acid, which in turn results into improved growth. Thus, this fungus can transfer to alternative hosts some advantages useful at its original habitat.

Calorific Value of Festuca rubra Biomass in the Phytostabilization of Soil Contaminated with Nickel, Cobalt and Cadmium Which Disrupt the Microbiological and Biochemical Properties of Soil

The choice of optimal plant species for phytoremediation and organic fertilization plays an important role in stabilizing the functions of soils contaminated with heavy metals. The influence of nickel, cobalt and cadmium on the biomass yield and calorific value of Festuca rubra, heavy metal concentrations in soil and plants and the microbiological, biochemical and physicochemical proprieties of soil were analyzed in a pot experiment. The tolerance index (TI) describing Festuca rubra’s ability to tolerate heavy metals, as well as the translocation (TF), accumulation (AF) and bioaccumulation (BF) factors of heavy metals in Festuca rubra were calculated. The experiment was conducted in two series: In soil fertilized and not fertilized with compost. Nickel and cobalt significantly inhibited the growth and development of Festuca rubra. The experiment demonstrated that this plant species can be grown on soil contaminated with heavy metals. Festuca rubra contained on average 46.05% C, 34.59% O, 5.91% H, 3.49% N, 0.19% S and 9.76% ash. Festuca rubra has a stable calorific value which is not affected by heavy metals; therefore, biomass harvested from heavy metal-polluted soil can be used for energy generation. The calorific value of Festuca rubra ranged from 15.924 to 16.790 MJ kg−1 plant d.m., and the heat of combustion from 17.696 to 18.576 MJ kg−1. It has a stable calorific value which is not affected by heavy metals, therefore biomass harvested from heavy metal-polluted soil can be used for energy generation. Festuca rubra is particularly useful for the phytostabilization of soil contaminated with cadmium and cobalt. Compost minimizes the adverse effects of heavy metal pollution on the microbiological, biochemical and physicochemical properties of soil.

Изменение общего проективного покрытия фитоценоза долголетнего

On the basis of the experiment, founded in 1946 with a seven-component, traditional at that time grass mixture, consisting of tall grass, low-grass and legumes, the effect of fertilizers on the productivity and botanical composition of the herbage was studied. In the first years of use, the herbage completely corresponded to the sown species. With long-term use, depending on fertilizers and meteorological conditions, the composition of the herbage has changed. In place of short-term types of cereals, self-renewing low-grass ones have been penetrate — red fescue, thin bent grass. Against the background of increased doses of fertilizers, the participation of tall grass species increased — meadow foxtail and awnless brome. Along with the determination of the botanical composition of the phytocenosis of long-term haymaking, from 1999 to 2002, a geobotanical assessment of the abundance of plants was carried out, which made it possible to more fully study the alternation over time of some types of phytocenosis with others and determine their participation. The abundance of plants was determined by their projective cover (PC) in three groups: grasses, legumes, motley grass, and it is represented by the total projective cover (TPC).Studies have shown the dynamics of changes in the types of phytocenosis depending on fertilizers and meteorological conditions of the growing season. In moisture-rich years, the total projective coverage reaches 80–95%, in dry years it decreases to 70–84%. The lack of moisture most strongly affects the creeping clover, the abundance of which has decreased to 0.2–0.1% in dry years.

Analytical purity of old New Zealand forage seed samples and detection of fungal and insect contaminants including ryegrass endophyte and Argentine stem weevil

ABSTRACT Pasture seed samples that were harvested around 1917 in New Zealand were analysed for purity, Epichloë endophyte and insects. Samples consisted of 13 packets of seed varying from 2.2 to 15.0 g and comprising, Chewings fescue (Festuca rubra L.), cocksfoot (Dactylis glomerata L.), oat (Avena sativa L.), perennial ryegrass (Lolium perenne L.) and red clover (Trifolium pratense L.). These findings show that in the period prior to modern seed testing laboratories only four of the 13 samples (31%) could possibly have met today’s seed certification standards as it relates to seed purity. When compared with published purities and weed content of seed of the era these samples appear typical. Endophyte testing on the four ryegrass seed samples and the ryegrass contaminants found in the Chewings fescue and cocksfoot samples showed sample-to-sample variation in endophyte infection from nil to 91%. One cocksfoot sample, most likely harvested from the Banks Peninsula, contained an Argentine stem weevil. Subsequent checking of entomological collection records also revealed specimens being present in the Wellington region from 1916. Together these occurrences precede the earliest published record for the species in New Zealand by ten years and suggest that it may have been widespread at that time.

