Search

Context: Rock phosphate reserves are decreasing, and requirements to mitigate environmental impacts of farming soils with excess phosphorus (P) are increasing. Aims: White clover is an allotetraploid hybrid between Trifolium pallescens and T. occidentale. Understanding the P response characteristics of these progenitor species will allow selection of germplasm for development of synthetic white clovers with improved phosphorus-use efficiency (PUE). Methods: Shoot and root weights and P nutrition characteristics were compared for three Trifolium pallescens , six T. occidentale accessions, and a white clover cultivar in a glasshouse experiment using a low P soil amended with five rates of P. Key results: White clover had the highest and most P responsive shoot and root dry weights (DW), and T. pallescens was least responsive to P. In the highest P treatment, T. pallescens had the highest shoot and root %P and the lowest shoot DW:total plant P ratio. There was significant variation among progenitor accessions. Spanish accessions of T. occidentale had comparable shoot DW to white clover and higher PUE. Traits of T. pallescens indicated strong adaptation to low P but low productivity, while traits of T. occidentale were more aligned with the white clover cultivar. Conclusions: The substantial variation in P nutrition characteristics within the progenitor species of white clover could be exploited in breeding programs. Implications: Comparing the P responses of a wider range of progenitor accessions could inform breeding to improve white clover's low soil P tolerance through development of synthetic white clovers. There are strong ethical, environmental, and economic reasons for increasing the phosphate-use efficiency of white clover, a natural hybrid between Trifolium pallescens and T. occidentale. White clover has poor phosphate-use efficiency, but we found significant variation for relevant characteristics between the two parental species and among populations within each species. Developing cultivars using superior populations of the parental species could be a very effective breeding strategy for increasing phosphate-use efficiency of white clover. [ABSTRACT FROM AUTHOR]

Herbicide restrictions require alternative strategies for turfgrass weed control. This growth chamber study investigated the interference of 27 Festuca cultivars selected from five Festuca species using white clover (Trifolium repens L.), lawn daisy (Bellis perennis L.), and yarrow (Achillea millefolium L.) as indicator species. At 13 days after sowing (DAS), 20 weed seeds were placed in between 60 grass seeds. Lawn daisy was highly sensitive to the presence of all grasses, and results are not presented. Festuca species or individual cultivars did not affect the germination percentage and mean germination period of white clover and yarrow. The presence of tall fescue [Schedonorus arundinaceus (Schreb.) Dumort., nom. cons.]) species reduced white clover root length by 71.6% and slender creeping red fescue [Festuca rubra L. ssp. littoralis (G.Mey.) Auquier] by 44.5% at 30 DAS. Within cultivars, reductions of white clover roots ranged from 81.7% (Regenerate) to 24.8% (Cathrine). Root length for yarrow was reduced by an average of 75% with no difference among Festuca species. Cultivar effects ranged from 91.8% for Barcesar to 62.9% for Samanta. For both white clover and yarrow, negative correlations were determined between Festuca biomass and the root length of both weeds: −0.241*** (white clover) and yarrow −0.168* (yarrow). Such a relationship suggests that part of the inhibiting effect can be directly attributed to Festuca biomass. We conclude that differences in interference potential between cultivars within species are as important as differences between species. White clover appeared to be the most discriminative species for growth interference studies with Festuca. Core Ideas: Pesticide restrictions require alternative strategies for turfgrass weed control.Daisy (Bellis perennis L.) was highly sensitive to the presence of 27 cultivars from five Festuca species.Festuca cultivars did not affect the germination percentage and mean germination period of clover and yarrow.Root length for yarrow was reduced by an average of 75% with no difference between Festuca species.Root length of white clover was reduced in the presence of Festuca cultivars. [ABSTRACT FROM AUTHOR]

Perennial cool-season grasses are the foundation of horse pastures in the North Central U.S. A majority of U.S. horses graze pastures as a way to encourage exercise and socialization, and to reduce feeding costs. However, other forages must be evaluated to help extend the grazing season and respond to emerging issues (e.g., floods and winter kill). This abstract summarizes the results of six individual grazing trials that aimed to evaluate forage yield, horse preference, forage nutritive value, and horse health parameters of perennial cool season grasses and alternative forages. Over 10 yr, multiple adult horses in good health grazed monocultures of perennial cool season grasses, annual cool season grasses, legumes, annual warm season grasses, and cover crops in replicated small plots designed in a randomized complete block. Yield was mechanically harvested, samples for forage nutritive value were hand harvested, and preference was visually assessed. Horses were allowed to rotationally graze forages using best management practices throughout multiple Minnesota growing seasons (May through October). Blood glucose and insulin concentrations were collected to determine the impact of certain forage species on horse health parameters. Data were analyzed using various procedures in SAS with P values ≤ 0.05. Forage yields varied greatly between forage types (P ≤ 0.05) and ranged from 13 to 2 Mgּ ha1 . Many forages that were higher yielding, were among the least preferred by horses, including orchardgrass, oat, alfalfa, sudangrass, radish, and turnip. The most preferred forages included Kentucky bluegrass, timothy, meadow fescue, annual ryegrass, winter wheat, red clover, white clover, teff, and berseem clover (P ≤ 0.05). Almost all forages had greater forage nutritive values that met or exceeded the nutritional needs of horses in maintenance. Many warm season grasses had inverted calcium to phosphorus ratios and increased nitrate-nitrogen content. While no consistent relationship was found, horse preference tended to be positively associated with crude protein and nonstructural carbohydrates. When evaluating health parameters, horses grazing teff, an annual warm season grass, had reduced average glucose, average insulin, and peak insulin compared with horses grazing perennial cool season grasses in the late fall (P ≤ 0.05). Collectively, these results suggest that strategic use of pasture forages can be used to help manage common horse health concerns (e.g., obesity and Equine Metabolic Syndrome). While perennial cool-season grasses will remain the foundation of horse pastures in the North Central U.S., this research identified other suitable forage alternatives. Placing a priority on the balance of forage yield and horse preference, annual ryegrass, alfalfa, teff, and berseem clover can be used as horse pasture forage alternatives to extend the grazing season, maximize yield, increase pasture nutritive value, help manage common horse health concerns, and when responding to emerging issues. [ABSTRACT FROM AUTHOR]

Rhizobial associations with leguminous plants are some of the most important symbioses on Earth, and they have economic relevance in agriculture. Because their interactions are positive and have advantages for both partners, nitrogen-fixing rhizobia also demand significant carbohydrate allocation in exchange for key nutrients, and this demand is reflected in the anatomy of roots. In the current scenario of climate change, rhizobia–legume interactions can be affected, and plants may need to compensate for carbon loss when light availability is not correct. Under such conditions, roots can modify their anatomy to accommodate symbionts' needs, and the outcome of an interaction can switch from mutualism to parasitism, resulting in changes in root allocation. We experimented with two legume species originating from well-irradiated environments (Coronilla juncea L. and Ornithopus compressus L.) and two species from shaded environments (Trifolium repens L. and Vicia sativa L.). We applied high radiation, intermediate radiation, and low radiation to two treatments of microbial inoculation (inoculation and control). After an incubation period of 105 days, we quantified the root area, size, and complexity, as well as the nodule production and mass, plant relative growth, and below-ground allocation. For plants originating in shaded environments, nodulation, root complexity, and below-ground allocation were enhanced in inoculated plants when they were transferred to conditions of high irradiance. Strikingly, plants from environments exposed to high light radiation were less plastic when exposed to changing light availability, and the symbionts were less beneficial than expected in stress-free environments. Our study proved that the stress imposed on plants due to high irradiance is overcome when plants are inoculated, and the positive effect is more evident in plants that are usually grown in shaded environments (e.g., Trifolium repens and Vicia sativa). [ABSTRACT FROM AUTHOR]

White clover (Trifolium repens L.; Fabaceae) is an important forage and cover crop in agricultural pastures around the world and is increasingly used in evolutionary ecology and genetics to understand the genetic basis of adaptation. Historically, improvements in white clover breeding practices and assessments of genetic variation in nature have been hampered by a lack of high-quality genomic resources for this species, owing in part to its high heterozygosity and allotetraploid hybrid origin. Here, we use PacBio HiFi and chromosome conformation capture (Omni-C) technologies to generate a chromosome-level, haplotype-resolved genome assembly for white clover totaling 998 Mbp (scaffold N50 = 59.3 Mbp) and 1 Gbp (scaffold N50 = 58.6 Mbp) for haplotypes 1 and 2, respectively, with each haplotype arranged into 16 chromosomes (8 per subgenome). We additionally provide a functionally annotated haploid mapping assembly (968 Mbp, scaffold N50 = 59.9 Mbp), which drastically improves on the existing reference assembly in both contiguity and assembly accuracy. We annotated 78,174 protein-coding genes, resulting in protein BUSCO completeness scores of 99.6% and 99.3% against the embryophyta_odb10 and fabales_odb10 lineage datasets, respectively. [ABSTRACT FROM AUTHOR]

