scholarly journals Protection of grapevine pruning wounds against Phaeomoniella chlamydospora and Diplodia seriata by commercial biological and chemical methods

2020 ◽  
pp. 105465
Author(s):  
María del Pilar Martínez-Diz ◽  
Emilia Díaz-Losada ◽  
Ángela Díaz-Fernández ◽  
Yolanda Bouzas-Cid ◽  
David Gramaje
2020 ◽  
Author(s):  
María del Pilar Martínez-Diz ◽  
Emilia Díaz-Losada ◽  
Ángela Díaz-Fernández ◽  
Yolanda Bouzas-Cid ◽  
David Gramaje

ABSTRACTThe grapevine trunk diseases (GTDs) Botryosphaeria dieback and esca threaten the sustainability of the grapevine industry worldwide. This study aimed to evaluate and compare the efficacy of various liquid (pyraclostrobin + boscalid and thiophanate methyl) and paste (paste + tebuconazole) formulation fungicide treatments, and biological control agents (Trichoderma atroviride SC1 and T. atroviride I-1237), for their potential to prevent infection of grapevine pruning wounds by Diplodia seriata and Phaeomoniella chlamydospora in two field trials over two growing seasons. Treatments were applied to freshly pruned wounds following their label dosages recommendations. After 24 hours, wounds were artificially inoculated with 400 spores of D. seriata or 800 spores of P. chlamydospora. Isolations were made from the treated pruning wounds after 12 months to evaluate the efficacy of the treatments. Fungicide formulations were superior to Trichoderma-based treatments for the control of both pathogens during both growing seasons, with mean percent disease control of 44 to 95% for D. seriata and 46 to 67% for P. chlamydospora. Pyraclostrobin + boscalid was the most effective treatment. Trichoderma atroviride-based treatments did not reduce infection by D. seriata or P. chlamydospora compared to the untreated inoculated control in both vineyards and seasons. This study represents the first vineyard assessment of several chemical and biological treatments to protect pruning wounds against GTDs fungi in Europe and provides growers with tangible preventative control practices to minimize yield losses due to GTDs.


Plant Disease ◽  
2015 ◽  
Vol 99 (7) ◽  
pp. 976-981 ◽  
Author(s):  
C. Agustí-Brisach ◽  
M. León ◽  
J. García-Jiménez ◽  
J. Armengol

Four vineyards visibly affected by trunk diseases were surveyed at pruning time in 2012 and 2013 in Spain, to determine whether pruning tools are capable of spreading grapevine trunk diseases from vine to vine. In each vineyard, pruning shears were regularly rinsed with sterile water, collecting liquid samples for analysis. Molecular detection of grapevine fungal trunk pathogens (GFTPs) was performed by nested polymerase chain reaction using specific primers to detect Botryosphaeriaceae spp. Eutypa lata, Cadophora luteo-olivacea, Phaeoacremonium spp., and Phaeomoniella chlamydospora. All of these GFTPs, with the exception of E. lata, were detected in samples from the four vineyards, C. luteo-olivacea and Phaeoacremonium spp. being the most prevalent. Co-occurrence of two, three, or four different GFTPs from the same sample were found, the simultaneous detection of C. luteo-olivacea and Phaeoacremonium spp. being the most prevalent. In addition, fungal isolation from liquid samples in semiselective culture medium for C. luteo-olivacea, Phaeoacremonium spp., and P. chlamydospora was also performed but only C. luteo-olivacea was recovered from samples collected in three of four vineyards evaluated. Pruning shears artificially infested with suspensions of conidia or mycelial fragments of C. luteo-olivacea, Diplodia seriata, E. lata, Phaeoacremonium aleophilum, and Phaeomoniella chlamydospora were used to prune 1-year-old grapevine cuttings of ‘110 Richter’ rootstock. Successful fungal reisolation from the cuttings 4 months after pruning confirmed that infested pruning shears were able to infect them through pruning wounds. These results improve knowledge about the epidemiology of GFTPs and demonstrate the potential of inoculum present on pruning shears to infect grapevines.


Plant Disease ◽  
2016 ◽  
Vol 100 (8) ◽  
pp. 1651-1659 ◽  
Author(s):  
Georgina Elena ◽  
Jordi Luque

Diplodia seriata and Phaeomoniella chlamydospora are two fungal pathogens associated with grapevine trunk diseases worldwide. This study aimed to evaluate the period during which grapevine pruning wounds remain susceptible to fungal infection and to describe the colonization of canes artificially inoculated with these pathogens. In the first experiment, pruning wounds made in either fall or winter were separately inoculated with each pathogen at different times after pruning. Wound susceptibility to both pathogens decreased as the period between pruning and inoculation increased, from high percentages recorded in the first inoculation round (D. seriata, 97.5% and P. chlamydospora, 75%) down to approximately 10% 12 weeks after pruning. Pruning wounds remained more susceptible to D. seriata after a late pruning in winter whereas no overall seasonal changes in wound susceptibility were detected for P. chlamydospora. In the second experiment, canes were pruned by leaving two different lengths between the top node and the pruning wound before inoculations. Pathogens were recovered at different incubation periods and from different sites along the canes to estimate fungal cane colonization. A longer pruned internode made cane colonization by P. chlamydospora difficult, as indicated by fungal recoveries lower than 10% at the lowest recovery site, whereas D. seriata was less inhibited.


