scholarly journals Infectious plant diseases: etiology, current status, problems and prospects in plant protection

Acta Naturae ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 46-59
Author(s):  
Pavel A. Nazarov ◽  
Dmitry N. Baleev ◽  
Maria I. Ivanova ◽  
Luybov M. Sokolova ◽  
Marina V. Karakozova

In recent years, there has been an increase in the number of diseases caused by bacterial, fungal, and viral infections. Infections affect plants at different stages of agricultural production. Depending on weather conditions and the phytosanitary condition of crops, the prevalence of diseases can reach 7080% of the total plant population, and the yield can decrease in some cases down to 8098%. Plants have innate cellular immunity, but specific phytopathogens have an ability to evade that immunity. This article examined phytopathogens of viral, fungal, and bacterial nature and explored the concepts of modern plant protection, methods of chemical, biological, and agrotechnical control, as well as modern methods used for identifying phytopathogens.

2021 ◽  
Author(s):  
Vasile Botnari ◽  

The Republic of Moldova is in the area of risky agriculture. Limited land and water resources make the food supply vulnerable to extreme weather conditions during the year. In order to increase agricultural production, it is necessary to implement investments in the material - technical and research base, to re-store the irrigation system. Climate change can lead to a decrease in the productivity potential of many crops, requiring a revision of crop rotation with the determination of risk areas, a revision of the spectrum of diseases and pests with the continuous updating of plant protection systems.


Author(s):  
Tiago Miguel Marques Monteiro Amaro ◽  
Jonathan Cope ◽  
Bárbara Franco-Orozco

Plant disease still plays a major role in limiting agricultural production worldwide. Pathogens and pests reduce crop yield and can cause large reductions in crop quality. Colombia is no exception as it contends with many devastating pathogens that present a major threat to the country’s agricultural sector. This review is important because it highlights four of the more damaging pathogens that affect the economics of important crops in Colombia - Xanthomonas phaseoli pv. manihotis (Xpm), Fusarium oxysporum f. sp. cubense (Foc), Phytophthora palmivora, and Hemileia vastatrix. This paper was based on an extensive literature search for plant diseases in Colombia in databases such as PubMed and Google Scholar. Moreover, this search was complemented with research on crop production in the country in databases made available by the Food and Agriculture Organization of the United Nations (FAO). The four pathogens reviewed in this paper were chosen not only because of their current devastating effects on Colombia’s agricultural production but also because of their potential to cause further damage in the near future. Understanding the current situation of these crop pathogens in Colombia is imperative for state directives aimed at developing informed and efficient control strategies.


Author(s):  
Koua Saman Hervé, ◽  
Alloue-Boraud Wazé Aimée Mireille ◽  
Coulibaly N’golo Antoine Marie-David

Fungal and viral infections represent a major cause of cocoa disease in agriculture. Plant protection through biological control is an alternative strategy in agriculture to control pests. Recognition of certain non-pathogenic rhizobacteria by plants can trigger a systemic resistance reaction that renders the host less susceptible to subsequent infection by a virulent agent. The impact of cocoa diseases as black pod, Cocoa Shollen Shoot Virus (CSSV), witches’ broom, and frosty pod rot, has increased dramatically in the world.This paper review emphasizes cocoa disease and utilisation of Bacillus subtilis as biocontrol agent against fungal and virus from cocoa disease in Côte d’Ivoire.


2016 ◽  
Vol Renewable Energy ◽  
pp. 80
Author(s):  
Tin, N.H. ◽  
Hue, B.T.B. ◽  
Thuy, T.L.K. ◽  
Phuong, T.L. ◽  
Duyen, C.M. ◽  
...  

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 916
Author(s):  
Hengsheng Fang ◽  
Adam D. Wegman ◽  
Kianna Ripich ◽  
Heather Friberg ◽  
Jeffrey R. Currier ◽  
...  

SARS-CoV-2 represents an unprecedented public health challenge. While the majority of SARS-CoV-2-infected individuals with mild-to-moderate COVID-19 resolve their infection with few complications, some individuals experience prolonged symptoms lasting for weeks after initial diagnosis. Persistent viral infections are commonly accompanied by immunologic dysregulation, but it is unclear if persistent COVID-19 impacts the development of virus-specific cellular immunity. To this end, we analyzed SARS-CoV-2-specific cellular immunity in convalescent COVID-19 patients who experienced eight days or fewer of COVID-19 symptoms or symptoms persisting for 18 days or more. We observed that persistent COVID-19 symptoms were not associated with the development of an overtly dysregulated cellular immune response. Furthermore, we observed that reactivity against the N protein from SARS-CoV-2 correlates with the amount of reactivity against the seasonal human coronaviruses 229E and NL63. These results provide insight into the processes that regulate the development of cellular immunity against SARS-CoV-2 and related human coronaviruses.