BACKGROUND: Beef from pasture‐fed animals is viewed as a healthier and more welfare‐friendly alternative to concentrate‐fed beef. Botanically‐diverse pastures consisting of numerous plant species may alter the fatty acid (FA) profile and the tocopherol content of beef, as well as the oxidative stability of the meat. In the present study, steers were assigned to one of three botanically‐diverse diets: perennial ryegrass (PRG), perennial ryegrass + white clover (PRG + WC) or multi‐species (MS), all with a finishing diet of the respective botanically‐diverse silages plus a cereal‐based concentrate, consistent with production systems in Ireland. The FA profile, tocopherol content, oxidative stability and colour of meat during storage were measured. RESULTS: Compared to the other diets, the MS diet resulted in higher proportions of linolenic acid (C18:3n‐3c), linoleic acid (C18:2n‐6c) and total polyunsaturated fatty acids (PUFA), with higher PUFA:saturated fatty acid and n‐6:n‐3 ratios in the meat. α‐Tocopherol concentrations were lowest in the meat of animals from the MS diet. In uncooked meat, lipid oxidation and colour values were affected by storage time across all diets, whereas the MS diet led to higher hue values only on day 14 of storage. When cooked, meat from animals on PRG + WC and MS diets had higher lipid oxidation on days 1 and 2 of storage than meat from animals on the PRG diet. CONCLUSION: Feeding steers on a botanically‐diverse diet consisting of six plant species can improve the n‐3 FA and PUFA concentration of beef, affecting the susceptibility of cooked, but not uncooked, beef to oxidation. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

A high-quality feed base is a must to ensure the growing of numerous animals via selecting promising high-yielding crops that can provide livestock with feeds at the entire production stage. This study purposed to develop new technologies for reinstating a balanced use of pastures in Kazakhstan's steppe and forest-steppe zones. Several investigations succeeded in 2019-2022 at the Service-ZHARS Limited Liability Partnership (LLP) production fields of District Kyzylzhar, North Kazakhstan. Five chosen pasture combinations created multifactor pasture lands, as follows: common alfalfa + Festulolium; awnless brome + yellow sweet clover; common alfalfa + pasture ryegrass + Festulolium; white sweet clover + awnless brome + Timothy grass, and sainfoin + Festulolium + pasture ryegrass + Timothy grass. For haymaking and pasture chain construction, the following grass combinations selected comprised two-pasture grasses (previous years' brome and Timothy grass + common alfalfa + sainfoin) and seven hay grasses (vetch + oats, Sudan grass, sorghum-Sudan grass hybrid + sorghum, corn for silage, sorghum, peas + oats + barley + wheat, and peas). The use of droughtresistant legumes, cereals, and arable crops and their mixtures positively impacted intensifying the feed base and reducing the pasture areas' degradation. Thus, in the first experiment, the green mass collection was higher than 3.33 t ha-1, while in the second one, it was below 4.75 t ha-1, which fully bestowed the physiological needs of animals. The species diversity of pasture vegetation has improved because of beans' inclusion, possibly enhancing the protein ratio in green feed and hay as the main component of the farm animals' diet. [ABSTRACT FROM AUTHOR]

While shaping of plant microbiome composition through 'host filtering' is well documented in legume–rhizobium symbioses, it is less clear to what extent different varieties and genotypes of the same plant species differentially influence symbiont community diversity and composition. Here, we compared how clover host varieties and genotypes affect the structure of Rhizobium populations in root nodules under conventional field and controlled greenhouse conditions. We first grew four Trifolium repens (white clover) F2 crosses and one variety in a conventional field trial and compared differences in root nodule Rhizobium leguminosarum symbiovar trifolii (Rlt) genotype diversity using high‐throughput amplicon sequencing of chromosomal housekeeping (rpoB and recA) genes and auxiliary plasmid‐borne symbiosis genes (nodA and nodD). We found that Rlt nodule diversities significantly differed between clover crosses, potentially due to host filtering. However, variance in Rlt diversity largely overlapped between crosses and was also explained by the spatial distribution of plants in the field, indicative of the role of local environmental conditions for nodule diversity. To test the effect of host filtering, we conducted a controlled greenhouse trial with a diverse Rlt inoculum and several host genotypes. We found that different clover varieties and genotypes of the same variety selected for significantly different Rlt nodule communities and that the strength of host filtering (deviation from the initial Rhizobium inoculant composition) was positively correlated with the efficiency of symbiosis (rate of plant greenness colouration). Together, our results suggest that selection by host genotype and local growth conditions jointly influence white clover Rlt nodule diversity and community composition. [ABSTRACT FROM AUTHOR]

White clover is a widely grown temperate legume forage with high nutritional value. Research on the functional genomics of white clover requires a stable and efficient transformation system. In this study, we successfully induced calluses from the cotyledons and leaves of 10 different white clover varieties. The results showed that the callus formation rate in the cotyledons did not vary significantly among the varieties, but the highest callus formation rate was observed in 'Koala' leaves. Subsequently, different concentrations of antioxidants and hormones were tested on the browning rate and differentiation ability of the calluses, respectively. The results showed that the browning rate was the lowest on MS supplemented with 20 mg L−1 AgNO3 and 25 mg L−1 VC, respectively, and the differentiation rate was highest on MS supplemented with 1 mg L−1 6-BA, 1 mg L−1 KT and 0.5 mg L−1 NAA. In addition, the transformation system for Agrobacterium tumefaciens-mediated transformation of 4-day-old leaves was optimized to some extent and obtained a positive callus rate of 8.9% using green fluorescent protein (GFP) as a marker gene. According to our data, by following this optimized protocol, the transformation efficiency could reach 2.38%. The results of this study will provide the foundation for regenerating multiple transgenic white clover from a single genetic background. [ABSTRACT FROM AUTHOR]

SUMMARY: Maintenance of stable mitochondrial respiratory chains could enhance adaptability to high temperature, but the potential mechanism was not elucidated clearly in plants. In this study, we identified and isolated a TrFQR1 gene encoding the flavodoxin‐like quinone reductase 1 (TrFQR1) located in mitochondria of leguminous white clover (Trifolium repens). Phylogenetic analysis indicated that amino acid sequences of FQR1 in various plant species showed a high degree of similarities. Ectopic expression of TrFQR1 protected yeast (Saccharomyces cerevisiae) from heat damage and toxic levels of benzoquinone, phenanthraquinone and hydroquinone. Transgenic Arabidopsis thaliana and white clover overexpressing TrFQR1 exhibited significantly lower oxidative damage and better photosynthetic capacity and growth than wild‐type in response to high‐temperature stress, whereas AtFQR1‐RNAi A. thaliana showed more severe oxidative damage and growth retardation under heat stress. TrFQR1‐transgenic white clover also maintained better respiratory electron transport chain than wild‐type plants, as manifested by significantly higher mitochondrial complex II and III activities, alternative oxidase activity, NAD(P)H content, and coenzyme Q10 content in response to heat stress. In addition, overexpression of TrFQR1 enhanced the accumulation of lipids including phosphatidylglycerol, monogalactosyl diacylglycerol, sulfoquinovosyl diacylglycerol and cardiolipin as important compositions of bilayers involved in dynamic membrane assembly in mitochondria or chloroplasts positively associated with heat tolerance. TrFQR1‐transgenic white clover also exhibited higher lipids saturation level and phosphatidylcholine:phosphatidylethanolamine ratio, which could be beneficial to membrane stability and integrity during a prolonged period of heat stress. The current study proves that TrFQR1 is essential for heat tolerance associated with mitochondrial respiratory chain, cellular reactive oxygen species homeostasis, and lipids remodeling in plants. TrFQR1 could be selected as a key candidate marker gene to screen heat‐tolerant genotypes or develop heat‐tolerant crops via molecular‐based breeding. [ABSTRACT FROM AUTHOR]