Author(s):  
Henry S. Slayter

Electron microscopic methods have been applied increasingly during the past fifteen years, to problems in structural molecular biology. Used in conjunction with physical chemical methods and/or Fourier methods of analysis, they constitute powerful tools for determining sizes, shapes and modes of aggregation of biopolymers with molecular weights greater than 50, 000. However, the application of the e.m. to the determination of very fine structure approaching the limit of instrumental resolving power in biological systems has not been productive, due to various difficulties such as the destructive effects of dehydration, damage to the specimen by the electron beam, and lack of adequate and specific contrast. One of the most satisfactory methods for contrasting individual macromolecules involves the deposition of heavy metal vapor upon the specimen. We have investigated this process, and present here what we believe to be the more important considerations for optimizing it. Results of the application of these methods to several biological systems including muscle proteins, fibrinogen, ribosomes and chromatin will be discussed.


Author(s):  
R. J. Narconis ◽  
G. L. Johnson

Analysis of the constituents of renal and biliary calculi may be of help in the management of patients with calculous disease. Several methods of analysis are available for identifying these constituents. Most common are chemical methods, optical crystallography, x-ray diffraction, and infrared spectroscopy. The application of a SEM with x-ray analysis capabilities should be considered as an additional alternative.A scanning electron microscope equipped with an x-ray “mapping” attachment offers an additional dimension in its ability to locate elemental constituents geographically, and thus, provide a clue in determination of possible metabolic etiology in calculus formation. The ability of this method to give an undisturbed view of adjacent layers of elements in their natural state is of advantage in determining the sequence of formation of subsequent layers of chemical constituents.


2019 ◽  
Author(s):  
Antoine Maruani ◽  
Peter A. Szijj ◽  
Calise Bahou ◽  
João C. F. Nogueira ◽  
Stephen Caddick ◽  
...  

<p>Diseases are multifactorial, with redundancies and synergies between various pathways. However, most of the antibody-based therapeutics in clinical trials and on the market interact with only one target thus limiting their efficacy. The targeting of multiple epitopes could improve the therapeutic index of treatment and counteract mechanisms of resistance. To this effect, a new class of therapeutics emerged: bispecific antibodies.</p><p>Bispecific formation using chemical methods is rare and low yielding and/or requires a large excess of one of the two proteins to avoid homodimerisation. In order for chemically prepared bispecifics to deliver their full potential, high-yielding, modular and reliable cross-linking technologies are required. Herein, we describe a novel approach not only for the rapid and high-yielding chemical generation of bispecific antibodies from native antibody fragments, but also for the site-specific dual functionalisation of the resulting bioconjugates. Based on orthogonal clickable functional groups, this strategy enables the assembly of functionalised bispecifics with controlled loading in a modular and convergent manner.</p>


Author(s):  
Y. N. Hua ◽  
G. B. Ang ◽  
S. Redkar ◽  
Yogaspari ◽  
Wilma Richter

Abstract In failure analysis of wafer fabrication, currently, three different types of chemical methods including 6:6:1 (Acetic Acid/HNO3/HF), NaOH and Choline are used in removing polysilicon (poly) layer and exposing the gate/tunnel oxide underneath. However, usage is limited due to their disadvantages. For example, 6:6:1 is a relatively fast etchant, but it is difficult to control the etch time and keep the oxide layer intact. Also, while using NaOH to remove poly and expose the silicon oxide, the solution needs to be heated. It is also difficult to etch a poly layer with a WSix or a CoSix silicide using NaOH. In this paper, we will discuss these 3 etchants in terms of their advantages and disadvantages. We will then introduce a new poly etchant, called HB91. HB91 is useful for removing poly to expose the gate/tunnel oxide for identification of related defects. HB91 is actually a mixture of two chemicals namely nitric acid (HNO3) and buffer oxide etchant (BOE) in a 9:1 ratio. The experimental results show that it is highly selective in poly removal with respect to the gate/tunnel oxide and is a suitable poly etchant especially for removing polysilicon with/without WSix and CoSix in the large capacitor structure. Application results of this poly etchant (HB91) will be presented.


Author(s):  
D. Zudhistira ◽  
V. Viswanathan ◽  
V. Narang ◽  
J.M. Chin ◽  
S. Sharang ◽  
...  

Abstract Deprocessing is an essential step in the physical failure analysis of ICs. Typically, this is accomplished by techniques such as wet chemical methods, RIE, and mechanical manual polishing. Manual polishing suffers from highly non-uniform delayering particularly for sub 20nm technologies due to aggressive back-end-of-line scaling and porous ultra low-k dielectric films. Recently gas assisted Xe plasma FIB has demonstrated uniform delayering of the metal and dielectric layers, achieving a planar surface of heterogeneous materials. In this paper, the successful application of this technique to delayer sub-20 nm microprocessor chips with real defects to root cause the failure is presented.


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