A NATIONAL DISEASE FORECASTING SYSTEM FOR APPLE BLACK SPOT (VENTURIA INAEQUALIS) IN NEW ZEALAND

1992 ◽  
pp. 285-296 ◽  
Author(s):  
R.M. Beresford ◽  
M. Spink
Keyword(s):  
New Zealand ◽  
Venturia Inaequalis ◽  
Black Spot ◽  
Disease Forecasting ◽  
Forecasting System

scholarly journals Speciesspecific PCR primers for Guignardia citricarpa and Guignardia mangiferae

2006 ◽  
Vol 59 ◽  
pp. 141-145 ◽  
Author(s):  
K.R. Everett ◽  
J. Rees-George
Keyword(s):  
New Zealand ◽  
Venturia Inaequalis ◽  
Black Spot ◽  
Pathogenic Fungi ◽  
Pcr Primers ◽  
Colletotrichum Acutatum ◽  
Botryosphaeria Dothidea ◽  
Guignardia Citricarpa ◽  
Citrus Black Spot ◽  
Polymerase Chain

The plant pathogen Guignardia citricarpa causes citrus black spot and is not considered to be present in New Zealand Speciesspecific polymerase chain reaction (PCR) primers were designed to identify G citricarpa and G mangiferae a closely related saprotroph that is present in New Zealand These PCR primers were tested against a range of other saprotrophic and pathogenic fungi viz Botrytis cinerea Botryosphaeria dothidea B parva Cladosporium sp Colletotrichum acutatum C gloeosporioides Cryptosporiopsis sp Epicoccum sp Nigrospora sp Penicillium sp Pestalotia sp Phialophora sp Phlyctema sp Phoma sp Phomopsis sp Stemphylium sp and Venturia inaequalis The primers JRGGc were specific to G citricarpa and JRGGm to G mangiferae A 226 bp product was amplified from G mangiferae DNA using JRGGm primers and a 501 bp product was amplified from G citricarpa DNA using JRGGc primers These primers thus distinguished G citricarpa from G mangiferae and can be used to rapidly identify incursions by citrus black spot

scholarly journals A synthetic agar assay for determining sensitivity of Venturia inaequalis to anilinopyrimidine fungicides in New Zealand apple orchards

2013 ◽  
Vol 66 ◽  
pp. 293-302 ◽  
Author(s):  
N.J. Larsen ◽  
R.M. Beresford ◽  
P.N. Wood ◽  
P.J. Wright ◽  
B.M. Fisher
Keyword(s):  
New Zealand ◽  
Disease Control ◽  
Botrytis Cinerea ◽  
Mycelial Growth ◽  
Venturia Inaequalis ◽  
Black Spot ◽  
Apple Trees ◽  
Colony Diameter ◽  
Growth Assay ◽  
Agar Method

A synthetic agar mycelial growth assay adapted from a Botrytis cinerea method was used to determine the sensitivity of Venturia inaequalis isolates (the cause of apple black spot) to anilinopyrimidine (AP) fungicides Nineteen singleconidium isolates were classified as sensitive (S) or resistant (R) to cyprodinil or pyrimethanil after 21 days growth according to concentrations that inhibited colony diameter by 50 (EC50) Isolate classification on agar was compared with leaf disease control by AP fungicides on potted apple trees inoculated with S or R isolates Three S isolates were completely inhibited by AP fungicides on plants Three R isolates were partially inhibited on fungicidetreated leaves One isolate classified as R for both fungicides on agar was inhibited by cyprodinil but not pyrimethanil on plants The agar method will be used for screening V inaequalis populations for AP resistance in orchard surveys with plant tests on some isolates to determine implications for orchard disease control

scholarly journals Treatment of overwintering apple leaves to reduce primary inoculum of apple black spot

2003 ◽  
Vol 56 ◽  
pp. 95-99
Author(s):  
K. Tshomo ◽  
I.J. Horner ◽  
M. Walter ◽  
A. Stewart ◽  
M.V. Jaspers
Keyword(s):  
Venturia Inaequalis ◽  
Black Spot ◽  
Field Trials ◽  
Water Control ◽  
Primary Inoculum ◽  
Apple Leaves ◽  
Fungal Isolates ◽  
Glass Slides ◽  
Ascospore Production ◽  
Nutrient Amendments

Field trials were conducted in Hawkes Bay and Lincoln into methods of treating overwintering apple leaves to reduce ascospore production by the apple black spot pathogen Venturia inaequalis The leaf treatments comprised three levels of nutrient amendments (including a water control) and five levels of saprophytic fungal isolates (including a nofungus control) in a factorial design Leaves were left to overwinter on the orchard floor and in spring the V inaequalis ascospores released were trapped on glass slides and counted Ascospore numbers were reduced (Plt;005) by the leaf amendment urea which alone caused 73 reduction but not by the BioStarttrade; product The effect of fungal isolates was not significant (P012) although when combined with the water treatment the isolates Chaetomium Phoma and Epicoccum spp and Trametes versicolor reduced numbers of ascospores by 33 27 15 and 28 respectively compared to the nofungus control When combined with urea the Chaetomium isolate reduced ascospore numbers by 92 and 82 compared to the nil fungus/water control treatments in Hawkes Bay and Lincoln respectively indicating that this treatment has potential for reducing primary inoculum of apple black spot

scholarly journals Environmental Conditions Associated with Stripe Rust in Kansas Winter Wheat

