Millet (Pennisetum glaucum (L.) R. Br.) is the Sahelian crop par excellence due to its adaptation to the particular production conditions in this region. Unfortunately, in recent years this crop has been threatened by...Millet (Pennisetum glaucum (L.) R. Br.) is the Sahelian crop par excellence due to its adaptation to the particular production conditions in this region. Unfortunately, in recent years this crop has been threatened by very strong parasitic pressure and drought during the production period. The objective of this study is to analyze the main constraints of millet production and the solutions known to producers. A survey was carried out in November 2022 with a sample of 298 producers in five municipalities in the Tahoua region. The main constraints are drought and pressure from crop pests (locust, millet ear miner, floricultural insects) according to 57.9% of respondents. The millet ear miner is the most formidable pest according to 55% of respondents. Thus, the average yield obtained in a year of good production without the leafminer is 194 kg/ha and that obtained in a year of millet ear leafminer is around 27 kg to 43 kg/ha depending on the municipality. The yield obtained this last campaign after the attack of this leafminer varies from 64 to 77 kg/ha depending on the municipalities compared to a potential yield of over 1000 kg/ha. More than half of producers (58.1%) are unaware of the existence of biological control compared to only 12.5% who are aware of this alternative method. Work to popularize this technology is necessary in the five municipalities and the entire region in general.展开更多
Biological control agents and soil amendments have been applied to control tobacco bacterial wilt, but the mechanism is not well-known. In the present study, a field experiment was performed to investigate the soil ph...Biological control agents and soil amendments have been applied to control tobacco bacterial wilt, but the mechanism is not well-known. In the present study, a field experiment was performed to investigate the soil physicochemical properties, disease index (DI) and disease incidence of tobacco bacterial wilt, and rhizosphere microbial community. The results show that the control efficacy of single application of antagonistic bacteria and calcium cyanamide was 46.43% and 51.92%, respectively. While the combined control efficacy of antagonistic bacteria and calcium cyanamide was 65.79%. Besides, the combined application of antagonistic bacteria and calcium cyanamide could increase soil pH, total N alkaline N, and exchangeable Ca, which were negatively associated with the microbial diversity, soil-borne pathogenic microorganisms, and incidence of tobacco bacterial wilt. Additionally, the combination of antagonistic bacteria and calcium cyanamide can improve the proportion of some antagonistic microbial species, and these antagonistic microbial species were inversely associated with the DI of tobacco bacterial wilt. In conclusion: The integrated measure may influence soil microbial communities through enhancing soil physicochemical properties and rebuild healthy soil microbial community structure to mitigate tobacco bacterial wilt. The current study presented valuable insights into the mechanisms enhancing soil health in the integrated measure.展开更多
With the increased prevalence of dengue infection in tropical countries, concerned members of the public are now pressing their local health ministries to act immediately and effectively in managing the rising numbers...With the increased prevalence of dengue infection in tropical countries, concerned members of the public are now pressing their local health ministries to act immediately and effectively in managing the rising numbers of reported cases. This includes reviews of the methodologies and the effectiveness of current combative systems to find other possible novel approaches that might yield better results. One of those novel approaches is the integration of a parasite into mosquito vector, manipulating the parasite-host interaction to reduce the transmission of dengue in endemic hotspots. Another alternative is by Sanofi-Pasteur’s dengue vaccine that showed over 60.8% success rate in reducing severe dengue infection in children aged 9 - 16 during its final clinical implementation phase. This report will compare and contrast these two novel ideas to determine which of the approaches are more likely to be effective in the long run. The aspects covered will include the application, effectiveness, functionality, and problems with these approaches. The results could then be utilised by governments or organizations to select precise and effective methods in reducing the prevalence of dengue infections in their countries.展开更多
Cucumber green mottle mosaic virus (CGMMV), a member of the Tobamovirus genus, causes a severe disease of cucurbits. In the Moscow region of Russian Federation, the incidence of infection on cucumber plants in greenho...Cucumber green mottle mosaic virus (CGMMV), a member of the Tobamovirus genus, causes a severe disease of cucurbits. In the Moscow region of Russian Federation, the incidence of infection on cucumber plants in greenhouses is high;however, the virus is poorly studied. In this work, the full-length genomes of two pathogenic MC-1 and MC-2 strains of CGMMV isolated from cucumber plants grown in greenhouses in the Moscow region and the attenuated VIROG-43M strain were sequenced. Comparison of VIROG-43M nucleotide sequence with those of the pathogenic strains revealed three missense mutations. Their role in attenuation is discussed. For the first time, in a number of trials conducted under laboratory conditions and in commercial greenhouses, the efficiency of the attenuated VIROG-43M strain as a biocontrol agent for cucumber plant protection resulting in significant yield gain was demonstrated. Phylogenetic analysis with 83 full-length CGMMV coat protein genes isolated in 16 different countries showed that Russian strains are related to isolates from Spain, Greece, USA and Israel.展开更多
The erosion of drains is a major limitation of the quality, the increasing of banana production and the environmental protection of industrial banana in Côte d'Ivoire. It leads inundations, death of banan...The erosion of drains is a major limitation of the quality, the increasing of banana production and the environmental protection of industrial banana in Côte d'Ivoire. It leads inundations, death of banana trees and significant loss of production. Thence, the construction and the maintenance of drain costs too much and causes injure, snake bite, physical traumatisms, many diseases, … These events compromise the sustainable production of banana by reducing seriously worker’s the activities and finally increase the cost of production. The aim of the present work is to contribute to the sustainable development and human capacity building in the third world nations as far as banana production is concerned. The methods used so far to address this phenomenon proved inefficient. The technology innovation in this area has been to grow grass on the outer edges of the channels drained water. This resulted in a systematic reduction of erosion. Better still, it helped fertilize the soil, reduce the deportations of fertilizer and improve the quality of landscape of the plantations. Stenotaphrum secondatum is the best vegetable specie adapted to the biological control against water erosion of drains.展开更多
