Silver Grass Research Articles

Optimizing micropropagation of Miscanthus sinensis ‘Gold Bar’ by shortening the production cycle and reducing acclimation stress through the use of selected growth regulators

Miscanthus, with its decorative qualities and low cultivation requirements in terms of soil fertility and temperature, is the most popular grass in gardens and urban areas. For years, micropropagation has been regarded as an effective method of its production. However, in order to meet the demands of customers and provide adequate quantities of high-quality planting materials, it is necessary to develop more efficient methods of Miscanthus production. The present study evaluated the influence of different media on Miscanthus sinensis (Thunb.) Andersson (silver grass) multiplication as well as assessing the effect of different concentrations of selected cytokinins and auxins on multiplication and rhizogenesis. To shorten the production cycle and reduce costs, ex vitro rooting was combined with acclimatization, and selected growth regulators were used to decrease stress associated with external conditions. Biochemical analyses were conducted at each stage to determine the content of basic organic compounds, hydrogen peroxide (H2O2) and catalase activity. Stomatal function was assessed at the acclimatization stage. The obtained results allowed for the production cycle of plants propagated in tissue culture to be shortened by simultaneous rooting and acclimatization of microcuttings sprayed with abscisic acid (ABA). This regulator has been shown to effectively reduce plant stress associated with acclimatization by reducing H2O2 concentration and increasing assimilation pigment content. Growth regulators reduced the number of stomata that developed on the leaves of silver grass and led to lower stomatal conductance. H2O2 should be considered not only a stress marker but a vital signaling molecule.

Secondary contact zone and genetic introgression in closely related haplodiploid social spider mites.

How frequently hybridisation and gene flow occur in the contact zones of diverging taxa is important for understanding the speciation process. Stigmaeopsis sabelisi and Stigmaeopsis miscanthi high-aggression form (hereafter, S. miscanthi HG) are haplodiploid, social spider mites that infest the Chinese silver grass, Miscanthus sinensis. These two species are closely related and parapatrically distributed in Japan. In mountainous areas, S. sabelisi and S. miscanthi HG are often found in the highlands and lowlands, respectively, suggesting that they are in contact at intermediate altitudes. It is estimated that they diverged from their common ancestors distributed in subtropical regions (south of Japan) during the last glacial period, expanded their distribution into the Japanese Archipelago, and came to have such a parapatric distribution (secondary contact). As their reproductive isolation is strong but incomplete, hybridisation and genetic introgression are expected at their distributional boundaries. In this study, we investigated their spatial distribution patterns along the elevation on Mt. Amagi using male morphological differences, and investigated their hybridisation status using single-nucleotide polymorphisms by MIG-seq. We found their contact zone at altitudes of 150-430 m, suggesting that their contact zone is prevalent in the parapatric area, which is in line with a previous study. Interspecific mating was predicted based on the sex ratio in the contact zone. No obvious hybrids were found, but genetic introgression was detected although it was extremely low.

Miscanthus sinensis 'Variegatus' Variegated Japanese Silver Grass

This document provides an overview of Miscanthus sinensis ‘Variegatus’, commonly known as variegated Japanese silver grass or maiden grass. It describes the plant’s distinctive features, including its variegated leaves, pink flowers, and upright growth habit. The document highlights its uses in landscaping, such as mass planting, borders, and as an accent plant. It also covers the plant’s adaptability to various soil types, its moderate drought tolerance, and its invasive potential. Additionally, it mentions other cultivars of Miscanthus sinensis and provides guidance on planting and maintenance. Original publication date October 1999.

Effect of Composted Organic Waste on Miscanthus sinensis Andersson Energy Value

At the time of rising urbanization and population growth, the search for renewable energy sources to ensure sustainable development is of extreme importance. The aim of this research was to determine the effects of different proportions of composted organic materials, i.e., mushroom substrate and municipal waste, on Chinese silver grass (Miscanthus sinensis Andersson) energy value. A three-year field experiment was established on experimental plots in the east-central part of Poland. Various treatment combinations, each introducing 170 kg N·ha−1 to the soil, had a positive effect on the energy parameters of Chinese silver grass biomass. The highest calorific value (17,964 kJ·kg−1) was noted for plants treated with mushroom compost on its own (MSC100%).

