Chemical control of bacterial canker (Pseudomonas syringae pv. syringae) of apricot and cherry in Victoria

1991 ◽  
Vol 31 (5) ◽  
pp. 705 ◽  
Author(s):  
DLS Wimalajeewa ◽  
R Cahill ◽  
G Hepworth ◽  
HG Schneider ◽  
JW Washbourne
Keyword(s):  
Pseudomonas Syringae ◽  
Chemical Control ◽  
Bordeaux Mixture ◽  
Weather Conditions ◽  
Hydrated Lime ◽  
Field Trials ◽  
Bacterial Canker ◽  
Copper Hydroxide ◽  
Low Concentrations ◽  
Excellent Control

Field trials were conducted during 1982-85, to develop a comprehensive spray program for the control of bacterial canker (Pseudomonas syringae pv, syringae) of apricot and cherry. Five spray schedules were evaluated as measures to reduce disease levels. Copper hydroxide at 2.5 g/L in water was applied to apricot, and bordeaux mixture at 6 g copper sulfate + 8 g hydrated lime/L in water was applied to cherry, during autumn, winter and pre-bloom spring. The effectiveness of copper sprays in reducing epiphytic populations of the pathogen during post-bloom spring was also tested. Copper hydroxide was applied to apricot, and a foliar copper nutrient and copper hydroxide were applied to cherry at low concentrations. Most spray schedules tested significantly (P<0.05) reduced canker incidence relative to controls. Excellent control of epiphytic populations of the pathogen on apricot and cherry was achieved with copper sprays applied at post-bloom in spring. A spray schedule consisting of 2 autumn, 1 winter and 2 pre-bloom spring sprays with copper hydroxide on apricot or bordeaux mixture on cherry was successful in reducing canker (>67% reduction) and is recommended for control of the disease. Two applications of copper hydroxide at 1.0 g/L in water in post-bloom spring considerably reduced (>9 1 %) epiphytic populations (P. syringae pv. syringae) on apricot and cherry leaves. Later sprays are recommended for use in combination with the autumn-winter-spring (pre-bloom) spray schedule, especially under excessively wet and cool weather conditions in spring.

Pseudomonas syringaepv.tagetis(PST) population dynamics both on and in Canada thistle (Cirsium arvense) leaves as affected by rain events

Weed Science ◽  
2006 ◽  
Vol 54 (5) ◽  
pp. 934-940 ◽  
Author(s):  
Ryan P. Tichich ◽  
Jerry D. Doll ◽  
Patricia S. McManus
Keyword(s):  
Population Dynamics ◽  
Pseudomonas Syringae ◽  
Leaf Surface ◽  
Weather Conditions ◽  
Field Trials ◽  
Primary Role ◽  
Canada Thistle ◽  
Population Composition ◽  
Antibiotic Resistant ◽  
Rain Events

Field trials were conducted to evaluate the season long population dynamics and location (in leaf or on leaf surface) of an antibiotic resistant strain of the bacteriumPseudomonas syringaepv.tagetis(PST) applied to Canada thistle leaves. An application preceding 2 to 3 d of hot dry weather was compared to an application preceding 2 to 3 d of cool wet weather. Leaf samples were taken weekly to assess the population of PST found inside the leaves and on the leaf surface. While PST populations initially differed, populations were similar for both treatments one week after application. While this suggests that environment did not have a major impact, weather conditions for testing this hypothesis were not ideal. Over the first 35 d of the experiment, little rainfall was observed. PST populations were low and stable. However, rain events over the 40 d that followed resulted in great oscillations in mean PST populations and in some cases significant population increases. During dry periods, internal and total PST populations differed significantly, suggesting the external populations played a major part in population composition. However, the two sampling periods that closely followed three consecutive days of rainfall indicated internal populations were not significantly different from the total, suggesting that internal populations played the primary role in population composition. The results of this research provide evidence that rain events lead to overall PST population increases and to greater proportions of PST inside Canada thistle leaves, suggesting that it is better to apply PST during wet periods than dry.