Plant Disease ◽  
2016 ◽  
Vol 100 (11) ◽  
pp. 2306-2312 ◽  
Author(s):  
B. S. Grabow ◽  
D. A. Shah ◽  
E. D. DeWolf
Keyword(s):  
Soil Moisture ◽  
Winter Wheat ◽  
Stripe Rust ◽  
Yield Loss ◽  
Initial Step ◽  
Disease Forecasting ◽  
Estimation Equations ◽  
Forecasting System ◽  
Moisture Conditions ◽  
General Estimation

Stripe rust has reemerged as a problematic disease in Kansas wheat. However, there are no stripe rust forecasting models specific to Kansas wheat production. Our objective was to identify environmental variables associated with stripe rust epidemics in Kansas winter wheat as an initial step in the longer-term goal of developing predictive models for stripe rust to be used within the state. Mean yield loss due to stripe rust on susceptible varieties was estimated from 1999 to 2012 for each of the nine Kansas crop reporting districts (CRD). A CRD was classified as having experienced a stripe rust epidemic when yield loss due to the disease equaled or exceeded 1%, and a nonepidemic otherwise. Epidemics were further classified as having been moderate or severe if yield loss was 1 to 14% or greater than 14%, respectively. The binary epidemic categorizations were linked to a matrix of 847 variables representing monthly meteorological and soil moisture conditions. Classification trees were used to select variables associated with stripe rust epidemic occurrence and severity (conditional on an epidemic having occurred). Selected variables were evaluated as predictors of stripe rust epidemics within a general estimation equations framework. The occurrence of epidemics within CRD was linked to soil moisture during the fall and winter months. In the spring, severe epidemics were linked to optimal (7 to 12°C) temperatures. Simple environmentally based stripe rust models at the CRD level may be combined with field-level disease observations and an understanding of varietal reaction to stripe rust as part of an operational disease forecasting system in Kansas.

The control of apple scab (Venturia inaequalis) with some recently developed fungicides

1964 ◽  
Vol 4 (12) ◽  
pp. 55
Author(s):  
J Kuiper ◽  
BS Janes
Keyword(s):  
Venturia Inaequalis ◽  
Apple Scab ◽  
Black Spot ◽  
Field Trials ◽  
The Other ◽  
Single Trial

In field trials, dodine (n-dodecylguanidine acetate) controlled apple scab or black spot, Venturia inaequalis (Cke.) Wint., more effectively than several other fungicides at commonly used concentrations. The other fungicides in decreasing order of effectiveness were :-glyodin (2-heptadecyl-2-imidazoline acetate), thiram (tetramethylthiuram disulphide) and tecoram (bis-(dimethyldithiocarbamoyl)-ethylenebisdithiocarbamate). In a single trial, glyodin was superior to 2-heptadecyl-2-imidazoline. No phytotoxicity was observed in the trials.

Managing Powdery Mildew of Cherry in Washington Orchards and Nurseries with Spray Oils

2000 ◽  
Vol 1 (1) ◽  
pp. 2 ◽  
Author(s):  
G. G. Grove ◽  
R. J. Boal ◽  
L. H. Bennett
Keyword(s):  
Powdery Mildew ◽  
Disease Control ◽  
Sweet Cherry ◽  
Primary Concern ◽  
Disease Forecasting ◽  
Development Of Resistance ◽  
Dmi Fungicides ◽  
Forecasting System ◽  
Serious Disease ◽  
Eastern Washington

Powdery mildew of sweet cherry is the most serious disease in irrigated orchards and nurseries of Washington. The fungus infects foliage and fruit, but fruit infections are of primary concern due to the potential for rejection of entire crops. Development of resistance to demethylation inhibiting (DMI) fungicides in the mid-1990s increased the difficulty in controlling this disease. Orchard mildew management programs that utilize oils, DMI and strobilurin fungicides have been developed for use in eastern Washington. A growth stage (phenology)/calendar-based program provides excellent disease control, utilizes three fungicidal modes of action, and minimizes oil-induced fruit and foliar phytotoxicity by limiting oil use to no later than the pit hardening stage. A second approach that utilizes oils in a temperature-based disease forecasting system provides excellent disease control with fewer fungicide applications. Accepted for publication 19 July 2000. Published 28 July 2000.

Race Determination of Nine Australian Isolates of the Apple Black Spot Fungus Venturia Inaequalis.

1991 ◽  
Vol 20 (4) ◽  
pp. 139 ◽  
Author(s):  
JB Heaton ◽  
SR Dullahide ◽  
LB Baxter ◽  
AD Mcwaters
Keyword(s):  
Venturia Inaequalis ◽  
Black Spot
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