Percentage Of Biomass Research Articles

Agronomic traits at the seedling stage, yield, and fiber quality in two cotton (Gossypium hirsutum L.) cultivars in response to phosphorus deficiency

ABSTRACT Cotton is critical for phosphorus demands and very sensitive for its deficiency. However, identifying the effect of low-phosphorus tolerance on cotton growth, yield, and fiber quality by reducing phosphorus consumption. This may help to develop phosphorus-tolerant high-yielding cotton cultivars. In a two-year repeated (2015 and 2016) hydroponic experiment (using 0.01 and 1 mM KH2PO4), two cotton cultivars with phosphorus sensitivity (Lu 54; a low-phosphorus sensitive and Yuzaomian 9110; a low-phosphorus tolerant) were screened on the base of agronomic traits and physiological indices through correlation analysis, cluster analysis and principal component analysis from 16 cotton cultivars. Low phosphorus nutrition reduced the plant height, leaf number, leaf area, phosphorus accumulation and biomass in various organs of seedlings. The deficiency negatively affected the morphogenesis of seedlings, as well as yield and fiber quality. Further, these screened cultivars were tested in a pot experiment with 0, 50, 100, 150, 200 kg P2O5 ha−1 during 2016 and 2017. It was found to have a significant (P< 0.05) difference in boll number, lint yield, fiber strength, and micronaire at the harvest. Furthermore, after collectively analyzed the characteristics of Lu 54 and Yuzaomian 9110, there were six key indices that could improve the low phosphorus tolerance of cotton cultivars. These were root phosphorus accumulation, stem phosphorus accumulation percentage, leaf and total biomass of seedlings, seed cotton weight per boll and fiber length.

Droplet size impact on lactofen and acifluorfen efficacy for Palmer amaranth (Amaranthus palmeri) control

AbstractHerbicide applications performed with pulse width modulation (PWM) sprayers to deliver specific spray droplet sizes could maintain product efficacy, minimize potential off-target movement, and increase flexibility in field operations. Given the continuous expansion of herbicide-resistant Palmer amaranth populations across the southern and midwestern United States, efficacious and cost-effective means of application are needed to maximize Palmer amaranth control. Experiments were conducted in two locations in Mississippi (2016, 2017, and 2018) and one location in Nebraska (2016 and 2017) for a total of 7 site-years. The objective of this study was to evaluate the influence of a range of spray droplet sizes [150 (Fine) to 900 μm (Ultra Coarse)] on lactofen and acifluorfen efficacy for Palmer amaranth control. The results of this research indicated that spray droplet size did not influence lactofen efficacy on Palmer amaranth. Palmer amaranth control and percent dry-biomass reduction remained consistent with lactofen applied within the aforementioned droplet size range. Therefore, larger spray droplets should be used as part of a drift mitigation approach. In contrast, acifluorfen application with 300-μm (Medium) spray droplets provided the greatest Palmer amaranth control. Although percent biomass reduction was numerically greater with 300-μm (Medium) droplets, results did not differ with respect to spray droplet size, possibly as a result of initial plant injury, causing weight loss, followed by regrowth. Overall, 900-μm (Ultra Coarse) droplets could be used effectively without compromising lactofen efficacy on Palmer amaranth, and 300-μm (Medium) droplets should be used to achieve maximum Palmer amaranth control with acifluorfen.

Potensi dan Pengaruh Batang Pisang Sebagai Media Filter Pada Pengolahan Air Limbah Pencucian Kendaraan Bermotor

Wastewater vehicle washing that discharged directly into water bodies can increase pollution levels. Wastewater treatment of small-scale vehicle washing businesses must be efficient, no need large areas, easy to operate and economical. The alternative technology is using simple wastewater filtration system. Banana stems can be used for filter media. Previous studies mention banana stems have cellulose content and have high hygroscopic ability. High cellulose content allows the potential to be used as an absorbent media. Hygroscopic properties are useful for absorbing harmful inorganic chemicals. The study was conducted by making a filtration reactor using banana stem filter media with a variation of residence time and filter media thickness. Sample testing by analyzing COD, TSS and Detergent parameters. The test results significant decrease in TSS and detergent parameters. The highest percentage decrease in TSS reached 91% and detergent 96%. COD decreased during the filtration treatment directly, but after that increased with the length of duration. This is due to biological influence and the high percentage of organic matter and biomass of banana stems. It can be concluded that the banana stem potential as a filter media for direct wastewater treatment and effective in reducing TSS and detergents for washing vehicles wastewater.

