White clover/perennial ryegrass mixtures (
Trifolium repens
L.,
Lolium perenne
L.) are potential understory candidates for temperate agroforestry systems. A 2-year artificial shade experiment was ...conducted to determine the effects of shade on herbage production and quality and on changes in sward composition under field conditions. Wooden frames covered by shade cloth or a slatted structure were used on the sward to mimic different shade patterns of trees. The sward was exposed to 30, 50, and 80 % reduction in sun irradiance as well as a non-shaded control (0 % reduction). Total annual herbage production was highest in non-shaded swards in second and third year after establishment (8 and 16 t DM ha
−1
, respectively) and declined with increased shade (up to 70 % with 80 % shade). Compared to the control (24 t ha
−1
), 50 % shade cloth and 50 % slatted structure reduced biennial herbage production by 4 and 7 t ha
−1
, respectively. A decline in clover content of up to 93 % under severe shade compared to the control in the second year of the field experiment highlighted the sensitivity of clover to reduced radiation. No differences in forage nutritive qualities were detected in response to shade intensity during either growing season. On a dry matter basis, average biennial quality values were 2.7 % N, 41.8 % NDF, 34.4 % ADF, and 4.7 % ADL. The findings of the biennial field experiment confirm a white clover/perennial ryegrass sward is a suitable understory under light to moderate shade conditions; however, within a temperate agroforestry practice under dense shade, sward productivity and clover content will rapidly decline. Long-term effects of shade on white clover/perennial ryegrass mixtures as an understory in temperate agroforestry systems need to be evaluated in future research activities.
White clover (Trifolium repens L.) is at a disadvantage to perennial ryegrass (Lolium perenne L.; PRG) due to its limited cold tolerance and low growth rates at colder temperatures, which can affect ...subsequent spring herbage dry matter (DM) availability. The effect of PRG ploidy on white clover morphology and growth over winter, and its subsequent recovery in spring and the following growing season, is poorly understood. The objective of this study was to compare the effect of white clover inclusion and PRG ploidy on sward structure, plant morphology and growth of PRG–white clover swards over winter. Four swards (diploid PRG only, tetraploid PRG only, diploid PRG–white clover and tetraploid PRG–white clover) were evaluated over a full winter period (November–February) at a farmlet scale. The PRG ploidy had no effect on herbage DM production, white clover content or tissue turnover (P > 0.05) over winter. However, white clover inclusion caused a significant decrease in herbage DM production (P < 0.001; −254 kg DM/ha) and tiller density (P < 0.001; −1,953 tillers/m
2
) over winter. Stolon mass was not affected by PRG ploidy (P > 0.05); however, stolon length and number of leaves per stolon were affected by PRG ploidy (P < 0.05). Including white clover in PRG swards can alter winter sward dynamics, potentially causing difficulties in subsequent spring management and performance due to the reduced over-winter growth rate when compared with PRG.
The chemical constituents in Trifolium repens L. were comprehensively studied by UPLC in this work, and a total number of 308 compounds were detected with 169 ones identified. The possible ...fragmentation pathways were proposed and fragmentation rules were summarized. On the basis of the concluded strategies, the characterized compounds could be classified into organic acids and their derivatives, alkaloids, amino acids, peptides, flavonoids, oligosaccharides, coumarins, and other types of compounds. This approach provided a rapid way for the identification of constituents in T. repens L., and even in other complex analytes. Among the separation and identification of the constituents, three compounds of great amount were isolated and characterized by NMR. The expression of iNOS and COX‐2 in LPS‐induced RAW 264.7 cells was suppressed by the pretreatment with three isolated constituents. The results implied they may potentially serve as a remedy for the therapy of inflammation.
Practical applications
This work provided a rapid method for the identification of the complex analyte, which could be used in TCM, natural food and so on. The summarized fragmentation rule could be applied for the analysis of several types of compounds, such as organic acids and their derivatives, alkaloids, amino acids and peptides, flavonoids, oligosaccharides, coumarins, and so on. Most of natural plants contain these kinds of compounds, so these rules could have wide applications. Except the phytochemical investigation, T. repens L. displayed anti‐inflammation activity according to the reported literature, and the three isolated constituents may potentially serve as a remedy for the therapy of inflammation referring to the result of this research.
In traditional ryegrass/white clover (
L./
L.) pastoral systems, forage herbs such as chicory (
L.) present an opportunity to fill feed deficits during late spring and summer. Although multiple ...research publications have evaluated the efficacy of chicory for enhancing milk production and milk fatty acid (FA) profile, no publication has quantitatively synthesised the body of research. This systematic review and meta-analysis examined the effect of chicory on milk production and composition, as well as on the milk fatty acid composition of dairy cattle. A total of 29 comparisons from 15 unique research publications involving 597 dairy cattle were used to develop a dataset for analysis. Three-level random-effect and robust variance estimator models were used to account for the hierarchical structure of the data and the dependency of effect sizes within publications. Chicory inclusion increased milk yield when compared to grass-based diets {weighted mean difference (WMD) = 1.07 (95% CI 0.54-1.60) kg/cow/d,
< 0.001}, but it provided a similar milk yield when compared to other forages such as legumes and herbs {dicots; WMD = -0.30, (95% CI -89-0.29) kg/cow/day,
= 0.312}. Increases in milk yield were congruent with differences in DM intake (
= 0.09) and ME intakes (
= 0.003), being similar in chicory-fed and dicot-fed cows but higher than grass-fed cows. Chicory feeding's effect on milk solids was twice as high during mid lactation {154 days in milk; WMD = 0.13, (95% 0.081-0.175) kg/cow/day,
< 0.001} as during late lactation {219 days in milk; WMD = 0.06, (95% 0.003-0.13) kg/cow/day,
= 0.041}. In line with milk yield, greater and more significant effect sizes were found for alpha linolenic acid {ALA; WMD = 0.20 (95% CI 0.06-0.35) g/100 g FA,
= 0.011} when chicory was compared to grass species only. Comparing chicory with dicots suggests that chicory inclusion did not impact ALA concentrations {WMD = 0.001 (95% CI -0.02-0.2) g/100 g FA,
= 0.99}. There were no differences in conjugated linoleic acid concentration in the milk of cows fed chicory or control diets. The study provides empirical evidence of chicory's efficacy for improved milk production and milk fatty acid composition.