Red clover (Trifolium pratense L.), a key perennial pastoral species used globally, can strengthen pastural mixes to withstand increasingly disruptive weather patterns from climate change. Breeding selections can be refined for this purpose by obtaining an in-depth understanding of key functional traits. A replicated randomized complete block glasshouse pot trial was used to observe trait responses critical to plant performance under control (15% VMC), water deficit (5% VMC) and waterlogged conditions (50% VMC) in seven red clover populations and compared against white clover. Twelve morphological and physiological traits were identified as key contributors to the different plant coping mechanisms displayed. Under water deficit, the levels of all aboveground morphological traits decreased, highlighted by a 41% decrease in total dry matter and 50% decreases in both leaf number and leaf thickness compared to the control treatment. An increase in root to shoot ratio indicated a shift to prioritizing root maintenance by sacrificing shoot growth, a trait attributed to plantwater deficit tolerance. Under waterlogging, a reduction in photosynthetic activity among red clover populations reduced several morphological traits including a 30% decrease in root dry mass and total dry matter, and a 34% decrease in leaf number. The importance of root morphology for waterlogging was highlightedwith low performance of red clover: there was an 83% decrease in root dry mass compared to white clover which was able to maintain root dry mass and therefore plant performance. This study highlights the importance of germplasm evaluation across water stress extremes to identify traits for future breeding programs. [ABSTRACT FROM AUTHOR]

Anthropogenic load on natural phytocenoses is manifested by disturbance of plant cover, synanthropization of the floristic composition of groups, destruction of plant distribution areas, reduction of biodiversity, and changes in plant growth and development conditions. The degree of anthropogenic load on natural phytocenoses is a global problem that requires detailed study and monitoring studies, especially in the conditions of urban ecosystems. The natural conditions affecting the state of the phytocenoses of Holosiiv Park named after Maxim Rylskyi city of Kyiv according to physical and geographical, climatic, edaphic, and orographic features. The influence of anthropogenic activity in the experimental plots was determined and the level of anthropogenic pressure on the state of the phytocenoses of Holosiiv Park named after Maxim Rylskyi city of Kyiv was carried out by analyzing available sources of industrial production, transport, etc. It has been established that Holosiiv Park named after Maksym Rylskyi is subjected to constant anthropogenic load, in particular, intensive recreational use, atmospheric air pollution has been established, which leads to the impoverishment of biodiversity in certain areas of the park. The level of atmospheric air pollution in the territory adjacent to the experimental sites was assessed using computational and instrumental methods. It was established that the estimated CO level exceeds the standards by 8 times on Holosiivskyi Avenue and by more than 30 times at the intersection of Maksym Rylskyi Street and Holosiivskyi Avenue. The analysis of the state of the atmospheric air using instrumental research methods did not show an excess of the content of the main pollutants, however, according to the Air Quality Index, it is moderately polluted by the content of dust with a diameter of 2.5 microns. The study of the state of the phytocenoses of Holosiiv Park named after Maksym Rylsky of the city of Kyiv within the experimental plots was carried out by studying their floristic composition and evaluating the ecological groups of plants. Because it is the analysis of ecological groups of plants that makes it possible to assess the ecological conditions of plant groups, the place of growth, and phytocenotypes of plant species that are part of the phytocenosis, that is their role in the formation of the phytocenosis. The ecological assessment of the state of phytocenoses of Holosiiv Park named after Maksym Rylskyi of the city of Kyiv was carried out using the method of bioindication and lichen indication (lichen research). These methods make it possible to determine the level of anthropogenic load acting quickly and relatively easily on phytocenoses within the experimental plots. To determine the state of the trees in the experimental plots, the method of assessing the asymmetry of morphological structures was used (using the example of the hanging hornbeam Carpinus betulus L.). A comparison of the floristic composition and the state of the phytocenoses showed that plot No. 1 has a depressed state, plants do not grow evenly, and drying of trees was observed. Plot No. 2 has the best condition, the plants of the plot are characterized by the best indicators of growth and development, the largest number of species, and the frequency of occurrence of species. Site No. 3 did not record significant degradation of the phytocenosis, but there is a certain mosaic of the phytocenosis, which may be due to atmospheric air pollution and significant recreational pressure, in particular, trampling. Plot No. 2 and Plot No. 3 have the highest coefficient of species composition commonality. Common plant species in the respective areas are: Carpinus betulus L., Anemonoides ranunculoides L., Ficaria verna, Trifolium repens and Corydalis solida. [ABSTRACT FROM AUTHOR]

The introduction of exotic legumes (Trifolium repens) in humid Puna grasslands improves forage quality and soil nutritional status. The objective was to determine the influence of phosphate fertilization and seeding density (legume) on the grass-legume ratio in a grassland dominated by Festuca dolichophylla and Calamagrostis vicunarum, during two years, based on the percentages of survival, establishment and relative cover of white clover. The experimental area was located in the Huancavelica region of Peru (4 500 masl). A completely randomized design with a 3x2 factorial arrangement was used, with three doses of phosphorus (0, 15 and 30 grams of rock phosphate) and two planting densities (20 and 40 seeds per hole). The best response to fertilization was obtained with the application of 15 g of rock phosphate per hole. The seeding density with which the best results were obtained in terms of percentage cover of clover in the native prairie was 20 seeds per hole. The white clover cover patterns varied with the season, with higher proportions in the rainy season than in the dry season, which did not exceed on average the recommended grass-legume ratio (70:30). The trials were conducted in the absence of grazing, a determining factor in the grass-legume balance. It is recommended to examine interactions between sowing density and fertilization under different grazing schemes on the grass-legume balance and ecosystem integrity. [ABSTRACT FROM AUTHOR]

Legume crop production has many benefits for agricultural systems. Through the rhizodeposition process, they release a significant amount of C and N into the soil, increasing soil organic C and reducing the use of N fertilizer. Rhizodeposition is known as a dynamic process influenced by many factors.The aim of this study was to study the contribution of root exudation and root senescence to the rhizodeposition of atmospheric C and N during vegetative and reproductive growth in annual and perennial legumes and to understand how this is linked to the fixation capacities of C and N and root functional traits.An original approach that combined 13CO2 labelling and the 15N dilution method was developed to measure the rhizodeposition of atmospheric C and N throughout plant growth by two annual grain legumes (pea and faba bean) and two perennial forage legumes (white and crimson clovers).C rhizodeposition was found to increase proportionally with N rhizodeposition during reproductive development and the differences observed between species were related to the C and N fixation abilities. The use of root traits such as specific root length, root tissue density and root dry matter content suggests a strong contribution of root exudation to C rhizodeposition at vegetative growth and a strong contribution of root senescence to both C and N rhizodeposition during reproductive growth.Synthesis. Both C and N rhizodeposition appeared to be controlled by traits indicative of resource acquisition and root development. [ABSTRACT FROM AUTHOR]

This study developed an unattended electric weeder (UEW) to control floor weeds in an orchard greenhouse. The UEW was a motor-driven dolly equipped with a spark exposer. The spark exposer was constructed by applying an alternating voltage (10 kV) to a conductor net (expanded metal net). The charged conductor net (C-CN) discharged into the surrounding space. Wild oat and white clover were used as test weed species. Weed seedlings growing on the floor were grounded by the biological conductor and were subjected to a spark from the C-CN when they reached the discharge space. The spark-exposed seedlings were singed and shrunk instantaneously. In the present experiment, the UEW was remotely controlled to move on the soil-cover metal nets, which were laid on the floor to make a flat surface, in a stop-and-go manner, and to eject a spark to the weed seedlings that emerged from the floor. All of the mono- and dicotyledonous weed seedlings, which had been artificially sown on the floor, were completely eradicated using this method. Thus, this study provides an experimental basis for developing an unattended technique for controlling floor weeds in an orchard greenhouse. [ABSTRACT FROM AUTHOR]

