scholarly journals Screening of Citrus Cultivars Against Citrus Canker and Its Allelopathic Management

Citrus canker is the most devastating bacterial disease. In Pakistan, where canker is endemic, cultural practices and chemical control is vital module of integrated management system. But due to non-prudent use of chemicals wicked impacts start to appear on human health and environment there was need of some alternative management which should be eco-friendly and has no adverse effect for human. Therefore, our present study was based on screening of different cultivars of citrus and allelopathic management of citrus canker. The results revealed that Cara cara navel and kinnow both performed as moderately susceptible response in field condition than all other cultivars of citrus in screening experiment. Consequently, disease incidence was observed increasing by increasing the lesion area and these cultivars can be suggested as a source of resistance against canker pathogen. In allelopathic management we observed that ethanolic extracts were more efficient than aqueous extracts and their efficacy was also increasing by increasing the concentration. Ethanolic extracts of jatropha (13.33cm) followed by amaltas (12.5cm), Arjun (11.13cm), Bougenvilla (7.21cm) have great potency against the pathogen. So these ethanolic extracts can be used as good and alternative management of citrus canker disease.

Plant Disease ◽  
2017 ◽  
Vol 101 (5) ◽  
pp. 761-765 ◽  
Author(s):  
Yasser E. Ibrahim ◽  
Amgad A. Saleh ◽  
Mohammed A. Al-Saleh

Applications of formulated bacteriophages with skim milk and sucrose or nonformulated bacteriophages combined with acibenzolar-S-methyl (ASM) were compared with copper bactericides applications for suppressing Asiatic citrus canker (ACC) caused by Xanthomonas citri subsp. citri (Xcc) on leaves under greenhouse and field conditions in Saudi Arabia. Bacteriophages were applied one day prior to inoculation of Mexican lime (Citrus aurantifolia) plants with Xcc, then twice a week until the end of the trials. Copper hydroxide was applied once prior to inoculation and then every seven days afterward, whereas ASM was applied one week prior to inoculation and then every 21 days afterward. Under greenhouse conditions, the incidence of ACC on leaves was reduced significantly from 75.2 to 12.8% or 18.3% for plants treated with copper hydroxide or bacteriophages in combination with ASM, respectively. Applications of formulated phages in combination with ASM as soil drench under field conditions significantly decreased disease incidence by 14.8% (Trial 1) and 16.8% (Trial 2) compared with untreated control plants. Overall, the Xcc-inoculated plants treated with bacteriophages + ASM combination showed significant ACC reduction under greenhouse and field conditions. The bacteriophages + ASM combination tested in these trials can be an effective tool in the integrated management programs of Asiatic citrus canker disease.


Plant Disease ◽  
2004 ◽  
Vol 88 (7) ◽  
pp. 745-750 ◽  
Author(s):  
J. H. Graham ◽  
R. P. Leite

Induced systemic resistance compounds (ISRs), acibenzolar-S-methyl (Actigard), and harpin protein (Messenger) were assayed in the greenhouse against Xanthomonas axonopodis pv. citrumelo, the cause of citrus bacterial spot (CBS), and X. axonopodis pv. citri, the cause of Asiatic citrus canker. Actigard and Messenger applied as foliar sprays 3 to 7 days before inoculation reduced numbers of lesions when either bacterium at 103 or 104 CFU/ml was injection-infiltrated into Swingle citrumelo leaves. Based on this activity, the ISRs were evaluated in southern Brazil in orchards of sweet oranges with low to moderate canker disease incidence in spray programs with and without copper oxychloride (COC) and copper hydroxide (CuOH). Actigard and Messenger were applied full season or in the first two or three sprays of a six-spray program in an attempt to reduce early canker disease on foliage and thereby reduce subsequent fruit infection and premature drop. Sprays of COC and CuOH were moderately to highly effective in reducing canker disease incidence and preventing premature fruit drop. Actigard or Messenger in combination with COC and CuOH, respectively, did not significantly reduce citrus canker incidence on foliage or fruit drop compared with Cu alone. The lack of additional control with ISRs means they cannot be recommended at this time to augment Cu programs for management of citrus canker.


2020 ◽  
Vol 26 (3) ◽  
pp. 14-19
Author(s):  
Laurențiu Bogdan Asalomia ◽  
Gheorghe Samoilescu

AbstractThe paper analyzes, starting from the Integrated Management System, the role of automation, the role of the officer and the role of the Energy Management System on board the ship. The implementation of an EnMS establishes the structure and discipline of identifying energy flows, implementing management actions and, finally, applying technical solutions, which significantly reduce energy costs, reduce non-productive time in production, and reduce emissions. of Greenhouse Gases in the environment. The steps to be highlighted in the realization of energy management are analyzed.


Author(s):  
V.V. Silaeva ◽  
◽  
V.P. Semenov ◽  

The relevance of creating integrated management systems for enterprises in a digital transformation environment is proved. New approaches to improving the management system in accordance with the new European excellence model (EFQM 2020) and international standards for achieving sustainable success and risk management are described. Approach to the development of integrated management system model based on the new EFQM 2020 model and international standards such as ISO 9004:2018 and ISO 31000:2018 is offered.