Management, harvest, and storage characteristics of low‐input cool‐season turfgrass sod mixtures

AbstractThe lack of turfgrass diversity in cool‐season sod production is related to information inefficiencies, such as the lack of agronomic information available on improved, low‐input species, such as fine fescues (Festuca spp.). Collaborative research between Purdue University and University of Minnesota investigated the influence of cool‐season turfgrass species mixtures on the harvest (production and strength) and storage limitations of sod. Field experiments were established in 2018 in West Lafayette, IN, and in 2019 in St. Paul, MN. Treatments included 12 turfgrass species mixtures that consisted of the following five species: strong creeping red fescue (Festuca rubra L. ssp. rubra Gaudin), Chewings fescue (F. rubra ssp. commutata Gaudin), hard fescue (F. brevipila Tracey), tall fescue (F. arundinacea Schreb.), and Kentucky bluegrass (Poa pratensis L.). Data on turf cover, vertical growth rate, sod tensile strength, sod handling, and shelf‐life storage and transplant success were collected at multiple harvest timings from 10 to 24 mo after planting. The majority of the sod mixtures, especially those containing ≥33% strong creeping red fescue, produced high quality sod similar to the standard comparison of 100% Kentucky bluegrass sod and transplant success was not severely affected when stored for 24–72 h immediately following a spring or autumn harvest. Sod mixtures containing tall fescue, including “rhizomatous tall fescue,” consistently resulted in the lowest sod strength and handling. Overall, sod producers growing fine fescue sod may be able to not only reduce management inputs, but also yield good sod strength with low‐input sod mixtures.

Microbial community from species rich meadow supports plant specialists during meadow restoration

Abstract Soil properties and soil microbial communities can greatly affect plant communities, especially in disturbed ecosystems. However, their relative contribution to the final effect on plants has rarely been assessed. We manipulated the soil microbial community in microcosms by inoculating sterilized soils originating from preserved species‐rich meadow and a restored meadow with a high and low diversity of microbial inoculum (manipulated by the dilution of microbial community extract) from those soils in full factorial manner, yielding eight treatments (2 soil origins × 2 inoculum sources × 2 levels of inoculum diversity). In general, the biomass of plant meadow specialists (Filipendula vulgaris, Phleum phleoides, and Prunella grandiflora) was greater with the preserved meadow inoculum than with the restored meadow inoculum but tended to be greater in the restored meadow soil than in the preserved meadow soil. Two meadow generalists (Festuca rubra and Centaurea jacea) were not significantly affected by soil origin, inoculum source, or inoculum diversity, but the third generalist Plantago media produced greater biomass in the preserved meadow soil than in the restored meadow soil. Total above‐ground biomass was not affected by the treatments, but total below‐ground biomass was greater with microbial inoculum from the preserved meadow than from the restored meadow, and this increase was greater in the restored meadow soil than in the preserved meadow soil. Our results indicate strong responses of the preserved meadow specialists to the soil microbial community, which may explain why they are rare in the meadows that were restored following agricultural use. Read the free Plain Language Summary for this article on the Journal blog.

Effect of soil contamination with polycyclic aromatic hydrocarbons from drilling waste on germination and growth of lawn grasses

In many studies, grasses were used to increase the biodegradation of polycyclic aromatic hydrocarbons (PAHs) in soil because they are the most common plant species on the ground level and are quite resistant to contamination with these compounds. One of the main failures in PAH remediation in soil using plant species was the negative impact on germination and seedling growth. The objective of this study was to evaluate grass seed germination and seedling growth affected by drill cuttings to determine the resistance of selected grass species to the impact of PAH and their suitability for an effective phytoremediation of soils contaminated with waste that contain compounds from this group. In the study four grass species: tall fescue (Festuca arundinacea), red fescue (Festuca rubra), perennial ryegrass (Lolium perenne) and common meadow-grass (Poa pratensis). The germination energy of all species decreased as the amount of drill cuttings increased. Among the species studied, the highest germination energy and capacity were found in Lolium perenne (54.1 and 73.2 respectively), and the lowest – in Poa pratensis (16.7 and 23.3 respectively). With an increasing amount of drill cuttings, the root and seedling height were decreased. Festuca arundinacea seedlings were distinctly the highest and had the longest roots (96.7 and 52.7, respectively), while Poa pratensis seedlings showed the significantly slowest seedling and root elongation rate (30.4 and 12.4, respectively). However, the strongest decrease in seedling height and root length compared to the control was observed in Festuca rubra. Based on IC50, the greatest tolerance to the addition of drilling waste to the substrate was found for Festuca arundinacea and Festuca rubra. The conducted investigation indicates that Festuca arundinacea and Lolium perenne are grass species that are least sensitive to drilling waste in the substrate because no significant differences were found in root length and seedling height between the control soil and the soil where a PAH dose of 5% and 10% was applied.