Pyrolysis of biomass harvested from heavy-metal contaminated area: Characteristics of bio-oils and biochars from batch-wise one-stage and continuous two-stage pyrolysis

This study evaluates pyrolysis products obtained from biomasses (silver grass, pine, and acacia) harvested from heavy-metal-contaminated soil. To do so, we utilized two methods: a batch one-stage pyrolysis, and a continuous two-stage pyrolysis. The study results show that the yields and characteristics of bio-oils and biochars varied depending on the pyrolysis process and the type of biomass. The two-stage pyrolysis having two reactors (auger and fluidized bed reactors) appeared to be very suitable for specific chemicals production such as acetic acid, acetol, catechol, and levoglucosan. The biochar obtained from the fluidized-bed reactor of two-stage pyrolysis had high thermal stability, high crystallinity, high inorganic content, and a small number of functional groups. In contrast, the biochar obtained from the one-stage pyrolysis had low thermal stability, low crystallinity, a high carbon content, and a large number of functional groups. The biochar obtained from the two-stage pyrolysis appeared to be suitable as a material for catalyst support and as an adsorbent. The biochar obtained from one-stage pyrolysis appeared to be a suitable as a soil amendment, as an adsorbent, and as a precursor of activated carbon. All biochars showed a negative carbon footprint. In the end, this study, which was conducted using two different processes, was able to obtain the fact that products of pyrolysis biomass contaminated with heavy metals have different characteristics depending on the process characteristics and that their utilization plans are different accordingly. If the optimal utilization method proposed through this study is found, pyrolysis will be able to gain importance as an effective treatment method for biomass contaminated with heavy metals.

Leveraging the sugarcane CRISPR/Cas9 technique for genetic improvement of non-cultivated grasses.

Under changing climatic scenarios, grassland conservation and development have become imperative to impart functional sustainability to their ecosystem services. These goals could be effectively and efficiently achieved with targeted genetic improvement of native grass species. To the best of our literature search, very scant research findings are available pertaining to gene editing of non-cultivated grass species (switch grass, wild sugarcane, Prairie cordgrass, Bermuda grass, Chinese silver grass, etc.) prevalent in natural and semi-natural grasslands. Thus, to explore this novel research aspect, this study purposes that gene editing techniques employed for improvement of cultivated grasses especially sugarcane might be used for non-cultivated grasses as well. Our hypothesis behind suggesting sugarcane as a model crop for genetic improvement of non-cultivated grasses is the intricacy of gene editing owing to polyploidy and aneuploidy compared to other cultivated grasses (rice, wheat, barley, maize, etc.). Another reason is that genome editing protocols in sugarcane (x = 10-13) have been developed and optimized, taking into consideration the high level of genetic redundancy. Thus, as per our knowledge, this review is the first study that objectively evaluates the concept and functioning of the CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 technique in sugarcane regarding high versatility, target specificity, efficiency, design simplicity, and multiplexing capacity in order to explore novel research perspectives for gene editing of non-cultivated grasses against biotic and abiotic stresses. Additionally, pronounced challenges confronting sugarcane gene editing have resulted in the development of different variants (Cas9, Cas12a, Cas12b, and SpRY) of the CRISPR tool, whose technicalities have also been critically assessed. Moreover, different limitations of this technique that could emerge during gene editing of non-cultivated grass species have also been highlighted.

Metal-rich biochar as an asphalt modifier to improve sustainability and reduce VOC emissions

Asphalt-surfaced areas have been recently reported as non-combustion sources emitting organic chemical compounds. These emissions from asphalt not only accelerate its aging but also negatively affect air quality and the health of people who inhale the emitted compounds. Trying to mitigate the latter emission and inspired by the phytoremediation capacity of the acacia plant, we have developed a metal-rich carbonaceous adsorbent (biochar) from the acacia plant. Here, we evaluate the efficacy of our acacia-derived adsorbent to reduce the hazardous volatile organic compounds (VOCs) emitted from asphalt-surfaced areas. We further compare the efficacy of our acacia-derived adsorbent with an adsorbent made from a low-metal plant (silver grass). The higher metal content of the adsorbent made from acacia correlated with its higher efficacy compared to that of silver grass in reducing the release of VOCs from the corresponding asphalt, displaying emissions of 16.9% in asphalt binder containing acacia biochar compared to emissions of 21.2% using silver-grass biochar. Using density functional theory (DFT)-based molecular modeling, we specifically investigated the adsorption behavior of three prominent metals present in acacia biochar: Ca with ≈8 wt%, Al with 6.9 wt%, and Fe with 4.4 wt%. Using DFT, we demonstrated the individual contribution of each metal to adsorbing each of six chemical air pollutants. The DFT results revealed the superiority of Fe at interacting with VOCs across all N-containing zones of the biochar surface: pyridine, pyrrole, amine, and amide. Specifically, in the pyridine and pyrrole zones of the biochar surface, the trend of interaction energy for gas pollutants is as follows: Fe > Ca > Al > no metal. Considering the high concentration of Ca in acacia biochar (≈8 wt%), this trend of energy (Fe > Ca > Al > no metal) highlights the crucial role of Ca in enhancing biochar adsorption. Our findings highlight the potential of using inherently metal-rich biomass feedstocks to reduce volatile emissions from asphalt-surfaced areas, improving air quality and extending the service life of roadway infrastructure.

