Seasonal variation in susceptibility of apricot to Pseudomonas syringae pv. syringae (bacterial canker), and site of infection in apricot and cherry

1987 ◽  
Vol 27 (3) ◽  
pp. 475 ◽  
Author(s):  
DLS Wimalajeewa
Keyword(s):  
Seasonal Variation ◽  
Pseudomonas Syringae ◽  
Natural Infection ◽  
Late Winter ◽  
Bacterial Canker ◽  
Late Autumn ◽  
Early Autumn ◽  
Autumn And Winter ◽  
And Control ◽  
Made In

The seasonal variation in susceptibility of buds, stems, leaves and fruit of apricot to Pseudomonas syringae pv. syringae, and sites through which infection occurs in apricot and cherry were studied. Infection of apricot and cherry occurred through buds, flowers, leaves, fruit and stems but not leaf scars through which natural infection can occur. Only stem and bud inoculations consistently led to the establishment of cankers. The proportion of buds showing infection was highest with inoculations made in late autumn and winter (May-July), and lowest with inoculations in summer (December-February). The number of stem inoculations, resulting in extensive cankers, was highest in late winter and spring (August-November) and lowest in summer and early autumn (December- March). Leaves and fruit were susceptible only during spring (September-November), when they were immature. The importance of these findings in relation to epidemiology and control of bacterial canker is discussed.

Cycles of reproduction and condition in Tasmanian blue mussels, Mytilus edulis planulatus

1984 ◽  
Vol 35 (3) ◽  
pp. 307 ◽  
Author(s):  
TG Dix ◽  
A Ferguson
Keyword(s):  
Mytilus Edulis ◽  
Early Spring ◽  
Late Winter ◽  
Reproductive Condition ◽  
Late Autumn ◽  
Blue Mussels ◽  
Early Autumn ◽  
Condition Indices ◽  
One Year ◽  
Autumn And Winter

Major spawning by M. e. planulatus occurred in the late winter or early spring at Hinders Reef, Margate and Birchs Bay in 1980 and 1981. Spawning occurred also over the summer and early autumn although a major spawning was indicated during this period at only one site in one year. At the two sites where temperatures were recorded, the major spring spawning occurred at about or just above 10�C. Gonads built up reproductive condition during late autumn and winter at all sites in 1980 and 1981. Condition indices were highest at these times and fell when spring spawning occurred.

The biology of Gammarus (Crustacea, Amphipoda) in the northwestern Atlantic. X. Gammarus finmarchicus Dahl

1975 ◽  
Vol 53 (8) ◽  
pp. 1110-1115 ◽  
Author(s):  
D. H. Steele ◽  
V. J. Steele
Keyword(s):  
Life Cycle ◽  
New Brunswick ◽  
Long Island ◽  
Long Island Sound ◽  
Western Atlantic ◽  
Late Autumn ◽  
Early Autumn ◽  
Autumn And Winter ◽  
Island Sound

Gammarus finmarchicus is an amphi-Atlantic species. In the western Atlantic it is found from the island of St. Pierre south to Long Island Sound. At St. Andrews, New Brunswick, 50% maturity occurs at 10.5 mm in the females. Reproduction is in progress throughout the year, but small females evidently are in a resting condition during September–October before breeding. The release of young by the population is greater in the spring, summer, and early autumn than it is in late autumn and winter. The young released in the spring and summer do not reproduce until the next year so that the life cycle is annual.

scholarly journals Recent progress on detecting understanding and controlling Pseudomonas syringae pv actinidiae a short review

2013 ◽  
Vol 66 ◽  
pp. 170-177 ◽  
Author(s):  
J.L. Vanneste
Keyword(s):  
Pseudomonas Syringae ◽  
Recent Progress ◽  
Short Review ◽  
Economic Importance ◽  
Whole Genome Sequence ◽  
Bacterial Canker ◽  
New Methods ◽  
The World ◽  
Epiphytic Survival ◽  
Made In

