scholarly journals A review on cocoa plant diseases and importance of Bacilus subtilis to induce resistance on crops in agriculture

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.

2001 ◽  
Vol 2 (1) ◽  
pp. 12 ◽  
Author(s):  
John H. Bowers ◽  
Bryan A. Bailey ◽  
Prakash K. Hebbar ◽  
Soumaila Sanogo ◽  
Robert D. Lumsden

Many factors contribute to a decline in production of cocoa beans worldwide. Plant diseases such as black pod, witches' broom, and frosty pod rot are major components of the decline in production. Plant pathologists and microbiologists must discover and devise means to reduce disease losses and to save chocolate for the enthusiastic consumers of the world. This review discusses the major disease of cacao and their effect on world production. Accepted for publication 14 June 2001. Published 9 July 2001.


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.


2007 ◽  
Vol 97 (12) ◽  
pp. 1640-1643 ◽  
Author(s):  
Harry C. Evans

This paper reviews the significant advances by the diseases themselves, as well as by the scientists, in the intervening period since the disease trilogy was first delimited in 1989. The impact of these diseases, black pod, witches' broom, and frosty pod rot, has increased dramatically. In addition, there have been radical changes in the taxonomic profiles of these pathogens, which have been based on both traditional (morphological, cytological) and modern (molecular) approaches. Black pod is caused by a complex of Phytophthora species, in which P. palmivora still is the most important worldwide. However, recent invasion of the principal cacao-growing countries of West Africa by the more virulent P. megakarya has been cause for concern. The latter evolved in the ancient forests straddling the Cameroon-Nigerian border as a primary coloniser of fallen fruit. Conversely, frosty pod rot, caused by Moniliophthora roreri, and witches' broom, caused by M. (Crinipellis) perniciosa, both neotropical diseases, are hemibiotrophic, coevolved pathogens. Respectively, M. roreri arose on Theobroma gileri in submontane forests on the north-western slopes of the Andes, whereas M. perniciosa developed as a complex of pathotypes with a considerably wider geographic and host range within South America; the cacao pathotype evolved on that host in the Amazon basin. The inter-relationships of these vicariant species and their recent spread are discussed, together with control strategies.


Agronomy ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 586 ◽  
Author(s):  
Ben-Jabeur ◽  
kthiri ◽  
Harbaoui ◽  
Belguesmi ◽  
Serret ◽  
...  

Septoria leaf blotch (SLB) is considered one of the most devastating diseases affecting global wheat production. Biostimulant application is among the modern approaches in plant protection to overcome the impact of SLB’s fungicide resistance. In this manner, the effect of coating seeds with thyme essential oil or Paraburkholderia phytofirmansPsJN strain on SLB severity and yield components (spikes/m2, straw yield (SY), grain yield (GY) and thousand kernel weight (TKW)) were assessed under field conditions for 3 years. The effect on physiological traits and nitrogen and carbon isotope composition (δ15Ngrain, δ13Cgrain) and nitrogen and carbon content (Ngrain, Cgrain) of grains was assessed in one year of study. The increasing SLB severity decreased all yield components, increased δ15Ngrain and Cgrain content and slightly decreased δ13Cgrain as the resulting effect of Z.tritici inducing stomatal opening and leaf necrosis. Across the years, both treatments alleviated the SLB adverse impact by reducing SLB severity, increasing spikes/m2, SY, GY and TKW. Both treatments ameliorated grain quality by increasing Cgrain content and decreasing δ13Cgrain and δ15Ngrain. The difference between the performance of thyme oil or PsJN strain in terms of intensity and stability is discussed and considered to be linked to the different triggered systemic resistance and the associated amount of costs deriving from resource allocation towards defense processes.


