On-time mapping dynamics of crop area,yield,and production is important for global food security.Such information,however,is often not available.Here,we used satellite information,a spectral-phenology integration appr...On-time mapping dynamics of crop area,yield,and production is important for global food security.Such information,however,is often not available.Here,we used satellite information,a spectral-phenology integration approach for mapping crop area,and a machine learning model for predicting yield in the war-stricken Ukraine.We found that in Ukraine crop area and production declined in 2022 relative to 2017–2021 and 2021 for wintertriticeae crops,which was invaded before the cropping season in February of that year.At the same time,crop area and production for rapeseed increased in Ukraine,with yields consistently lower by 6.5%relative to 2021.The low precipitation and the Russian-Ukrainian conflict-related factors contributed to such yield variations by-1.3%and-0.9%for winter-triticeae crops and-4.2%and-0.5%for rapeseed in 2022.We demonstrate a robust framework for monitoring country-wide crop production dynamics in near real-time,serving as an early-foodsecurity-warning system.展开更多
The aim of this study is to produce large quantities of yam tubers in the field from seed tubers derived from vitroplants regenerated from aerial stem cuttings and farmers’ tuber seeds. Seed tubers from ten yam culti...The aim of this study is to produce large quantities of yam tubers in the field from seed tubers derived from vitroplants regenerated from aerial stem cuttings and farmers’ tuber seeds. Seed tubers from ten yam cultivars, including five from Dioscorea alata (cDa083, cDa053, cDa115, cDa150 and cDa266) and five from Dioscorea cayenensis-rotundata (cDr015, cDr027, cDr150, cDr206 and cDr148) with distinct agro-morphological characteristics, were used as material. A completely randomized block design with 3 replications was used. In each block, all cultivars and seed types were represented. When put into cultivation, the tubers produced by the vitroplants all germinated and gave 100% healthy plants, compared with 86% to 100% healthy plants for the seed tubers produced by the farmers. Yields per hectare ranged from 10 to 25 tonnes for seed tubers produced by in vitro plants, and from 4 to 9 tons for seed tubers produced by farmers. Seed tubers from vitroplants can therefore be recommended to farmers as a solution to the problem of seed tuber unavailability.展开更多
Fire is regarded as management practice for maintaining grasslands and savannas. The vegetation occurring in fire prone areas becomes highly adapted to fire occurrences in savannas and grasslands. However, documentati...Fire is regarded as management practice for maintaining grasslands and savannas. The vegetation occurring in fire prone areas becomes highly adapted to fire occurrences in savannas and grasslands. However, documentation on the influence of burning on vegetation is still limited in an albany thicket biome. The aim of the study was to evaluate the short-term influence of burning on species abundance, biomass production, wood plant density and browsing unit. Six plots (2500 m<sup>2</sup>) were demarcated;in each plot two parallel transects of 120 m<sup>2</sup> with 5 m distance apart were measured. Three plots were burned in spring season, while no burning was done on the other remaining plots. Forty points per plot were obtained using step-point method to determine the relative abundance at burned and unburned plots. Woody plants occurred within a transect were identified, counted and recorded to determine density and browsing unit. Three quadrats (<em>i.e</em>. 0.25 m<sup>2</sup>) per plot were randomly laid within the transect;aboveground plant material within a quadrat were harvested. A total of 18 samples were harvested and oven dried at 60<span style="white-space:nowrap;"><span style="white-space:nowrap;">˚</span></span>C for 48 hours to determine biomass production. The results showed that <em>Themeda triandra</em> (14%) and <em>Panicum maximum</em> (10%) were most abundant grass species at the burned plots. Burned plots had significantly higher biomass production (4804 kg/ha) compared to unburned plots (3641 kg/ha). <em>Vachellia karoo</em> (burned: 65.85% & unburn: 13.70%) and <em>Searsia pallens </em>(burned: 26.83% & unburned: 6.85%) were most dominant wood plant species at both burned and unburned plots. Burned plots had the highest browsing unit (3221 BU/ha) compared to unburned plots (2058 BU/ha). The decrease of woody plants at the burned plots proved that fire has a tremendous potential for managing woody plants. This study provided information on short-term influence of burning, however further long-term trials are required to determine the effects of burning.展开更多
The production of crops is badly affected by climate change globally.Mitigation of adverse effects of climate change is in need of time through different management practices such as developing tolerant genetic resour...The production of crops is badly affected by climate change globally.Mitigation of adverse effects of climate change is in need of time through different management practices such as developing tolerant genetic resources,hormonal applications to boost defense systems,nanoparticles,and balanced fertilization.The nano-hormonal syn-ergy had the potential to mitigate the adverse effects of climate change by modulation of morpho-physiological and biochemical activities.Plant growth,yield,and quality can be enhanced with the supplementation of nano-hormonal interactions.Therefore,the current study explores the synergy between nanoparticles and phytohormonal use.The nanoparticles,even in low concentrations,had an excellent capability to improve the endogenous hormones contributing to the regulation of plant responses under stress conditions.Nano-hormonal interaction improved the plant tolerance against climate change by activation of signaling molecules and the plant defense system.Nano-hormonal contact triggers several enzymic and non-enzymatic activities that can scavenge toxic substances generated within the plants.The reduction in electrolyte leakage,malondialdehyde(MDA),and hydrogen peroxide(H_(2)O_(2))was due to the supplementation of nano-hormonal exchange.The optimum production of reactive oxygen species(ROS)is necessary for normal plant growth and various developmental processes.However,the overproduction of ROS can be eliminated with nano-hormonal synergy.However,inappropriate applications can cause phytotoxicity such as germination inhibition,root malformation,and chlorosis.The optimum doses can vary depending on the kind of crop and stress conditions.The nano-hormonal interface is beneficial for crop growth,yield,and quality.Moreover,these are also effective in repairing plants damaged from adverse climatic conditions.Hence,these are effective for sustainable agriculture production.展开更多
Essential oils(EOs)derived from medicinal plants are gaining recognition as sustainable alternatives to synthetic fungicides in the management of plant pathogens.This study investigates the chemical composition,chroma...Essential oils(EOs)derived from medicinal plants are gaining recognition as sustainable alternatives to synthetic fungicides in the management of plant pathogens.This study investigates the chemical composition,chromatographic profile,and antifungal of Mentha rotundifolia essential oil against Fusarium oxysporum f.sp.albedinis(Foa),the pathogen responsible for Bayoud disease in date palm.The oil was extracted through hydrodistillation and characterized using thin-layer chromatography(TLC)and gas chromatography–mass spectrometry(GC-MS),revealing multiple fractions corresponding to terpenoid constituents and 23 chemical constituents,predominantly oxygenated monoterpenes(68.51%),with piperitenone oxide as the major component(62.53%).The antifungal efficacy was evaluated against ten(10)isolates of F.o.a across seven(07)concentrations different concentrations.(0;0.25;0.5;0.75;1;1.25;1.5μL/mL).The results obtained show a progressive decrease in the diameters of the colonies of F.o.a isolates by increasing the doses of EOMR.The percentage of inhibition varies from 7.82 to 83.41%;However,the dose of 1.75μL/mL showed 100%inhibition for all F.o.a isolates tested.These outcomes demonstrate the potential of M.rotundifolia essential oil as a natural,environmentally friendly antifungal agent,supporting its application in sustainable management strategies for Bayoud disease in date palm.展开更多
