Biological control of air-borne pathogens

1988 ◽  
Vol 318 (1189) ◽  
pp. 265-281 ◽  
Keyword(s):  
Biological Control ◽  
Fungal Pathogens ◽  
Population Level ◽  
Reproductive Capacity ◽  
Forest Trees ◽  
Subsequent Growth ◽  
Field Crops ◽  
Direct Penetration ◽  
Successful Control ◽  
Biological Methods

Some pathogens are partly controlled by microorganisms that occur naturally on aerial surfaces of plants, and many attempts have been made to improve control by applying selected antagonists to such surfaces. Antagonists often compete for nutrients with the pathogen, and antibiotics may be formed that reduce germination of its spores and subsequent growth. Hyphae of fungal pathogens may be killed on contact with the antagonist or by direct penetration. The plant’s defences may be stimulated before challenge by a pathogen. Apart from killing the pathogen, an antagonist may reduce its reproductive capacity. The examples given illustrate the operation of these different mechanisms in the control of a wide variety of diseases. For diseases of foliage, flowers or fruit, glasshouse crops offer more attractive possibilities for control than field crops because the population level of antagonists is easier to maintain. In some cases plants can be protected by inoculation before transplanting them to the field. Foliage and canker diseases of forest trees present problems too intractable for successful control, but in orchards the prospects are better; for example, methods are available for combining pruning with application of inoculum. Similarly, in some circumstances tree stumps can be inoculated to prevent colonization by a pathogen. Where biological methods are as effective as chemical ones and comparable in cost, they are to be preferred on environmental grounds. In some cases they can be combined with advantage; for example a lower concentration of fungicide may suffice if applied with an antagonist.

scholarly journals Strobilurins: New group of fungicides

2021 ◽  
Vol 5 (2) ◽  
pp. 063-064
Author(s):  
Selim Rasha E ◽  
Khalil Mohamed S
Keyword(s):  
Fungal Pathogens ◽  
Fungal Diseases ◽  
Complex Iii ◽  
Forest Trees ◽  
Tree Nuts ◽  
Field Crops ◽  
Downy Mildews ◽  
Powdery Mildews ◽  
Group Control ◽  
Basidiomycete Fungus

Strobilurin is a group of natural products and their synthetic analogs have been widely used to control and prevent fungal diseases. Strobilurins were firstly isolated in 1977 from the mycelium of Strobilurus tenacellus, a saprobic Basidiomycete fungus causing wood-rotting on forest trees. This group of pesticides was designed to manage fungal pathogens classes such as Ascomycetes, Basidiomycetes, and Oomycetes. Also, Strobilurin commercialized included derivatives such as are azoxystrobin, kresoxim-methyl, picoxystrobin, fluoxastrobin, oryzastrobin, dimoxystrobin, pyraclostrobin and trifloxystrobin. This group is a part of the larger group of QoI inhibitors, which act to inhibit the respiratory chain at the level of Complex III. Strobilurins group control an unusually wide array of fungal diseases, included water molds, downy mildews, powdery mildews, leaf spotting and rusts. This group are used on cereals, field crops, fruits, tree nuts, vegetables, turfgrasses and ornamentals. Also, Strobilurins found to enhance the plant growth in some cases.

scholarly journals Principles of Biological Weed Control

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 750D-750
Author(s):  
Susan M. Boyetchko
Keyword(s):  
Biological Control ◽  
Weed Management ◽  
Fungal Pathogens ◽  
The United States ◽  
Reproductive Capacity ◽  
Biological Weed Control ◽  
Weed Biocontrol ◽  
Weed Growth ◽  
Inundative Biological Control ◽  
High Concentrations

Weeds continue to have a tremendous impact on crop yield losses in Canada and the United States, despite efforts to control them with chemicals. Biological control offers an additional means for reducing weed populations while reducing the reliance of the agri-food industry on chemical pesticides. Effective biological strategies that are compatible with good soil conservation practices would benefit farmers while maintaining environmental quality and a sustained production for the future. Inundative biological control of weeds with microbial agents involves the mass production and application of high concentrations of a plant pathogen to a target weed. Historically, biocontrol agents used on weeds have been foliar fungal pathogens. More recently, the soil has become a source for microorganisms, such as rhizobacteria, for development as biological control agents. Several naturally occurring rhizobacteria have weed suppressive properties, where growth and development of weeds such as downy brome, wild oats, leafy spurge, and green foxtail are significantly inhibited. Although the focus in weed biocontrol has been on the eradication of weeds, rhizobacteria may be used to improve seedling establishment of the crop by reducing the weed competition. This can be achieved through a reduction in weed growth, vigor, and reproductive capacity and improvement in the ability of the crop to compete with the weed. Current research in weed biocontrol with microorganisms and its application to weed management systems will be discussed.