Species, clover‐inclusion, and nitrogen fertilizer effects on sod tensile strength of fine fescue taxa

AbstractIncreasing fertilization rates from 0 to 49 kg N ha−1 during establishment of fine fescue (Festuca spp.) taxa can promote faster grow‐in; however, the influence on sod production (tensile strength and handling) is unknown. More information is needed on both fine fescue taxa and the effects N fertilizer or inclusion of clover (Trifolium spp.) during establishment on sod strength. Field experiments were repeated in 2019–2020 and 2020–2021 in Indiana to quantify differences among four fine fescue taxa and N fertilizer or clover‐inclusion effects on sod production. Six N fertilizer levels ranged from 0 to 122.5 kg N ha−1 during the first 8 weeks after planting (WAP), and two treatments consisted of inclusion of either annual or perennial clover + 0 kg N ha−1 at seeding. Sod harvest variables were measured at harvests from 9 to 12 months after planting (MAP). Results indicate fine fescue growth habit characteristics play a large role in sod strength differences. The highest to lowest sod strength and handling was ranked as follows: strong creeping red fescue (F. rubra L. ssp. rubra Gaudin) > slender creeping red fescue [F. rubra ssp. littoralis (G. Mey.) Auquier] ≥ Chewings fescue (F. rubra ssp. commutata Gaudin) ≥ hard fescue (F. brevipila Tracey). A minimal effect on sod strength and handling at multiple sod harvests (9–12 MAP) was observed from increasing N fertilizer levels during first 8 wk of establishment or from clover inclusion.

Effect of Rosa gorenkensis Besser aqueous extracts on germination and early growth of native plant species

In Europe, Rosa gorenkensis Besser is considered an invasive species. However, its negative impact on native flora components or other habitat components has not been described so far. In the experiment, the germination reactions of mono- and dicotyledonous plant seeds to the aqueous extracts of R. gorenkensis were investigated to determine the allelopathic potential of this plant. Seeds of common plants – wild-growing Festuca rubra L. and cultivated Raphanus sativus L. var. radicula Pers. cv. ‘Rowa’ were treated with aqueous extracts from the roots, stalks, leaves, and flowers of rosa at concentrations of 1%, 2.5%, and 5%. Along with the increase in the concentration of allelochemical compounds in the extracts, the negative influence of the extracts on the germination capacity of the tested seeds species was found. Regardless of the type of extract, inhibition of the growth of the underground and aboveground parts of seedlings was also observed. Changes in biomass and water content, depending on the concentration and type of the extract, were found. The greatest differences in the electrolytes leakage in seedlings watered with 5% extracts were revealed. The study showed that the aqueous extracts of leaves and flowers of this species had the greatest allelopathic potential.

Deciphering the Colonization Strategies in Roots of Long-Term Fertilized Festuca rubra

Festuca rubra is one of the dominant species in mountain high natural values grasslands. Most herbaceous plants are involved in a symbiotic partnership with arbuscular mycorrhizas for maintaining their abundance and cover. This research was conducted to explore the changes in mycorrhizal colonization patterns and structure development due to the long-term application of treatments. A large database of microscopic images was deeply analyzed with the MycoPatt tool, for the extraction of clear mycorrhizal maps that present particular colonization strategies. The overall colonization frequency and intensity varied largely between treatments, with a maximum in organic conditions. The presence of both arbuscules and vesicles in the same root area indicate a continuous alternance of fungal strategy, from storage to enhanced transfer of nutrients. A low-mineral organic treatment permits a clear separation of colonization strategy in different parts of roots. The nutrient availability due to mineral treatment induced a restriction in mycorrhizal development, which was maintained colonization by a resistance conditions strategy. The use of mycorrhizal maps permits a deep scanning of colonized roots, identifying the real positioning of fungal structures, along with their developmental potential and the assessment of the colonization strategy.