Utilization of banana peel waste for citric acid production by Aspergillus niger

The potential of Banana peel waste of Pisang Ayam (Musa acuminata), Pisang Raja (Musa Paradisiaca cv. Raja genom AAB), and Pisang Nipah (Musa balbisiana) as substrat for citric acid production by Aspergilus niger have been investigated. The main purpose of this research was to determine the percentages of citric acid production, pH, and total biomass at differences of media of banana peel waste. The results showed that the percentages of citric acid production using media of Musa acuminata, Musa Paradisiaca cv. Raja genom AAB and Musa balbisiana were 58.80, 69.84, and 46.80% respectively. The pH values of each media were 2.50, 1.50, and 2.0 respectively. The results also founded that the total biomass of each media were 2.442, 2.649, and 2.407 respectively. Overall, the results showed that banana peel waste of Musa Paradisiaca produce the highest amount of citric acid after 240 h fermentation.

Modeling and performance analysis of subcritical and supercritical coal-fired power plants with biomass co-firing and CO2 capture

Coal-fired power plants are the largest source of carbon dioxide (CO2) emissions into the atmosphere, and these emissions can be effectively reduced by improving the efficiency of the plants, co-firing sustainably grown biomass and applying carbon capture and storage technologies. In this study, the energy and environmental performances of both subcritical (SubC) and supercritical (SC) pulverized coal-fired power plants with biomass co-firing and integrated with an advanced amine-based postcombustion CO2 capture system were evaluated and compared. The impact of biomass (hybrid poplar) addition was investigated at different co-firing ratios varying up to 30% on a heat input basis. All plant configurations were modeled and simulated with Aspen Plus process simulation software. The results show that the use of a SC steam cycle has a positive impact on the energy and environmental performance of the investigated plants, improving the efficiency by 2.4% points and reducing the total fuel consumption and CO2 emissions by 6% in comparison to those of the SubC cases. Biomass co-firing has a negative impact on the energy performance of plants while significantly reducing fossil-based carbon emissions. The reduction of net CO2 emissions is almost proportional to the biomass percentage in the feed. At 30% biomass co-firing, the net plant efficiency is reduced by approx. 1% point, while the net CO2 emissions are 28% lower than those in coal-fired only plants. The introduction of CO2 capture has a major impact both on the emissions generated and on the energy efficiency. Depending on the plant type and co-firing ratio used, the net plant efficiencies are 8.7–9.3% points lower than those of non-capture cases. The net CO2 emissions achieve negative values when carbon is captured from the biomass co-firing plants.

Biobutanol production from sulfuric acid-pretreated red algal biomass by a newly isolated Clostridium sp. strain WK.

Marine biomass, especially the algal biomass, is currently considered to be one of the most potential candidates for biofuels conversion during the development of biomass utilization. In this study, a diluted sulfuric acid pretreatment method was established for biobutanol from red algal biomass Gelidium amansii using a newly isolated Clostridium sp. strain WK. Under the optimal condition of 2% sulfuric acid treated in 20Min at 131°C, the maximal hydrolysis percentage of biomass can reach up to 80.95%, and the biobutanol production was obtained to be 3.46g/L with a yield of 0.20g/g after the fermentation of biomass hydrolysate. This result demonstrated a 12.5-fold enhancement of conversion efficiency compared with the untreated control, which provides a new and efficient way to develop the biobutanol industry by utilizing the abundant, low cost, and carbohydrate-rich algal biomass.