Three endemic plants rhizosphere (Astragalus gombo Coss. & Dur., Daucus sahariensis Murb., Ononis angustissima Lam.), were used for actinomycetes isolation. Ninety-three (93) isolates have been screened to evaluat...Three endemic plants rhizosphere (Astragalus gombo Coss. & Dur., Daucus sahariensis Murb., Ononis angustissima Lam.), were used for actinomycetes isolation. Ninety-three (93) isolates have been screened to evaluate their antagonistic properties against phytopathogenic microorganisms and to determine their biocontrol properties against Fusarium culmorum, especially responsible for several cereal diseases like font’s seedlings, rust, and burn of ears. Four (04) isolates (D2, D5, D8, and AST1) have been in vitro tested to determine PGPR effect and biocontrol characters of bread wheat (Triticum aestivum L.), Hidhab (HD) variety cultivated in the Murashigue and Skoog (MS) culture medium. The aim of this study is the evaluation of antagonistic isolates of pathogenic fungi F. culmorum, without and within commercial fungicide (Tebuconazole, 60 g/l) solution. Our results showed clearly that these isolates have a significant effect on seed germination and seedling growth. However, results argue that these actinomycetes isolates show a very interesting activity compared to the commercial fungicide. As a result, these bacteria isolates can be used as biocontrol agents against Fusarium wilt disease of wheat, which have a beneficial effect on growth parameters.展开更多
The report sets out to summarize the past and current situation regarding the practice of biologicalcontrol inrelationtothe use and exchange of genetic resources relevant for BCAs.It considers the twomain categories o...The report sets out to summarize the past and current situation regarding the practice of biologicalcontrol inrelationtothe use and exchange of genetic resources relevant for BCAs.It considers the twomain categories of biological control:classical and augmentative.Allowing access to BCAs for use inanother country imposes no risk of liability to the source country.Local scientific knowledge abouthabitats,fauna andflora,can be展开更多
Ten isolates of Erwinia carotovora ssp. carotovora (Ecc) were isolated from infected potato tubers of Picasso, Sante, and Nevskiy varieties collected from different regions in Kyrgyzstan. Isolates were identified as E...Ten isolates of Erwinia carotovora ssp. carotovora (Ecc) were isolated from infected potato tubers of Picasso, Sante, and Nevskiy varieties collected from different regions in Kyrgyzstan. Isolates were identified as Erwinia carotovora ssp. carotovora (Ecc) by standard bacteriological techniques and pathogenicity tests on tubers and also by PCR analyses. Tests on the pathogenicity of E. carotovora ssp. carotovora (Ecc) strains to host plants by artificial inoculation have shown a high sensibility of the Picasso variety. As a result, five isolates were chosen, three isolates (EcPo1, EcPo2, and Eco3) were highly pathogenic, while two isolates (Eco4 and Eco5) were weakly pathogenic. The antagonistic bacteria, Streptomyces diastatochromogenes strain sk-6, and Streptomyces graminearuss strain sk-2, have a highly significant effect on soft rot bacteria isolates (Ecc), more than the other tested antagonistic organisms in vitro screening biotests. The Streptomyces diastatochromogenes sk-6 was selected for the control assay of storage potatoes against the most common soft rot bacterial strain in Kyrgyzstan, Erwinia carotovora sp. carotovora EcPo2. The pretreatment of potato tubers with antagonistic bacteria successfully prevented the initial infection multiplication of soft rot bacteria and reduced soft rot disease of potatoes in storage. These results justify selection of the dose 10<sup>6</sup> cells/ml of bacteria Streptomyces diastatochromogenes sk-6 for use in powdering the infected or non-infected potato tubers to suppress the development soft rot during storage. Streptomyces diastatochromogenes sk-6 as a biological disinfectant could destroy surface and internal infections, protect the tubers from the growth of phytopathogenic bacteria in the early period of their reproduction, and improve the overwintering of winter crops.展开更多
The entomopathogenic nematode,Steinernema carpocapsae,was evaluated for control of the potato tuber moth,Phthorimaea operculella,under laboratory conditions.We evaluated different concentrations of S.carpocapsae for c...The entomopathogenic nematode,Steinernema carpocapsae,was evaluated for control of the potato tuber moth,Phthorimaea operculella,under laboratory conditions.We evaluated different concentrations of S.carpocapsae for control of 2 nd,3 rd,and 4 th instar P.operculella.The median lethal concentration(LC50)of S.carpocapsae infective juveniles(IJs)to 2 nd,3 rd and 4 th instar larvae of P.operculella was 200,363,181 IJs mL–1,respectively.With the extension of treatment time,the cumulative mortality increased for 2 nd,3 rd,and 4 th instar larvae and pupae of P.operculella.Fourth instars were the most susceptible for all observation periods.Therefore,our results suggest that S.carpocapsae could be an effective biological control agent for P.operculella.展开更多
Biological control(biocontrol) is a safe, sustainable approach that takes advantage of natural enemies such as predators, parasitic insects or pathogens to manage pests in agroecosystems. Parasitoid wasps, a very larg...Biological control(biocontrol) is a safe, sustainable approach that takes advantage of natural enemies such as predators, parasitic insects or pathogens to manage pests in agroecosystems. Parasitoid wasps, a very large evolutionary group of hymenopteran insects, are well-known biological control agents for arthropod pests in agricultural and forest ecosystems. Here, we summarize the recent progress on the application of parasitoid wasps in biocontrol in China for the last five years. These include species diversity of parasitoid wasps, identification of dominant parasitoid wasps associated with insect pests and biocontrol practices(three types of biological control, i.e., classical, augmentative and conservation biological control) in several Chinese agroecosystems. We then treat different mass-rearing and release technologies and the commercialization of several parasitoid wasp species. We also summarize other work that may have a potential use in biocontrol, including the effect of plant volatiles on parasitoids and recent advance in the molecular mechanisms underlying the host regulation by parasitoid wasps. Future research area and applied perspectives are also discussed, noting that advances in biocontrol technologies in Chinese agriculture informs research at the global level.展开更多