White clover (Trifolium repens L.) is one of the legume herbages with high feed quality, but it is sensitive to water deficiency. The objectives of this study were to compare morpho-physiological responses to drought stress and post-drought recovery in four-leafed white clover cultivars. Under well-watered conditions, drought stress (3 d, 6 d, 9 d and 12 d), and rehydration, the relative water content (RWC), membrane lipid permeability, osmoregulatory substances, photosynthetic characteristics and stomatal features of Chinese native Longping No.1 (LP, small-leafed) and three introduced cultivars, namely Pudi (PD, small-leafed), Rivendel (RD, medium-leafed) and Koala (KL, large-leafed), were evaluated. Results showed that small-leafed white clover maintained higher RWC and better membrane stability and osmotic regulation with increased drought intensities, compared to the medium-leafed and large-leafed cultivars. Following rewatering, small-leafed white clover recovered more rapidly with all of the parameters than the other cultivars. The increase of drought stress intensity led to the decline of net photosynthetic rate (Pn), transpiration rate (Tr) and stomatal conductance (Cs). However, the decreased range of Pn, Tr and Cs in the small-leafed white clover was significantly smaller than that in the medium-leafed and large-leafed white clovers. Meanwhile, the small-leafed white clover showed a smaller size and higher density of stoma either under normal or drought conditions than the intermediate- and large-leafed cultivars. Taken together, the results indicated that the adaptability of small-leafed white clover to drought stresses and post-drought recovery was better than that of medium-leafed and large-leafed white clovers. The study will provide better insights into the mechanism of drought response and recovery potential in different white clover cultivars. [ABSTRACT FROM AUTHOR]

Introduction-- The most critical impact of weeds is the negative effect on cultivated plants exerted through competition for limited resources and allelopathies. Studies have demonstrated the dominance of weeds in crops and have established ecological methods for good integrated management. Objective-- To characterize the diversity of weed species in 60 smallholder farms in five municipalities of Boyacá, planned for polycultures. Methodology-- The research was carried out in 60 farms in five municipalities of the Department: Aquitania, Belén, Garagoa, Panqueba and Soatá, in each one two plots of 0.5 ha were sampled where the weeds present were determined in two frames of 1m2. Results-- The presence of 109 species of weeds located in 93 genera and 38 botanical families was observed, being the most representative Poaceae with 18 species, Asteraceae with 15 species and Fabaceae with 9. The families Amarantaceae Apiaceae, Lamiaceae, Oxalidaceae, Poligonaceae and Solanaceae were represented by 4 species. The farms were grouped into 3 or 4 groups in each municipality according to the biodiversity indicators of the weeds, while the municipalities formed three groups. Conclusions-- From the point of view of their agricultural importance, the species most frequently present in the municipalities were: P. clandestinum, Sonchus oleraceus L, Trifolium repens and Rumex crispus. In general, species richness at the farm level was low, equity medium and dominance high, while at the municipal level were observed high species richness, medium indicators of diversity and equity and low dominance. [ABSTRACT FROM AUTHOR]

The EFSA Panel on Plant Health performed a pest categorisation of Hoplolaimus galeatus (Nematoda: Hoplolaimidae) for the EU. H. galeatus belongs to the order Rhabditida, subfamily Hoplolaiminae. This nematode is not reported from the EU and is not included in the EU Commission Implementing Regulation 2019/2072. It is widely distributed in the USA and is also reported from South America, Africa, Asia and Australia. The identity of H. galeatus is clearly defined and methods for its identification are available. H. galeatus is polyphagous and natural hosts include barley, wheat, rye, red and white clover, alfalfa, cabbage, pine, spruce, oak, apple, grapevine, as well as various ornamental plants and turf grasses. These hosts are grown over vast areas of the EU. The climate of the EU is suitable for the establishment of H. galeatus. Pathways of entry are host plants for planting except seeds, but also soil as a contaminant. Soil import to the EU is prohibited and special requirements apply to import of machinery for agricultural/forestry purposes from third countries. Impact of the nematode is best known for North American plant species. The nematode has been reported to damage cotton, maize, soybean, pine, oak and turfgrass. Many of the hosts represent a considerable economic and environmental value to the EU. Therefore, the Panel concludes that H. galeatus satisfies all the criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest. [ABSTRACT FROM AUTHOR]

Context: High-quality, summer-active pastures could improve meat production in south-eastern Australia by facilitating livestock finishing over summer, with legumes critical for enhancing the nutritive value of pasture mixes. Available legumes vary in their ability to withstand moisture stress and grazing. Aims: We aimed to identify legumes suitable for a summer–autumn finishing system. Methods: We tested pure swards of 12 cultivars across eight legume species in replicated small-plot experiments at Goulburn and Bombala, New South Wales, assessing productivity, persistence and warm-season nutritive characteristics over 2–3 years. Key results: Lucerne (Medicago sativa) was clearly the most productive species during summer and outperformed the clovers (Trifolium spp.) in terms of persistence and productivity throughout most of the experimental period at both sites, except during autumn 2021 after high rainfall in March. Caucasian clover (T. ambiguum) was also highly persistent at both sites. Talish clover (T. tumens) and strawberry clover (T. fragiferum) were more persistent than white clover (T. repens) and red clover (T. pratense). White clover recovered strongly under high rainfall after drought, whereas red clover established rapidly but showed less capacity for post-drought recovery. Hybrid Caucasian × white clover was the least productive legume. Alternative clover species sometimes had slightly lower values of nutritive characteristics than white clover; red clover sometimes had distinctly lower values. Conclusions: Lucerne performed best but several clovers were also productive, persistent and of high nutritive value over the summer–autumn period. Implications: Talish, Caucasian and strawberry clovers warrant further investigation for inclusion in summer-active pastures in south-eastern Australia. Profitability of livestock production over summer–autumn in the temperate environment of south-eastern Australia could be improved by including legumes in pastures that are persistent, productive and of high nutritive value. Evaluation of a range of legume species and cultivars showed that lucerne remained the most reliably productive warm-season option where soil conditions support it. Talish, Caucasian and strawberry clovers were persistent and of high nutritive value, warranting further evaluation in special-purpose warm-season pastures. [ABSTRACT FROM AUTHOR]

Context: Improving the stability of legumes in grasslands in the face of variable seasonal conditions is key to mitigating risks posed by drought. Aims: We assessed the persistence of a range of legume species and cultivars in order to inform legume choice for pasture improvement and identify priority species for further development. Methods: Twenty field experiments in four series were conducted at sites with contrasting seasonal and soil characteristics in the 'high-rainfall' (560–920 mm long-term average) Tablelands and Monaro regions of New South Wales, Australia. Legumes were grown as pure swards and assessed periodically for seedling density, plant frequency and dry matter for up to 5 years. Key results: Legume dry matter production was positively correlated with plant frequency. However, most legumes persisted poorly at most sites, particularly on soils of lower fertility. Subterranean clover (Trifolium subterraneum) cv. Goulburn was the best performing cultivar of that species across sites on the Southern Tablelands and Monaro. Yellow serradella (Ornithopus compressus) cvv. Avila and Yellotas showed promising persistence, particularly under drought conditions. White clover (T. repens) was the most broadly adapted of the perennial legumes across a range of soils, but persistence was still inadequate at many sites. Lucerne (Medicago sativa) was approximately twice as productive as the next-most productive species when soil conditions suited its growth, but it failed to persist on acidic, low-fertility soils. Conclusions: Serradella species (yellow and French, O. sativus) and white clover, in conjunction with subterranean clover, offer the best near-term prospects for diversifying legume productivity and resilience under variable seasonal conditions in tableland environments. Implications: An increased focus on phenology and seed characteristics is suggested to improve the persistence of annual and facultative perennial legume species in grasslands. Serradella and white clover are identified as the highest priorities for cultivar development for tableland environments of south-eastern Australia. This study evaluated the stability and persistence of a range of legume species and cultivars to identify viable options for grasslands of south-eastern Australia. Yellow and French serradella, white clover and subterranean clover were identified as priority species because they are already, or are close to being, viable options for use in grasslands. An increased focus on phenology and seed characteristics is suggested to improve the persistence of white clover and serradella in grasslands. [ABSTRACT FROM AUTHOR]

Legumes have underpinned transformational change on New Zealand sheep and beef farms over the last 30 years. This was through an emphasis on ewe nutrition based on lucerne or red clover dominant pastures, and increased use of subterranean and white clovers on uncultivatable hill country. Pre- and post-weaning lamb growth rates have increased, and enabled earlier slaughter of heavier lambs. The farm systems results include greater numbers of hoggets mated, higher lambing percentages and greater ewe efficiency (kg lamb weaned/kg ewe mated). Extension packages to support legume use have compared growth rates of resident and legume-based pastures, economic analyses of successful farms and management packages for the most appropriate legume in different environments. Over the same period, the dairy industry rapidly expanded in cow numbers and area onto flat irrigated land on the Canterbury Plains. The nitrogen deficiency of perennial ryegrass was overcome by a linear increase in nitrogen fertiliser use. Environmental concerns from this intensification has led to a legislated nitrogen cap of 190 kg/ha.year. This, coupled with a recent trebling in urea price, has returned attention to increasing the white clover content of these pastures. Nitrogen applications can be minimised by using diverse pastures sown with a legume, herb and <8 kg/ha of perennial ryegrass. Work on other legumes, including annuals and those with condensed tannins, has to date failed to increase their use in most pastoral settings, with the exception of the perennial lupin which is adapted to high-aluminium soils in the South Island High Country. Legumes have underpinned the New Zealand pastoral-based economy for over 100 years. White clover remains the most widely sown, but specialist red clover based pastures are providing high quality feed for fattening livestock in wetter regions of the country. In the drier east coast, lucerne management has been refined based on crop physiology principles. This has allowed earlier lambing, leading to transformational change on-farm. Subterranean clover remains the dominant annual legume used. Successful integration of legumes on-farm has required understanding of the genotype by environment by management interactions. [ABSTRACT FROM AUTHOR]