In the last few years the causal agent of bacterial canker of kiwifruit Pseudomonas syringae pv actinidiae (Psa) has become a global pathogen of economic importance Since the beginning of this global outbreak many laboratories in the world have been working on Psa Today it is known that Psa is not a homogeneous pathovar and tools that allow the distinction between biovars (subpathovar classification) have been developed The whole genome sequence of several strains of Psa has now been published Some of the assumptions on the life cycle (ports of entry epiphytic survival etc) made in the early days of the outbreak have now been confirmed Although few new methods have been found to control Psa there is now a better understanding of how to reduce the incidence of this disease This paper reviews the progress made in understanding the pathogen the disease and how to control it

scholarly journals Bacterial Canker of Sweet Cherry in Oregon—Infection of Horticultural and Natural Wounds, and Resistance of Cultivar and Rootstock Combinations

Plant Disease ◽  
2010 ◽  
Vol 94 (3) ◽  
pp. 345-350 ◽  
Author(s):  
Robert A. Spotts ◽  
Kelly M. Wallis ◽  
Maryna Serdani ◽  
Anita N. Azarenko
Keyword(s):  
Pseudomonas Syringae ◽  
Tree Mortality ◽  
Sweet Cherry ◽  
Prunus Avium ◽  
Integrated Management ◽  
Management Program ◽  
Bacterial Canker ◽  
Relative Resistance ◽  
Injuries And Wounds ◽  
Made In

This study was done to (i) compare seven types of natural or horticultural injuries and wounds for incidence, severity, and mortality of infection of sweet cherry (Prunus avium) by Pseudomonas syringae pv. syringae; (ii) determine the relative resistance to bacterial canker of 14 cultivar–rootstock combinations; (iii) determine if P. syringae pv. syringae is transmitted by contaminated pruning tools; and (iv) determine if summer and winter pruning cuts become resistant to infection. Infection occurred at all of the seven types of injury and wound sites on both cvs. Sunset Bing and Golden Heart. Infection of inoculated wounds made in spring and summer (heading cuts when trees were planted, scoring cuts, and summer pruning) resulted in the greatest canker incidence and severity. Inoculation of heading cuts resulted in the highest tree mortality (86%). ‘Bing’ and ‘Sweetheart’ were the most susceptible cultivars while ‘Regina’ and ‘Rainier’ appeared to be more resistant. Bing trees had the highest mortality of any cultivar with 70% dead at the end of the 3-year study. Canker severity of the three rootstocks varied considerably but mortality was greatest for trees on Gisela 6 (77%). Bacterial canker was not transmitted in summer or winter by cutting through active cankers, then immediately using the same pruning tool to make heading cuts on healthy trees. Heading cuts became resistant to infection after about 1 week in summer and 3 weeks in winter. Results are discussed as part of an integrated management program for bacterial canker of sweet cherry.

Seasonal Water Content and Distribution in Eastern White Pine

1969 ◽  
Vol 45 (1) ◽  
pp. 38-43
Author(s):  
S. N. Linzon
Keyword(s):  
Water Content ◽  
Pinus Strobus ◽  
Late Winter ◽  
Early Winter ◽  
White Pine ◽  
Eastern White Pine ◽  
Seasonal Rhythm ◽  
Late Autumn ◽  
Early Autumn

Studies over a 30-month period revealed the presence of a seasonal rhythm in water content in the sapwood and in wet and dry portions of the heartwood of eastern white pine, Pinus strobus L. The data, indicated an increase in water content in late autumn and early winter, a drying out in late winter, a slight increase in the spring, fluctuations during the summer strongly influenced by weather, and a slight decrease in early autumn prior to the increase at the end of the year. The newest parts of the crown were the wettest in the tree. Outer rings in the sapwood of the crown were wetter than those in the bole and butt. Wet heartwood possessed as high a water content as sapwood, whereas dry heartwood contained the lowest water content of all the parts of the tree examined.