Ecuaciones alométricas para estimar biomasa en especies de encino en Guanajuato, México

Los bosques de encino son importantes en el equilibrio de los ecosistemas donde estos cohabitan, ya que son un grupo de especies con mayor capacidad para fijar y almacenar carbono atmosférico. El objetivo de este trabajo fue desarrollar ecuaciones alométricas para estimar biomasa aérea de seis especies de encino (Quercus rugosa, Q. obtusata, Q. sideroxyla, Q. coccolobifolia, Q. laurina y Q. candicans) con un muestreo destructivo de 165 árboles. Se ajustaron ecuaciones para estimar biomasa por componentes estructurales (fuste, ramas y follaje), y de forma aditiva se estimó la biomasa total, así como una ecuación generalizada para las seis especies, y ecuaciones para estas divididas en dos grupos. Para mejorar la capacidad predictiva de las ecuaciones se ajustaron modelos que incluyen las variables de diámetro normal, altura total y densidad de la madera. El mayor porcentaje de biomasa se concentró en el fuste con 60.6%, mientras que ramas y follaje representaron 36.1% y 3.28%, respectivamente. Las ecuaciones ajustadas explicaron más de 95% de la variabilidad en la biomasa total del árbol y, comparadas con ecuaciones desarrolladas en otros lugares para el mismo género, presentaron un menor sesgo porcentual. Las ecuaciones alométricas generadas pueden ser utilizadas para la región, así como en bosques con características estructurales y de crecimiento similares a las de las comunidades de encino de la sierra de Guanajuato.

The Persistence of Container Nursery Treatments on the Field Performance and Root System Morphology of Longleaf Pine Seedlings

In recent decades, container stock has become the preferred plant material to regenerate longleaf pine (Pinus palustris Mill.) forests in the southeastern United States. We evaluated the effects of container nursery treatments on early and long-term field performance in central Louisiana. Seedlings were grown in four cavity volumes (60–336 mL) with or without copper oxychloride root pruning (Cu or no-Cu) and fertilized at three nitrogen (N) rates. Across treatments, 91% of the seedlings emerged from the grass stage by the second field season, and 88% of the seedlings survived eight years after outplanting (Year 8). Seedlings grown in the largest cavities had greater total heights and stem diameters than those cultured in the 60- and 95-mL cavities through Year 8. Seedlings receiving the least amount of N in the nursery were consistently smaller in stature through Year 8 than seedlings receiving more N. Field growth was unaffected by copper root pruning through Year 8. Foliar mineral nutrient concentrations and seedling nutrient contents of Year 2 seedlings did not respond to nursery treatments. Independent of nursery treatments, seedlings excavated in Year 2 had at least 60% of their first-order lateral roots (FOLRs) originating from the top 4.0 cm of the taproots. The Cu-root-pruned seedlings had twofold the percentage of FOLRs egressed from the top 8.0 cm of the root plug when compared with the no-Cu seedlings. Moreover, the Cu root pruning treatment decreased the percentage of root plug biomass allocated to FOLRs, total within root plug FOLR lengths, and FOLR deformity index. The effects of increasing cavity volume or N rate on the root plug FOLR variables were opposite those of the Cu root pruning treatment. Our results suggest that a tradeoff may exist between seedling stature and a more natural FOLR morphology in outplanted container longleaf pine seedlings.

Pertumbuhan dan Alokasi Biomassa Organ Tanaman Mahoni (Swietenia mahagoni L.) yang Ditanam Pada Tanah Bekas Tambang Emas dengan Perlakuan Pupuk Kandang

Abstract. The purpose of this study is to determine the growth and biomass allocation of Mahagony plant organs are planted on ex-gold mining soil with manure treatment. The experimental research with four treatments are control (without manure), manure (cow, goat, chicken) with five replications. The plant growth parameters are observed consist of plant height, stem diameter, leaf number, leaf area, rooth lenght, dry weight, and biomass percentage are located to leaves, stems and plant roots. The data are tested anova and continue with t-test. The result showed that the treatment of manure had efeect on the growth and mahagony planted on ex-golg mining soil. Plant biomass on all manure treatment are largest alloccated to leaves organ then to stems and roots. Based on t-test result that the cow manure treatment is better to supporting growth and biomass of mahagony plant than chicken manure, goat manure and control.Keywords: growth, biomass, mahagony, ex-gold mining soil, manure