Symbiotic microorganisms such as arbuscular mycorrhizal fungi (AMF) and rhizobia (Rh) both promote host plant N acquisition, but whether and how the combination affects host plant nitrogen (N) assimilation remains unclear. To clarify the role of AMF and rhizobia on N assimilation in white clover (Trifolium repens), the effect of single or combined inoculation with an arbuscular mycorrhizal fungus Paraglomus occultum and a rhizobium Rhizobium trifolii on plant growth, photosynthesis, leaf N and amino acid contents, and the activities of N assimilation-related enzymes were analyzed in white clover under potted conditions. The results obtained were as follows: (1) The plant height, stolon length, leaf number, shoot biomass, total biomass, chlorophyll b and total chlorophyll contents, steady-state light quantum efficiency, and leaf N contents of white clover were significantly increased by single inoculation with Paraglomus occultum, single Rhizobium trifolii, and combined inoculations of Paraglomus occultum and Rhizobium trifolii, along with the order of combined inoculations of Paraglomus occultum and Rhizobium trifolii > single Paraglomus occultum > single Rhizobium trifolii > non-inoculation control. (2) Combined inoculations of Paraglomus occultum and Rhizobium trifolii significantly increased the contents of various amino acids including alanine, arginine, asparagine, aspartate, glutamine, glutamic acid and histidine in leaves of white clover, and distinctly improved the activities of nitroreductase, nitrite reductase, glutamine synthetase, glutamate synthetase, glutamate dehydrogenase, asparagine synthetase, and aspartate aminotransferase. In addition, the introduction of Rhizobium trifolii significantly promoted the colonization of Paraglomus occultum to roots of white clover, suggesting the partnership between the two. Therefore, it is concluded that combined inoculations of AMF and rhizobia promote N assimilation, generate more amino acids, and further promote the growth of white clover by activating the activities of N assimilation-related enzymes. It is further demonstrated that AMF and rhizobia have synergistic effects on promoting N assimilation of white clover. [ABSTRACT FROM AUTHOR]

Background: White clover (Trifolium repens L) is a high-quality forage grass with a high protein content, but it is vulnerable to cold stress, which can negatively affect its growth and development. WRKY transcription factor is a family of plant transcription factors found mainly in higher plants and plays an important role in plant growth, development, and stress response. Although WRKY transcription factors have been studied extensively in other plants, it has been less studied in white clover. Methods and Results: In the present research, we have performed a genome-wide analysis of the WRKY gene family of white clover, in total, there were 145 members of WRKY transcription factors identified in white clover. The characterization of the TrWRKY genes was detailed, including conserved motif analysis, phylogenetic analysis, and gene duplication analysis, which have provided a better understanding of the structure and evolution of the TrWRKY genes in white clover. Meanwhile, the genetic regulation network (GRN) containing TrWRKY genes was reconstructed, and Gene Ontology (GO) annotation analysis of these function genes showed they contributed to regulation of transcription process, response to wounding, and phosphorylay signal transduction system, all of which were important processes in response to abiotic stress. To determine the TrWRKY genes function under cold stress, the RNA-seq dataset was analyzed; most of TrWRKY genes were highly upregulated in response to cold stress, particularly in the early stages of cold stress. These results were validated by qRT-PCR experiment, implying they are involved in various gene regulation pathways in response to cold stress. Conclusion: The results of this study provide insights that will be useful for further functional analyses of TrWRKY genes in response to biotic or abiotic stresses in white clover. These findings are likely to be useful for further research on the functions of TrWRKY genes and their role in response to cold stress, which is important to understand the molecular mechanism of cold tolerance in white clover and improve its cold tolerance. [ABSTRACT FROM AUTHOR]

Allelopathy is a unique phenomenon in nature that refers to direct or indirect, positive or negative, impact of one plant (including microorganisms, insects, and herbivores) on another plant through chemical secretions (allelochemicals). Ambrosia artemisiifolia (ragweed) is a well-known invasive plant possessing allelochemicals that have been found to inhibit the growth and development of plants in their immediate environment. This study aimed to determine the allelopathic impact of the aqueous leaf extract isolated from ragweed leaves (concentrated extract, 1:2, 1:4, and 1:8) on seed germination and early seedling growth of barley (Hordeum vulgare L.) and white clover (Trifolium repens L.). The examined aqueous extract of ragweed had a higher inhibitory effect on the germination of white clover seeds compared to barley. The germination of barley seeds was the lowest at the concentrated leaf extract (up to 70%), while the same process in barley seeds was not determined at this concentration. In the other treatments, germination was significantly lower in both examined species compared to the control. Shoot and root growth of both researched species was inhibited in all treatments compared to the control. The obtained results indicate that the aqueous ragweed extract significantly inhibits the growth of roots and shoots of both tested species, which increases the need for more intensive research on this topic. [ABSTRACT FROM AUTHOR]

The long-term influence of several living mulches on apple tree growth, nutrient status, yield, and fruit quality concerning the year of cover crop sowing in tree rows was evaluated in the Lower Silesia region in the southwestern part of Poland. The estimation was conducted in six apple tree 'Ligol' populations differentiated by the rootstock: M.26, M.9, P 60, P 2, P 16, and P 22. In experiment no. 1, one-year-old nursery stock was planted, and perennial living mulches were sown: colonial bent grass (Agrostis vulgaris With.) and white clover (Trifolium repens L.) in the same year and blue fescue (Festuca ovina L.) in the following year. In experiment no. 2, which involved two-year-old stock, the sowing of blue fescue was delayed until the second, third, fourth, and fifth years following orchard planting. The presence of the cover crop significantly affected young tree growth when one-year-old trees were planted. The sowing of the living mulch in the first or the second year after tree planting led to a significant reduction in the cumulative yield obtained from the young trees. The living mulch improved the red coloration of the fruit skin in the young orchard, but it caused a reduction in the mean fruit weight and size. However, it also contributed to decreased nitrogen concentration in the leaves of the apple trees, the tree tolerance to living mulch increased as the orchard aged. A choice of semidwarf rootstock, postponed sowing of cover crop, and high-quality nursery stock were recognized as the most important factors for fostering apple tree tolerance to living mulches in tree rows. [ABSTRACT FROM AUTHOR]

The experiment was to study nutritional composition of eight native leguminous forage in Xing'an league. The grey-correlation-analysis method was used to comprehensively evaluate eight types of potato family forage in rural areas. The results showed that the crude fat content of Medicago ruthenica L. Trautv. and Trifolium repens L. were significantly higher than that of other forage (P<0.05). The crude protein content of Trifolium pratense L. and Medicago ruthenica L. Trautv. were significantly higher than that of other forage (P<0.05). The acid detergent fiber content of Medicago lupulina L. and Astragalus laxmannii Jacquin were significantly lower than that of other forage (P<0.05). The content of neutral detergent fiber in Astragalus laxmannii Jacquin and Medicago lupulina L. were significantly lower than that of other forage (P<0.05). The crude ash content of Astragalus laxmannii Jacquin was significantly higher than that of other forage (P<0.05). The relative feeding value of Astragalus laxmannii Jacquin was significantly higher than that of other forage (P<0.05). The experiment indicates that nutritional quality of Vicia sepium L. and Melilotus albus Desr. are better, which have high development and utilization value in Xing'an league. [ABSTRACT FROM AUTHOR]