scholarly journals The Potential of Rhizoctonia-Like Fungi for the Biological Protection of Cereals against Fungal Pathogens

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 349
Author(s):  
Dominik Bleša ◽  
Pavel Matušinský ◽  
Romana Sedmíková ◽  
Milan Baláž
Keyword(s):  
Biological Control ◽  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Higher Plants ◽  
Fusarium Culmorum ◽  
Suppressive Effect ◽  
Plant Production ◽  
Shoot Biomass ◽  
Organic Substrates

The use of biological control is becoming a common practice in plant production. One overlooked group of organisms potentially suitable for biological control are Rhizoctonia-like (Rh-like) fungi. Some of them are capable of forming endophytic associations with a large group of higher plants as well as mycorrhizal symbioses. Various benefits of endophytic associations were proved, including amelioration of devastating effects of pathogens such as Fusarium culmorum. The advantage of Rh-like endophytes over strictly biotrophic mycorrhizal organisms is the possibility of their cultivation on organic substrates, which makes their use more suitable for production. We focused on abilities of five Rh-like fungi isolated from orchid mycorrhizas, endophytic fungi Serendipita indica, Microdochium bolleyi and pathogenic Ceratobasidium cereale to inhibit the growth of pathogenic F. culmorum or Pyrenophora teres in vitro. We also analysed their suppressive effect on wheat infection by F. culmorum in a growth chamber, as well as an effect on barley under field conditions. Some of the Rh-like fungi affected the growth of plant pathogens in vitro, then the interaction with plants was tested. Beneficial effect was especially noted in the pot experiments, where wheat plants were negatively influenced by F. culmorum. Inoculation with S. indica caused higher dry shoot biomass in comparison to plants treated with fungicide. Prospective for future work are the effects of these endophytes on plant signalling pathways, factors affecting the level of colonization and surviving of infectious particles.

Lantana camara (lantana).

2021 ◽  
Author(s):  
Sarah E. Thomas ◽  
Julissa Rojas-Sandoval ◽  
Pedro Acevedo-Rodríguez
Keyword(s):  
South Africa ◽  
Biological Control ◽  
Control Measures ◽  
Economic Losses ◽  
Pests And Diseases ◽  
Control Programmes ◽  
Agricultural Weed ◽  
Successful Control ◽  
The Tropics ◽  
Ornamental Shrub

Abstract L. camara is a highly variable ornamental shrub, native of the neotropics. It has been introduced to most of the tropics and subtropics as a hedge plant and has since been reported as extremely weedy and invasive in many countries. It is generally deleterious to biodiversity and has been reported as an agricultural weed resulting in large economic losses in a number of countries. In addition to this, it increases the risk of fire, is poisonous to livestock and is a host for numerous pests and diseases. L. camara is difficult to control. In Australia, India and South Africa aggressive measures to eradicate L. camara over the last two centuries have been largely unsuccessful, and the invasion trajectory has continued upwards despite control measures. This species has been the target of biological control programmes for over a century, with successful control only being reported in a few instances.

Evaluation of pruning wound protection products for the management of almond canker diseases in California

Plant Disease ◽  
2021 ◽  
Author(s):  
Leslie Amanda Holland ◽  
Renaud Travadon ◽  
Daniel P. Lawrence ◽  
Mohamed Taieb Nouri ◽  
Florent P Trouillas
Keyword(s):  
Biological Control ◽  
Fungal Pathogens ◽  
Tree Mortality ◽  
Biological Control Agent ◽  
Field Trials ◽  
Control Agent ◽  
Thiophanate Methyl ◽  
Pruning Wound ◽  
Wound Protection ◽  
Canker Pathogens