Carbon sequestration via afforestation as a sustainable action to mitigate climate change in Western Iran

Climate change involves increasing atmospheric carbon dioxide concentration which is driven by anthropogenic emissions. Afforestation, which is the establishment of forests on previously non‐forested lands, could be a suitable climate change mitigation strategy. The aim of this research is to evaluate the carbon sequestration capability of the Eucalyptus and Prosopis species in the Reza‐Abad afforestation park in western Iran. For this aim, three stands of any species were selected. For quantitative assessment, a transect was implemented at the length of 100 m. In trees located of transects, the general characteristics of species were measured. Also, for estimating the amount of litter, a sample plot has been measured at the center of the quadrate. These samples were taken from the afforested area, the control area inside the afforested area and another control area outside. In each stand, species were selected randomly and one‐eighth of the whole stand was taken for calculating the percentage of carbon and aerial biomass. Then the aboveground organs were weighted and after the transfer of different plant organs to the laboratory, the conversion factor of carbon sequestration of the plant organs was determined individually by combustion method. Also, soil samples were also collected from two depths of 0–15 and 15–30 cm in each of the cultivated and control parts. The results showed that there is a significant difference between the species and Prosopis has higher carbon sequestration than Eucalyptus. The carbon sequestration among different organs showed a significant difference, carbon sequestration was 19.24 t/ha for Eucalyptus and 18.43 t/ha for Prosopis. After an economic calculation, it was concluded that afforestation has a positive effect on the reduction of atmospheric carbon dioxide. Hence, these results allow decision makers to change land use from desert area to forest, and planting the Prosopis species is more recommendable than Eucalyptus for afforestation in such areas which are economically profitable.

Estimating belowground plant abundance with DNA metabarcoding.

Most work on plant community ecology has been performed above ground, neglecting the processes that occur in the soil. DNA metabarcoding, in which multiple species are computationally identified in bulk samples, can help to overcome the logistical limitations involved in sampling plant communities belowground. However, a major limitation of this methodology is the quantification of species' abundances based on the percentage of sequences assigned to each taxon. Using root tissues of five dominant species in a semi-arid Mediterranean shrubland (Bupleurum fruticescens, Helianthemum cinereum, Linum suffruticosum, Stipa pennata and Thymus vulgaris), we built pairwise mixtures of relative abundance (20%, 50% and 80% biomass), and implemented two methods (linear model fits and correction indices) to improve estimates of root biomass. We validated both methods with multispecies mixtures that simulate field-collected samples. For all species, we found a positive and highly significant relationship between the percentage of sequences and biomass in the mixtures (R2 =.44-.66), but the equations for each species (slope and intercept) differed among them, and two species were consistently over- and under-estimated. The correction indices greatly improved the estimates of biomass percentage for all five species in the multispecies mixtures, and reduced the overall error from 17% to 6%. Our results show that, through the use of post-sequencing quantification methods on mock communities, DNA metabarcoding can be effectively used to determine not only species' presence but also their relative abundance in field samples of root mixtures. Importantly, knowledge of these aspects will allow us to study key, yet poorly understood, belowground processes.

Effects of Frequency of Irrigation on Dry-Season Furrow-Irrigated Maize and Peanut Production in the Rice-Growing Lowlands of the Lower Mekong Basin