Background: White clover (Trifolium repens L.), an excellent perennial legume forage, is an allotetraploid native to southeastern Europe and southern Asia. It has high nutritional, ecological, genetic breeding, and medicinal values and exhibits excellent resistance to cold, drought, trample, and weed infestation. Thus, white clover is widely planted in Europe, America, and China; however, the lack of reference genome limits its breeding and cultivation. This study generated a white clover de novo genome assembly at the chromosomal level and annotated its components. Results: The PacBio third-generation Hi-Fi assembly and sequencing methods generated a 1096 Mb genome size of T. repens, with contigs of N50 = 14 Mb, scaffolds of N50 = 65 Mb, and BUSCO value of 98.5%. The newly assembled genome has better continuity and integrity than the previously reported white clover reference genome; thus provides important resources for the molecular breeding and evolution of white clover and other forage. Additionally, we annotated 90,128 high-confidence gene models from the genome. White clover was closely related to Trifolium pratense and Trifolium medium but distantly related to Glycine max, Vigna radiata, Medicago truncatula, and Cicer arietinum. The expansion, contraction, and GO functional enrichment analysis of the gene families showed that T. repens gene families were associated with biological processes, molecular function, cellular components, and environmental resistance, which explained its excellent agronomic traits. Conclusions: This study reports a high-quality de novo assembly of white clover genome obtained at the chromosomal level using PacBio Hi-Fi sequencing, a third-generation sequencing. The generated high-quality genome assembly of white clover provides a key basis for accelerating the research and molecular breeding of this important forage crop. The genome is also valuable for future studies on legume forage biology, evolution, and genome-wide mapping of quantitative trait loci associated with the relevant agronomic traits. [ABSTRACT FROM AUTHOR]

Although traditional ryegrass pastures are still commonly used, they require intense management and input and do not perform well during the summer months. Multispecies systems have been recognised as more sustainable, needing less fertiliser and being tolerant to drought and heat. While data on monoculture system fat composition exist, information for multispecies is scarce. The present study compared the fatty acid (FA), carotenoid and fat-soluble composition of a multispecies system (consisting of perennial ryegrass, timothy, white clover, red clover, chicory and plantain) (MULTI) with two other conventional grazing systems (monoculture perennial ryegrass (PRG) and a binary mixture of perennial ryegrass and white clover (PRG+WC)) over the Irish late-summer grazing season of dairy cattle (July–September). The results showed that the three systems had similar levels of FAs (p > 0.05), with mean α-linolenic acid values of 20.00 mg/g in PRG, 18.51 mg/g in PRG+WC, and 17.90 mg/g in MULTI and mean linoleic acid values of 3.84 mg/g in PRG, 4.16 mg/g in PRG+WC, and 4.39 mg/g in MULTI. Fourfold and twofold increases in the concentrations of α-linolenic acid and linoleic acid, respectively, were observed throughout July–September. Variations in stearic acid concentrations were not significant (p > 0.05), and palmitic acid concentrations increased over time (p < 0.05). The average values of lutein (36.68 mg/kg in PRG, 31.26 mg/kg in PRG+WC, and 35.75 mg/kg in MULTI) and α-tocopherol (2.28 mg/kg in PRG, 1.49 mg/kg in PRG+WC, and 1.83 mg/kg in MULTI) were similar among the grazing systems (p > 0.05), and the average β-carotene value was 25% higher in monoculture ryegrass (140.74 mg/kg) than in the multispecies (102.51 mg/kg) (p < 0.05). Nonetheless, the levels of β-carotene found in the multispecies were still above the recommended intake required for ruminants. In conclusion, multispecies pastures could be included in dairy cattle production systems as a sustainable alternative to traditional pastures while also providing typically adequate sources of fats for animal diets. [ABSTRACT FROM AUTHOR]

The article provides information on the discovery of Lolium multiflorum Lam., a grass species in the Lolium genus, in Sikkim, India. This species had not been previously recorded in Sikkim and was confirmed through a detailed study of its characteristics. The article offers a taxonomic treatment, including a description and illustrations of the species, to aid in its future identification and reference.

This experiment investigated the variation in enteric methane production and associated gas exchange parameters, nutrient digestibility, rumen fermentation, and rumen microbiome when a range of silages based on different forage types (grass or clover), and different species within the 2 types, were fed as the sole feed to heifers. Three grass species (perennial ryegrass, festulolium, and tall fescue) and 2 clover species (red clover and white clover) were included. Perennial ryegrass was harvested at 2 maturity stages in the primary growth, white clover was harvested once in the primary growth, and 4 cuts of festulolium and tall fescue and 3 cuts of red clover were harvested during the growing season, giving 14 different silage batches in total. Sixteen Holstein heifers 16 to 21 mo old and 2 to 5 mo in pregnancy were fed the silages ad libitum as the sole feed in an incomplete crossover design. Each silage was fed to 4 heifers, except for the 2 perennial ryegrass silages, which were fed to 8 heifers; in total 64 observations. The CH 4 production was measured for 3 d in respiration chambers. Heifers fed clover silages had higher dry matter intake (DMI) compared with heifers fed grass silages, and heifers fed tall fescue silages had the numerically the lowest DMI. Compared with grass silages, feeding clover silages led to higher crude protein digestibility but lower neutral detergent fiber (NDF) digestibility. Rumen pH was higher in heifers fed clover silages compared with those fed grass silages. Based on composition analysis, the rumen microbiota of the heifers clustered clearly according to forage type and species. More specifically, 7 of the 34 dominating rumen bacterial genus-level groups showed higher relative abundances for the clover silages, whereas 7 genus-level groups showed higher abundances for the grass silages. Methane yield was higher for heifers fed grass silages than for those fed clover silages when methane production was related to dry matter and digestible organic matter intake, whereas the opposite was seen when related to NDF digestion. The gross energy lost as methane (CH 4 conversion factor, %) reduced from 7.5% to 6.7%, equivalent to an 11% reduction. The present study gives the outlines for choosing the optimal forage type and forage species with respect to nutrient digestibility and enteric methane emission in ruminants. [ABSTRACT FROM AUTHOR]

Plantain (Plantago lanceolata L.) is recognised for its ability to improve summer feed productivity as well as mitigate nitrous oxide (N2O) emissions from grazed pastoral soils. This study aims to determine the proportion of plantain required in perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.), or RWC, mixed swards to maintain yield stability and to quantify N2O emission reductions. The botanical composition was monitored when plantain was sown at different rates of 0%, 30%, 50% and 70% in RWC pastures under grazing by dairy cows over 2 grazing years. Urine from cows grazing RWC (6.15 g N L−1), 30% (5.40 g N L−1) and 50% (4.40 g N L−1) plantain mixed pastures was used to measure N2O emissions (n = 5) from the pastures of their origin and to assess the impact of the plantain rhizosphere on N2O emissions by applying the RWC urine to the 50% plantain mixed pasture, and vice versa, in late summer–autumn using the static chambers technique. After declining in spring, the plantain content recovered in early autumn and reached a peak of 40% in the 30% plantain mixed pasture and around 50% in the 50% and 70% plantain mixed pastures in winter. A lower N content in urine, and therefore a lower urine N-loading rate from cows grazing in the 50% plantain mixed pasture, resulted in 39% lower total N2O emissions compared to RWC urine treatment. In conclusion, 30% to 50% plantain in mixed pastures was stable throughout the 2 years, and it not only reduced the urinary N concentration in grazing cattle but also contributed to reduced N2O EFs. [ABSTRACT FROM AUTHOR]

International seed trading provides a significant introductory pathway for weed seeds, and many globally established weeds originated as contaminants in agricultural seed lots. Management of these trade systems helps minimize agricultural losses and is an important means of preventing future biological incursions. Forage crop seed lots could be considered higher risk than seed lots of arable and vegetable crops, as they have been found to have a higher percentage of contaminated seed lots. Two of the most commonly used temperate forage crops worldwide are perennial ryegrass (Lolium perenne) and white clover (Trifolium repens). New Zealand is one of the top producers of these crop seeds globally, and both species are commonly used in New Zealand pastures. Using historical and current seed lot analytical purity test results, we examined the frequency, identity and temporal changes of weed seeds found within agricultural seed lots of perennial ryegrass and white clover grown in New Zealand from 1912 to 2019. Overall, the percentage of contaminated forage seed lots decreased between approximately three to sixfold over the study period, indicating that herbicide availability, seed certification and improved crop management have been effective for weed control. However, we identified a handful of annual weed species that could become more problematic in the future, either because they showed an increasing presence trend in seed lots or were identified as the most common contaminants. In 2019, Vulpia bromoides was the most common contaminant in perennial ryegrass seed lots, and Chenopodium album was the most common in white clover seed lots. Sherardia arvensis and Poa annua, both significant species with an increasing presence trend, had the largest increases in perennial ryegrass seed lots over the study period. Conversely, Rumex acetosella had the largest presence decline for both crop species. There was a significant difference between the percentage of contaminant species that were grass weeds between study crops, where perennial ryegrass seed lots had approximately four times more grass species than white clover. Considering New Zealand trades crop seed with approximately half of the world's countries and contributes substantially to the global supply of forage seed, our study provides a unique insight into changes of the weed spectrum throughout the seed for sowing system over the last century. [ABSTRACT FROM AUTHOR]