Biological control through habitat management leads to sustainable insect pest control. Different types of land composition such as multiple landscapes, patchiness of landscapes enhance the natural enemies which ultim...Biological control through habitat management leads to sustainable insect pest control. Different types of land composition such as multiple landscapes, patchiness of landscapes enhance the natural enemies which ultimately lead to control of insect pest. Plant characteristics such as flower shape, flower color and blooming period ensures excess food for natural enemies like nectar and pollen. Moreover, some agricultural practices such as tillage, crop rotation, and intercropping influence the natural enemies especially parasitoid and preda-tors. Consequently, they increase longevity and fecundity of parasitoid and predator that help to control insect pest. One of the most important recently used methods is push-pull which consists of semiochemicals called Herbi-vore-Induced Plant Volatiles (HIPVs). This compound has been used to pre-vent pest and attract natural enemies.展开更多
Greenhouse production systems typically involve growing multiple crop types simultaneously, including ornamentals and vegetables. Therefore, greenhouse producers commonly deal with multiple pest complexes. Two importa...Greenhouse production systems typically involve growing multiple crop types simultaneously, including ornamentals and vegetables. Therefore, greenhouse producers commonly deal with multiple pest complexes. Two important insect pests of greenhouse-grown horticultural crops are fungus gnats (Bradysia spp.) and western flower thrips (Frankliniella occidentalis). A plant protection strategy that can be used to manage both pests is biological control. The rove beetle (Dalotia coriaria) and insidious flower bug (Orius insidiosus) are generalist predators commercially available for use in greenhouse production systems targeting fungus gnats and the western flower thrips. This article describes the biology, behavior, ecology, and role of both natural enemies in greenhouse production systems, and discusses the direct and indirect effects of pesticides (insecticides, miticides, and fungicides) on D. coriaria and O. inisidiosus.展开更多
Strain OH11,a Gram-negative,nonspore forming,rod-shaped bacterium with powerful antagonistic activity,was isolated from rhizosphere of green pepper in Jiangsu Academy of Agricultural Sciences of China and characterize...Strain OH11,a Gram-negative,nonspore forming,rod-shaped bacterium with powerful antagonistic activity,was isolated from rhizosphere of green pepper in Jiangsu Academy of Agricultural Sciences of China and characterized to determine its taxonomic position.16S rRNA gene sequence analysis revealed that strain OH11 belongs to the Gammaproteobacteria and had the highest degree of sequence similarity to Lysobacter enzymogenes strain C3(AY074793)(99%),Lysobacter enzymogenes strain N4-7(U89965)(99%),Lysobacter antibioticus strain(AB019582)(97%),and Lysobacter gummosus strain(AB16136)(97%).Chemotaxonomic data revealed that strain OH11 possesses a quinine system with Q-8 as the predominant compound and C15:0 iso,C17:1 iso ω9c as the predominant iso-branched fatty acids,all of which corroborated the assignment of strain OH11 to the genus Lysobacter.Results of DNA-DNA hybridization and physiological and biochemical tests clearly showed that strain OH11 was classified as Lysobacter enzymogenes.Strain OH11 could produce protease,chitinase,and β-1,3-glucanase.It showed strong in vitro antifungal activity against Rhizoctonia solani,Sclerotinia scletotiorum,and several other phytopathogenic fungi.This is the first report of identification and characterization of Lysobacter enzymogenes as a biological control agent of plant diseases in China.展开更多
Tea is a perennial and evergreen plant. Cultivated tea trees provide a habitat for insect pests and their natural enemies. In Japan, granuloviruses (GVs) have successfully controlled two of the most important pests of...Tea is a perennial and evergreen plant. Cultivated tea trees provide a habitat for insect pests and their natural enemies. In Japan, granuloviruses (GVs) have successfully controlled two of the most important pests of tea, Adoxophyes honmai and Homona magnanima (Tortricidae: Lepidoptera). The GVs are produced in vivo and a single application sustains pesticidal efficacy throughout a year, which encompasses 4 to 5 discrete generations of both species. A. honmai and H. magnanima also have various natural enemies, especially hymenopteran parasitoids. Such resident natural enemies also play a role in reducing the pest density in virus-controlled fields, but the effect of virus infection on parasitoids sharing the same host larva has not been well studied. Survival of one of the major parasitoids of A. honmai, Ascogaster reticulata (Braconidae: Hymenoptera), is reduced by virus infection of the host. Viruses, including GV and entomopoxvirus (EPV), and certain koinobiont endoparasitoids, including A. reticulata, are both known to regulate host endocrinology. However, the GV and EPV have distinct host regulation mechanisms, and consequently have different impacts on the survival of A. retuculata, when A. reticulata parasitizes a host that is infected with either GV or EPV. These additional effects on host regulation displayed by both viruses and parasitoids affect the outcome of virus-parasitoid interactions.展开更多
The relationship between pest population and other factors is rather complex within the forest ecosystem. A number of environmental factors, such as extreme climatic conditions,infection of natural enemies, may cause ...The relationship between pest population and other factors is rather complex within the forest ecosystem. A number of environmental factors, such as extreme climatic conditions,infection of natural enemies, may cause the death of pest insects directly. The effect of these factors reflects basically the situation and cause of death of insects at different stages of entire process of growth and development, so that they may be cmployed as the basic records of the quantitative dynamic of the population, and are of important value to the study of population quantitative dynamics of pests. Since Morris and Miller (1954) applied the life table technique to study natural population of insects, the insect lif e table technique has becoming an important means for the study of quantitative dynamics of pest populations. In foreign countries, the study of the life table of forest pest began in 50 year’s already. Moreovcr. the rcsults of invcstigation were applicd to the productive practice, such as thc sprucc budworm (Choristoneura fumiferana Clemens),winter moth (Opperophtera brumala Linnaeus), while in our country, the quantitative dynamics of many forest pests were not investigated. The larch caterpillar is one of the great pest of larch plantation in China. Every ycar, the outbrcak of this pcst occur in some places, causing large economic loss. Many studies wcre performcd on the biological and chenlical controls, but the investigation on quantitative dynamics of the natural population of larch caterpi1Iar was lacking.Since 1980, we studicd the quantitative dynamics of the natural population of larch caterpillar in Shangzhi County, Heilongiiang Province and worked out lif e tables of two generations.展开更多