Investigations on chemical control of common bunt of wheat. 1

1967 ◽  
Vol 7 (26) ◽  
pp. 275 ◽  
Author(s):  
J Kuiper
Keyword(s):  
Chemical Control ◽  
South Australia ◽  
Good Control ◽  
Field Trials ◽  
Common Bunt ◽  
Tilletia Caries ◽  
Selective Action ◽  
Excellent Control ◽  
Mixed Populations ◽  
High Degree

Field trials were conducted at five sites in Victoria and one in South Australia in 1963-64 and 1965-66 to test a number of chemicals alone and in combination for the control of common bunt of wheat (Tilletia caries (DC.) Tul. and T. foetida (Wallr.) Liro) using mixed populations of the species as inoculum. On seed-borne bunt, fentin hydroxide and ziram were sufficiently active to warrant further testing. The chlorobenzenes hexachlorobenzene (HCB) and 2, 3, 5, 6 tetrachloronitroanisole had a strong selective action : they gave excellent control of T . caries, but HCB, especially, failed to control T . foetida. In contrast, the dithiocarbamates tested tended to be more effective on T. foetida. None of the chemicals tested, including HCB, controlled soil-borne bunt. The available evidence suggests that an hitherto unknown race of T. foetida had been used which has a high degree of field tolerance to HCB. A combination seed dressing of phenylmercuric acetate and CCC ('Cycocel') gave good control of seedborne bunt, but did not promote tillering or yield.

Effect of a protectant copper application on Psa infection of kiwifruit trap plants

2017 ◽  
Vol 70 ◽  
pp. 310-314
Author(s):  
J.L. Tyson ◽  
S.J. Dobson ◽  
M.A. Manning
Keyword(s):  
New Zealand ◽  
Disease Control ◽  
Pseudomonas Syringae ◽  
Low Risk ◽  
Bacterial Canker ◽  
Complete Protection ◽  
Leaf Spots ◽  
Copper Compounds ◽  
Trap Plants

Pseudomonas syringae pv. actinidiae (Psa) causes bacterial canker of kiwifruit, which is an ongoing threat to New Zealand kiwifruit production. Disease control depends on orchard practices such as removal of visibly diseased material, pruning during low-risk periods, and the application of foliar bactericides. Although the use of copper compounds on Actinidia species (kiwifruit) can cause phytotoxicity, copper-based formulations remain a key component of Psa control in New Zealand. The effect of single copper applications on Psa infection of ‘Hort16A’ trap plants was studied over the Spring of 2014 (Sept—Nov). Psa leaf spots were observed at the beginning of October, appearing first on the untreated plants. Although the copper sprays did not achieve complete protection, particularly as the inoculum built up during November, the copper-sprayed plants always had less disease than the untreated plants.

BIOASSAY TO DETERMINE CHERRY ROOTSTOCK TOLERANCE TO `BACTERIAL CANKER' CAUSED BY PSEUDOMONAS SYRINGAE PV SYRINGAE

HortScience ◽  
1990 ◽  
Vol 25 (11) ◽  
pp. 1354F-1355
Author(s):  
Elzbieta Krzesinska ◽  
Anita Nina Miller
Keyword(s):  
Relative Humidity ◽  
Pseudomonas Syringae ◽  
Bacterial Suspension ◽  
Avirulent Strain ◽  
Bacterial Canker ◽  
Symptom Development ◽  
Virulent Strains ◽  
Callus Production ◽  
Root Stock ◽  
One Year