Physiological Response of Miscanthus sinensis (Anderss.) to Biostimulants

Soil salinity stress is a serious problem in plant cultivation. The effect of this stress is to disrupt the photosynthetic process, which can cause growth restrictions and a decrease in plant productivity. The use of biostimulants can be one of the stress mitigation strategies in plant cultivation. Biostimulants increase the tolerance of plants to abiotic stresses, thus mitigating their adverse effects. In the present study, based on a pot experiment, the effect of foliar application of biostimulants differentiated in terms of chemical composition (Bombardino (B1), Quantis® (B2), Biofol Plex (B3) and Megafol (B4)) on the physiological properties of Chinese silver grass (Miscanthus sinensis (Anderss.)) plants growing under salt stress conditions was determined. Salt stress was induced by soil application of NaCl at concentrations of 200 and 400 mM. The application of salt solutions was followed by spraying Miscanthus plants with biostimulants using a hand-held sprayer. Physiological investigations (chlorophyll content, chlorophyll fluorescence and gas exchange) have been carried out twice: on the 1st (Term I) and 7th (Term II) day after spraying with biostimulants. It was shown that salt stress causes a decrease in the values of most of the physiological indicators tested (except Ci). On both measurement dates, the application of biostimulants, especially B2, caused an improvement in the values of the physiological indices studied, both for plants growing under optimal conditions and under salt stress. Term II showed an upward trend in most of the analyzed parameters compared to Term I, indicating plant acclimatization to stress conditions. Conducted studies have shown that using biostimulants contributes to the alleviation of the effects of soil salinity stress. The implementation of these practices can contribute to the advancement of sustainable farming.

Co-production of ethanol and polyhydroxybutyrate from lignocellulosic biomass using an engineered Saccharomyces cerevisiae

The development of glucose/xylose co-fermenting Saccharomyces cerevisiae has improved bioethanol yield from lignocellulosic biomass, the most abundant and sustainable resource for net-zero production of fuels and chemicals. The co-production of value-added chemicals would further improve the economic feasibility of lignocellulosic bioethanol production. Here, we developed a glucose/xylose co-fermenting S. cerevisiae strain capable of co-producing polyhydroxybutyrate, a prominent biodegradable polymer, as an intracellularly accumulated co-product by introducing a polycistronic polyhydroxybutyrate biosynthetic pathway. The engineered strain accumulated polyhydroxybutyrate with a content of 64 mg/g DCW while maintaining extracellular production of ethanol with a high yield (0.43 g ethanol/g sugar). The co-production of ethanol and polyhydroxybutyrate was then evaluated using various types of biomass, including sugarcane bagasse, silver grass, and even cardboard boxes. This study demonstrates the feasibility of co-production of bioethanol and value-added chemicals to maximize the values derivable from lignocellulosic biomass.

Catalytic pyrolysis for upgrading silver grass (Miscanthus sinensis) and carbon dioxide into flammable gases

This study proposes a sustainable hydrogen production platform using a fast-growing and inedible biomass waste, silver grass (Miscanthus sinensis). Pyrolysis of silver grass waste (SGW) was investigated using CO2 as a co-feedstock, focusing on the distribution of hydrogen in different products. When the catalyst was absent, hydrogen element distribution to H2 gas during pyrolysis of SGW at 800 °C reached 10 wt%. During pyrolysis with the Ni/SiO2 catalyst, 60.3 wt% of hydrogen was converted into H2 gas, and 7.3 wt% of hydrogen was distributed in gaseous hydrocarbons at 600 °C. Owing to the addition of CO2, CO production was promoted by the catalytic conversion of CO2 and volatile matter. Notably, CO2 has been proven to be a useful reactant for producing value-added CO. Thus, catalytic pyrolysis in the presence of CO2 can be considered as a renewable approach to produce flammable gases with the mitigation of CO2 emissions.