Drought,as the most catastrophic abiotic stress,poses a significant threat to the growth and development of plants.Among the mechanisms employed by plants to cope with drought-induced stress,abscisic acid(ABA)which is...Drought,as the most catastrophic abiotic stress,poses a significant threat to the growth and development of plants.Among the mechanisms employed by plants to cope with drought-induced stress,abscisic acid(ABA)which is the sesquiterpene hormone,occupies a pivotal role.A hypothesis has emerged that the exogenous application of ABA can positively influence the terpenoid content of Lavandula angustifolia cv Hidcote essential oil(EO),thereby conferring enhanced resilience to drought stress.A randomized complete block design experiment was conducted with three replicationsandfour irrigation regimes,including I4[30%-40%of field capacity(FC)],I3(50%-60%FC),I2(70%-80%FC),andI1(90%-100%FC)as control.Application of ABAspraying included three concentrations,A3(30μmol·L^(-1)ABA),A2(15μmol·L^(-1)ABA),and A1 as control(distilled water).Results revealed that drought significantly affected all studied traits except for relative water content(RWC)and shoot dry mass.The ABA impact application on the observed traits was found to be dependent upon the level of drought to which the plants were exposed.Specifically,the highest levels of flavonoid content,total antioxidant activity,peroxidase(POX)activity,and EO percentage were observed under I4A2 conditions.Conversely,the highest levels of superoxide dismutase(SOD)and catalase(CAT)activity,and proline were recorded under I4A3 conditions,while the highest EO yield was obtained under I3A2 conditions.Analysis of the EO revealed that there were common indicative compounds across the varying levels of droughtandABAapplication,including linalool,camphor,borneol,bornyl formate,andcaryophyllene oxide.Theproduction pattern ofmonoterpene and sesquiterpene compounds demonstrated a distinct trend,with the highest concentration of monoterpene hydrocarbon compounds(average of 12.92%)being observed in the I2A3 treatment group,andthe highest concentration of oxygenatedmonoterpenecompounds(average of 64.76%)being recorded in the I1A1 group.Conversely,the most significant levels of sesquiterpene hydrocarboncompounds(14.98%)andoxygenated sesquiterpene compounds(10.46%)were observed in the I4A3 and I4A1 groups,respectively,showing the efficacy of monoterpenes and sesquiterpenes from the action of ABA under drought conditions.The observed results indicated that the concentration of oxygenated monoterpene compounds decreases with an increase in drought level.Conversely,the application of ABA at any given drought level appears to resulted in increased concentrations of oxygenated monoterpene compounds in the same conditions.It may be concluded that plants under high-stress drought conditions allocate more terpene precursors to the production of sesquiterpene hydrocarbon compounds,aided by ABA with the same properties.展开更多
China is in a dominant position in apple production globally with both the largest apple growing area and the largest export of fresh apple fruits. However, the annual productivity of China＇s apple is significantly l...China is in a dominant position in apple production globally with both the largest apple growing area and the largest export of fresh apple fruits. However, the annual productivity of China＇s apple is significantly lower than that of other dominant apple producing countries. In addition, apple production is based on excessive application of chemical fertilizers and the nutrient use efficiency （especially nitrogen） is therefore low and the nutrient emissions to the environment are high. Apple production in China is considerably contributes to farmers＇ incomes and is important as export product. There is an urgent need to enhance apple productivity and improve nutrient use efficiencies in intensive apple production systems in the country. These can be attained by improved understanding of production potential, yield gaps, nutrient use and best management in apple orchards. To the end, priorities in research on apple production systems and required political support are described which may lead to more sustainable and environmental-friendly intensification of apple production in China.展开更多
The study was conducted at Zengena forest, a fragmented remnant montane forest in northwestern Ethiopia, which surrounds Lake Zengena. The purpose was to assess the species composition, diversity and the regeneration ...The study was conducted at Zengena forest, a fragmented remnant montane forest in northwestern Ethiopia, which surrounds Lake Zengena. The purpose was to assess the species composition, diversity and the regeneration status of woody plants. A total of 27 plots of 20 m - 20 m were sampled along the line transects laid down the altitudinal gradient from the edge of the forest encompassing the lake to the edge of the lake in eight aspects. In each plot, woody species were counted and the diameter at breast height and the height of trees and shrubs were measured. A total of 50 woody species belonging to 31 families were found, of which 17 （34%） were trees, 7 （14%） trees or shrubs, 23 （46%） shrubs and 3 （6%） lianas. The overall Shannon-Wiener diversity and evenness indices of woody species were 2.74 and 0.7, respectively. Clausena anisata had the highest relative density （23.5%）, Rapanea rhododendroides the highest relative frequency （6.5%） and Prunus afri- cana the highest relative dominance （45%） and importance value index （IVI, 51.6）. The total basal area and density of woody plants were 22.3 m2.ha-1 and 2,202 individuals.ha1, respectively. The population structure showed variations among woody plants and revealed varied regeneration patterns of different species. The importance value index and population structure revealed that some species are threatened and need prioritization for conservation measures. The results suggest that remnant forest patches in the highlands of northern Ethiopia host several woody plant species that are almost disappearing in other areas due to deforestation.展开更多
Composite top- and subsoil samples were collected from the greenhouses in the Al-Balawneh area,Jordan,where intensive greenhouse production system(IGPS) has been practiced since 1998,to study the impact of IGPS on soi...Composite top- and subsoil samples were collected from the greenhouses in the Al-Balawneh area,Jordan,where intensive greenhouse production system(IGPS) has been practiced since 1998,to study the impact of IGPS on soil quality as measured by the chemical and biological properties to develop a sustainable production system.The study showed that IGPS led to higher electrical conductivity in top- and subsoils compared to an uncultivated soil(control).Quality and amount of irrigation water,lack of efficient drainage,and quantity and types of applied fertilizers were major factors resulting in salt buildup.IGPS resulted in lower total N(TN) and NO_3-N in the soil compared to the control.The lower TN was due to crop uptake,microbial immobilization,volatilization,and irregular application of composted animal manure or poultry manure.In contrast,higher residual Olsen-P content was detected in both soil layers of greenhouses than in the control.Residual P was classified as very high in the topsoil layers and sufficient to high in the subsoil layers.Residual available K in the soils of greenhouses was relatively lower than that in the control and it was,however,classified as high to very high.A large increase of Cl and a considerable decrease in the bacterial count were observed in both soil layers of IGPS compared to the control treatment.Economically sustainable soil management practices need to be adopted by farmers to achieve a sustainable and profitable production.This can be accomplished through education,targeted towards the farming community in the central Jordan Valley.展开更多
Increasing crop production is necessary to maintain food security for the growing global population.Reducing the gap between actual and potential yield is one of the important ways to increase yield per unit area.Pote...Increasing crop production is necessary to maintain food security for the growing global population.Reducing the gap between actual and potential yield is one of the important ways to increase yield per unit area.Potential yield and the yield gap of soybean were determined for Golestan Province,Iran,using Soybean Simulation Model (SSM-i Crop2) and Geographical Information System (GIS).Information from 24 weather stations and soil data of the region were used.Yield gap and production gap were calculated at county and province levels.The average actual yield of soybean in this province was2.28 t ha^(–1) while the province’s potential yield was 4.73 t ha^(–1),so the yield gap was estimated 2.44 t ha^(–1).Thus,there is a great potential for increasing soybean yield in Golestan,which is possible through improving crop management of soybean in farmers’fields.The average water productivity of soybean was estimated to be 0.81 kg m^(–3).Spatial distribution of water productivity in soybean farms showed that the highest and the lowest water productivities (0.99 and 0.44 kg m^(–3)) were in western and eastern regions of the province,respectively,in accordance to vapour pressure deficit.It was concluded that soybean production in the province could increase by 66%(from 109 970 to 182 170 tons) if 80% of the current yield gap could be removed.展开更多