Objective:To evaluate the entomological impact of chlorpyrifos-methyl,Bacillus thuringiensis, and Gambusia affinis on mosquitoes control in artificial breeding places.Methods:A Latin square design with 4 replicates wa...Objective:To evaluate the entomological impact of chlorpyrifos-methyl,Bacillus thuringiensis, and Gambusia affinis on mosquitoes control in artificial breeding places.Methods:A Latin square design with 4 replicates was performed in order to evaluate the efficacy of chlorpyrifosmethyl, Bacillus thuringiensis,and Gambusia affinis on larva.The larvicide was applied at the dosage of 100 mg a.h/ha,Bacillus thuringiensis at the recommended dosage and 10 fishes per m^2 were applied at 1×1 m^2 artificial breeding sites.The larval densities for both anopheline and culicine were counted according to larvae /10 dippers prior and 24 h after application.Results: All three control agents are effective for mosquito density reduction,and the difference between the three agents and the control is significant(P【0.05).There is also significant difference among chlorpyrifos-methyl,Bacillus thuringiensis and Gambusia affinis.Bacillus thuringiensis exhibited more reduction on mosquito larval density than fish and larvicide(P【0.05).Conclusions: Bacillus thuringiensis in comparison with two other agents is the appropriate method for larviciding in the breeding places.Although long term assessing for biological activities as well as monitoring and mapping of resistance is required.展开更多
Objective:Rice fields are dynamic mosquito larval habitats with assemblage of different predator taxa,including the larva of the mosquitoes Lutzia.Entomological surveillance in the ricefields is essential to evaluate ...Objective:Rice fields are dynamic mosquito larval habitats with assemblage of different predator taxa,including the larva of the mosquitoes Lutzia.Entomological surveillance in the ricefields is essential to evaluate the potential of these predators as biological resource to regulate vector mosquito population.In view of this,a survey of ricefields for immatures of different mosquito species including Lutzia was conducted.Methods:Survey of selected ricefields was carried out to evaluate the species composition of mosquitoes.Laboratory evaluation of the immatures of Lutzia mosquitoes was carried out to assess its predation potential using mosquitoes and chironomid as preys.Results:The survey revealed the presence of five mosquito species belonging to the genera Anopheles and Culex and the predatory immatures of the mosquito Lutzia Juscana(Wiedemann,1820).The ratio of prey and predatory larva ranged between 1.46 and 4.78 during the study period,with a significant correlation on the relative abundance of the larval stages of Lt.Juscana and Anopheles and Culex larvae.Under laboratory conditions,a single IV instar larvae of Lt.fuscana was found to consume on an average 5 to 15 equivalent instars of Anopheles sp.and Culex sp.larvae per day depending on its age.The prey consumption reduced with the larval stage approaching pupation.When provided with equal numbers of chironomid and Anopheles or Culex larvae,larva of Lt.fuscana consumed mosquito larvae significantly more compared to chironomids.Conclusion: The survey results and the preliminary study on predation are suggestive of the role of Lt.Juscana in the regulation of vector mosquito populations naturally in the ricefields.Since Lt.Juscana is common in many Asian countries,further studies on bioecology will be helpful to justify their use in mosquito control programme.展开更多
Colletotrichum truncatum, grown on rice grain (3 to 4 weeks, 22°C to 24°C) produced a fungus-infested rice mixture of microsclerotia and conidia (spores) in a ratio of ~9:1, respectively. Greenhouse tests of...Colletotrichum truncatum, grown on rice grain (3 to 4 weeks, 22°C to 24°C) produced a fungus-infested rice mixture of microsclerotia and conidia (spores) in a ratio of ~9:1, respectively. Greenhouse tests of this formulation (0.4 to 50 mg finely-ground fungus-rice product) which applied pre-emergence to 5 cm2 of soil surface, caused 22% to 96% hemp sesbania plant mortality, after 14 days. Post-emergence treatment (fungus-rice aqueous formulation;2.4 × 105 microsclerotia ml-1, 30% unrefined corn oil and 0.2% Silwet L-77 surfactant) of weeds surviving the pre-emergence application, resulted in 93% mortality, after 14 days. Based on greenhouse results, field tests were undertaken: 1) pre-emergence treatment (fungus-rice formulation at 2.4 × 105 microsclerotia cm-2), 2) post-emergence (fungus-rice product in 30% unrefined corn oil, 0.2% Silwet) only treatment, applied 15 days after planting and 3) pre-emergence treatment followed by post-emergence treatment (fungus-rice product in 30% unrefined corn oil, 0.2% Silwet) applied 15 days after planting to surviving weeds. Control treatments were: 1) autoclaved rice product sans fungus, 2) unrefined corn oil (30% unrefined corn oil, 0.2% Silwet in water) and 3) untreated plants. Planting dates were: early season (April-May), early-mid season (June-July), late-mid season (July-August), and late season (September-October). Weed mortality was recorded at 15 days for the pre-plus post-treatment, and at 30 days after planting for the pre-emergence only and the post-treatment only. The early season, pre-emergence treatment caused 67% hemp sesbania mortality (3-yr average) within 15 days and the post-emergence treatment caused 91% mortality of the surviving weeds. In the late-mid-season, pre-emergence treatment caused minimal (<5%) mortality at 15 days, but mortality in the post-emergence treatment was >80%. Results suggest that seasonal environmental conditions are important in the efficacy of this C. truncatum-rice product formulation when applied pre- or post-emergence to this onerous weed.展开更多
Neozygites tanajoae is an entomopathogenic fungus which has been used for biocontrol of the cassava green mite(Mononychellus tanajoa,CGM)in Africa. Establishment and dispersal of Brazilian isolates which have been int...Neozygites tanajoae is an entomopathogenic fungus which has been used for biocontrol of the cassava green mite(Mononychellus tanajoa,CGM)in Africa. Establishment and dispersal of Brazilian isolates which have been introduced into some African countries in recent years to improve CGM control was followed with specific PCR assays.Two primer pairs,展开更多