Almond trunk and branch canker diseases constitute a major cause of tree mortality in California. Numerous fungal pathogens have been associated with these canker diseases and pruning wounds act as major infection courts. Prior to this study, there were no products registered in California for the management of these diseases. In this study, fungicidal products including synthetic chemistries, biocontrols, paint and a sealant were evaluated for preventing fungal pathogen infection via pruning wounds. In four field trials conducted over two dormant seasons, sixteen pruning wound treatments were tested using hand-held spray applications, against five almond canker pathogens, namely Botryosphaeria dothidea, Neofusicoccum parvum, Cytospora sorbicola, Ceratocystis destructans, and Eutypa lata. The fungicide thiophanate-methyl (Topsin M) provided 82% overall disease prevention against four fungal pathogens. The biological control agent, Trichoderma atroviride SC1 (Vintec), tested at three application rates, resulted in 90 to 93% protection of pruning wounds in field trials, and for individual pathogens ranged from 81-100% protection for the three rates. At the time of this publication, Vintec is being considered for registration as a biological control product for the prevention of almond canker diseases, while Topsin M is recommended to growers for the prevention of almond canker diseases. This research indicates that effective protection of pruning wounds from infection by almond canker pathogens can be achieved with a one-time spray application of thiophanate-methyl or the biocontrol, T. atroviride SC1 (recommended 2 g/liter) after pruning.

Contrasting research approaches to managing mistletoes in commercial forests and wooded pasturesThis minireview is one of a collection of papers based on a presentation from the Stem and Shoot Fungal Pathogens and Parasitic Plants: the Values of Biological Diversity session of the XXII International Union of Forestry Research Organization World Congress meeting held in Brisbane, Queensland, Australia, in 2005.

Botany ◽  
2009 ◽  
Vol 87 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Nick Reid ◽  
Simon F. Shamoun
Keyword(s):  
Biological Control ◽  
Fungal Pathogens ◽  
Biological Diversity ◽  
Management Strategies ◽  
Biodiversity Loss ◽  
Classical Biological Control ◽  
Dwarf Mistletoe ◽  
Silvicultural Treatments ◽  
Inundative Biological Control

Many mistletoe species are pests in agricultural and forest ecosystems throughout the world. Mistletoes are unusual “weeds” as they are generally endemic to areas where they achieve pest status and, therefore, classical biological control and broad-scale herbicidal control are usually impractical. In North American coniferous forests, dwarf mistletoe ( Arceuthobium spp.) infection results in major commercial losses and poses a public liability in recreation settings. Hyperparasitic fungi have potential as biological control agents of dwarf mistletoe, including species which attack shoots, berries, and the endophytic systems of dwarf mistletoe. Development of an inundative biological control strategy will be useful in situations where traditional silvicultural control is impractical or undesirable. In southern Australia, farm eucalypts are often attacked and killed by mistletoes ( Amyema spp.) in grazed landscapes where tree decline and biodiversity loss are major forms of land degradation. Although long-term strategies to achieve a balance between mistletoe and host abundance are promoted, many graziers want short-term options to treat severely infected trees. Recent research has revisited the efficiency and efficacy of silvicultural treatments and selective herbicides in appropriate situations. The results of recent research on these diverse management strategies in North America and Australia are summarized.

scholarly journals Genetic differentiation in seed stands of European beech (Fagus sylvatica L.) in part of Bosnia and Herzegovina

Genetika ◽  
2013 ◽  
Vol 45 (3) ◽  
pp. 895-906
Author(s):  
Dalibor Ballian ◽  
Vasilije Isajev ◽  
Vanja Danicic ◽  
Branislav Cvjetkovic ◽  
Faruk Bogunic ◽  
...  
Keyword(s):  
Bosnia And Herzegovina ◽  
Fagus Sylvatica ◽  
Biochemical Analysis ◽  
European Beech ◽  
Population Level ◽  
Forest Trees ◽  
Individual Gene ◽  
Enzyme Systems ◽  
Fagus Sylvatica L ◽  
High Quality Seed

Beech (Fagus sylvatica L.) is one of the most important forest trees in Bosnia and Herzegovina in both economic and environmental terms. The total area of forest in which beech is present is approx. 1,652,400 ha. There is a proportionate need to plant new forests and produce genetically high quality seed and saplings. Biochemical analysis of the genetic structure of eight populations of beech using ten enzyme systems from 16 isoenzyme gene loci revealed significant differences between the populations analyzed. Variance levels were high in some gene loci, while in some populations monomorphism was recorded only for individual gene loci. The average number of alleles per locus ranged from 2.1875 to 2.5625, and the average number of genotypes per locus varied from 2.6875 to 3.2500. The multilocus genetic diversity at the population level ranged from 63.276 to 162.001, and the genofund diversity varied from 1.2708 to 1.3416.The average differentiation value obtained for all populations was fairly low (Dj=5.81), indicating a percentage of overall variance of about 94.194%.

