scholarly journals Control of Apple Scab and Cytospora Canker with Paclobutrazol

2012 ◽  
Vol 38 (3) ◽  
pp. 112-116
Author(s):  
Gary Watson ◽  
Karel Jacobs
Keyword(s):  
Disease Control ◽  
Growth Regulation ◽  
Apple Scab ◽  
Canker Disease ◽  
Significant Growth ◽  
Picea Pungens ◽  
The Third ◽  
Moderate Growth ◽  
Canker Development ◽  
Cytospora Canker

Forty Malus ‘Radiant’ crabapples, a variety known to be highly susceptible to apple scab disease, were field-planted then treated three months later with paclobutrazol (PBZ) as a basal drench, at rates of 0, 0.8, 1.6, and 2.4 g a.i./cm caliper. Apple scab was significantly reduced for two years post treatment by all rates of PBZ applied. However, significant growth regulation occurred through the third and final year of the study. Thirty Picea pungens (Colorado spruce) trees in containers were treated with PBZ, applied as a basal drench, at rates of 0, 1.6, and 3.2 g a.i./cm caliper. Cytospora canker development from subsequent branch inoculations was significantly reduced by both PBZ treatment rates and persisted through the end of the two year monitoring period. Cytospora canker disease control with only moderate growth regulation indicates that a PBZ basal drench could be developed into a viable landscape treatment.

scholarly journals Fungal Disease Control in Banana, a Tropical Monocot : Transgenic Plants in the Third World?

1998 ◽  
Vol 79 (4) ◽  
pp. 117 ◽  
Author(s):  
László Sági ◽  
Serge Remy ◽  
Rony Swennen
Keyword(s):  
Transgenic Plants ◽  
Disease Control ◽  
Third World ◽  
Fungal Disease ◽  
The Third ◽  
The Third World

scholarly journals Paclobutrazol Soil Drenches Provide Partial Reductions in Symptoms of Apple Scab of Ornamental Trees and Guignardia Leaf Blotch of Horse Chestnut

2008 ◽  
Vol 26 (2) ◽  
pp. 87-92
Author(s):  
G.C. Percival
Keyword(s):  
Fungal Pathogens ◽  
Growth Regulation ◽  
Venturia Inaequalis ◽  
Apple Scab ◽  
Control Policy ◽  
Leaf Size ◽  
Horse Chestnut ◽  
Leaf Blotch ◽  
Pathogen Control ◽  
Leaf Chlorophyll Fluorescence

Abstract A three year field trial was conducted using established apple (Malus cv. Crown Gold) and horse chestnut (Aesculus hippocastanum L.) to assess the efficacy of paclobutrazol (PBZ) root drenches against the foliar pathogens apple scab (Venturia inaequalis (Cooke) G. Wint.,) and Guignardia leaf blotch (Guignardia aesculi (Peck) VB Stewart). In the case of horse chestnut, pathogen severity of Guignardia leaf blotch was less (23–79%) in each of the three-year experimental periods in PBZ-treated trees compared to non-treated controls. Pathogen severity of apple scab was not affected during the first year after PBZ application; however, less (25–73%) disease severity was recorded in years 2 and 3 compared to non-PBZ treated controls. An increased PBZ concentration was associated with lower pathogen severity of both fungal pathogens. Irrespective of species, less pathogen severity in PBZ-treated trees was accompanied with greater leaf chlorophyll fluorescence (16–49%) values as measures of leaf photosynthetic efficiency. Marked differences in growth regulation between apple cv. Crown Gold (tolerant) and horse chestnut (sensitive) were recorded. PBZ applications resulted in less mean stem extension in both tree species but only reduced mean leaf size of horse chestnut. Based on the results of this investigation it is suggested that PBZ root drenches potentially offer a means of reducing the severity of apple scab and Guignardia leaf blotch for professionals involved with the nursery industry. However, where a zero pathogen control policy is required supplementary fungicide sprays would be needed. Similarly, the potential loss of aesthetics due to excessive growth regulation needs to be weighed against the benefits of pathogen protection and failure of PBZ to achieve total pathogen control may result in strong selection pressure for PBZ resistance in surviving populations.

scholarly journals Systematic Analysis and Functional Validation of Citrus Pectin Acetylesterases (CsPAEs) Reveals that CsPAE2 Negatively Regulates Citrus Bacterial Canker Development

2020 ◽  
Vol 21 (24) ◽  
pp. 9429
Author(s):  
Qiang Li ◽  
Jia Fu ◽  
Xiujuan Qin ◽  
Wen Yang ◽  
Jingjing Qi ◽  
...  
Keyword(s):  
Susceptible Variety ◽  
Resistant Variety ◽  
Potential Candidate ◽  
Bacterial Canker ◽  
Citrus Pectin ◽  
Systematic Analysis ◽  
Canker Disease ◽  
Potential Candidate Gene ◽  
Citrus Bacterial Canker ◽  
Canker Development

The present study was designed to serve as a comprehensive analysis of Citrus sinensis (C. sinensis) pectin acetylesterases (CsPAEs), and to assess the roles of these PAEs involved in the development of citrus bacterial canker (CBC) caused by Xanthomonas citri subsp. citri (Xcc) infection. A total of six CsPAEs were identified in the genome of C. sinensis, with these genes being unevenly distributed across chromosomes 3, 6, and 9, and the unassembled scaffolds. A subset of CsPAEs were found to be involved in responses to Xcc infection. In particular, CsPAE2 was identified to be associated with such infections, as it was upregulated in CBC-susceptible variety Wanjincheng and inversely in CBC-resistant variety Calamondin. Transgenic citrus plants overexpressing CsPAE2 were found to be more susceptible to CBC, whereas the silencing of this gene was sufficient to confer CBC resistance. Together, these findings provide evolutionary insights into and functional information about the CsPAE family. This study also suggests that CsPAE2 is a potential candidate gene that negatively contributes to bacterial canker disease and can be used to breed CBC-resistant citrus plants.