Aflatoxin is the most powerful carcinogen and highly toxic mycotoxin known in nature. It can cause serious toxin pollution to agricultural products, foods and fodders, and is extremely harmful to human and animal heal...Aflatoxin is the most powerful carcinogen and highly toxic mycotoxin known in nature. It can cause serious toxin pollution to agricultural products, foods and fodders, and is extremely harmful to human and animal health. For aflatoxin pollution, the emphasis is on the control of source, and biological control is favored by scientists because of its advantages of environmental protection and ecological safety. According to the morphology, color and appearance of microbial colonies isolated from maize kernels, 300 bacterial strains were obtained from main maize-producing areas including Tangshan City, Handan City, Shijiazhuang City and Cangzhou City. Two biocontrol bacterial strains(B120 and B65) having a strong control effect on aflatoxins were screened. After identification by molecular biology and physical and chemical properties, the two biocontrol bacterial strains were identified as Bacillus amyloliquefaciens. Their effects on spore germination, mycelial growth and toxin degradation of Aspergillus flavus were investigated. The results showed that strains B120 and B65 could significantly inhibit the spore germination and mycelial growth of A. flavus and reduce aflatoxin production. This study provides a new way to prevent and control the pollution control of aflatoxins in agricultural products.展开更多
文摘Millet (Pennisetum glaucum (L.) R. Br.) is the Sahelian crop par excellence due to its adaptation to the particular production conditions in this region. Unfortunately, in recent years this crop has been threatened by very strong parasitic pressure and drought during the production period. The objective of this study is to analyze the main constraints of millet production and the solutions known to producers. A survey was carried out in November 2022 with a sample of 298 producers in five municipalities in the Tahoua region. The main constraints are drought and pressure from crop pests (locust, millet ear miner, floricultural insects) according to 57.9% of respondents. The millet ear miner is the most formidable pest according to 55% of respondents. Thus, the average yield obtained in a year of good production without the leafminer is 194 kg/ha and that obtained in a year of millet ear leafminer is around 27 kg to 43 kg/ha depending on the municipality. The yield obtained this last campaign after the attack of this leafminer varies from 64 to 77 kg/ha depending on the municipalities compared to a potential yield of over 1000 kg/ha. More than half of producers (58.1%) are unaware of the existence of biological control compared to only 12.5% who are aware of this alternative method. Work to popularize this technology is necessary in the five municipalities and the entire region in general.
文摘Biological control agents and soil amendments have been applied to control tobacco bacterial wilt, but the mechanism is not well-known. In the present study, a field experiment was performed to investigate the soil physicochemical properties, disease index (DI) and disease incidence of tobacco bacterial wilt, and rhizosphere microbial community. The results show that the control efficacy of single application of antagonistic bacteria and calcium cyanamide was 46.43% and 51.92%, respectively. While the combined control efficacy of antagonistic bacteria and calcium cyanamide was 65.79%. Besides, the combined application of antagonistic bacteria and calcium cyanamide could increase soil pH, total N alkaline N, and exchangeable Ca, which were negatively associated with the microbial diversity, soil-borne pathogenic microorganisms, and incidence of tobacco bacterial wilt. Additionally, the combination of antagonistic bacteria and calcium cyanamide can improve the proportion of some antagonistic microbial species, and these antagonistic microbial species were inversely associated with the DI of tobacco bacterial wilt. In conclusion: The integrated measure may influence soil microbial communities through enhancing soil physicochemical properties and rebuild healthy soil microbial community structure to mitigate tobacco bacterial wilt. The current study presented valuable insights into the mechanisms enhancing soil health in the integrated measure.
文摘With the increased prevalence of dengue infection in tropical countries, concerned members of the public are now pressing their local health ministries to act immediately and effectively in managing the rising numbers of reported cases. This includes reviews of the methodologies and the effectiveness of current combative systems to find other possible novel approaches that might yield better results. One of those novel approaches is the integration of a parasite into mosquito vector, manipulating the parasite-host interaction to reduce the transmission of dengue in endemic hotspots. Another alternative is by Sanofi-Pasteur’s dengue vaccine that showed over 60.8% success rate in reducing severe dengue infection in children aged 9 - 16 during its final clinical implementation phase. This report will compare and contrast these two novel ideas to determine which of the approaches are more likely to be effective in the long run. The aspects covered will include the application, effectiveness, functionality, and problems with these approaches. The results could then be utilised by governments or organizations to select precise and effective methods in reducing the prevalence of dengue infections in their countries.
文摘Cucumber green mottle mosaic virus (CGMMV), a member of the Tobamovirus genus, causes a severe disease of cucurbits. In the Moscow region of Russian Federation, the incidence of infection on cucumber plants in greenhouses is high;however, the virus is poorly studied. In this work, the full-length genomes of two pathogenic MC-1 and MC-2 strains of CGMMV isolated from cucumber plants grown in greenhouses in the Moscow region and the attenuated VIROG-43M strain were sequenced. Comparison of VIROG-43M nucleotide sequence with those of the pathogenic strains revealed three missense mutations. Their role in attenuation is discussed. For the first time, in a number of trials conducted under laboratory conditions and in commercial greenhouses, the efficiency of the attenuated VIROG-43M strain as a biocontrol agent for cucumber plant protection resulting in significant yield gain was demonstrated. Phylogenetic analysis with 83 full-length CGMMV coat protein genes isolated in 16 different countries showed that Russian strains are related to isolates from Spain, Greece, USA and Israel.