Tea plants are sensitive to soil moisture deficit,with the level of soil water being a critical factor affecting their growth and quality.Arbuscular mycorrhizal fungi(AMF)can improve water and nutrient absorption,but ...Tea plants are sensitive to soil moisture deficit,with the level of soil water being a critical factor affecting their growth and quality.Arbuscular mycorrhizal fungi(AMF)can improve water and nutrient absorption,but it is not clear whether AMF can improve the photosynthetic characteristics of tea plants.A potted study was conducted to determine the effects of Claroideoglomus etunicatum on plant growth,leaf water status,pigment content,gas exchange,and chlorophyll fluorescence parameters in Camellia sinensis cv.Fuding Dabaicha under well-watered(WW)and drought stress(DS)conditions.Root mycorrhizal colonization and soil hyphal length were significantly reduced by the eightweek DS treatment.AMF inoculation displayed a significant increase in shoot and root biomass production.The relative water content,leaf water potential,nitrogen balance index,pigment content,maximum photometric effect(Fv/Fm,QY_max),and steady-state photometric effect Y(II)(QY_Lss)decreased dramatically,while the leaf water saturation deficit and steady-state non-photochemical fluorescence quenching(NPQ_Lss)generally increased under DS conditions.Mycorrhizal treatment induced significantly higher relative water content,leaf water potential,nitrogen balance index,pigment(chlorophyll,flavonoid,and anthocyanin)content,net photosynthesis rate,transpiration rate,stomatal conductance,intercellular CO_(2)concentration,QY_max,and QY_Lss;however,it resulted in a lower leaf water saturation deficit and NPQ_Lss under both WW and DS conditions,as compared with nonmycorrhizal plants.These results imply that AMF promoted tea plant growth and alleviated negative effects of DS by promoting gas exchange,regulating the water status of leaves,and regulating photosynthetic parameters.展开更多
Background: Coupling biomass models with nutrient concentrations can provide sound estimations of carbon and nutrient contents, enabling the improvement of carbon and nutrient balance in forest ecosystems. Although nu...Background: Coupling biomass models with nutrient concentrations can provide sound estimations of carbon and nutrient contents, enabling the improvement of carbon and nutrient balance in forest ecosystems. Although nutrient concentrations are often assumed to be constant for some species and specific tree components, at least in mature stands,the concentrations usually vary with age, site index and even with tree density. The main objective of this study was to evaluate the sources of variation in nutrient concentrations in biomass compartments usually removed during harvesting operations, covering a range of species and management conditions: semi-natural forest, conventional forest plantations and short rotation forestry(SRF). Five species(Betula pubescens, Quercus robur, Eucalyptus globulus, Eucalyptus nitens and Populus spp.) and 14 genotypes were considered. A total of 430 trees were sampled in 61 plots to obtain 6 biomass components:leaves, twigs, thin branches, thick branches, bark and wood. Aboveground leafless biomass was pooled together forpoplar.The concentrations of C, N, K, P, Ca, Mg, S, Fe, Mn, Cu, Zn and B were measured and the total biomass of each sampled tree and plot were determined. The data were analysed using boosted regression trees and conventional techniques.Results: The main sources of variation in nutrient concentrations were biomass component > > genotype(species) ≈ age >tree diameter. The concentrations of Ca, Mg and K were most strongly affected by genotype and age. The concentrations of P, K, Ca, Mg, S and Cu in the wood component decreased with age, whereas C concentrations increased, with a trend to reach 50% in the older trees. In the SRF, interamerican poplar and P. trichocarpa genotypes were comparatively more efficient in terms of Ca and K nutrient assimilation index(NAI)(+65-85%) than eucalypts, mainly because leafless biomass can be removed. In the conventional eucalypt plantations(rotation 15 years), debarking the wood at logging(savings of225% of Ca and 254% of Mg for E. globulus) or the use of selected genotypes(savings of 45% of P and 35% of Ca) will provide wood at a relatively lower nutrient cost. Considering all the E. globulus genotypes together, the management for pulp with removal of debarked wood shows NAI values well above(x 1.7-x 3.9) the ones found for poplar or eucalypt SRF and also higher(x 1.6-x4.0) than the ones found for oak and birch managed in medium or long rotations.The annual rates of nutrient removal were low in the native broadleaved species but the rates of available soil nutrients removed were high as compared to poplar or eucalypts. Management of native broadleaved species should consider nutrient stability through selection of the biomass compartments removed.(Continued on next page)(Continued from previous page)Conclusions: The nutrient assimilation index is higher in poplar grown under short rotation forestry management than in the other systems considered. Nutrient management of fast growing eucalyptus plantations could be improved by selecting efficient genotypes and limiting removal of wood. The values of the nutrient assimilation index are lower in the natural stands of native broadleaved species than in the other systems considered.展开更多
Objective:To evaluate larvicidal,pupicidal and oviposition deterrent activities of four plant essential oils from Alpinia galanga(L.)Willd rhizome,Anethum graveolens L.(An.graveolens)fruit,Foeniculum vulgare Mill.frui...Objective:To evaluate larvicidal,pupicidal and oviposition deterrent activities of four plant essential oils from Alpinia galanga(L.)Willd rhizome,Anethum graveolens L.(An.graveolens)fruit,Foeniculum vulgare Mill.fruit,and Pimpinella anisum L.fruit against Aedes aegypti(Ae.aegypti).Methods:Four essential oils at 1%,5%and 10%concentrations were assessed for insecticidal activity against larvae and pupae of Ae.aegypti,following the procedure of a dipping method assay.Oviposition deterrent activity of four essential oils was evaluated on gravid female of Ae.aegypti by a dual-choice oviposition bioassay.Results:The results revealed that An.graveolens oil provided the strongest larvicidal activity against Ae.aegypti among four tested plant essential oils with the highest mortality rate of 100%and LC_(50)value of-0.3%.From the pupicidal experiment,An.graveolens also showed the highest toxicity against Ae.aegypti pupae with the highest mortality rate of 100%at 72 h and LC_(50)value of2.9%.In addition,10%An.graveolens had an oviposition deterrent effect against Ae.aegypti with effective repellency of 100%and an oviposition activity index of-1.0.Conclusions:An.graveolens oil has a good potential as a larvicidal,pupicidal and oviposition deterrent agent for controlling Ae.aegypti.展开更多
The present research was undertaken to explor the possibility of arbuscular mycorrhizal （AM） associa- tion with Asteraceae plants in the arid lands of Saudi Arabia （AI-Ghat, Buraydah, Thumamah and Huraymila）. AM f...The present research was undertaken to explor the possibility of arbuscular mycorrhizal （AM） associa- tion with Asteraceae plants in the arid lands of Saudi Arabia （AI-Ghat, Buraydah, Thumamah and Huraymila）. AM fungal colonization in the roots, spore numbers in the rhizosphere soil, fungal species diversity and correlation between AM properties and soil properties were determined. The highest colonization was in Conyza bonariensis （65%） from AI-Ghat, Anthemis cotula （52%） from Buraydah and C. bonariensis （53%） from Thumamah. The lowest was in Vernonia schimperi （41%） from AI-Ghat, Pulicaria undulata （25%） from Buraydah, Acanthospermum his- pidum （34%） from Thumamah, Asteriscus graveolens （22%） and V. schimperi （22%） from Huraymila. Vesicular and arbuscular colonization were also presented in all plant species examined. The number of spores were 112-207 in AI-Ghat, 113-133 in Buraydah, 87-148 in Thumamah and 107-158 in Huraymila. Funneliformis mosseae, Glomus etunicatum, G. fasciculatum and G aggregatum were identified. Relative frequency of AM fungal species varied widely and was irrespective of location and plant species. Diversity index varied with the rhizosphere soils of dif- ferent plant species at various locations. Soil properties varied with locations and no distinct correlations were ob- served among the soil properties, root colonization and the number of spores. The results of the present study specified the association of AM fungi in different plants of Asteraceae and its significance in the ecological func- tioning of annual plants in the punitive environments of the rangelands in Saudi Arabia.展开更多