scholarly journals PENGGUNAAN JAMUR ENTOMOPATHOGEN (Beauveria bassiana ) UNTUK MENEKAN TINGKAT SERANGAN HAMA PENGGEREK BUAH KAKAO (Conopomorpha cramerella Snell.) DI KEBUN RAKYAT DESA BETUNG KABUPATEN MUARO JAMBI

2018 ◽  
Vol 3 (2) ◽  
pp. 47
Author(s):  
Hayata Hayata
Keyword(s):  
Biological Control ◽  
Beauveria Bassiana ◽  
Block Design ◽  
Reproductive Capacity ◽  
Chemical Insecticide ◽  
Treatment Factor ◽  
Dark Color ◽  
Negative Impacts ◽  
Unfavorable Condition ◽  
Condition B

ABSTRACTOne of the barriers in the cacao caltivation is attacking of hama penggerek Buah Kakao (PBK) that caused by conopomorpha cramerella.Inflicted Damage caused by PBK larvae was look like broken and wrinkled seeds, and there was a dark color on its skin that caused the decreasing of products weight and its quality.To control this BPK pests of cocoa could C Cramerella, generally farmers used chemical insecticide. The continously use of this insecticide was feared a bigger trouble such as pest resistance, environmental pollution, and product refusing caused by the pesticide leftover over the standard. Biological control using entomopatogen was one of PHT. Concept. The useness of entomopatogen such as beauveria bassiana fungi as a controller agent is one way to avoid the negative impacts of chemicals toward to the environment .B. bassiana Fungi possess the high reproductive capacity, easily produced and it is able to produce a long surviving spores on a unfavorable condition. B. bassiana has a high potential in controlling various types of pest. Beside, this fungi shows easily obtained, it also easy propagated so that it can be reduces the control cost.The useness of B. bassiana fungi as a cacao pest control that will be conducted in small cocoa plantations in the Kebun Sembilan village will show how its ability in reducing the cacao pest population.The research uses completly randomsed block design which rice media with B. bassiana as a treatment factor. The result should has relation with cacao quality.Key word: Conopomorpha cramerella , beauveria bassiana , attacking intensitas.ABSTRAKSalah satu kendala dalam pengembangan tanaman kakao adalah serangan hama penggerek buah kakao (PBK) yang disebabkan oleh Conopomorpha cramerella. Kerusakan yang ditimbulkan oleh larva PBK berupa rusak dan mengeriputnya biji, timbulnya warna gelap pada kulit biji yang mengakibatkan turunnya berat dan mutu produk. Untuk mengendalikan hama penggerak buah kakao C. cramerella tersebut umumnya petani menggunakan insektisida kimia. Penggunaan insektisida secara terus-menerus dikhawatirkan menimbulkan masalah yang lebih berat, antara lain terjadinya resistensi hama, pencemaran lingkungan, dan ditolaknya produk akibat residu pestisida yang melebihi ambang toleransi.Pengendalian hayati dengan menggunakan entomopatogen merupakan salah satu dari konsep PHT. Penggunaan entomopatogen jamur Beauveria bassiana sebagai agen pengendali merupakan salah satu cara untuk menghindari dampak negatif dari bahan kimia terhadap lingkungan. Jamur B. bassiana mempunyai kapasitas reproduksi yang tinggi, mudah diproduksi dan pada kondisi yang kurang menguntungkan dapat membentuk spora yang mampu bertahan lama di alam. B. bassiana memiliki potensi yang besar dalam mengendalikan berbagai jenis hama. Selain mudah didapat, jamur ini mudah diperbanyak sehingga dapat menurunkan biaya pengendalian. Pengunaan jamur B. bassiana untuk pengendalian penggerek buah kakao yang akan dilakukan di perkebunan kakao rakyat di desa kebun sembilan akan memperlihatkan bagaimana kemampuan jamur tersebut dalam menekan populasi penggerek buah kakao. Penelitian menggunakan rancangan acak kelompok dengan faktor perlakuan berat media beras nasi yang terkandung B. bassiana. hasil akhirnya adalah kualitas buah kakao.Kata kunci : Conopomorpha cramerella, Beauveria bassiana, Intensitas serangan,

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