Incorporation of dry-season crops in the lowland production systems of the Lower Mekong Basin (LMB) may provide local smallholder farmers the opportunity to increase household cash income through diversification. However, water availability and lowland rice-growing soil characteristics often limit the yield potential of dry-season crops in rotation with wet-season rice. This work studied the effects of three frequencies of irrigation on the crop performance of dry-season furrow-irrigated maize (Zea mays Linnaeus) and peanut (Arachis hypogaea Linnaeus) grown on lowland rice-growing soils in terms of biomass, yield and water productivity (WP). In addition, the response of maize to two fertiliser rates was evaluated. The study was carried out in sites with typical lowland rice-growing soils located in Cambodia and Laos. Soil matric potential (Ψm) was monitored during the season at the centre of the beds and percentage of canopy cover, aboveground biomass (AGB), yield and WP were determined. The results showed that within the first weeks of furrow irrigation (~two weeks after emergence), Ψm dropped considerably (&lt;−200 kPa) after all treatments at both sites, suggesting that water movement from the furrows to the centre of the beds was limited. Shorter frequency of irrigation led to significantly (p &lt; 0.05) higher AGB and yield in maize but not in peanut. Fertiliser rates did not have a significant effect on maize. WP ranged from 0.84 kg m−3 to 1.42 kg m−3 for maize and from 0.27 kg m−3 to 0.49 kg m−3 for peanut with no significant differences among treatments. This work provides evidence of a lateral water movement limitation that is not well documented for the establishment of furrow-irrigated dry-season crop production in the lowlands of the LMB. Further research on methodologies that could help to overcome this limitation in these soils, such as the application of soil amendments or implementation of alternative irrigation systems, would be of great value.

Predation by Long-Tailed Weasels Mustela frenata during a Richardson's Ground Squirrel Urocitellus richardsonii Population Outbreak in Southwestern Saskatchewan

Long-tailed weasels (Mustela frenata) are known to feed on mice and voles. However, in the Canadian Prairies, where Richardson's ground squirrels (Urocitellus richardsonii) are abundant (particularly during drought periods), long-tailed weasel predation on these medium-size rodents is poorly documented. In this study, predation by long-tailed weasels on Richardson's ground squirrels was documented from April 2008 to September 2008 in southwestern Saskatchewan during a drought period. I found that Richardson's ground squirrel remains were the dominant food item in percentage of occurrence, volume, and biomass from April to July. In August–September, however, deer mice (Peromyscus maniculatus) and insects became more important. During years of Richardson's ground squirrel abundance, weasels may temporarily switch predation onto these rodents.

Phytotoxicity of Methiozolin on Fine Fescue

Methiozolin is a new herbicide that controls annual bluegrass (Poa annua) in turfgrasses, but the differential tolerance levels of fine fescues (Festuca sp.) has received limited investigation. The objective of this study was to investigate the potential injury from methiozolin when applied to chewings fescue (Festuca rubra ssp. fallax), strong creeping red fescue (Festuca rubra ssp. rubra), and hard fescue (Festuca brevipila). Nine different fine fescue populations (14W2 Comp, Fairmont, and Survivor chewings fescue; FT345, Miser, and Fenway strong creeping red fescue; and 14H4 Comp, Stonehenge, and Oxford hard fescue) were sprayed with methiozolin at five different rates (0.42, 0.83, 1.25, 1.67, and 2.09 lb/acre) at four different application timings [4 weeks before seeding (WBS), 2 WBS, at seeding (AS), and 2 weeks after germination (WAG)]. Untreated controls were also included for each combination. Significant reduction in germination of fine fescue was observed when methiozolin was applied before emergence for all tested application rates. Methiozolin at 1.25, 1.67, and 2.09 lb/acre applied before or at the day of seeding led to complete inhibition of germination in all fine fescue species tested. It was less injurious compared with methiozolin applied at 2 WAG, although a reduction in the percentage of green cover and biomass was observed for application rates greater or equal to 0.83 lb/acre. The hierarchical ranking of species injury from high to low is as follows: hard fescue, chewings fescue, and strong creeping red fescue. A possible solution for annual bluegrass control in fine fescue species with methiozolin is multiple postemergence applications up to a maximum rate of 0.83 lb/acre. Turf managers need to make adjustments in methiozolin application rates and timings based on fine fescue species to maximize selectivity for annual bluegrass control.

Soil Moisture Determines Horizontal and Vertical Root Extension in the Perennial Grass Lolium perenne L. Growing in Karst Soil.