scholarly journals First Report of Bacterial Canker on Blueberry (Vaccinium corymbosum) Caused by Pseudomonas syringae pv. syringae in Serbia

Plant Disease ◽  
2021 ◽  
Author(s):  
Nevena Zlatkovic ◽  
Goran Aleksić ◽  
Katarina Gašić
Keyword(s):  
Pseudomonas Syringae ◽  
Natural Infection ◽  
Vaccinium Corymbosum ◽  
Bacterial Suspension ◽  
Rrna Gene ◽  
Highbush Blueberry ◽  
Bacterial Canker ◽  
First Report ◽  
Appl Environ ◽  
Symptomatic Tissue

During May 2021, necrosis of young twigs and flower buds were observed on two-year-old highbush blueberry plants (Vaccinium corymbosum) cv. Draper, in a 1 hectare orchard in the municipality of Šabac, Serbia. Disease symptoms included reddish-brown to black irregularly shaped cankers developing on the shoot tips that extended downwards along the branches. In some plants, cankers surrounded the stem, causing shoot-tip dieback and necrosis of the buds. Beneath the bark, a distinct margin between diseased and healthy tissue was visible. A few weeks before symptoms development, seven freezing events with temperature from -3°C to -1°C, and five near-freezing temperatures were recorded in this area, leading to the hypothesis that symptoms were associated to the presence of ice nucleating bacteria belonging to Pseudomonas syringae. The observed disease incidence was 80%, while 10% of the plants died. Bacteria were isolated from symptomatic tissue on King’s medium B (KB). After 2 to 3 days of incubation at 27°C, predominantly grey-whitish, shiny, round, convex bacterial colonies were observed on agar plates. Ten isolates producing a fluorescent pigment on KB were selected for further characterization by biochemical and molecular tests. The isolates were Gram, oxidase and arginine-dihydrolase negative, levan positive, induced hypersensitive response on tobacco leaves and showed no pectinolytic activity on potato slices. Based on the results of API 20E and API 20NE tests (BioMerieux, France), and the fact that isolates did not utilize tartrate nor had tyrosinase activity, they were preliminarly identified as Pseudomonas syrinage pv. syringae (Braun-Kiewnick and Sands 2001). Additionally, all tested isolates had ice-nucleation activity at -5°C. The syrB gene responsible for syringomycin synthesis, was amplified in all isoaltes with the specific primer pair B1/B2 (Sorensen et al. 1998). The 16S rRNA gene sequences of five selected isolates (GenBank MZ410287 to 91) showed 100% identity to P. s. pv. syringae isolated from Prunus avium in United Kingdom (GenBank CP026568) and France (GenBank LT962480). Sequences of gyrB gene (Sarkar and Guttman 2004) of two selected isolates (GenBank MZ420633 and MZ420634) showed 98,44% identity to the P. s. pv. syrinage strain isolated in France (GenBank LT962480). Pathogenicity of the isolates was confirmed on 2-year-old blueberry plants cv. Draper, by inoculating two plants per isolate. One-cm long wounds were made on branches using a scalpel and 20 µl of bacterial suspension (106 CFU/ml) was infiltrated into the tissue. The cuts were then covered with moist sterile cotton pads and wraped in parafilm for 3 days. Inoculation was also performed on two leaves per plant by needleless syringe infiltration (106 CFU/ml). Sterile distilled water was used as a negative control. Plants were maintained in greenhouse at 27°C day and 15°C night temperature. Three weeks after inoculation, the inoculated branches and leaves developed necrosis, leaves spots and cankers respectively, resembling the natural infection. Symptoms were not observed on the control plants. Bacteria were reisolated from symptomatic tissue and their identity was confirmed by amplifying the syrB gene sequence and additional biochemical tests. This is the first report of bacterial canker of highbush blueberry caused by P. s. pv. syringae in Serbia. In Europe, there was only one report on Pseudomonas spp. causing disease on blueberry leaves in Poland (Kaluzna et al. 2013). Due to market demands and export potential, blueberry production in Serbia has been rapidly increasing. In 2015, highbush blueberry was cultivated on 220 ha, while in 2020 the area increased to 1899 ha. However, under favourable environmental conditions, blueberry production might be severely affected by bacterial canker. References: Braun-Kiewnick, A. and Sands, D.C. Page 84 in: Laboratory Guide for Identification of Plant Pathogenic Bacteria. 3rd ed. N. W. Schaad et al., eds. The American Phytopathological Society, St. Paul, MN, 2001. Kaluzna, M., et al. 2013. J Plant Protec Res 53:32. Sarkar, S. F., and Guttman, D. S. 2004. Appl. Environ. Microbiol. 70:1999. https://doi.org/10.1128 Sorensen, K. N., et al. 1998. Appl. Environ. Microbiol. 64:226.