2009 ◽  
Vol 147 (5) ◽  
pp. 523-535 ◽  
Author(s):  
D. R. WALTERS ◽  
J. M. FOUNTAINE

SUMMARYPlants resist pathogen attack through a combination of constitutive and inducible defences. Different types of induced resistance have been defined based on differences in signalling pathways and spectra of effectiveness. Systemic acquired resistance (SAR) occurs in distal plant parts following localized infection by a necrotizing pathogen. It is controlled by a signalling pathway that depends upon the accumulation of salicylic acid (SA) and the regulatory protein NPR1. In contrast, induced systemic resistance (ISR) is promoted by selected strains of non-pathogenic plant growth-promoting rhizobacteria (PGPR). ISR functions independently of SA, but requires NPR1 and is regulated by jasmonic acid (JA) and ethylene (ET).Resistance can be induced by treatment with a variety of biotic and abiotic inducers. The resistance induced is broad spectrum and can be long-lasting, but is rarely complete, with most inducing agents providing between 0·20 and 0·85 disease control. In the field, expression of induced resistance is likely to be influenced by the environment, genotype, crop nutrition and the extent to which plants are already induced. Unfortunately, understanding of the impact of these influences on the expression of induced resistance is rudimentary. So too is understanding of how best to use induced resistance in practical crop protection. This situation will need to change if induced resistance is to fulfil its potential in crop protection.


Biology ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 248 ◽  
Author(s):  
Ahmed Abdelkhalek ◽  
Mohamed Z. M. Salem ◽  
Elsayed Hafez ◽  
Said I. Behiry ◽  
Sameer H. Qari

In this study, ethanol whole plant extract (WPE) of Haplophyllum tuberculatum was characterized and tested for its antifungal and antiviral activities against Fusarium culmorum, Rhizoctonia solani and tobacco mosaic virus (TMV). High Performance Liquid Chromatography (HPLC) analysis showed that the main phytochemical constituents of H. tuberculatum WPE were resveratrol (5178.58 mg/kg), kaempferol (1735.23 mg/kg), myricetin (561.18 mg/kg), rutin (487.04 mg/kg), quercetin (401.04 mg/kg), and rosmarinic acid (387.33 mg/kg). By increasing H. tuberculatum WPE at concentrations of 1%, 2%, and 3%, all of the fungal isolates were suppressed compared to the two positive and negative controls. Under greenhouse conditions, WPE-treated Chenopodium amaranticolor plants strongly inhibited TMV infection and significantly reduced TMV accumulation levels when compared to non-treated plants. Moreover, the induction of systemic resistance with significant increases in the transcriptional levels of the pathogenesis-related protein-1 (PR-1), chalcone synthase (CHS), and hydroxycinnamoyl-CoA quinate transferase (HQT) genes for treated plants were noticed at 3 and 5 days post-inoculation (dpi) for both assays. To the best of our knowledge, this is the first reported observation of the antiviral activity of H. tuberculatum extract against plant viral infections. Finally, the results obtained suggest that H. tuberculatum WPE can be considered a promising source of both antifungal and antiviral substances for practical use and for developing plant-derived compounds for the effective management of plant diseases.


The application of preparations of biological origin in the protection system of soybean grown under conditions of intensive irrigated crop rotations conforms to the modern tendencies of science and production development. The use of them contributes to solving ecological, production and social-economic problems. The study presents the three-year research on the efficiency of systems protecting soybean from pests and diseases based on biological and chemical preparations. The research was conducted in typical soil and climate conditions of the South of Ukraine. Zonal agricultural methods and generally accepted research methodology were used. The purpose of the research was to create a soybean protection system based on preparations of biological origin, ensuring high productivity of high-quality products reducing a negative impact of the crop production on the environment. The study emphasizes that, under irrigated conditions of the South of Ukraine, the application of biological preparations has a positive impact on the indexes of growth, development and formation of the elements of soybean yield structure. There was an increase in the crop biological weight by 13.8 % and 22.1 % and the number of seeds per plant rose by 11.6 and 14.6 % as a consequence of eliminating harmful organisms with the plant protection systems. The larger ground mass was formed by medium-ripe varieties Danai and Svyatogor, on which the increase from protection measures was higher. Weight 1000 pcs. the seeds did not undergo significant changes. It is established that the larger seeds were formed by Danaya and Svyatogor varieties, in which the average weight is 1000 pcs. seeds were 142 and 136 g, respectively, while in the variety Diona this figure was 133 g. There was an increase in the height of the lowest pod when the total plant height rose. For medium-ripe varieties was characterized by a higher attachment of beans, where the highest values of this indicator acquired in the variety Svyatogor. The medium maturing soybean variety Danaia formed the maximum yield of 3.23 and 3.35 t/ha respectively, when biological and chemical protection systems were applied. The research establishes that the application of the bio-fungicide Psevdobakterin 2 (2.0 l/ha) in the crop protection system at the beginning of soybean flowering and the bio-fungicide Baktofit (2.5 l/ha) with the bio-insecticide Lepidotsid-BTU (10.0 l/ha) at the beginning of pod formation does not reduce the productivity of the soybean varieties under study considerably, when compared to the application of chemical preparations. The research determines that the soybean protection system under study ensures a decrease in the coefficient of soybean water uptake by 7.2-13.0 %, increasing the total water intake to an inconsiderable degree. Biologization of the soybean crop protection system leads to a reduction in production costs compared to the chemical protection system. Taking into account the needs for the collection of additional products, costs increase by an average of 1 thousand UAH/ha, while for chemical protection systems by 1.8 thousand UAH/ha. At the same time, the cost is reduced by 220-360 UAH/t and the profitability of growing crops is increased by 3.8-7.8 %. There has been a reduction in the burden of pesticides on the environment and the production of cleaner products. This indicates the prospect of using the biofungicides Pseudobacterin 2 and Bactophyte and the bioinsecticide Lepidocid-BTU on soybeans to protect plants from pests.