Vaccines ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 266 ◽  
Author(s):  
Aryamav Pattnaik ◽  
Bikash R. Sahoo ◽  
Asit K. Pattnaik

The recently emerged Zika virus (ZIKV) spread to the Americas, causing a spectrum of congenital diseases including microcephaly in newborn and Guillain-Barré syndrome (GBS) in adults. The unprecedented nature of the epidemic and serious diseases associated with the viral infections prompted the global research community to understand the immunopathogenic mechanisms of the virus and rapidly develop safe and efficacious vaccines. This has led to a number of ZIKV vaccine candidates that have shown significant promise in human clinical trials. These candidates include nucleic acid vaccines, inactivated vaccines, viral-vectored vaccines, and attenuated vaccines. Additionally, a number of vaccine candidates have been shown to protect animals in preclinical studies. However, as the epidemic has waned in the last three years, further development of the most promising vaccine candidates faces challenges in clinical efficacy trials, which is needed before a vaccine is brought to licensure. It is important that a coalition of government funding agencies and private sector companies is established to move forward with a safe and effective vaccine ready for deployment when the next ZIKV epidemic occurs.


2021 ◽  
pp. 24-27
Author(s):  
Л.М. Соколова ◽  
А.В. Янченко ◽  
А.Ю. Федосов ◽  
М.И. Азопков ◽  
В.С. Голубович

Морковь и свекла столовая – одни из самых распространенных в овощеводстве корнеплодных культур. Важный признак семян высокого качества – отсутствие болезней, передаваемых через семена. Эффективный контроль болезней растений имеет решающее значение для надежного производства овощей и потенциально может привести к значительной экономии использования воды, земли, топлива и других ресурсов в сельском хозяйстве. Присутствие в семенах патогенов, передающихся через семена, либо препятствует прорастанию, либо может привести к эпифитотиям из-за передачи возбудителя болезни от семени к растению. За последние годы отмечено увеличение числа заболеваний, вызванных фитопатогенными грибами, бактериями и вирусами. В зависимости от погодных условий и фитосанитарного состояния посевов, распространенность болезней может достигать 70-80% от всей популяции растений, а урожайность снижаться в ряде случаев на 80-98%. Цель исследований – выявить инфицированность и родовую принадлежность патокомплекса грибных болезней на семенах моркови и свеклы столовой, а также подобрать оптимальный режим обработки семян. Термическая обработка семян представляет собой жизнеспособную альтернативу химической обработке для уничтожения патогенов. Задача термической обработки – найти наилучшее сочетание продолжительности экспозиции и температуры, которое обеспечивает максимальную гибель патогенов при минимальном разрушающем воздействии на семена. Основное предположение, оправдывающее термическую обработку, заключается в том, что патоген-мишень более чувствителен к высокотемпературному стрессу, чем семена. Целевыми патогенными микроорганизмами являются в основном грибы, вирусы и бактерии, находящиеся на поверхности и внутри семян. В настоящей статье отображено влияние термической обработки семян столовой свеклы и моркови на всхожесть и их зараженность патогенами. Показана высокая эффективность термической обработки семян столовой свеклы и моркови против Alternaria. Дана визуальная оценка эффективности термической обработки на питательной среде Чапека. One of the most common root vegetables in vegetable growing are carrots and beets. One of the important signs of qualitative changes is the absence of diseases transmitted through seeds. Effective control of plant diseases is crucial for the reliable production of vegetables and can potentially lead to a significant reduction in the use of water, land, fuel and other resources in agriculture. The presence of pathogens transmitted through seeds in seeds either prevents germination, or can lead to epiphytotics of diseases due to the transmission of the pathogen from the seed to the plant. In recent years, there has been an increase in the number of diseases caused by phytopathogenic fungi, bacteria and viruses. Depending on the weather conditions and the phytosanitary condition of crops, the prevalence of diseases can reach 70-80% of the entire plant population, and the yield can decrease in some cases by 80-98%. The purpose of the research is to identify the infection and generic affiliation of the pathocomplex of fungal diseases on carrot and beet seeds, as well as to choose the optimal seed treatment regime. Heat treatment of seeds is a viable alternative to chemical treatment for the destruction of pathogens. The task of heat treatment is to find the best combination of time and temperature that maximizes the reduction in the survival of pathogens with minimal destructive effects on seeds. The main assumption justifying heat treatment is more sensitive to high-temperature stress than seeds. The target pathogenic microorganisms are mainly fungi, viruses and bacteria located on the surface and inside the seeds. This article shows the effect of heat treatment of table beet and carrot seeds on germination and their infection with pathogens. The high efficiency of heat treatment of table beet and carrot seeds against Alternariais shown. A visual assessment of the effectiveness of heat treatment on the Czapek nutrient medium was carried out.