Author(s):  
Robert Towoliu

In order to know the coral reef conditions at several diving points around Bunaken Island, three dive locations (Ron’s point, Lekuan, and Tawara) were chosen as representative locations receiving pressures from snorkeling and SCUBA diving activities, while  core zone was representative of location for  no diving and fishing activities.  Results showed that location with diving activities had live coral cover  ranging from 16.89% to 45.78% at 3 and 10m depths, with condition range of bad to moderate, while the location for no diving and fishing activities (core zone) had live coral cover of 55.03% at 3m and 58.15% at 10m, respectively,  with good condition category.  The present study indicated that the diving activities have affected the coral reef condition, so that a sustainable integrated management system is needed to use the marine ecotourism potency without degrading the coral reef condition in Bunaken Island. Untuk mengetahui kondisi terumbu karang di beberapa lokasi penyelaman di Pulau Bunaken, tiga lokasi penyelaman(Ron’s point, Lekuan, dan Tawara) dipilih mewakili lokasi dengan tekanan aktivitas penyelaman snorkeling maupun SCUBA, sedangkan satu lokasi lainnya yaitu zona inti dipilih mewakili lokasi tanpa aktivitas penyelaman maupun aktivitas penangkapan ikan.  Hasil penelitian ini memperlihatkan bahwa lokasi dengan tekanan aktivitas penyelaman memiliki prosentase tutupan karang batu/hidup berkisar antara 16,89% - 45,78% pada kedalaman 3 dan 10m, dengan kategori kondisi terumbu karang buruk sampai cukup, sedangkan pada lokasi yang tidak memiliki aktivitas penyelaman memiliki prosentase tutupan karang batu/hidup sebesar 53,03% pada 3m dan 58,15% pada 10m dengan kategori kondisi terumbu karang adalah baik.  Hasil penelitian ini mengindikasikan bahwa aktivitas penyelaman snorkeling maupun SCUBA berdampak pada kondisi terumbu karang di Pulau Bunaken, sehingga sangat diperlukan system pengelolaan yang terpadu dan berkesinambungan dalam memanfaatkan secara maksimal potensi ekowisata bahari tanpa merusak ekosistem terumbu karang di Pulau Bunaken.


1975 ◽  
Vol 2 (1) ◽  
pp. 14-16
Author(s):  
Elisabeth Mann Borgese

Pacem in Maribus once again stressed that an ocean regime must encompass the oceans as a whole and be considered as a sub-system of the entire global system. Jurisdictional decisions, including those affecting the Exclusive Economic Zone (EEZ), must reflect that paramount concern. It is not a matter of geographical realignment or of partition; marine ecosystem do not correspond to political demarcations. Nor is mankind, for which the concept of the common heritage is prescribed, confined to coastal states or to the present generation.In its discussions and studies, Pacem in Maribus has consistently stressed the significance of rapid scientific and technological developments which have radically changed the nature of many conventional uses of the sea and call for management as the only alternative to conflict and possible disasters. In its commitment to an Ocean Space Authority rather than to an International Sea-bed Authority, Pacem in Maribus contends that activities on the sea-bed cannot be dissociated from activities in the water-column, at the surface, and at the atmospheric interface; that the sea-bed must become part of an integrated management system for ocean space; and that claims to national jurisdiction carry a surrogate responsibility in that management.Pacem in Maribus contends that any Law of the Sea which does not respect and embody these overriding considerations will prove to be ineffective if not inoperable.


2021 ◽  
Vol 9 (6) ◽  
pp. 1176
Author(s):  
Simone Cristina Picchi ◽  
Laís Moreira Granato ◽  
Maria Júlia Festa Franzini ◽  
Maxuel Oliveira Andrade ◽  
Marco Aurélio Takita ◽  
...  

Xanthomonas citri subsp. citri (X. citri) is a plant pathogenic bacterium causing citrus canker disease. The xanA gene encodes a phosphoglucomutase/phosphomannomutase protein that is a key enzyme required for the synthesis of lipopolysaccharides and exopolysaccharides in Xanthomonads. In this work, firstly we isolated a xanA transposon mutant (xanA::Tn5) and analyzed its phenotypes as biofilm formation, xanthan gum production, and pathogenesis on the sweet orange host. Moreover, to confirm the xanA role in the impaired phenotypes we further produced a non-polar deletion mutant (ΔxanA) and performed the complementation of both xanA mutants. In addition, we analyzed the percentages of the xanthan gum monosaccharides produced by X. citri wild-type and xanA mutant. The mutant strain had higher ratios of mannose, galactose, and xylose and lower ratios of rhamnose, glucuronic acid, and glucose than the wild-type strain. Such changes in the saccharide composition led to the reduction of xanthan yield in the xanA deficient strain, affecting also other important features in X. citri, such as biofilm formation and sliding motility. Moreover, we showed that xanA::Tn5 caused no symptoms on host leaves after spraying, a method that mimetics the natural infection condition. These results suggest that xanA plays an important role in the epiphytical stage on the leaves that is essential for the successful interaction with the host, including adaptive advantage for bacterial X. citri survival and host invasion, which culminates in pathogenicity.


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