2020 ◽  
Vol 12 ◽  
Author(s):  
Sai Akilesh M ◽  
Ashish Wadhwani

: Infectious diseases have been prevalent since many decades and viral pathogens have caused global health crisis and economic meltdown on a devastating scale. High occurrence of newer viral infections in the recent years, in spite of the progress achieved in the field of pharmaceutical sciences defines the critical need for newer and more effective antiviral therapies and diagnostics. The incidence of multi-drug resistance and adverse effects due to the prolonged use of anti-viral therapy is also a major concern. Nanotechnology offers a cutting edge platform for the development of novel compounds and formulations for biomedical applications. The unique properties of nano-based materials can be attributed to the multi-fold increase in the surface to volume ratio at the nano-scale, tunable surface properties of charge and chemical moieties. Idealistic pharmaceutical properties such as increased bioavailability and retention times, lower toxicity profiles, sustained release formulations, lower dosage forms and most importantly, targeted drug delivery can be achieved through the approach of nanotechnology. The extensively researched nano-based materials are metal and polymeric nanoparticles, dendrimers and micelles, nano-drug delivery vesicles, liposomes and lipid based nanoparticles. In this review article, the impact of nanotechnology on the treatment of Human Immunodeficiency Virus (HIV) and Herpes Simplex Virus (HSV) viral infections during the last decade are outlined.


2021 ◽  
Vol 11 (9) ◽  
pp. 4071
Author(s):  
Yali Zhang ◽  
Xinrong Huang ◽  
Yubin Lan ◽  
Linlin Wang ◽  
Xiaoyang Lu ◽  
...  

Aerial electrostatic spray technology for agriculture is the integration of precision agricultural aviation and electrostatic spray technology. It is one of the research topics that have been paid close attention to by scholars in the field of agricultural aviation. This study summarizes the development of airborne electrostatic spray technology for agricultural use in China, including the early research and exploration of Chinese institutions and researchers in the aspects of nozzle structure design optimization and theoretical simulation. The research progress of UAV-based aerial electrostatic spray technology for agricultural use in China was expounded from the aspects of nozzle modification, technical feasibility study, influencing mechanism of various factors, and field efficiency tests. According to the current development of agricultural UAVs and the characteristics of the farmland environment in China, the UAV-based aerial electrostatic spray technology, which carries the airborne electrostatic spray system on the plant protection UAVs, has a wide potential in the future. At present, the application of UAV-based aerial electrostatic spray technology has yet to be further improved due to several factors, such as the optimization of the test technology for charged droplets, the impact of UAV rotor wind field, comparison study on charging modes, and the lack of technical accumulation in the research of aerial electrostatic spray technology. With the continuous improvement of the research system of agricultural aviation electrostatic spray technology, UAV-based electrostatic spray technology will give play to the advantages in increasing the droplets deposition on the target and reducing environmental pollution from the application of pesticides. This study is capable of providing a reference for the development of the UAV-based agricultural electrostatic spray technology and the spray equipment.


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