2021 ◽  
Vol 66 (3) ◽  
Author(s):  
Dipriya R. Lyngkhoi

The present study was undertaken to estimate the costs and returns structure of maize cultivation and identifying the prominent production constraints in West Khasi Hills district of Meghalaya. A sample of 60 farmers was randomly drawn from six villages of Mawthadraishan and Nongstoin block of the selected district. The costs and returns per hectare were calculated on the basis of cost concepts and Garett ranking method was used for employed for determination of constraints in maize production. The overall cost of cultivation was found to be ` 37185.22 per ha and the major cost components were manures (48.25%) and human labour (34.73%). The overall net return was evaluated at ` 19038.20 with small, medium and large farmers having similar returns with the exception of marginal farmers gaining a net return of only ` 13889.83 which was 27.04 per cent lower than the average return among the sample farmers. It may be attributed to their heavy dependence on labour and lack of investment on irrigation, plant protection and better-quality seeds. The realised average yield was found to be 23.65 q/ha which was abysmally low compared to other maize producing states of India. A positive trend between the return over cost ratio and the operational holding was observed with an average of 1.51. The prominent constraints as perceived by the farmers were unfavorable weather conditions, the incidence of pests and diseases and costly fertilizers and manures with the Garrett’s score of 64.70, 62.75 and 54.40 respectively


Author(s):  
Yu. O. Tararico ◽  
Yu. V. Soroka ◽  
R. V. Saidak

Relevance of research. Due to ongoing climate change, almost the entire territory of the Steppe of Ukraine by annual humidity factor belongs to the dry and very dry zones, the relative area of ​​which has increased by 13.2% of the total area of ​​the country compared to the 1960-1990s. At the same time, for today in Ukraine only about 500 thousand hectares are actually irrigated, that is 19% of the potential area. Purpose of research. To determine the patterns and trends of climate change in the western part of the dry Steppe of Ukraine and analyze the economic indicators of production activity in the region as to the variable weather conditions. Research methodology. Climate change was estimated on the basis of Climate Water Balance (CWB) and Hydrothermal Coefficient (HTC) values. The analysis of the economic efficiency of agricultural production was carried out by analyzing the statistical data for Odessa region and for the chosen agricultural enterprise. Research results and conclusions. The use of significant heat supply in the dry Steppe zone is limited by insufficient water supply conditions. In the years of 1991-2016  the average annual rainfall was 480 mm and since the early 2000s there has been a slight increase in that. However, even having 500-550 mm of average annual rainfall that has been observed over the past five years, it is not enough for providing high-yield agricultural production. High thermal regime couses high evaporation that in turn, leads to water supply deficit, which at the end of the growing season amounts to 336-436 mm. According to the HTC index in the region 80% of cases show severe and moderately arid vegetation conditions. At the same time, irrigation area in the region has decreased to a minimum, which has led to the domination of winter cereals and sunflower in the cropping system. Under variable weather conditions, winter wheat yields ranged from 19.4 to 38.5 c/ ha (31.4 c/ha on average) and sunflower - from 12.2 to 21.4 c/ha (17.4 c/ha on average), winter rape - from 13.1 to 20.9 c/ha (18.2 c/ha). It was proved a close direct relationship between the sale price of products of all studied crops and their cost price, as well as the inverse relationship of these indicators with the crop yield. The profitability of winter wheat from 2011 till 2016 ranged from 17 to 153 USD/ha with an average value of 86 USD/ha, winter rape - from 39 to 273 USD/ha with an average value of 166 USD  ha and sunflower - from 116 to 315 USD/ha with an average value of 192 USD/ha. Corn and soybeans have proven to be unprofitable in some years, which obviously explains rather small areas under these crops in the region. Above mentioned demonstrates the high economic instability of agricultural production in changing weather conditions, which is accompanied by significant risks for producers, especially when attracting credits. This situation, in turn, leads to a limited use of intensification means, in particular mineral fertilizers, which promotes agrochemical soil degradation. Under unstable water supply, the magnitude of net profit variation per hectare of arable land in Odessa region is 33-188 USD/ha (111 USD/ha on average). It is possible to increase these indicators by increasing the share of winter rape in the cropping system. With the optimization of the water and air soil regimes as well as crop rotation factor, the profitability of agricultural production in the region can be increased up to 580-600 USD/ha. Similar results were obtained after analyzing the statistical data from the southern regions within the dry steppe zone.


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