scholarly journals Cereal rye to extend the grazing season

1995 ◽  
pp. 115-118
Author(s):  
David H. Sample' ◽  
Henry M. Bartholomew ◽  
R.Marc Sulc
Keyword(s):  
Crude Protein ◽  
Late Summer ◽  
Early Spring ◽  
Grazing Season ◽  
Cereal Rye ◽  
Late Autumn ◽  
Protein Levels ◽  
Winter Grazing ◽  
Autumn And Winter ◽  
Made In

Eleven cereal rye (&cafe cereale) cultivars, one triticale (Triticum secale) and one winter wheat (Triticum aestivum) cultivar were evaluated in 2 studies for their ability to extend the grazing season into the autumn and winter in southern Ohio. The cultivars, 5 in 1993 and 9 in 1994, were randomly assigned to replicated plots and planted in late summer. Plots were harvested in late autumn to determine dry matter (DM) yield and forage quality. Results from the two years indicate significant differences (P=O.O5) between cultivars for DM yield, crude protein(CP) and NDF levels. DM yields ranged from 1389 to 2470 kg/ha (1993) and 1018 to 2 124 kg/ha (1994). Crude protein levels ranged from 25.2 to 27.9% (1993) and 28.8 to 33.7% (1994). A second harvest of the 1994 plots was made in early spring 1995 for continued evaluation. Statistically significant differences again existed between the stockpiled cultivars. DM yields ranged from 1979 to 2980 kg/ha while crude protein levels ranged between 21.5 and 27.0% of DM. Results support the conclusion that selected cereal rye cultivars can produce excellent yields of high quality forage for late autumn and winter grazing in the Ohio climate. Keywords: cereal rye, extended grazing season, Secale cereale, triticale, wheat

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.

An Efficient Approach for Modeling and Control of a Quadrotor

2016 ◽  
Vol 4 (2) ◽  
pp. 1-16
Author(s):  
Ahmed S. Khusheef
Keyword(s):  
Pid Control ◽  
Control Method ◽  
Mechanical Design ◽  
Loop Control ◽  
Modeling And Control ◽  
Loop Control System ◽  
And Control ◽  
Close Loop Control ◽  
Close Loop Control System ◽  
Made In

 A quadrotor is a four-rotor aircraft capable of vertical take-off and landing, hovering, forward flight, and having great maneuverability. Its platform can be made in a small size make it convenient for indoor applications as well as for outdoor uses. In model there are four input forces that are essentially the thrust provided by each propeller attached to each motor with a fixed angle. The quadrotor is basically considered an unstable system because of the aerodynamic effects; consequently, a close-loop control system is required to achieve stability and autonomy. Such system must enable the quadrotor to reach the desired attitude as fast as possible without any steady state error. In this paper, an optimal controller is designed based on a Proportional Integral Derivative (PID) control method to obtain stability in flying the quadrotor. The dynamic model of this vehicle will be also explained by using Euler-Newton method. The mechanical design was performed along with the design of the controlling algorithm. Matlab Simulink was used to test and analyze the performance of the proposed control strategy. The experimental results on the quadrotor demonstrated the effectiveness of the methodology used.

Sign in / Sign up

Export Citation Format

Share Document