Complete genome sequence of a novel potyvirus infecting Miscanthus sinensis (silver grass)

Here, we describe the full-length genome sequence of a novel potyvirus, tentatively named “Miscanthus sinensis mosaic virus” (MsiMV), isolated from Miscanthus sinensis (silver grass) held in a post-entry quarantine facility after being imported into Western Australia, Australia. The MsiMV genome is 9604 nucleotides (nt) in length, encoding a 3071-amino-acid (aa) polyprotein with conserved sequence motifs. The MsiMV genome is most closely related to that of sorghum mosaic virus (SrMV), with 74% nt and 78.5% aa sequence identity to the SrMV polyprotein region. Phylogenetic analysis based on the polyprotein grouped MsiMV with SrMV, sugarcane mosaic virus (SCMV), and maize dwarf mosaic virus (MDMV). This is the first report of a novel monopartite ssRNA virus in Miscanthus sinensis related to members of the genus Potyvirus in the family Potyviridae.

Making plant methane formation visible-Insights from application of 13C-labeled dimethyl sulfoxide.

Methane (CH4) formation by vegetation has been studied intensively over the last 15 years. However, reported CH4 emissions vary by several orders of magnitude, thus making global estimates difficult. Moreover, the mechanism(s) for CH4 formation by plants is (are) largely unknown.Here, we introduce a new approach for making CH4 formation by plants clearly visible. By application of 13C-labeled dimethyl sulfoxide (DMSO) onto the leaves of tobacco plants (Nicotiana tabacum) and Chinese silver grass (Miscanthus sinensis) the effect of light and dark conditions on CH4 formation of this pathway was examined by monitoring stable carbon isotope ratios of headspace CH4 (δ13C-CH4 values).Both plant species showed increasing headspace δ13C-CH4 values while exposed to light. Higher light intensities increased CH4 formation rates in N. tabacum but decreased rates for M. sinensis. In the dark no formation of CH4 could be detected for N. tabacum, while M. sinensis still produced ~50% of CH4 compared to that during light exposure.Our findings suggest that CH4 formation is clearly dependent on light conditions and plant species and thus indicate that DMSO is a potential precursor of vegetative CH4. The novel isotope approach has great potential to investigate, at high temporal resolution, physiological, and environmental factors that control pathway-specific CH4 emissions from plants.

Drying and dehydration of native ornamental plants of Arunachal Pradesh and its value addition

Wild and underutilized plant species particularly ornamental flowers and foliage can be converted into value added products using drying and dehydration technique. The present studies have been carried out to explore the potential of wild ornamental plants of Arunachal Pradesh for the purpose of dry flower making. The plant parts have been collected from different places viz. Pasighat, Bodak, Renging, Menchuka, Bomdilla, Tenga Valley, Yingkiong, etc. A total of fourteen (14) potential plant species had been identified for drying and dehydration without any loss in quality and appearance. The species identified includes Pteridium aquilinum (Eagle Fern/Western Bracken Fern), Lycopodium clavatum (Stag’s Horn Clubmoss/Ground pine), Nicandra phylasoides (Apple of Peru), Scirpus cyperinus (Wool grass), Barleria cristata (Phillipine violet), Cortaderia selloana (Pampas grass), Anaphilis busua (Tall pearly everlasting), Miscanthus spp. (Silver grass), lichens, Phragmites spp. (common reed grass), Davallia bullata (Rabbit foot fern), Tillandsia spp. (Spanish moss), Elsholtzia cristata (Crested late summer mint) and Setaria parviflora (Bristly foxtail). Maximum number of genera belongs to the family of Poaceae followed by Cyperaceae. Seed heads of Cortaderia selloana, Miscanthus spp., Phragmites spp., Erioscirpus comosus, Scirpus cyperinus, Setaria parviflora; leaves of Pteridium aquilinum, Lycopodium clavatum, Davallia bullata; fruits of Nicandra phylasoides, Elsholtzia cristata; flower of Anaphilis busua; dried calyx of Barleria cristata and stem of Tillandsia spp. had also been used for drying and value addition. A cottage industry based on floral craft can become a new area for self-employment of rural youth’s and women through this creative occupation. The quest for searching new materials which can be utilized as dried flowers never ends and in fact is the demand of the hour.