Drought stress, during growth season along with plant density, is an important problem that needs attention. In order to investigate the influence of both factors in increasing the water use efficiency, field experime...Drought stress, during growth season along with plant density, is an important problem that needs attention. In order to investigate the influence of both factors in increasing the water use efficiency, field experiments were laid out in split-plot design at Agriculture Research Station, Collage of Food and Agriculture Sciences, King Saud University, to investigate the effects of irrigation intervals viz., irrigation every (6, 9 and 12 days) under different plant densities i.e., (6, 8 and 10 plants/m<sup>2</sup>) on growth, yield and yield component parameters as well as grain quality of sorghum local variety (Gizani). Results revealed that almost all growth, yield and yield component parameters were significantly influenced by both factors as well as their interaction. Chemical composition of seeds, leaf proline content and WUE were also considered. Severe drought stress condition caused gradual decrease in most of the growth characters as compared to watered treatment and reflected in decreasing yield and yield component characters. Increasing plant densities led to raise biomass production and seed yield per unit area and not able to compensated the low number and weight of grains per panicle. Contrary, low plant density, under adequate irrigation conditions, can be compensated by a high number of grains per panicle and high weight of the grain. Maximum seed yield per hectare was recorded by the interactional effects of most watered treatments (irrigation every 6 days) and plant density of 10 plants per square meter.展开更多
Within the semi-desert landscape of northern Libya, two sub-humid escarpments occur: Al-Akhdar in the east and Nafusa (Jabal Al-Gharbi) in the west. This study compares plant communities in the two regions, which are ...Within the semi-desert landscape of northern Libya, two sub-humid escarpments occur: Al-Akhdar in the east and Nafusa (Jabal Al-Gharbi) in the west. This study compares plant communities in the two regions, which are along an elevation gradient, in terms of species composition and diversity, frequency of different Raunkiaer life forms, and reproductive phenology. The two regions differed in species composition and life-form frequency between regions and between elevation zones within each region. Patterns were associated with the lower rainfall and lower moisture-holding capacity of soils at Nafusa, resulting in more xeric conditions. Only 13% of species were shared between the two regional landscapes. Species diversity, life-form frequency, and duration of the flowering-fruiting phenophase were all affected by elevation above sea level. The duration of flowering and fruiting in spring and fall was associated with environmental conditions, although there were different thresholds in the two regions. There was both a spring and fall episode of flowering at Nafusa, but only spring flowering at Al-Akhdar. It is anticipated that there will be a gradual shift of plant communities to higher elevations and loss of certain sensitive species in response to ongoing climate change.展开更多
The present research aimed at producing a biopesticide with proper formulation of invert emulsion (water-in-oil type) and effective strain of?Trichoderma harzianum?then, testing it against pathogens of postharvest mol...The present research aimed at producing a biopesticide with proper formulation of invert emulsion (water-in-oil type) and effective strain of?Trichoderma harzianum?then, testing it against pathogens of postharvest mold infections(Botrytis cinerea?&?Penicillium expansum) on fresh fruits of apple and pear. The?proper formulation of invert emulsion (IE#3) used for biopesticide production has the following ingredients (100% w/w): soybean oil (28.50%), coconut oil (19.50%), oil-soluble emulsifier: Tween 20 (2.0%), glycerine (4.25%), water-soluble emulsifier:?dehymuls k (0.75%),?sterile distilled water (22.5%) and conidial suspension of the effective strain ofT. harzianum?“TrichoPAL1” in water (22.5%, concentration 1 ×?107?conidia/ml). Testing efficacy of the produced biopesticide has indicated a significant reduction in the disease lesion diameter of mold infections on wounded apple and pear fruits stored at?20℃?± 1℃?compared to the untreated fruits or control (reduction from up to 38.75 to about 7.50 mm, respectively, according to?the type of mold infections and fruit type). Also, the treatment with the produced biopesticide has resulted in?a long protection period from mold infections on wounded and un-wounded fresh fruits of apple and pear stored under controlled and semi-commercial conditions(up to 2.5 months according to the type of mold infections and fruit type). In conclusion, the overall results have demonstrated the effectiveness of produced biopesticide on stored fruits under controlled and semi-commercial conditions therefore,?it is recommended to test this effectiveness on marketed fruits stored under variable conditions before applying it at a large scale.展开更多
The initial phase of tomato is critical to the infestation of insect vectors of viruses. Therefore, this study aimed to test the use of yellow card traps around the crop to manage insect vectors of viruses and test th...The initial phase of tomato is critical to the infestation of insect vectors of viruses. Therefore, this study aimed to test the use of yellow card traps around the crop to manage insect vectors of viruses and test the best density of traps/tomato plants. Yellow card traps were placed on the border of the crop plot to capture adult insect vectors. Density of trap/tomato plant was assessed in 10 blocks at the following levels： 1/25; 1/50; 1/75; 1/100; 1/125; 1/150. The monitoring was carded out in 1% of the crop during 60 days in 2011 and 2012 crop. The evaluated systems were Conventional and Phytosanitary Pest Management （PPM）. During 2011 season the Conventional system received 14 insecticide applications whereas only 6 insecticide applications were made on the PPM, representing a reduction of 133%. In 2012, the crop under Conventional system was subjected to 15 applications of insecticides, over 8 on PPM, with a reduction of 87.5%. The PPM allowed a 90% reduction in application cost for this insects, obtaining a reduction of R$1,345.00/ha. The highest density was 60 plants/trap. We can conclude that the yellow card traps in tomato crop decreased infestations of insect vectors of viruses.展开更多
To evaluate the toxicity against house fly Musca domestica L.(M. domestica)-larvicidal, pupicidal, and oviposition deterrent activities of essential oils(EOs) from five plants: Anethum graveolens L.(A. graveolens), Ce...To evaluate the toxicity against house fly Musca domestica L.(M. domestica)-larvicidal, pupicidal, and oviposition deterrent activities of essential oils(EOs) from five plants: Anethum graveolens L.(A. graveolens), Centratherum anthelminticum L.(C. anthelminticum), Foeniculum vulgare Mill.(F. vulgare), Pimpinella anisum L.(P. anisum), and Trachyspermum ammi L.(T. ammi) Sprague. Methods: Dipping, topical and dual-choice assays were performed by using each EO at three concentrations(1%, 5% and 10%) as well as cypermethrin(positive control) and ethyl alcohol(negative control) in order to determine their larvicidal, pupicidal and oviposition deterrent activities against M. domestica mortality rate and morphogenic abnormality of larvae and pupae were recorded after 3 and 10 days of incubation. Oviposition deterrent activity was recorded for 5 consecutive days from the beginning of the assay. Results: All EOs at the highest concentration(10%) were highly effective in oviposition deterrent with 100% effective repellency and an oviposition activity index of-1.00. Ten percent of F. vulgare oil exhibited the highest efficacy against the larvae with 89.6% mortality rate at 3 days and an LC50 value of 5.4%. Ten percent of A. graveolens and T. ammi oils showed the highest efficacy against the pupae with 100% mortality and an LC50 value ranging from 1.81%-2.24%. Conclusions: These results indicate that F. vulgare, A. graveolens and T. ammi EOs are effective larvicidal, pupicidal and oviposition deterrent agents against house fly M. domestica.展开更多
The study was conducted at the nursery of Malta station/Duhok. Kurdistan region-lraq, during the season 2011 to study the effect of GA3 and Fe on vegetative growth of two year old of two olive （Olea europaea L.） cul...The study was conducted at the nursery of Malta station/Duhok. Kurdistan region-lraq, during the season 2011 to study the effect of GA3 and Fe on vegetative growth of two year old of two olive （Olea europaea L.） cultivars （Kithary and Sorany）, the transplant were sprayed with four levels （0, 250, 500 and 750 mg L^-1 GA3） and four levels of chelated iron （0, 25, 50 and 75 mg Fe L^-1）. Foliar application of GA3 at 500 mg Ll increased significantly stem diameter （mm）, leaf number, increasing GA3 level up 750 mg L^-1 significantly increase shoot length （cm） plantl, leaf area. However, 50 mg Fe L^-1 increased significantly leaf number, leaf area, chlorophyll content, and when treated with 75 mg Fe L^-1 significantly increase stem diameter, shoot length cm plant^-1, leaf fresh weight （g）, leaf dry weight （g）. While, Kithary cultivar significant dominated Sorany cultivar of the most studied characteristics. The interactions between GA3, Fe and cultivars significantly affected on the most of the characteristics studied, foliar sprays of Kithary cultivar with 750 mg Ll GA^-1 and 0 mg Fe Ll significantly increase chlorophyll content and leaf area, and Kithary cultivar when treated only by 75 mg Fe Ll increase significantly plant high （cm）, stem diameter （mm）, leaf dry weight （g） and leaf fresh weight when compared with the control.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.42061144003).