文摘The erosion of drains is a major limitation of the quality, the increasing of banana production and the environmental protection of industrial banana in Côte d'Ivoire. It leads inundations, death of banana trees and significant loss of production. Thence, the construction and the maintenance of drain costs too much and causes injure, snake bite, physical traumatisms, many diseases, … These events compromise the sustainable production of banana by reducing seriously worker’s the activities and finally increase the cost of production. The aim of the present work is to contribute to the sustainable development and human capacity building in the third world nations as far as banana production is concerned. The methods used so far to address this phenomenon proved inefficient. The technology innovation in this area has been to grow grass on the outer edges of the channels drained water. This resulted in a systematic reduction of erosion. Better still, it helped fertilize the soil, reduce the deportations of fertilizer and improve the quality of landscape of the plantations. Stenotaphrum secondatum is the best vegetable specie adapted to the biological control against water erosion of drains.
文摘Three endemic plants rhizosphere (Astragalus gombo Coss. & Dur., Daucus sahariensis Murb., Ononis angustissima Lam.), were used for actinomycetes isolation. Ninety-three (93) isolates have been screened to evaluate their antagonistic properties against phytopathogenic microorganisms and to determine their biocontrol properties against Fusarium culmorum, especially responsible for several cereal diseases like font’s seedlings, rust, and burn of ears. Four (04) isolates (D2, D5, D8, and AST1) have been in vitro tested to determine PGPR effect and biocontrol characters of bread wheat (Triticum aestivum L.), Hidhab (HD) variety cultivated in the Murashigue and Skoog (MS) culture medium. The aim of this study is the evaluation of antagonistic isolates of pathogenic fungi F. culmorum, without and within commercial fungicide (Tebuconazole, 60 g/l) solution. Our results showed clearly that these isolates have a significant effect on seed germination and seedling growth. However, results argue that these actinomycetes isolates show a very interesting activity compared to the commercial fungicide. As a result, these bacteria isolates can be used as biocontrol agents against Fusarium wilt disease of wheat, which have a beneficial effect on growth parameters.
文摘The report sets out to summarize the past and current situation regarding the practice of biologicalcontrol inrelationtothe use and exchange of genetic resources relevant for BCAs.It considers the twomain categories of biological control:classical and augmentative.Allowing access to BCAs for use inanother country imposes no risk of liability to the source country.Local scientific knowledge abouthabitats,fauna andflora,can be
文摘Ten isolates of Erwinia carotovora ssp. carotovora (Ecc) were isolated from infected potato tubers of Picasso, Sante, and Nevskiy varieties collected from different regions in Kyrgyzstan. Isolates were identified as Erwinia carotovora ssp. carotovora (Ecc) by standard bacteriological techniques and pathogenicity tests on tubers and also by PCR analyses. Tests on the pathogenicity of E. carotovora ssp. carotovora (Ecc) strains to host plants by artificial inoculation have shown a high sensibility of the Picasso variety. As a result, five isolates were chosen, three isolates (EcPo1, EcPo2, and Eco3) were highly pathogenic, while two isolates (Eco4 and Eco5) were weakly pathogenic. The antagonistic bacteria, Streptomyces diastatochromogenes strain sk-6, and Streptomyces graminearuss strain sk-2, have a highly significant effect on soft rot bacteria isolates (Ecc), more than the other tested antagonistic organisms in vitro screening biotests. The Streptomyces diastatochromogenes sk-6 was selected for the control assay of storage potatoes against the most common soft rot bacterial strain in Kyrgyzstan, Erwinia carotovora sp. carotovora EcPo2. The pretreatment of potato tubers with antagonistic bacteria successfully prevented the initial infection multiplication of soft rot bacteria and reduced soft rot disease of potatoes in storage. These results justify selection of the dose 10<sup>6</sup> cells/ml of bacteria Streptomyces diastatochromogenes sk-6 for use in powdering the infected or non-infected potato tubers to suppress the development soft rot during storage. Streptomyces diastatochromogenes sk-6 as a biological disinfectant could destroy surface and internal infections, protect the tubers from the growth of phytopathogenic bacteria in the early period of their reproduction, and improve the overwintering of winter crops.
基金supported in part by the National Key Research and Development Program of China (2018YFD0200802)
文摘The entomopathogenic nematode,Steinernema carpocapsae,was evaluated for control of the potato tuber moth,Phthorimaea operculella,under laboratory conditions.We evaluated different concentrations of S.carpocapsae for control of 2 nd,3 rd,and 4 th instar P.operculella.The median lethal concentration(LC50)of S.carpocapsae infective juveniles(IJs)to 2 nd,3 rd and 4 th instar larvae of P.operculella was 200,363,181 IJs mL–1,respectively.With the extension of treatment time,the cumulative mortality increased for 2 nd,3 rd,and 4 th instar larvae and pupae of P.operculella.Fourth instars were the most susceptible for all observation periods.Therefore,our results suggest that S.carpocapsae could be an effective biological control agent for P.operculella.
基金supported by the Key Program(31630060)Fund for Excellent Young Scholars(31230068)General Program(31672079 and 31501700) of the National Natural Science Foundation of China
文摘Biological control(biocontrol) is a safe, sustainable approach that takes advantage of natural enemies such as predators, parasitic insects or pathogens to manage pests in agroecosystems. Parasitoid wasps, a very large evolutionary group of hymenopteran insects, are well-known biological control agents for arthropod pests in agricultural and forest ecosystems. Here, we summarize the recent progress on the application of parasitoid wasps in biocontrol in China for the last five years. These include species diversity of parasitoid wasps, identification of dominant parasitoid wasps associated with insect pests and biocontrol practices(three types of biological control, i.e., classical, augmentative and conservation biological control) in several Chinese agroecosystems. We then treat different mass-rearing and release technologies and the commercialization of several parasitoid wasp species. We also summarize other work that may have a potential use in biocontrol, including the effect of plant volatiles on parasitoids and recent advance in the molecular mechanisms underlying the host regulation by parasitoid wasps. Future research area and applied perspectives are also discussed, noting that advances in biocontrol technologies in Chinese agriculture informs research at the global level.