An excised twig assay was developed to evaluate cherry geno-types for their tolerance to Pseudomonas syringae pv. syringae. One-year-old wood was collected at monthly intervals from October until January of `Royal Ann', `Corum', and a number of cherry rootstock. The rootstock included; F/12–1 and Giessen (GI) and M × M selections. A 2-cm incision (“^”-shaped flap) was made on each twig. A 20-μl droplet of inoculum or water was placed onto each incision. The inoculum was prepared with one avirulent (K4) and three virulent strains (W4N54, AP2, B15) concentrations (105, 106, or 107 cfu). Inoculated twigs were placed in test tubes and incubated at 15C in high relative humidity for 3 weeks. After incubation, twigs were evaluated for gummosis production (0–3, 0 = no gummosis), incision browning (1–4, 1 = yellow pith), and callus production (0–1, 0 = no callus). The concentration of bacterial suspension had no effect on symptom development. No gummosis or browning was observed on twigs inoculated with water or the avirulent strain. Based on the gummosis and browning ratings, rootstock M × M 2, M × M 39, M × M 60, GI 148-1, GI 154-2, and GI 154-4 were found to be resistant to these three strains of P. syringae in this assay. Root-stock F 12-1, GI 169–15, GI 172–9, and GI 173-9 were found to be tolerant.

scholarly journals A Synergic Potential of Antimicrobial Peptides against Pseudomonas syringae pv. actinidiae

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1461
Author(s):  
Nuno Mariz-Ponte ◽  
Laura Regalado ◽  
Emil Gimranov ◽  
Natália Tassi ◽  
Luísa Moura ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Antimicrobial Peptides ◽  
Pseudomonas Syringae ◽  
Pathogenic Bacteria ◽  
High Efficiency ◽  
Bacterial Canker ◽  
Membrane Permeation ◽  
Flow Cytometry Analysis ◽  
Pathogenic Agent ◽  
Peptide Mixtures

Pseudomonas syringae pv. actinidiae (Psa) is the pathogenic agent responsible for the bacterial canker of kiwifruit (BCK) leading to major losses in kiwifruit productions. No effective treatments and measures have yet been found to control this disease. Despite antimicrobial peptides (AMPs) having been successfully used for the control of several pathogenic bacteria, few studies have focused on the use of AMPs against Psa. In this study, the potential of six AMPs (BP100, RW-BP100, CA-M, 3.1, D4E1, and Dhvar-5) to control Psa was investigated. The minimal inhibitory and bactericidal concentrations (MIC and MBC) were determined and membrane damaging capacity was evaluated by flow cytometry analysis. Among the tested AMPs, the higher inhibitory and bactericidal capacity was observed for BP100 and CA-M with MIC of 3.4 and 3.4–6.2 µM, respectively and MBC 3.4–10 µM for both. Flow cytometry assays suggested a faster membrane permeation for peptide 3.1, in comparison with the other AMPs studied. Peptide mixtures were also tested, disclosing the high efficiency of BP100:3.1 at low concentration to reduce Psa viability. These results highlight the potential interest of AMP mixtures against Psa, and 3.1 as an antimicrobial molecule that can improve other treatments in synergic action.

scholarly journals Epidemiology and management of bacterial leaf spot on watermelon caused byPseudomonas syringae

Plant Disease ◽  
2017 ◽  
Vol 101 (7) ◽  
pp. 1222-1229 ◽  
Author(s):  
E. A. Newberry ◽  
L. Ritchie ◽  
B. Babu ◽  
T. Sanchez ◽  
K. A. Beckham ◽  
...  
Keyword(s):  
Disease Severity ◽  
Pseudomonas Syringae ◽  
Leaf Spot ◽  
Negative Relationship ◽  
Disease Outbreaks ◽  
Field Trials ◽  
Multiple Regression Model ◽  
Bacterial Leaf Spot ◽  
Progress Curve ◽  
Cool Conditions