文摘On-time mapping dynamics of crop area,yield,and production is important for global food security.Such information,however,is often not available.Here,we used satellite information,a spectral-phenology integration approach for mapping crop area,and a machine learning model for predicting yield in the war-stricken Ukraine.We found that in Ukraine crop area and production declined in 2022 relative to 2017–2021 and 2021 for wintertriticeae crops,which was invaded before the cropping season in February of that year.At the same time,crop area and production for rapeseed increased in Ukraine,with yields consistently lower by 6.5%relative to 2021.The low precipitation and the Russian-Ukrainian conflict-related factors contributed to such yield variations by-1.3%and-0.9%for winter-triticeae crops and-4.2%and-0.5%for rapeseed in 2022.We demonstrate a robust framework for monitoring country-wide crop production dynamics in near real-time,serving as an early-foodsecurity-warning system.
文摘The aim of this study is to produce large quantities of yam tubers in the field from seed tubers derived from vitroplants regenerated from aerial stem cuttings and farmers’ tuber seeds. Seed tubers from ten yam cultivars, including five from Dioscorea alata (cDa083, cDa053, cDa115, cDa150 and cDa266) and five from Dioscorea cayenensis-rotundata (cDr015, cDr027, cDr150, cDr206 and cDr148) with distinct agro-morphological characteristics, were used as material. A completely randomized block design with 3 replications was used. In each block, all cultivars and seed types were represented. When put into cultivation, the tubers produced by the vitroplants all germinated and gave 100% healthy plants, compared with 86% to 100% healthy plants for the seed tubers produced by the farmers. Yields per hectare ranged from 10 to 25 tonnes for seed tubers produced by in vitro plants, and from 4 to 9 tons for seed tubers produced by farmers. Seed tubers from vitroplants can therefore be recommended to farmers as a solution to the problem of seed tuber unavailability.
文摘Fire is regarded as management practice for maintaining grasslands and savannas. The vegetation occurring in fire prone areas becomes highly adapted to fire occurrences in savannas and grasslands. However, documentation on the influence of burning on vegetation is still limited in an albany thicket biome. The aim of the study was to evaluate the short-term influence of burning on species abundance, biomass production, wood plant density and browsing unit. Six plots (2500 m<sup>2</sup>) were demarcated;in each plot two parallel transects of 120 m<sup>2</sup> with 5 m distance apart were measured. Three plots were burned in spring season, while no burning was done on the other remaining plots. Forty points per plot were obtained using step-point method to determine the relative abundance at burned and unburned plots. Woody plants occurred within a transect were identified, counted and recorded to determine density and browsing unit. Three quadrats (<em>i.e</em>. 0.25 m<sup>2</sup>) per plot were randomly laid within the transect;aboveground plant material within a quadrat were harvested. A total of 18 samples were harvested and oven dried at 60<span style="white-space:nowrap;"><span style="white-space:nowrap;">˚</span></span>C for 48 hours to determine biomass production. The results showed that <em>Themeda triandra</em> (14%) and <em>Panicum maximum</em> (10%) were most abundant grass species at the burned plots. Burned plots had significantly higher biomass production (4804 kg/ha) compared to unburned plots (3641 kg/ha). <em>Vachellia karoo</em> (burned: 65.85% & unburn: 13.70%) and <em>Searsia pallens </em>(burned: 26.83% & unburned: 6.85%) were most dominant wood plant species at both burned and unburned plots. Burned plots had the highest browsing unit (3221 BU/ha) compared to unburned plots (2058 BU/ha). The decrease of woody plants at the burned plots proved that fire has a tremendous potential for managing woody plants. This study provided information on short-term influence of burning, however further long-term trials are required to determine the effects of burning.
文摘The production of crops is badly affected by climate change globally.Mitigation of adverse effects of climate change is in need of time through different management practices such as developing tolerant genetic resources,hormonal applications to boost defense systems,nanoparticles,and balanced fertilization.The nano-hormonal syn-ergy had the potential to mitigate the adverse effects of climate change by modulation of morpho-physiological and biochemical activities.Plant growth,yield,and quality can be enhanced with the supplementation of nano-hormonal interactions.Therefore,the current study explores the synergy between nanoparticles and phytohormonal use.The nanoparticles,even in low concentrations,had an excellent capability to improve the endogenous hormones contributing to the regulation of plant responses under stress conditions.Nano-hormonal interaction improved the plant tolerance against climate change by activation of signaling molecules and the plant defense system.Nano-hormonal contact triggers several enzymic and non-enzymatic activities that can scavenge toxic substances generated within the plants.The reduction in electrolyte leakage,malondialdehyde(MDA),and hydrogen peroxide(H_(2)O_(2))was due to the supplementation of nano-hormonal exchange.The optimum production of reactive oxygen species(ROS)is necessary for normal plant growth and various developmental processes.However,the overproduction of ROS can be eliminated with nano-hormonal synergy.However,inappropriate applications can cause phytotoxicity such as germination inhibition,root malformation,and chlorosis.The optimum doses can vary depending on the kind of crop and stress conditions.The nano-hormonal interface is beneficial for crop growth,yield,and quality.Moreover,these are also effective in repairing plants damaged from adverse climatic conditions.Hence,these are effective for sustainable agriculture production.
文摘Essential oils(EOs)derived from medicinal plants are gaining recognition as sustainable alternatives to synthetic fungicides in the management of plant pathogens.This study investigates the chemical composition,chromatographic profile,and antifungal of Mentha rotundifolia essential oil against Fusarium oxysporum f.sp.albedinis(Foa),the pathogen responsible for Bayoud disease in date palm.The oil was extracted through hydrodistillation and characterized using thin-layer chromatography(TLC)and gas chromatography–mass spectrometry(GC-MS),revealing multiple fractions corresponding to terpenoid constituents and 23 chemical constituents,predominantly oxygenated monoterpenes(68.51%),with piperitenone oxide as the major component(62.53%).The antifungal efficacy was evaluated against ten(10)isolates of F.o.a across seven(07)concentrations different concentrations.(0;0.25;0.5;0.75;1;1.25;1.5μL/mL).The results obtained show a progressive decrease in the diameters of the colonies of F.o.a isolates by increasing the doses of EOMR.The percentage of inhibition varies from 7.82 to 83.41%;However,the dose of 1.75μL/mL showed 100%inhibition for all F.o.a isolates tested.These outcomes demonstrate the potential of M.rotundifolia essential oil as a natural,environmentally friendly antifungal agent,supporting its application in sustainable management strategies for Bayoud disease in date palm.
基金We appreciate the financial support of this work by Gorgan University of Agricultural Sciences and Natural Resources from Golestan Province(Grant No.9413184180).