文摘Biological control through habitat management leads to sustainable insect pest control. Different types of land composition such as multiple landscapes, patchiness of landscapes enhance the natural enemies which ultimately lead to control of insect pest. Plant characteristics such as flower shape, flower color and blooming period ensures excess food for natural enemies like nectar and pollen. Moreover, some agricultural practices such as tillage, crop rotation, and intercropping influence the natural enemies especially parasitoid and preda-tors. Consequently, they increase longevity and fecundity of parasitoid and predator that help to control insect pest. One of the most important recently used methods is push-pull which consists of semiochemicals called Herbi-vore-Induced Plant Volatiles (HIPVs). This compound has been used to pre-vent pest and attract natural enemies.
文摘Greenhouse production systems typically involve growing multiple crop types simultaneously, including ornamentals and vegetables. Therefore, greenhouse producers commonly deal with multiple pest complexes. Two important insect pests of greenhouse-grown horticultural crops are fungus gnats (Bradysia spp.) and western flower thrips (Frankliniella occidentalis). A plant protection strategy that can be used to manage both pests is biological control. The rove beetle (Dalotia coriaria) and insidious flower bug (Orius insidiosus) are generalist predators commercially available for use in greenhouse production systems targeting fungus gnats and the western flower thrips. This article describes the biology, behavior, ecology, and role of both natural enemies in greenhouse production systems, and discusses the direct and indirect effects of pesticides (insecticides, miticides, and fungicides) on D. coriaria and O. inisidiosus.
基金supported by the National High Technology Research and Development Program of China(2006AA10A211)
文摘Strain OH11,a Gram-negative,nonspore forming,rod-shaped bacterium with powerful antagonistic activity,was isolated from rhizosphere of green pepper in Jiangsu Academy of Agricultural Sciences of China and characterized to determine its taxonomic position.16S rRNA gene sequence analysis revealed that strain OH11 belongs to the Gammaproteobacteria and had the highest degree of sequence similarity to Lysobacter enzymogenes strain C3(AY074793)(99%),Lysobacter enzymogenes strain N4-7(U89965)(99%),Lysobacter antibioticus strain(AB019582)(97%),and Lysobacter gummosus strain(AB16136)(97%).Chemotaxonomic data revealed that strain OH11 possesses a quinine system with Q-8 as the predominant compound and C15:0 iso,C17:1 iso ω9c as the predominant iso-branched fatty acids,all of which corroborated the assignment of strain OH11 to the genus Lysobacter.Results of DNA-DNA hybridization and physiological and biochemical tests clearly showed that strain OH11 was classified as Lysobacter enzymogenes.Strain OH11 could produce protease,chitinase,and β-1,3-glucanase.It showed strong in vitro antifungal activity against Rhizoctonia solani,Sclerotinia scletotiorum,and several other phytopathogenic fungi.This is the first report of identification and characterization of Lysobacter enzymogenes as a biological control agent of plant diseases in China.
基金This work was partially supported by Grant-in-Aid for Scientific Research (B) (18380038)
文摘Tea is a perennial and evergreen plant. Cultivated tea trees provide a habitat for insect pests and their natural enemies. In Japan, granuloviruses (GVs) have successfully controlled two of the most important pests of tea, Adoxophyes honmai and Homona magnanima (Tortricidae: Lepidoptera). The GVs are produced in vivo and a single application sustains pesticidal efficacy throughout a year, which encompasses 4 to 5 discrete generations of both species. A. honmai and H. magnanima also have various natural enemies, especially hymenopteran parasitoids. Such resident natural enemies also play a role in reducing the pest density in virus-controlled fields, but the effect of virus infection on parasitoids sharing the same host larva has not been well studied. Survival of one of the major parasitoids of A. honmai, Ascogaster reticulata (Braconidae: Hymenoptera), is reduced by virus infection of the host. Viruses, including GV and entomopoxvirus (EPV), and certain koinobiont endoparasitoids, including A. reticulata, are both known to regulate host endocrinology. However, the GV and EPV have distinct host regulation mechanisms, and consequently have different impacts on the survival of A. retuculata, when A. reticulata parasitizes a host that is infected with either GV or EPV. These additional effects on host regulation displayed by both viruses and parasitoids affect the outcome of virus-parasitoid interactions.
文摘The relationship between pest population and other factors is rather complex within the forest ecosystem. A number of environmental factors, such as extreme climatic conditions,infection of natural enemies, may cause the death of pest insects directly. The effect of these factors reflects basically the situation and cause of death of insects at different stages of entire process of growth and development, so that they may be cmployed as the basic records of the quantitative dynamic of the population, and are of important value to the study of population quantitative dynamics of pests. Since Morris and Miller (1954) applied the life table technique to study natural population of insects, the insect lif e table technique has becoming an important means for the study of quantitative dynamics of pest populations. In foreign countries, the study of the life table of forest pest began in 50 year’s already. Moreovcr. the rcsults of invcstigation were applicd to the productive practice, such as thc sprucc budworm (Choristoneura fumiferana Clemens),winter moth (Opperophtera brumala Linnaeus), while in our country, the quantitative dynamics of many forest pests were not investigated. The larch caterpillar is one of the great pest of larch plantation in China. Every ycar, the outbrcak of this pcst occur in some places, causing large economic loss. Many studies wcre performcd on the biological and chenlical controls, but the investigation on quantitative dynamics of the natural population of larch caterpi1Iar was lacking.Since 1980, we studicd the quantitative dynamics of the natural population of larch caterpillar in Shangzhi County, Heilongiiang Province and worked out lif e tables of two generations.