Karst regions are characterized by heterogeneous soil habitats, with shallow wide soil (SW) on hilly slopes and deep narrow soil (DN) in rocky trenches. To make full use of limited water and nutrients, plants have therefore developed a number of root extension strategies. This study investigated the effect of soil moisture on horizontal root extension in SW and vertical root extension in DN by assessing root growth responses, biomass allocation, and root distribution. A full two-way factorial blocked design of soil dimensions by water availability was followed. The perennial grass Lolium perenne L. was grown in SW and DN under high (W100%), moderate (W50%), and low (W30%) water availability, respectively. The main results were as follows: (1) The total biomass of L. perenne was not influenced either by soil habitat or by water application. Root length, root surface area, root biomass and root to shoot ratio all decreased with decreasing water application in SW, but not in DN soil. (2) With decreasing water application, the cumulative percentage of root length, root surface area and root biomass in 4 rings from the center out to 12 cm of SW soil showed a trend of W50% > W30% > W100% in SW, however, the cumulative percentage of root biomass in 4 layers from the surface to a depth of 36 cm was not significantly different between different water treatments in DN. (3) Under all three water treatments, specific root length showed an increase but root length density showed a decreasing trend from the center outward in SW soil or from the surface to bottom in DN soil. Overall, these results suggest that in SW habitat, soil moisture determines horizontal expansion of the roots in L. perenne, although the overall expansion ability was limited in severe drought. However, due to the relatively strong water retention ability, soil moisture changes were less obvious in DN, resulting in no significant vertical extension of the root system. The root response of L. perenne helps our understanding of how herbaceous plants can adjust their belowground morphology to support their growth in harsh karst soil environments.

Estimating protein quantities from microalgae: protein per biomass percentage, spectroscopic concentration, and lectin content

Protein quantifications can be essential steps in the screening of microalgae strains. The protein per biomass percentage of seven species of Chlorophyceae microalgae was estimated by a procedure that includes a protein precipitation step for removal of interfering substances. Ankistrodesmus fusiformis, Coelastrum microporum and Scenedesmus obliquus presented the highest protein content (22%, 21%, and 25%, respectively), whereas Chlamydocapsa bacillus presented the lowest protein per biomass ratio (11%). Specific values of percent extinction coefficients (E1%) for each strain was used as a strategy for rapid estimations of total protein concentrations from microalgae by absorbance readings at 280 nm. The species found with the highest lectin contents were Kirchneriella lunaris, Pseudokirchneriella subcapitata and C. bacillus, since they rendered the highest specific hemagglutinating activity (SHA) values for their total protein precipitates (5.2, 3.5, and 2.3, respectively), which was defined as the ratio between the hemagglutinating activity titer and the logarithm of its total protein concentration in μg/mL. Because the titer is indirectly associated to the concentration of lectins in a sample before the serial dilution, the SHA is more convenient for screening of different species, as it also includes the protein concentration of the titer.

Effects of seed furrow liquid spraying device on sowing quality and seedling growth of maize

The two cultivation patterns, no-tillage and ridge cultivation, are widely used in maize planting in Northeast China. However, the seed bounce in the falling process and drought seriously at the seedling stage often occur to affect the sowing quality, mean emergence time, percentage of emergence, root biomass, aboveground biomass and root shoot ratio of maize, and eventually reduces the grain yield. To solve the problems, a seed furrow liquid spraying device was designed and thereby the effects of spraying water volumes [0 L/m (V0), 0.6 L/m (V1), 1.2 L/m (V2) and 1.8 L/m (V3)] and nozzle types [conical nozzle (N1) and sectorial nozzle (N2)] on the sowing quality and seedling growth of maize were studied. The water volume and nozzle type had significant effects on the sowing quality (QR, CV, LD), not seedling growth (MET, PE, RB, AB, RSR) (p V2 > V1 > V0). However, the variability coefficient of seed spacing and lateral deviation of seed position were the opposite. The larger spraying water volume led to shorter mean emergence time (V0 > V1 > V2 > V3) and higher percentage of emergence (V3 > V2 > V1 > V0). The root biomass and aboveground biomass increased significantly with the enlargement of spraying water volume. Under different water volumes, the root shoot ratio differed significantly. The plants in the V1, V2 and V3 treatments had lower root shoot ratios compared with the V0 treatment. The increase of spraying water volume significantly reduced the root shoot ratio. The seed furrow liquid spraying device provides a reference for improving sowing quality and promoting seedling growth. Keywords: seed bounce, drought, spraying water volume, nozzle type, seed spacing uniformity, root shoot ratio DOI: 10.25165/j.ijabe.20191202.3799 Citation: Wang W J, Wang W P, Jia H L, Zhuang J, Wang Q. Effects of seed furrow liquid spraying device on sowing quality and seedling growth of maize. Int J Agric & Biol Eng, 2019; 12(2): 68–74.