文摘Drought,as the most catastrophic abiotic stress,poses a significant threat to the growth and development of plants.Among the mechanisms employed by plants to cope with drought-induced stress,abscisic acid(ABA)which is the sesquiterpene hormone,occupies a pivotal role.A hypothesis has emerged that the exogenous application of ABA can positively influence the terpenoid content of Lavandula angustifolia cv Hidcote essential oil(EO),thereby conferring enhanced resilience to drought stress.A randomized complete block design experiment was conducted with three replicationsandfour irrigation regimes,including I4[30%-40%of field capacity(FC)],I3(50%-60%FC),I2(70%-80%FC),andI1(90%-100%FC)as control.Application of ABAspraying included three concentrations,A3(30μmol·L^(-1)ABA),A2(15μmol·L^(-1)ABA),and A1 as control(distilled water).Results revealed that drought significantly affected all studied traits except for relative water content(RWC)and shoot dry mass.The ABA impact application on the observed traits was found to be dependent upon the level of drought to which the plants were exposed.Specifically,the highest levels of flavonoid content,total antioxidant activity,peroxidase(POX)activity,and EO percentage were observed under I4A2 conditions.Conversely,the highest levels of superoxide dismutase(SOD)and catalase(CAT)activity,and proline were recorded under I4A3 conditions,while the highest EO yield was obtained under I3A2 conditions.Analysis of the EO revealed that there were common indicative compounds across the varying levels of droughtandABAapplication,including linalool,camphor,borneol,bornyl formate,andcaryophyllene oxide.Theproduction pattern ofmonoterpene and sesquiterpene compounds demonstrated a distinct trend,with the highest concentration of monoterpene hydrocarbon compounds(average of 12.92%)being observed in the I2A3 treatment group,andthe highest concentration of oxygenatedmonoterpenecompounds(average of 64.76%)being recorded in the I1A1 group.Conversely,the most significant levels of sesquiterpene hydrocarboncompounds(14.98%)andoxygenated sesquiterpene compounds(10.46%)were observed in the I4A3 and I4A1 groups,respectively,showing the efficacy of monoterpenes and sesquiterpenes from the action of ABA under drought conditions.The observed results indicated that the concentration of oxygenated monoterpene compounds decreases with an increase in drought level.Conversely,the application of ABA at any given drought level appears to resulted in increased concentrations of oxygenated monoterpene compounds in the same conditions.It may be concluded that plants under high-stress drought conditions allocate more terpene precursors to the production of sesquiterpene hydrocarbon compounds,aided by ABA with the same properties.
基金the project "Cash Crops Research Network of China" of the Center for Resources, Environment and Food Security, China Agricultural UniversityProfessor Oene Oenema from Alterra Wageningnen University, the Netherlands, for his financial support of the research
文摘China is in a dominant position in apple production globally with both the largest apple growing area and the largest export of fresh apple fruits. However, the annual productivity of China＇s apple is significantly lower than that of other dominant apple producing countries. In addition, apple production is based on excessive application of chemical fertilizers and the nutrient use efficiency （especially nitrogen） is therefore low and the nutrient emissions to the environment are high. Apple production in China is considerably contributes to farmers＇ incomes and is important as export product. There is an urgent need to enhance apple productivity and improve nutrient use efficiencies in intensive apple production systems in the country. These can be attained by improved understanding of production potential, yield gaps, nutrient use and best management in apple orchards. To the end, priorities in research on apple production systems and required political support are described which may lead to more sustainable and environmental-friendly intensification of apple production in China.
基金financed by Bahir Dar University Research and Community Service as a study grant (BDU/RCS/Sc/03/06)The National Herbarium, Ethiopia for their support during species identification
文摘The study was conducted at Zengena forest, a fragmented remnant montane forest in northwestern Ethiopia, which surrounds Lake Zengena. The purpose was to assess the species composition, diversity and the regeneration status of woody plants. A total of 27 plots of 20 m - 20 m were sampled along the line transects laid down the altitudinal gradient from the edge of the forest encompassing the lake to the edge of the lake in eight aspects. In each plot, woody species were counted and the diameter at breast height and the height of trees and shrubs were measured. A total of 50 woody species belonging to 31 families were found, of which 17 （34%） were trees, 7 （14%） trees or shrubs, 23 （46%） shrubs and 3 （6%） lianas. The overall Shannon-Wiener diversity and evenness indices of woody species were 2.74 and 0.7, respectively. Clausena anisata had the highest relative density （23.5%）, Rapanea rhododendroides the highest relative frequency （6.5%） and Prunus afri- cana the highest relative dominance （45%） and importance value index （IVI, 51.6）. The total basal area and density of woody plants were 22.3 m2.ha-1 and 2,202 individuals.ha1, respectively. The population structure showed variations among woody plants and revealed varied regeneration patterns of different species. The importance value index and population structure revealed that some species are threatened and need prioritization for conservation measures. The results suggest that remnant forest patches in the highlands of northern Ethiopia host several woody plant species that are almost disappearing in other areas due to deforestation.
文摘Composite top- and subsoil samples were collected from the greenhouses in the Al-Balawneh area,Jordan,where intensive greenhouse production system(IGPS) has been practiced since 1998,to study the impact of IGPS on soil quality as measured by the chemical and biological properties to develop a sustainable production system.The study showed that IGPS led to higher electrical conductivity in top- and subsoils compared to an uncultivated soil(control).Quality and amount of irrigation water,lack of efficient drainage,and quantity and types of applied fertilizers were major factors resulting in salt buildup.IGPS resulted in lower total N(TN) and NO_3-N in the soil compared to the control.The lower TN was due to crop uptake,microbial immobilization,volatilization,and irregular application of composted animal manure or poultry manure.In contrast,higher residual Olsen-P content was detected in both soil layers of greenhouses than in the control.Residual P was classified as very high in the topsoil layers and sufficient to high in the subsoil layers.Residual available K in the soils of greenhouses was relatively lower than that in the control and it was,however,classified as high to very high.A large increase of Cl and a considerable decrease in the bacterial count were observed in both soil layers of IGPS compared to the control treatment.Economically sustainable soil management practices need to be adopted by farmers to achieve a sustainable and profitable production.This can be accomplished through education,targeted towards the farming community in the central Jordan Valley.
文摘Increasing crop production is necessary to maintain food security for the growing global population.Reducing the gap between actual and potential yield is one of the important ways to increase yield per unit area.Potential yield and the yield gap of soybean were determined for Golestan Province,Iran,using Soybean Simulation Model (SSM-i Crop2) and Geographical Information System (GIS).Information from 24 weather stations and soil data of the region were used.Yield gap and production gap were calculated at county and province levels.The average actual yield of soybean in this province was2.28 t ha^(–1) while the province’s potential yield was 4.73 t ha^(–1),so the yield gap was estimated 2.44 t ha^(–1).Thus,there is a great potential for increasing soybean yield in Golestan,which is possible through improving crop management of soybean in farmers’fields.The average water productivity of soybean was estimated to be 0.81 kg m^(–3).Spatial distribution of water productivity in soybean farms showed that the highest and the lowest water productivities (0.99 and 0.44 kg m^(–3)) were in western and eastern regions of the province,respectively,in accordance to vapour pressure deficit.It was concluded that soybean production in the province could increase by 66%(from 109 970 to 182 170 tons) if 80% of the current yield gap could be removed.
基金This work was supported by the Open Fund of State Key Laboratory of Tea Plant Biology and Utilization(SKLTOF20200122).