Background: In the Western Highlands of Cameroon (WHC), information on the nutritional value of fodder species consumed by ruminants is very limited. Methods: Through interviews with farmers and monitoring of animals on the range, information was obtained on the types of fodder resources consumed by the ruminants. Samples of each forage species were collected in 15 districts, mixed, chopped, and dried in a ventilated oven at 60°C, and then ground for chemical composition analysis. Results: Twenty‐two forage species were identified. Among these species, Vernonia amygdalina (29.43% ± 0.45% dry matter [DM]) and Pennisetum clandestinum (87.21% ± 1.33% DM) were, respectively, the highest in protein and neutral detergent fiber contents. Manihot esculenta was one of the most energy‐rich forages in terms of forage unit for lactation and forage unit for meat production. Hierarchical ascending classification revealed three main groups of forages, respectively, rich in crude fiber (Group 1), protein (Group 2), and energy (Group 3). Conclusions: The present study identified 22 forage species browsed by ruminants in WHC. Further studies should be carried out to determine the antinutritional factors and to evaluate their nutrient value using in vitro or in situ digestibility techniques. [ABSTRACT FROM AUTHOR]

Mixed-species grassland containing legumes were suggested to increase yield compared to monocultures. Furthermore, some legumes were suggested to be able to sustain growth, even under drought conditions. The first aim of the current study was to measure if multispecies grassland with legumes is also more productive when their N input due to symbiotic N2 fixation is taken into account. Our second aim was to determine the benefit of grass–legume mixtures in terms of dry matter production under naturally occurring drought conditions. Mixed-species grasslands, consisting of monocultures and variable mixtures of (a) Trifolium pratense, (b) Trifolium. repens, (c) Lolium perenne, and (d) a mixture of drought-tolerant grasses (GSWT based), were assessed for their dry matter production over two years with contrasting weather patterns. The legume–grass seeding mixtures received either a fixed (180 kg N ha−1) or adapted N-fertilizer application (0–180 kg N ha−1), with the latter taking the assumed symbiotic N2 fixation by legumes into account. Mixed-species grassland showed improved yield compared to monocultures both in comparably humid and drought-affected years. The benefits of multispecies grass–legume mixtures were considerably more obvious under a fixed but still measurable under an adapted N-fertilizer regime. The species diversity effect appears to be significantly dependent on the additional N supply enabled by legumes' symbiotic N2-fixation. Legumes and drought-tolerant grasses yielded equally well under drought conditions, although legumes showed major advantages during moderate drought and humid conditions. White and red clover, although both legumes, differed significantly in their persistence under elevated-N and their dry matter production under low-N fertilizer application, but were equal in their tolerance towards drought. [ABSTRACT FROM AUTHOR]

Copyright of Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A major concern with interseeding summer cover crops alongside cash crops is the possibility of cover crops competing with the main crop for water and nutrients and thus, reducing the main crop yields. We conducted on‐farm trials in the sandy loam soils of the upstate of South Carolina in 2020 and 2021 to evaluate the effect of white clover (Trifolium repens L.), buckwheat (Fagopyrum esculentum Moench), and pigeon pea (Cajanus cajan (L.) Millsp.) and their mixture interseeded at V4, V7, and V10 corn growth stages on silage corn performance and soil moisture content. We found that none of the cover crops affected silage corn height and aboveground biomass production regardless of the interseeding time. Further, the volumetric water content in the upper 20‐cm soil profile was not decreased by cover crops irrespective of their interseeding time. At physiological maturity, corn height, aboveground biomass, and volumetric water content ranged between 131 and 163 cm, 9 and 23 Mg ha−1, and 10% and 22%, respectively, in season‐1 and between 181 and 216 cm, 0.48 and 1.03 Mg ha−1, and 10% and 17%, respectively, in season‐2 when interseeded with cover crops. When cover crops were not interseeded, the average corn height, aboveground biomass, and volumetric water content values were 152 cm, 13 Mg ha−1, and 13%, respectively, in season‐1 and 204 cm, 0.7 Mg ha−1, and 14%, respectively, in season‐2. These results would encourage farmers who want to consider cover crop interseeding with corn in the regional production systems. Core Ideas: Interseeded white clover, buckwheat, and pigeon pea did not affect silage corn height and biomass yield.Interseeded cover crops did not decrease water content in the upper 20‐cm soil profile.Interseeding between V4 and V10 corn stages does not negatively impact silage corn production in South Carolina. [ABSTRACT FROM AUTHOR]

The chemical composition, in vitro total gas and CH4 production and performance of cattle fed on factory black tea waste (Camellia sinensis) (BTW), alfalfa (Medicago Sativa), sainfoin (Onobrychis sativa) and white clover (Trifolium repens) was investigated. The gas production was quantified at the 24th hour of the incubation process. BTW was found to vary from roughages in chemical composition (p < 0.05). In addition, the roughages differed in terms of nutrient composition and gas production (p < 0.05). In legume roughages, acetic acid (AA), propionic acid (PA), butyric acid (BA), and total volatile fatty acids (TVFA) values ranged from 52.36–57.00 mmol/L, 13.46–17.20 mmol/L, 9.79–12.43 mmol/L, and 79.71–89.05 mmol/L, respectively. In comparison with black tea waste, legume roughages had higher values of AA, PA, BA, and TVFA. Black tea waste contained a higher acetic acid ratio than legume roughages when compared as a percentage. There was a similar ratio of propionic acid to the rate calculated for sainfoin (Onobrychis sativa) and clover (Trifolium repens), and a similar ratio of butyric acid to the ratio determined for alfalfa (Medicago Sativa). The current study shows that the 5.7–6.3% tannin content of black tea waste can be used in ruminant rations with high-quality roughages. Due to the fact that BTW reduces methane emissions from ruminants and eliminates energy waste from them, the environment can be improved. To obtain more reliable results, further animal feeding experiments on legume roughages and BTW are required. [ABSTRACT FROM AUTHOR]

Information regarding relationships between forage yield and soil enzymes of legume-grass mixtures under nitrogen (N) fertilization can guide the decisionmaking during sustainable forage production. The objective was to evaluate the responses of forage yield, nutritional quality, soil nutrients, and soil enzyme activities of different cropping systems under various N inputs. Alfalfa (Medicago sativa L.), white clover (Trifolium repens L.), orchardgrass (Dactylis glomerata L.), and tall fescue (Festuca arundinacea Schreb.) were grown in monocultures and mixtures (A1: alfalfa, orchardgrass, and tall fescue; A2: alfalfa, white clover, orchardgrass, and tall fescue) under three N inputs (N1: 150 kg ha-1; N2, 300 kg ha-1; and N3: 450 kg ha-1) in a split plot arrangement. The results highlight that A1 mixture under N2 input had a greater forage yield of 13.88 t ha-1 year-1 than the other N inputs, whereas A2 mixture under N3 input had a greater forage of 14.39 t ha-1 year-1 than N1 input, but it was not substantially greater than N2 input (13.80 t ha-1 year-1). The crude protein (CP) content of grass monocultures and mixtures significantly (P < 0.05) increased with an increase in the rate of N input, and A1 and A2 mixtures under N3 input had a greater CP content of 18.91% and 18.94% dry matter, respectively, than those of grass monocultures under various N inputs. The A1 mixture under N2 and N3 inputs had a substantially greater (P < 0.05) ammonium N content of 16.01 and 16.75 mg kg-1, respectively, whereas A2 mixture under N3 had a greater nitrate N content of 4.20 mg kg-1 than the other cropping systems under various N inputs. The A1 and A2 mixtures under N2 input had a substantial higher (P < 0.05) urease enzyme activity of 0.39 and 0.39 mg g-1 24 h-1 and hydroxylamine oxidoreductase enzyme activity of 0.45 and 0.46 mg g-1 5 h-1, respectively, than the other cropping systems under various N inputs. Taken together, growing legume-grass mixtures under N2 input is cost-effective, sustainable, and eco-friendly, which provide greater forage yield and improved nutritional quality by the better utilization of resources. [ABSTRACT FROM AUTHOR]