Identifying Fraudulent Natural Products: A Perspective on the Application of Carbon-14 Analysis.

Across food and supplement industries, there is a growing trend toward products comprised of natural ingredients. As manufacturers strive to offer "natural" products to consumers, adulteration of ingredients with cheaper synthetic alternatives becomes a concern. This perspective highlights the application of carbon-14 analysis to screen for potential adulteration of natural ingredients, such as garlic oil. Carbon-14 testing determines if a product is comprised of solely plant- or animal-based ingredients by measuring the percentage of biomass versus petrochemical-derived sources. Through comparison to other analytical techniques used for quality control, carbon-14 testing stands out as being able to detect petrochemical-derived nature-identical compounds.

Effects of crude extracts of &lt;i&gt;Aspergillus fumigatus&lt;/i&gt; and &lt;i&gt;Penicillium citrinum&lt;/i&gt; on the biomass of &lt;i&gt;Eleusine indica&lt;/i&gt; (L.) Gaertn

In a pot experiment, two fungal strains namely Aspergillus fumigatus and Penicillium citrinum were evaluated for their herbicidal properties on the biomass of Eleusine indica using the biomass reduction method. Crude extracts of Aspergillus fumigatus and Penicillium citrinum made up of 10 treatments at three levels each with positive and negative controls in three replications in a Completely Randomised Block Design was adopted. Infections were evident within 48 hours after the application of the various treatments. At 1, 3, 5 and 7 days after application of the treatments, the percentage biomass yields and biomass reductions of E. indica were determined. The data collected were subjected to analysis of variance and the means separated using Duncan Multiple Range Test. The percentage reductions in biomass yields (88.46% and 35.61%) of Eleusine indica especially at the highest inocula concentration (1010 spores/ml) of the crude extracts showed significant differences (p≤ 0.001). The results indicate that both crude extracts possess the potentials for herbicidal control of Eleusine indica with evidence that the concentrated crude extracts of Aspergilus fumigatus had the greatest impact on its biomass yields. Therefore, it is recommended that further work be carried out on the purification of both crude extracts to confirm the effective biological metabolites accountable for their herbicidal properties and also evaluate these herbicidal properties on other weed species adopting different time and methods of application. Keywords: Fungal strains, Herbicidal properties, Biological metabolites, Concentrated crude extracts, Biomass yields and Biomass reductions

Seasonal distribution of increased precipitation in maternal environments influences offspring performance of Potentilla tanacetifolia in a temperate steppe ecosystem

Precipitation is predicted to increase in arid and semiarid regions under climate change, with greater changes in intra- and inter-annual distribution in the future. As a major limiting factor in these regions, changes in precipitation undoubtedly influence plant growth and productivity. However, how the temporal shifts in precipitation will impact plant populations are uncertain. A 3-year field experiment and a greenhouse experiment were conducted in a temperate grassland in northern China to examine the impacts of seasonal (spring and summer) increased precipitation on offspring performance of a common species, Potentilla tanacetifolia. Our results showed that the amounts and timing of increased precipitation both played important roles in regulating offspring performance of P. tanacetifolia in the temperate steppe ecosystem. Increased precipitation in spring at maternal stage stimulated seed production, germination percentage and seedling biomass, whereas increased precipitation in summer at maternal stage stimulated seedling biomass. The timing of increased precipitation influenced seed attributes, whereas the amount of increased precipitation influenced offspring seedling biomass. Our results indicate that population development of P. tanacetifolia may be underestimated under future increased precipitation regime, if the transgenerational effect is not taken into account.