文摘Objective:To evaluate the entomological impact of chlorpyrifos-methyl,Bacillus thuringiensis, and Gambusia affinis on mosquitoes control in artificial breeding places.Methods:A Latin square design with 4 replicates was performed in order to evaluate the efficacy of chlorpyrifosmethyl, Bacillus thuringiensis,and Gambusia affinis on larva.The larvicide was applied at the dosage of 100 mg a.h/ha,Bacillus thuringiensis at the recommended dosage and 10 fishes per m^2 were applied at 1×1 m^2 artificial breeding sites.The larval densities for both anopheline and culicine were counted according to larvae /10 dippers prior and 24 h after application.Results: All three control agents are effective for mosquito density reduction,and the difference between the three agents and the control is significant(P【0.05).There is also significant difference among chlorpyrifos-methyl,Bacillus thuringiensis and Gambusia affinis.Bacillus thuringiensis exhibited more reduction on mosquito larval density than fish and larvicide(P【0.05).Conclusions: Bacillus thuringiensis in comparison with two other agents is the appropriate method for larviciding in the breeding places.Although long term assessing for biological activities as well as monitoring and mapping of resistance is required.
文摘Objective:Rice fields are dynamic mosquito larval habitats with assemblage of different predator taxa,including the larva of the mosquitoes Lutzia.Entomological surveillance in the ricefields is essential to evaluate the potential of these predators as biological resource to regulate vector mosquito population.In view of this,a survey of ricefields for immatures of different mosquito species including Lutzia was conducted.Methods:Survey of selected ricefields was carried out to evaluate the species composition of mosquitoes.Laboratory evaluation of the immatures of Lutzia mosquitoes was carried out to assess its predation potential using mosquitoes and chironomid as preys.Results:The survey revealed the presence of five mosquito species belonging to the genera Anopheles and Culex and the predatory immatures of the mosquito Lutzia Juscana(Wiedemann,1820).The ratio of prey and predatory larva ranged between 1.46 and 4.78 during the study period,with a significant correlation on the relative abundance of the larval stages of Lt.Juscana and Anopheles and Culex larvae.Under laboratory conditions,a single IV instar larvae of Lt.fuscana was found to consume on an average 5 to 15 equivalent instars of Anopheles sp.and Culex sp.larvae per day depending on its age.The prey consumption reduced with the larval stage approaching pupation.When provided with equal numbers of chironomid and Anopheles or Culex larvae,larva of Lt.fuscana consumed mosquito larvae significantly more compared to chironomids.Conclusion: The survey results and the preliminary study on predation are suggestive of the role of Lt.Juscana in the regulation of vector mosquito populations naturally in the ricefields.Since Lt.Juscana is common in many Asian countries,further studies on bioecology will be helpful to justify their use in mosquito control programme.
文摘Colletotrichum truncatum, grown on rice grain (3 to 4 weeks, 22°C to 24°C) produced a fungus-infested rice mixture of microsclerotia and conidia (spores) in a ratio of ~9:1, respectively. Greenhouse tests of this formulation (0.4 to 50 mg finely-ground fungus-rice product) which applied pre-emergence to 5 cm2 of soil surface, caused 22% to 96% hemp sesbania plant mortality, after 14 days. Post-emergence treatment (fungus-rice aqueous formulation;2.4 × 105 microsclerotia ml-1, 30% unrefined corn oil and 0.2% Silwet L-77 surfactant) of weeds surviving the pre-emergence application, resulted in 93% mortality, after 14 days. Based on greenhouse results, field tests were undertaken: 1) pre-emergence treatment (fungus-rice formulation at 2.4 × 105 microsclerotia cm-2), 2) post-emergence (fungus-rice product in 30% unrefined corn oil, 0.2% Silwet) only treatment, applied 15 days after planting and 3) pre-emergence treatment followed by post-emergence treatment (fungus-rice product in 30% unrefined corn oil, 0.2% Silwet) applied 15 days after planting to surviving weeds. Control treatments were: 1) autoclaved rice product sans fungus, 2) unrefined corn oil (30% unrefined corn oil, 0.2% Silwet in water) and 3) untreated plants. Planting dates were: early season (April-May), early-mid season (June-July), late-mid season (July-August), and late season (September-October). Weed mortality was recorded at 15 days for the pre-plus post-treatment, and at 30 days after planting for the pre-emergence only and the post-treatment only. The early season, pre-emergence treatment caused 67% hemp sesbania mortality (3-yr average) within 15 days and the post-emergence treatment caused 91% mortality of the surviving weeds. In the late-mid-season, pre-emergence treatment caused minimal (<5%) mortality at 15 days, but mortality in the post-emergence treatment was >80%. Results suggest that seasonal environmental conditions are important in the efficacy of this C. truncatum-rice product formulation when applied pre- or post-emergence to this onerous weed.
文摘Neozygites tanajoae is an entomopathogenic fungus which has been used for biocontrol of the cassava green mite(Mononychellus tanajoa,CGM)in Africa. Establishment and dispersal of Brazilian isolates which have been introduced into some African countries in recent years to improve CGM control was followed with specific PCR assays.Two primer pairs,
基金Supported by Forage Industry Technical System Project of Hebei Province(HBCT2018160403)
文摘Aflatoxin is the most powerful carcinogen and highly toxic mycotoxin known in nature. It can cause serious toxin pollution to agricultural products, foods and fodders, and is extremely harmful to human and animal health. For aflatoxin pollution, the emphasis is on the control of source, and biological control is favored by scientists because of its advantages of environmental protection and ecological safety. According to the morphology, color and appearance of microbial colonies isolated from maize kernels, 300 bacterial strains were obtained from main maize-producing areas including Tangshan City, Handan City, Shijiazhuang City and Cangzhou City. Two biocontrol bacterial strains(B120 and B65) having a strong control effect on aflatoxins were screened. After identification by molecular biology and physical and chemical properties, the two biocontrol bacterial strains were identified as Bacillus amyloliquefaciens. Their effects on spore germination, mycelial growth and toxin degradation of Aspergillus flavus were investigated. The results showed that strains B120 and B65 could significantly inhibit the spore germination and mycelial growth of A. flavus and reduce aflatoxin production. This study provides a new way to prevent and control the pollution control of aflatoxins in agricultural products.