Nitrogen (N) is an essential nutrient for plant growth. In grazed pasture systems in New Zealand, N fertiliser is regularly applied to maintain high productivity of ryegrass (Lolium perenne L.)/white clover (Trifolium repens L.) pastures. Several decades of trials/research have established the scientific basis for N management and N fertiliser application in grass/clover pasture systems. However, despite, or perhaps because of the rich diversity of this work, it isn’t always easy to see the full picture of this research; the seminal research and sometimes more recent advances are not always easily discoverable. This paper therefore seeks to amalgamate and summarise some of the vast amount of research on N fertiliser use in grazed pasture systems undertaken in New Zealand over the last 50 years. It provides an overview of research, raising the awareness of key findings, and importantly providing a pathway for decision makers to find and access the research on N fertiliser use and management. It also assists in the identification of knowledge gaps for new avenues of enquiry that could improve the efficiency of N fertiliser use and reduce environmental impacts of N loss from grazed pasture systems. [ABSTRACT FROM AUTHOR]

Phenotypic and genetic clines frequently evolve due to varying selection along environmental gradients. However, the specific environmental factors that impose differential selection are often multivariate and difficult to tease apart. We addressed this complexity using a factorial manipulation of watering, soil nutrients and (simulated) herbivory in controlled conditions to better understand the agents of selection driving the evolution of clines in a polymorphic chemical antiherbivore defence, hydrogen cyanide (HCN), of the plant white clover Trifolium repens. We found the presence or absence of the two metabolic components required for HCN production (cyanogenic glucosides and linamarase) to be more prominent determinants of vegetative growth and sexual reproduction in T. repens than HCN itself. We also found that the ability to produce one or both of cyanogenic glucosides or linamarase resulted in a growth advantage under drought and simulated herbivory that outweighs the metabolic cost of their production. These results support the view that the metabolic components underlying HCN play important roles beyond defence by increasing plant tolerance to stress. The growth advantage under drought, however, was diminished in the absence of nutrient addition, consistent with multivariate interactions as drivers of selection. This study provides novel insight into how a cosmopolitan plant has adapted to environmental gradients, and more generally, highlights the importance of considering interactions between multiple environmental factors when studying the evolution of phenotypic and genetic clines. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal fungi (AMF) confer positive and negative effects on many plants, but it is unclear whether AMF has an effect on soil fertility, aggregate distribution, and stability. The aim of this study was to analyze the effects of Rhizoglomus intraradices on plant growth, root morphology, leaf chlorophyll and gas exchange, sugar concentrations, and soil nutrients, aggregate distribution, and stability in marigold (Tagetes erecta L.), maize (Zea mays L.), white clover (Trifolium repens L.), and vetch (Vicia villosa Roth.) plants. Twelve weeks after R. intraradices inoculation, maize presented the highest mycorrhizal development, while mycorrhizal dependence was shown to be the decreasing trend in marigold > white clover > vetch > maize. AMF inoculation significantly increased the chlorophyll index of marigold and white clover, the net photosynthetic rate of white clover, the stomatal conductance of maize and white clover, and the transpiration rate of maize. Fructose, glucose, and sucrose in the four plants were differentially affected by R. intraradices. R. intraradices significantly increased the soil organic carbon (SOC) of marigold, maize, and white clover, the Olsen-P of white clover, the available K content of marigold, the easily extractable glomalin-related soil protein (GRSP) of maize, and the difficultly extractable and total GRSP levels of marigold and vetch. In addition, R. intraradices significantly increased the stability of soil water-stable aggregates (WSAs) in all four plants, plus it increased WSA at 0.5–4 mm sizes. Root AMF colonization was significantly positively correlated with WSA stability, SOC, difficultly extractable GRSP, and total GRSP. It is concluded that AMF-triggered changes in plant growth, physiological activities, and soil fertility depended on plant species, but AMF-improved WSA distribution and stability were not dependent on plant species. [ABSTRACT FROM AUTHOR]

White clover (Trifolium repens L.) is an important perennial legume forage and ornamental plant, and is widely distributed and cultivated in the world. Recently, white clover plants showing symptoms of leaf mosaic and redding were observed in Hohhot, Inner Mongolia of China. In this work, flexuous filamentous viral particles of about 700 × 13 nm in size were observed in the symptomatic leaf samples. The infection of clover yellow vein virus (ClYVV) was confirmed by small RNA sequencing and RT-PCR validation. Mechanical inoculation assays showed that this ClYVV isolate (ClYVV-IM) can infect a range of herbaceous species, including Nicotiana benthamiana, N. occidentalis, Chenopodium quinoa, C. amaranticolor, Vicia faba, Vigna unguiculata, and Solanum lycopersicum, causing various symptoms. The complete genome sequence of ClYVV-IM consists of 9565 nt and shared sequence identities, ranging from 83.05% to 96.30%, with those of the other ClYVV isolates published in GenBank. Phylogenetic analyses based on the polyprotein nucleotide and amino acid sequences clustered 15 ClYVV isolates into two groups and ClYVV-IM located in Group I. Two potential recombination events located at 914–2970 nt and 5153–5694 nt were detected in the genome of ClYVV-IM. To our knowledge, this is the first report of occurrence and complete genome of ClYVV infecting white clover in China. [ABSTRACT FROM AUTHOR]

Europe is currently experiencing a huge decline in biodiversity, with the greatest reduction observed in plant species associated with grassland areas. There is therefore a need for more appropriate land management practices that do not endanger native populations. The focus of our research was to assess the modification of the species composition of the phytocenoses found in sloping meadows in the mountain–forest belt using organic and mineral fertilization and by reseeding cultural swards (with a mixture of Poaceae or Trifolium repens L.), while applying various meadow usage methods: multipurpose use (cut four times) and hay production (cut two times). The highest botanic richness (41 species from 16 families and 90% of perennial plants) was observed from the multipurpose usage of the meadow, which resulted in 28.1% more species than the haymaking usage. With regard to species stability, the most appropriate fertilization of the meadows was P30K60, regardless of the usage method. Fertilization with nitrogen fertilizers improved the yield of meadows but reduced the number of species. When meadows were reseeded with P. pratense and F. Pratensis and fertilized for haymaking, the number of families and species reduced, with a 25% decline in the number of T. repens families. This study concludes that to maintain the richness of plant species in these grasslands, farmers must receive financial subsidies to limit fertilization and plant cultivated species. [ABSTRACT FROM AUTHOR]

Context: Plant secondary metabolites are of increasing interest for agriculture due to their diverse beneficial ecological functions. The forage crop white clover (Trifolim repens L.) has been intensively studied for its heritable polymorphism in the production of hydrogen cyanide (HCN), a toxic defense phytochemical. In fodder production, white clover accessions are selected for biomass production, whereby HCN production is an unwanted trait. Aim: Although white clover is a legume crop species of global importance, little is known about the linkage between cyanogenesis and growth traits, in particular in combination with resistance-related phytochemicals, such as flavonoids. We aimed to identify differences in biomass production, estimated leaf flavonoid content, and trait correlations in cyanogenic (HCN-producing) and acyanogenic (not HCN-producing) individuals and accessions of white clover. Methods: We analysed 51 white clover accessions from a German germplasm collection for variability in selected traits: cyanogenesis as equivalent electrode potential, estimated leaf flavonoid content, root and shoot production, leaf area, specific leaf area, and number of leaves produced. Key results: Most accessions considered as cyanogenic were heterogeneous for HCN production. Chemical–morphological trait correlations differed between cyanogenic and acyanogenic plants. Acyanogenic individuals and accessions produced more and larger leaves compared to cyanogenic ones. Within cyanogenic accessions, the higher the HCN level of a plant, the fewer but larger leaves were produced. Conclusions: Our results highlight the variation in HCN production within the selected accessions, which calls for a consistent approach for cyanogenesis-based categorisation. Implication: This study demonstrates the potential of combining phytochemical traits with biomass production in white clover when selecting material in a breeding program. White clover is a widely grown legume and of particular interest as a forage and pasture crop due to its high nutritional value. Besides this, the ability to produce hydrogen cyanide, a toxic chemical compound involved in herbivore defence, represents a trait which entails advantages and disadvantages for agricultural practice. Plants producing this compound differ in growth from those not producing it, indicating the potential to integrate the linkage of this chemical trait with plant growth into future selection for breeding. [ABSTRACT FROM AUTHOR]