文摘Tea plants are sensitive to soil moisture deficit,with the level of soil water being a critical factor affecting their growth and quality.Arbuscular mycorrhizal fungi(AMF)can improve water and nutrient absorption,but it is not clear whether AMF can improve the photosynthetic characteristics of tea plants.A potted study was conducted to determine the effects of Claroideoglomus etunicatum on plant growth,leaf water status,pigment content,gas exchange,and chlorophyll fluorescence parameters in Camellia sinensis cv.Fuding Dabaicha under well-watered(WW)and drought stress(DS)conditions.Root mycorrhizal colonization and soil hyphal length were significantly reduced by the eightweek DS treatment.AMF inoculation displayed a significant increase in shoot and root biomass production.The relative water content,leaf water potential,nitrogen balance index,pigment content,maximum photometric effect(Fv/Fm,QY_max),and steady-state photometric effect Y(II)(QY_Lss)decreased dramatically,while the leaf water saturation deficit and steady-state non-photochemical fluorescence quenching(NPQ_Lss)generally increased under DS conditions.Mycorrhizal treatment induced significantly higher relative water content,leaf water potential,nitrogen balance index,pigment(chlorophyll,flavonoid,and anthocyanin)content,net photosynthesis rate,transpiration rate,stomatal conductance,intercellular CO_(2)concentration,QY_max,and QY_Lss;however,it resulted in a lower leaf water saturation deficit and NPQ_Lss under both WW and DS conditions,as compared with nonmycorrhizal plants.These results imply that AMF promoted tea plant growth and alleviated negative effects of DS by promoting gas exchange,regulating the water status of leaves,and regulating photosynthetic parameters.
基金Funding for this research was obtained from MINECO(Spain)through the project RTA2014-00007-C03-02Additional funding was derived from the projects AGL2010-22308-C02-01 and AGL2007-66739-C02-01/FOR
文摘Background: Coupling biomass models with nutrient concentrations can provide sound estimations of carbon and nutrient contents, enabling the improvement of carbon and nutrient balance in forest ecosystems. Although nutrient concentrations are often assumed to be constant for some species and specific tree components, at least in mature stands,the concentrations usually vary with age, site index and even with tree density. The main objective of this study was to evaluate the sources of variation in nutrient concentrations in biomass compartments usually removed during harvesting operations, covering a range of species and management conditions: semi-natural forest, conventional forest plantations and short rotation forestry(SRF). Five species(Betula pubescens, Quercus robur, Eucalyptus globulus, Eucalyptus nitens and Populus spp.) and 14 genotypes were considered. A total of 430 trees were sampled in 61 plots to obtain 6 biomass components:leaves, twigs, thin branches, thick branches, bark and wood. Aboveground leafless biomass was pooled together forpoplar.The concentrations of C, N, K, P, Ca, Mg, S, Fe, Mn, Cu, Zn and B were measured and the total biomass of each sampled tree and plot were determined. The data were analysed using boosted regression trees and conventional techniques.Results: The main sources of variation in nutrient concentrations were biomass component > > genotype(species) ≈ age >tree diameter. The concentrations of Ca, Mg and K were most strongly affected by genotype and age. The concentrations of P, K, Ca, Mg, S and Cu in the wood component decreased with age, whereas C concentrations increased, with a trend to reach 50% in the older trees. In the SRF, interamerican poplar and P. trichocarpa genotypes were comparatively more efficient in terms of Ca and K nutrient assimilation index(NAI)(+65-85%) than eucalypts, mainly because leafless biomass can be removed. In the conventional eucalypt plantations(rotation 15 years), debarking the wood at logging(savings of225% of Ca and 254% of Mg for E. globulus) or the use of selected genotypes(savings of 45% of P and 35% of Ca) will provide wood at a relatively lower nutrient cost. Considering all the E. globulus genotypes together, the management for pulp with removal of debarked wood shows NAI values well above(x 1.7-x 3.9) the ones found for poplar or eucalypt SRF and also higher(x 1.6-x4.0) than the ones found for oak and birch managed in medium or long rotations.The annual rates of nutrient removal were low in the native broadleaved species but the rates of available soil nutrients removed were high as compared to poplar or eucalypts. Management of native broadleaved species should consider nutrient stability through selection of the biomass compartments removed.(Continued on next page)(Continued from previous page)Conclusions: The nutrient assimilation index is higher in poplar grown under short rotation forestry management than in the other systems considered. Nutrient management of fast growing eucalyptus plantations could be improved by selecting efficient genotypes and limiting removal of wood. The values of the nutrient assimilation index are lower in the natural stands of native broadleaved species than in the other systems considered.
基金sponsored in part by the National Research Council of Thailand,(Grant no.GRAD6006 KMITL)by the Faculty of Agricultural Technology,King Mongkut's Institute of Technology Ladkrabang(KMITL)(Grant no.01-04-001)
文摘Objective:To evaluate larvicidal,pupicidal and oviposition deterrent activities of four plant essential oils from Alpinia galanga(L.)Willd rhizome,Anethum graveolens L.(An.graveolens)fruit,Foeniculum vulgare Mill.fruit,and Pimpinella anisum L.fruit against Aedes aegypti(Ae.aegypti).Methods:Four essential oils at 1%,5%and 10%concentrations were assessed for insecticidal activity against larvae and pupae of Ae.aegypti,following the procedure of a dipping method assay.Oviposition deterrent activity of four essential oils was evaluated on gravid female of Ae.aegypti by a dual-choice oviposition bioassay.Results:The results revealed that An.graveolens oil provided the strongest larvicidal activity against Ae.aegypti among four tested plant essential oils with the highest mortality rate of 100%and LC_(50)value of-0.3%.From the pupicidal experiment,An.graveolens also showed the highest toxicity against Ae.aegypti pupae with the highest mortality rate of 100%at 72 h and LC_(50)value of2.9%.In addition,10%An.graveolens had an oviposition deterrent effect against Ae.aegypti with effective repellency of 100%and an oviposition activity index of-1.0.Conclusions:An.graveolens oil has a good potential as a larvicidal,pupicidal and oviposition deterrent agent for controlling Ae.aegypti.
基金financially supported by the Deanship of Scientific Research, College of Food and Agriculture, King Saud University, Saudi Arabia
文摘The present research was undertaken to explor the possibility of arbuscular mycorrhizal （AM） associa- tion with Asteraceae plants in the arid lands of Saudi Arabia （AI-Ghat, Buraydah, Thumamah and Huraymila）. AM fungal colonization in the roots, spore numbers in the rhizosphere soil, fungal species diversity and correlation between AM properties and soil properties were determined. The highest colonization was in Conyza bonariensis （65%） from AI-Ghat, Anthemis cotula （52%） from Buraydah and C. bonariensis （53%） from Thumamah. The lowest was in Vernonia schimperi （41%） from AI-Ghat, Pulicaria undulata （25%） from Buraydah, Acanthospermum his- pidum （34%） from Thumamah, Asteriscus graveolens （22%） and V. schimperi （22%） from Huraymila. Vesicular and arbuscular colonization were also presented in all plant species examined. The number of spores were 112-207 in AI-Ghat, 113-133 in Buraydah, 87-148 in Thumamah and 107-158 in Huraymila. Funneliformis mosseae, Glomus etunicatum, G. fasciculatum and G aggregatum were identified. Relative frequency of AM fungal species varied widely and was irrespective of location and plant species. Diversity index varied with the rhizosphere soils of dif- ferent plant species at various locations. Soil properties varied with locations and no distinct correlations were ob- served among the soil properties, root colonization and the number of spores. The results of the present study specified the association of AM fungi in different plants of Asteraceae and its significance in the ecological func- tioning of annual plants in the punitive environments of the rangelands in Saudi Arabia.