Carbon and nitrogen dynamics as affected by land-use and management change from original rice paddies to orchard, wetland, parking area and uplands in a mountain village located in Shonai region, Northeast Japan

ABSTRACT This study investigated the effect of land-use and management change (LUMC) on carbon (C) and nitrogen (N) dynamics after 15–40 years. LUMC constituted change from rice paddies to chestnut orchard, wetland, and buckwheat upland fields in Shonai region, Yamagata Prefecture, Northeast Japan. Soil samples were collected from the top – (0–15 cm) and sub-layers (15–30 cm) for analysis of soil organic C (SOC) and its δ13C value, total N (TN), and their stocks. C decomposition (Dec-C) and net N mineralization (Net Min-N) were determined according to the production of CO2 and NH4 + + NO3 – by aerobic incubation and CO2 + CH4 and NH4 + by anaerobic incubation, respectively. The results reveal that 40 years after change from rice paddy to orchard and wetland, the SOC and TN contents in the top-layer were not significantly altered. However, in buckwheat upland fields and in the parking area where vegetation was absent, the SOC content decreased significantly. Conversion of rice paddies to amur silver grass wetland altered the soil δ13C the most, leading to an increase of 5.1‰ and 2.9‰ for the top – and sub-layers, respectively. In general, the incubation experiment results revealed that a change to orchard and wetland did not significantly decrease the Dec-C and Net Min-N. Whereas, the change from rice paddies to parking area significantly decreased the Dec-C and Net Min-N in both aerobic and anaerobic conditions. We conclude that LUMC over decades had various effects on the SOC and TN contents and stocks as well as their mineralization potentials.

Design of antibiofilm surfaces by immobilization of biogenic silver nanoparticles on amine self-assembled monolayers

Hospital-acquired infections (HAIs) are a serious medical threat nowadays, compromising the efficacy of the existing medical infrastructure. HAIs driven impact on the antibiotics usage resulted in further complications of (a) developing multi-drug resistant bacterial strain and (b) insignificant potential towards eradicating biofilm formation. To address this serious issue, we have developed silver nanoparticles (AgNPs) based antimicrobial surfaces using amine self-assembled monolayers. The biogenic spherical AgNPs (76 ± 15 nm) were synthesized using a plant extract of Miscanthus khasiana (silver grass) as a reducing agent. The surface energy of AgNPs-amine surface was 38.2 mJ/m2 and remained constant after the in-vitro stability test. The prepared surfaces hampered the bacterial adhesion and biofilm formation of Pseudomonas aeruginosa. A 67% reduction in the viability of the adhered bacteria was observed in the presence of the designed AgNPs-amine surface, confirming its antibiofilm potential.

Miscanthus sp. – Perennial lignocellulosic biomass as feedstock for greener fumaric acid bioproduction

The potential use of lignocellulosic biomass as the feedstock for fumaric acid production and to select the specific Rhizopus oryzae strain for bioproduction was investigated in the current work. For this purpose, alkaline pretreatment of the biomass from perennial grasses, silver grass (Miscanthus sp.) and switchgrass (Panicum virgatum), and hemp (Cannabis sativa) was performed followed by enzymatic saccharification. The hydrolysate so obtained, was used as the feedstock for fumaric acid production. Silver grass was identified as the ideal perennial lignocellulosic biomass due to its higher reducing sugar concentration of 39.55 g/L as well as a yield of 0.79 g/g of pretreated biomass. The use of the hydrolysate for fumaric acid production, by three R. oryzae strains namely NRRL 1526, NRRL 6400 and NRRL 2582, yielded acid concentrations of 8 – 9 g/L. The strain NRRL 1526 was identified as the promising strain for fumaric acid bioproduction, as it provided the highest fumaric acid productivity of 0.19 gL−1h−1.

Suppressive Effects of Traditional Mulching Using Japanese Knotweed (Fallopia japonica) on Solanaceae Crop Diseases

Poaceae plant species, such as silver grass, are commonly used in mulching activities Japan. In contrast, local farmers have traditionally used Japanese knotweed (Fallopia japonica) mulch in the cultivation of solanaceous crops in the Nishi-Awa area of Japan, which is a Globally Important Agricultural Heritage Systems site. We have previously evaluated the positive effects of Japanese knotweed mulching on solanaceous crops, such as eggplants, tomato, and potato. In the present study, we observed that the naturally occurring diseases in the solanaceous crops tended to decrease when the knotweed mulching system was adopted, in comparison to when Poaceae mulch was adopted. In eggplants, leaf mold and powdery mildew decreased under Japanese knotweed mulching. We further evaluated the effects of Japanese knotweed mulching by inoculating test plants with Pseudomonas cichorii. We observed suppression of bacterial disease and tomato mosaic virus under Japanese knotweed mulching and following spraying with Japanese knotweed extracts. In addition, disease-resistance genes were expressed at high levels in Arabidopsis thaliana, a model plant, following treatment with Japanese knotweed extracts. The results suggest that Japanese knotweed has potential applications in future sustainable agriculture activities.