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.
The soybean aphid, Aphis glycines Matsumura, is an important pest of soybean. During some years with occurrences of heavy aphid infestations in field, A. glycines can cause serious damage to ...soybeans. A. glycines has a heteroecious and holocyclic life cycle, with migration occurring between the primary and secondary hosts during each year. The primary hosts of A. glycines are Rhamnus spp., and the secondary hosts are soybean, Glycine max (L.) Merrill, and wild soybean species, Glycine soja Sieb & Zucc. In this study, A. glycines were fed on detached leaves and live plants of Trifolium repens L. and Metaplexis japonica (Thunb.) Makino, and their survival, development and reproduction were studied at five constant temperatures. These data were compared to those of controls fed on the known host plant G. max. When A. glycines were fed on detached leaves of T. repens and M. japonica, they showed vigorous development and reproduction. The novel and striking results were that: (1) A. glycines could not thrive on live plants of M. japonica, and only a few nymphs were deposited. (2) When A. glycines were fed on live plants of vegetative stage T. repens, adult longevity and fecundity were as long as 11.64 ± 1.17 days and as great as 12.92 ± 1.23 nymphs per adult, respectively. This work provides important evidence that M. japonica is not a host of A. glycines, but T. repens is probably an important host for this aphid.
Display omitted
•Soybean aphid survived on detached leaf of Trifolium repens and Metaplexis japonica.•Soybean aphid could not thrive on live plants of M. japonica.•Soybean aphid flourished on live plants of vegetative stage T. repens.
Purpose
Rhizodegradation is the breakdown of organic contaminants such as polycyclic aromatic hydrocarbons (PAHs) using plants and rhizospheric microorganisms. The influence of two phytoremediating ...plants,
Miscanthus
×
giganteus
(M × G) and
Trifolium repens
L., was studied on a PAH-contaminated technosol composed of soil and sediments. More specifically, microbial density and diversity were studied along with the density of the population of PAH-degrading bacteria.
Methods
M × G and white clover were tested in mono- and co-culture on the technosol in a mesocosm over 263 days (life cycle of M × G until its senescence). At the beginning and the end of the phytoremediation experiment, microbial density was measured by real-time PCR, targeting bacteria (16S rDNA), fungi (18S rDNA), and PAH-degrading bacteria (PAH-RHDα GP). Bacterial and fungal diversity were determined by metagenomic analysis.
Results
The M × G monoculture appeared to increase bacterial diversity compared to non-planted technosol, in contrast to other planting patterns, while fungal diversity appeared to decrease in the presence of any of the plants. Overall, the plants increased the bacterial density in the technosol, while only white clover and the co-culture increased the fungal density, with the latter having a greater impact. Concerning the degrading bacteria, only the co-culture stimulated the PAH-degrading bacterial population. This is remarkable for the PAH rhizodegradation.
Conclusion
Even though the co-culture seemed to decrease the microbial diversity in the technosol, this condition was the most interesting with respect to the increase of the bacterial and fungal density as well as the enhancement of the PAH-degrading bacteria in the technosol.
A greenhouse pot experiment was conducted to investigate the influence of soil moisture content and plant species on soil microbial community structure using cultivation-independent methods. White ...clover and ryegrass were grown individually or in a mixture. Plants were subjected to soil moisture content corresponding to 60% field capacity (FC) and 80% FC. Total plant biomass of white clover and ryegrass increased with increasing soil moisture contents. At a given soil moisture content, total biomass of white clover was lower in the ryegrass–clover (RC) mixture compared with those grown individually, while total biomass of ryegrass was higher. Microbial community structure assessed by phospholipid fatty acid analysis (PLFA) was more affected by plant species than soil moisture. Community level physiological profiles (CLPP), in terms of diversity of substrate utilization and average well colour development (AWCD) were affected by plant species and soil moisture. Soil moisture effects were more pronounced in clover than in ryegrass. AWCD and diversity of substrate utilization in the ryegrass–clover mix were similar to those of sole clover while they differed from that of ryegrass suggesting a dominant effect of clover in the mix.
Allelopathic compounds can inhibit or stimulate the growth of nearby plants. This research examined the allelopathic effects of aqueous stem extract of
Euphorbia royleana
Boiss on in vitro seed ...germination in
Brassica campestris
L.,
Trifolium repens
L. and
Trigonella foenum-graecum
L. The fresh stem aqueous extract of
E. royleana
significantly stimulated seed germination with increasing concentration. Germination of seeds, radical and plumule growth were stimulated significantly in the three species tested. It is concluded that the aqueous extract of
E. royleana
has the potential to be used as a source of organic fertilizer, which could enhance the productivity of some important plants.
PDF