文摘Drought stress, during growth season along with plant density, is an important problem that needs attention. In order to investigate the influence of both factors in increasing the water use efficiency, field experiments were laid out in split-plot design at Agriculture Research Station, Collage of Food and Agriculture Sciences, King Saud University, to investigate the effects of irrigation intervals viz., irrigation every (6, 9 and 12 days) under different plant densities i.e., (6, 8 and 10 plants/m<sup>2</sup>) on growth, yield and yield component parameters as well as grain quality of sorghum local variety (Gizani). Results revealed that almost all growth, yield and yield component parameters were significantly influenced by both factors as well as their interaction. Chemical composition of seeds, leaf proline content and WUE were also considered. Severe drought stress condition caused gradual decrease in most of the growth characters as compared to watered treatment and reflected in decreasing yield and yield component characters. Increasing plant densities led to raise biomass production and seed yield per unit area and not able to compensated the low number and weight of grains per panicle. Contrary, low plant density, under adequate irrigation conditions, can be compensated by a high number of grains per panicle and high weight of the grain. Maximum seed yield per hectare was recorded by the interactional effects of most watered treatments (irrigation every 6 days) and plant density of 10 plants per square meter.
基金funded by Libyan Missions Department and Cairo University
文摘Within the semi-desert landscape of northern Libya, two sub-humid escarpments occur: Al-Akhdar in the east and Nafusa (Jabal Al-Gharbi) in the west. This study compares plant communities in the two regions, which are along an elevation gradient, in terms of species composition and diversity, frequency of different Raunkiaer life forms, and reproductive phenology. The two regions differed in species composition and life-form frequency between regions and between elevation zones within each region. Patterns were associated with the lower rainfall and lower moisture-holding capacity of soils at Nafusa, resulting in more xeric conditions. Only 13% of species were shared between the two regional landscapes. Species diversity, life-form frequency, and duration of the flowering-fruiting phenophase were all affected by elevation above sea level. The duration of flowering and fruiting in spring and fall was associated with environmental conditions, although there were different thresholds in the two regions. There was both a spring and fall episode of flowering at Nafusa, but only spring flowering at Al-Akhdar. It is anticipated that there will be a gradual shift of plant communities to higher elevations and loss of certain sensitive species in response to ongoing climate change.
文摘The present research aimed at producing a biopesticide with proper formulation of invert emulsion (water-in-oil type) and effective strain of?Trichoderma harzianum?then, testing it against pathogens of postharvest mold infections(Botrytis cinerea?&?Penicillium expansum) on fresh fruits of apple and pear. The?proper formulation of invert emulsion (IE#3) used for biopesticide production has the following ingredients (100% w/w): soybean oil (28.50%), coconut oil (19.50%), oil-soluble emulsifier: Tween 20 (2.0%), glycerine (4.25%), water-soluble emulsifier:?dehymuls k (0.75%),?sterile distilled water (22.5%) and conidial suspension of the effective strain ofT. harzianum?“TrichoPAL1” in water (22.5%, concentration 1 ×?107?conidia/ml). Testing efficacy of the produced biopesticide has indicated a significant reduction in the disease lesion diameter of mold infections on wounded apple and pear fruits stored at?20℃?± 1℃?compared to the untreated fruits or control (reduction from up to 38.75 to about 7.50 mm, respectively, according to?the type of mold infections and fruit type). Also, the treatment with the produced biopesticide has resulted in?a long protection period from mold infections on wounded and un-wounded fresh fruits of apple and pear stored under controlled and semi-commercial conditions(up to 2.5 months according to the type of mold infections and fruit type). In conclusion, the overall results have demonstrated the effectiveness of produced biopesticide on stored fruits under controlled and semi-commercial conditions therefore,?it is recommended to test this effectiveness on marketed fruits stored under variable conditions before applying it at a large scale.
文摘The initial phase of tomato is critical to the infestation of insect vectors of viruses. Therefore, this study aimed to test the use of yellow card traps around the crop to manage insect vectors of viruses and test the best density of traps/tomato plants. Yellow card traps were placed on the border of the crop plot to capture adult insect vectors. Density of trap/tomato plant was assessed in 10 blocks at the following levels： 1/25; 1/50; 1/75; 1/100; 1/125; 1/150. The monitoring was carded out in 1% of the crop during 60 days in 2011 and 2012 crop. The evaluated systems were Conventional and Phytosanitary Pest Management （PPM）. During 2011 season the Conventional system received 14 insecticide applications whereas only 6 insecticide applications were made on the PPM, representing a reduction of 133%. In 2012, the crop under Conventional system was subjected to 15 applications of insecticides, over 8 on PPM, with a reduction of 87.5%. The PPM allowed a 90% reduction in application cost for this insects, obtaining a reduction of R$1,345.00/ha. The highest density was 60 plants/trap. We can conclude that the yellow card traps in tomato crop decreased infestations of insect vectors of viruses.
基金supported by King Mongkut’s Institute of Technology Ladkrabang,Ladkrabang,Bangkok 10520,Thailand(Grant No.2560-01-04-001)The National Research Council of Thailand(Grant No.GRAD6006KMITL)
文摘To evaluate the toxicity against house fly Musca domestica L.(M. domestica)-larvicidal, pupicidal, and oviposition deterrent activities of essential oils(EOs) from five plants: Anethum graveolens L.(A. graveolens), Centratherum anthelminticum L.(C. anthelminticum), Foeniculum vulgare Mill.(F. vulgare), Pimpinella anisum L.(P. anisum), and Trachyspermum ammi L.(T. ammi) Sprague. Methods: Dipping, topical and dual-choice assays were performed by using each EO at three concentrations(1%, 5% and 10%) as well as cypermethrin(positive control) and ethyl alcohol(negative control) in order to determine their larvicidal, pupicidal and oviposition deterrent activities against M. domestica mortality rate and morphogenic abnormality of larvae and pupae were recorded after 3 and 10 days of incubation. Oviposition deterrent activity was recorded for 5 consecutive days from the beginning of the assay. Results: All EOs at the highest concentration(10%) were highly effective in oviposition deterrent with 100% effective repellency and an oviposition activity index of-1.00. Ten percent of F. vulgare oil exhibited the highest efficacy against the larvae with 89.6% mortality rate at 3 days and an LC50 value of 5.4%. Ten percent of A. graveolens and T. ammi oils showed the highest efficacy against the pupae with 100% mortality and an LC50 value ranging from 1.81%-2.24%. Conclusions: These results indicate that F. vulgare, A. graveolens and T. ammi EOs are effective larvicidal, pupicidal and oviposition deterrent agents against house fly M. domestica.
文摘The study was conducted at the nursery of Malta station/Duhok. Kurdistan region-lraq, during the season 2011 to study the effect of GA3 and Fe on vegetative growth of two year old of two olive （Olea europaea L.） cultivars （Kithary and Sorany）, the transplant were sprayed with four levels （0, 250, 500 and 750 mg L^-1 GA3） and four levels of chelated iron （0, 25, 50 and 75 mg Fe L^-1）. Foliar application of GA3 at 500 mg Ll increased significantly stem diameter （mm）, leaf number, increasing GA3 level up 750 mg L^-1 significantly increase shoot length （cm） plantl, leaf area. However, 50 mg Fe L^-1 increased significantly leaf number, leaf area, chlorophyll content, and when treated with 75 mg Fe L^-1 significantly increase stem diameter, shoot length cm plant^-1, leaf fresh weight （g）, leaf dry weight （g）. While, Kithary cultivar significant dominated Sorany cultivar of the most studied characteristics. The interactions between GA3, Fe and cultivars significantly affected on the most of the characteristics studied, foliar sprays of Kithary cultivar with 750 mg Ll GA^-1 and 0 mg Fe Ll significantly increase chlorophyll content and leaf area, and Kithary cultivar when treated only by 75 mg Fe Ll increase significantly plant high （cm）, stem diameter （mm）, leaf dry weight （g） and leaf fresh weight when compared with the control.