Photothermal controls of vegetative dormancy in Poa secunda

AbstractBackgroundSummer vegetative dormancy is a desirable trait in cool‐season grasses when they are interplanted with annual crops. Sandberg bluegrass (Poa secunda J. Presl.) shows summer dormancy, but the environmental cues that control dormancy remain unknown.MethodsA controlled environment study using temperature and day length combinations of 32.2°C/15 h, 26.6°C/14 h, 21.1°C/13 h, and 15.5°C/12 h was conducted with P. secunda accessions PI232347, PI639272, and PI232348, and ‘Audubon’ red fescue as a nondormant control to determine the optimum treatment for dormancy induction. A second study using treatments of 26.6°C/14 h, 21.1°C/13 h, and 15.5°C/12 h was conducted to determine the thresholds for dormancy release. A third study used a factorial experiment with two temperatures (32.2°C and 15.5°C) and two day lengths (15 and 12 h) to differentiate between temperature and day length effects on dormancy induction.ResultsOf the four temperature and day length combinations, all except for 15.5°C/12 h resulted in dormancy by the end of 6 weeks, with 32.2°C/15 h inducing dormancy in only 17 days. Of the three treatments for dormancy release, 15.5°C/12 h broke dormancy the fastest in all accessions and released the most number of plants from dormancy. Considerable variation existed between accessions for the speed of dormancy release in the 21.1°C/13 h and 26.6°C/14 h treatments. The third study showed that temperature is the primary inducer for summer dormancy, while longer day length may promote dormancy under inductive temperatures.ConclusionsThis study identified the optimum photothermal for induction and release of summer dormancy in P. secunda, which will help future studies in elucidating the mechanism of summer dormancy.

Средообразующая роль многолетних трав и эффективность использования микробиологических препаратов в качестве деструкторов их дернины

The most affordable and environmentally friendly way to improve the condition of soils is the biologization of agriculture by increasing the share of perennial grasses in crop rotations. Among legumes, black medic (Medicago lupulina L.) is considered one of the best crops for use as a green fertilizer, which, thanks to the accumulation of biological nitrogen, ensures the preservation and increase of humus content in the soil. During the long-term cultivation of perennial bluegrass grasses, sod is formed in one place in the upper layer of the soil. The sod of red fescue (Festuca rubra L.) is characterized by the highest degree of adhesion compared to other types of grasses and has one of the highest rates of tearing force. During mechanized cutting of the field, after plowing the grass stands of red fescue, a large number of sod lumps remain on the surface, which prevents high-quality soil preparation and sowing operations of subsequent crops in the crop rotation. The average volume of sod lumps after pre-sowing preparation of the soil in the spring for the next year is 1194 cm3. The duration of complete decomposition of red fescue sod in sod-podzolic soils reaches four years. One of the ways to accelerate the decomposition and increase the coefficient of humification of sod, which has become widespread in recent years in agricultural practice, is post-harvest inoculation of stubble with microbiological preparations-destructors. The introduction of preparations-destructors ensures the introduction of active strains of microorganisms into the turf. As a result of the use of the drug Biocomplex-BTU, the biological activity of the microflora for the decomposition of organic matter increases by 3.3-5.1 times. The next year after using the destructor, the remains of the red fescue sod when cutting the soil are structured to small lumps and do not interfere with the operation of the sowing units.

Nitrogen fertilizer and clover inclusion effects on the establishment of fine fescue taxa

AbstractLittle information exists on establishment vigor differences among fine fescue taxa (Festuca L. spp.) and on the effects N fertilizer levels or clover (Trifolium L. spp.)‐inclusion during establishment. Five replicated field experiments in Indiana, Minnesota, and Oregon were conducted from 2019 to 2021. Data collection continued for 9 mo after planting to investigate differences among four fine fescue taxa and determine optimal N fertility or clover‐inclusion programs for the establishment of fine fescue taxa. Six N fertilizer levels ranged from 0 to 122.5 kg N ha−1 during the 8 wk after planting, and two treatments included clover‐inclusion + 0 kg N ha−1 at seeding. The three taxa of the Festuca rubra complex—strong creeping red fescue (F. rubra L. ssp. rubra Gaudin), slender creeping red fescue [F. rubra ssp. littoralis (G. Mey.) Auquier], and Chewings fescue (F. rubra ssp. commutata Gaudin)—were similar to one another and required the shortest amount of time until 90% establishment (i.e., faster establishment) compared with hard fescue (Festuca brevipila Tracey). Providing 24.5 kg N ha−1 at seeding hastened establishment of all fine fescues compared with no N fertilizer (0 kg N ha−1). Applying 49 kg N ha−1 at establishment provided faster establishment than the 24.5 kg N ha−1 treatment; however, treatments receiving 73.5–122.5 kg N ha−1 during the first 8 wk after planting provided a similar rate of establishment as 49 kg N ha−1. Inclusion of clover with fine fescue resulted in slower establishment than fertilizer levels of ≥24.5 kg N ha−1.