Root Characteristics and Water Erosion-Reducing Ability of Alpine Silver Grass and Yushan Cane for Alpine Grassland Soil Conservation

In Taiwan, intensive forest fires frequently cause serious forest degradation, soil erosion and impacts on alpine vegetation. Post-fire succession often induces the substitution of forest by alpine grassland. Alpine silver grass (Miscanthus transmorrisonensis Hay.) and Yushan cane (Yushania niitakayamensis (Hay.) Keng f.) are two main endemic species emerging on post-fire alpine grassland. These species play a major role in the recovery of alpine vegetation and soil conservation of alpine grassland. However, their root traits, root mechanical properties and water erosion-reducing ability have still not been well studied. In the present study, root characteristics were examined using a complete excavation method. Root mechanical characteristics were estimated by utilizing the uprooting test and root tensile test, and hydraulic flume experiments were performed to investigate the water erosion-reducing ability using 8-month-old plants. The results show that the root architecture system of Alpine silver grass belongs to fibrous root system, while the Yushan cane has sympodial-tufted rhizomes with a fibrous root system. Root characteristics reveal that relative to Alpine silver grass, Yushan cane has remarkably larger root collar diameter, higher root biomass, larger root volume, higher root density, and a higher root tissue density. Furthermore, uprooting resistance of Yushan cane is notably higher than that of Alpine silver grass. However, the root tensile strength of Alpine silver grass is significantly higher than that of Yushan cane. Additionally, hydraulic flume experiments reveal that Yushan cane has significantly lower soil detachment rates than that of Alpine silver grass. Collectively, these findings clearly show that Yushan cane has superior root characteristics and water erosion-reducing ability than Alpine silver grass and is thus more suitable for the conservation of alpine grassland.

Effect of Japanese Knotweed (Fallopia japonica) Mulching on Continuous Potato Cropping: Modern Evaluation of Traditional Japanese Knotweed-Mulch Farming in Nishi-Awa Steep Slope Land Agriculture System, Japan

Poaceae species such as silver grass or reed are commonly used in traditional mulch farming in Japan, where the Nishi-Awa area is a Globally Important Agricultural Heritage Systems (GIAHS) site. Farmers here have traditionally used silver grass for mulch farming; furthermore, local farmers have learned from long-standing experience that Japanese knotweed (Fallopia japonica, Polygonaceae) is better for cultivation of solanaceous crops in this area. However, it is unclear why Japanese knotweed mulching is beneficial for cultivation of solanaceous crops. Thus, in this study, we hypothesized that Japanese knotweed mulching may be effective in avoiding hazards associated with continuous potato cropping, as native potato used to be cultivated twice a year in the past. Therefore, we investigated the effects of Japanese knotweed mulching on continuous potato cropping and after tomato cropping, which is another solanaceous crop species. Field experiments were conducted in 2018. First, we compared Japanese knotweed mulching, silver grass mulching and no grass mulching (control) in a soil under continuous potato cultivation and in an uncultivated soil. As a result, the extent of the potato yield decrease was reduced by Japanese knotweed mulching. Secondly, we compared Japanese knotweed-mulching and no grass mulching in a soil after a tomato crop and in an uncultivated soil. The extent of decrease in potato growth and yield was also reduced by Japanese knotweed mulching. These findings indicate that mulching with Japanese knotweed helped to avoid the risks associated with continuous potato cropping.

Two new species of Coccomorpha (Hemiptera: Sternorrhyncha) collected from Japanese silver grass, Miscanthus sinensis (Poaceae) in Okinawa Island, Japan.

Two new species of Coccomorpha collected from Japanese silver grass, Miscanthus sinensis Andersson (Poaceae), in Okinawa Island, Japan, are described based on the morphology of adult females: Aspidiella kijimuna sp. nov. (Diaspididae) and Dysmicoccus bunagaya sp. nov. (Pseudococcidae). Aspidiella kijimuna is similar to A. phragmitis (Takahashi, 1931) but differs from it by having relatively well-developed and recognisable third lobes, and median lobes with rounded apices. Dysmicoccus bunagaya is similar to Trionymus okiensis Tanaka, 2018 but differs from it by having more than eight pairs of cerarii. Keys to all the Japanese species of Aspidiella and Dysmicoccus are provided.