Bacterial leaf spot of watermelon caused by Pseudomonas syringae has been an emerging disease in the southeastern United States in recent years. Disease outbreaks in Florida were widespread from 2013 to 2014 and resulted in foliar blighting at the early stages of the crop and transplant losses. We conducted a series of field trials at two locations over the course of two years to examine the chemical control options that may be effective in management of this disease, and to investigate the environmental conditions conducive for bacterial leaf spot development. Weekly applications of acibenzolar-S-methyl (ASM) foliar, ASM drip, or copper hydroxide mixed with ethylene bis-dithiocarbamate were effective in reducing the standardized area under the disease progress curve (P < 0.05). Pearson’s correlation test demonstrated a negative relationship between the average weekly temperature and disease severity (–0.77, P = 0.0002). When incorporated into a multiple regression model with the square root transformed average weekly rainfall, these two variables accounted for 71% of the variability observed in the weekly disease severity (P < 0.0001). This information should be considered when choosing the planting date for watermelon seedlings as the cool conditions often encountered early in the spring season are conducive for bacterial leaf spot development.

Chemical control of potato tuber moth, Phthorimaea operculella (Zell.), in Rhodesia

1967 ◽  
Vol 57 (2) ◽  
pp. 271-278 ◽  
Author(s):  
Margaret E. Richardson ◽  
D. J. W. Rose
Keyword(s):  
Chemical Control ◽  
Good Control ◽  
Field Trials ◽  
Phthorimaea Operculella ◽  
Macrosiphum Euphorbiae ◽  
Control Field ◽  
Azinphos Methyl ◽  
History Of ◽  
New Compounds ◽  
Made In

An account is given of the history of chemical control Phthorimaea operculella (Zell.) in potato fields in Rhodesia since the introduction of DDt prior to 1952. The failure of DDT and endrin, in routine spraying, to control field infestations is reproted, and some evidence that this is due to insecticide resistance is given. The results of critical field trials made in 1961, 1964 and 1965 to evaluate a range of insecticides for control of P. operculella and for their effects on populations of Macrosiphum euphorbiae (Thos.) are presented, together with the results of some laboratory tests. Good control of P. operculella in the field was obtained with sprays of azinphos-methyl at the rate of 0.5 lb active ingredient in 20 gal. water per acre, and two new compounds, methidathion and chlorfenvinphos, showed promise for the future.

Biological activity of Pyraclostrobin against Coniella granati causing pomegranate crown rot

Plant Disease ◽  
2021 ◽  
Author(s):  
Xue Yang ◽  
Chun-Yan Gu ◽  
Yang Bai ◽  
Jia-Zhi Sun ◽  
Hao-Yu Zang ◽  
...  
Keyword(s):  
Biological Activity ◽  
Mycelial Growth ◽  
Field Trials ◽  
Crown Rot ◽  
Germination Inhibition ◽  
Control Efficacy ◽  
Intracellular Organelle ◽  
Transmission Electron ◽  
Excellent Control ◽  
Conidium Germination

Pomegranate crown rot caused by Coniellagranati is one of the most severe diseases of pomegranate. To date, no fungicides have been registered for controlling this disease in China. Pyraclostrobin, belonging to strobilurin fungicides, has a broad spectrum of activity against many phytopathogens. In this study, based on the mycelial growth and conidial germination inhibition methods, we investigated the biological activity of pyraclostrobin against C. granati at the presence of 50 μg/mL SHAM using 80 isolates collected from different orchards in China during 2012-2018. The EC50 (50% effective concentration) values ranged from 0.040-0.613 μg/mL for mycelial growth and 0.013-0.110 μg/mL for conidium germination, respectively. Treated with pyraclostrobin, the hyphae morphology changed and conidial production of C. granati decreased significantly. The result of transmission electron microscope showed that treatment of pyraclostrobin could make the cell wall thinner, and lead to ruptured cell membrane and formation of intracellular organelle autophagosomes. The pyraclostrobin showed good protective and curative activities against C. granati on detached pomegranate fruits. In field trials, pyraclostrobin showed excellent control efficacy against this disease in which the treatment of 25% pyraclostrobin EC 1000× provided 92.25% and 92.58% control efficacy in 2019 and 2020, respectively, significantly higher than that of other treatments. Therefore, pyraclostrobin could be a candidate fungicide for the control of pomegranate crown rot.

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