scholarly journals Fusarium spp., Cylindrocarpon spp., and Environmental Stress in the Etiology of a Canker Disease of Cold-Stored Fruit and Nut Tree Seedlings in California

Plant Disease ◽  
2013 ◽  
Vol 97 (2) ◽  
pp. 259-270 ◽  
Author(s):  
Stephen M. Marek ◽  
Mohammad A. Yaghmour ◽  
Richard M. Bostock
Keyword(s):  
Cold Storage ◽  
Signs And Symptoms ◽  
Tissue Loss ◽  
Tree Seedlings ◽  
Canker Disease ◽  
Almond Trees ◽  
Asymptomatic Infections ◽  
Canker Development ◽  
Stem Segments ◽  
Increased Susceptibility

The principal objective of this study was to determine the etiology of a canker disease in dormant stone fruit and apple tree seedlings maintained in refrigerated storage that has significantly impacted California fruit and nut tree nurseries. Signs and symptoms of the disease develop during storage or soon after planting, with subsequent decline and death of young trees. Isolations from both diseased and healthy almond and apple trees and Koch's postulates using stem segments of desiccation-stressed almond trees as hosts implicated Fusarium avenaceum and F. acuminatum as the primary causal agents. F. solani, Ilyonectria robusta, and Cylindrocarpon obtusiusculum were also capable of causing similar symptoms but were less frequently encountered in isolations of diseased tissue. Loss of bark turgidity in excised almond stem segments, as can occur in cold-stored seedlings, correlated with increased susceptibility to F. acuminatum, with maximum canker development occurring after relative bark turgidity dropped below a threshold of approximately 86%. Healthy almond trees, almond scion budwood, and a wheat cover crop used in fields where tree seedlings were grown and maintained until cold storage all possessed asymptomatic infections of F. acuminatum, F. avenaceum, and C. obtusiusculum as determined by activation following overnight freezing, cold storage, or desiccation.

scholarly journals Effects of an Apple Scab-Resistant Cultivar on Use Patterns of Inorganic and Organic Fungicides and Economics of Disease Control

Plant Disease ◽  
1998 ◽  
Vol 82 (4) ◽  
pp. 428-433 ◽  
Author(s):  
M. A. Ellis ◽  
D. C. Ferree ◽  
R. C. Funt ◽  
L. V. Madden
Keyword(s):  
Disease Control ◽  
Apple Scab ◽  
Farm Size ◽  
Total Treatment Cost ◽  
Total Cost ◽  
Use Patterns ◽  
Sooty Blotch ◽  
Scab Control ◽  
Total Treatment ◽  
The Cost

An inorganic (sulfur) and a conventional organic fungicide spray program were evaluated on an apple scab-resistant (Liberty) and a scab-susceptible (McIntosh) cultivar for control of scab and for cost effectiveness. Trees of both cultivars were either nontreated, treated with inorganic fungicides only, or treated with a conventional fungicide program. McIntosh trees received full-season fungicide applications and Liberty trees received only the summer cover sprays (after petal fall) for control of summer diseases. In 1991, the number of fungicide applications ranged from 0 for nontreated Liberty to 12 for the full-schedule inorganic program on McIntosh, with both treatments providing excellent scab control. All nontreated McIntosh fruit were unmarketable due to scab infection. Due to a dry growing season and lack of summer disease development, nontreated Liberty fruit was of high quality. In 1992, the number of fungicide applications ranged from 0 for nontreated Liberty to 14 for the full-schedule inorganic treatment on McIntosh, with both treatments providing good to excellent disease control. Results were very similar in 1993. Scab incidence was low for all treatments except the nonsprayed McIntosh over all years. Over 3 years of testing, the conventional fungicide program resulted in an average of 9 and 5 applications per year for McIntosh and Liberty, respectively, compared to 12.6 and 7 applications, respectively, for the inorganic fungicide program. The large reduction in the number of sprays for both programs was due to the elimination of all pre-petal-fall applications on Liberty; post-petal-fall applications are needed to control summer diseases such as flyspeck and sooty blotch. An economic analysis for total cost of fungicide applications for each spray program and cultivar was conducted for hypothetical 4.0-, 8.1- and 16.2-ha farms. Regardless of farm size, the cost of fungicides per ha varied among treatments and cultivars. The inorganic and conventional spray program for McIntosh had similar total costs. On Liberty, the inorganic and conventional programs had 73 and 57% less total cost, respectively, than on McIntosh. Fungicides for the conventional program on Liberty were 1.45 times more costly per ha than fungicides in the inorganic program, but the inorganic program required more applications, resulting in a small difference in total treatment cost per ha.

scholarly journals Can phosphorous acid be used to control Neonectria ditissima in New Zealand grown apples?

2019 ◽  
Vol 72 ◽  
pp. 117-122
Author(s):  
Jason Smith ◽  
Monika Walter ◽  
Rebecca E. Campbell ◽  
Lauren Turner
Keyword(s):  
New Zealand ◽  
Disease Control ◽  
Apple Tree ◽  
Phosphorous Acid ◽  
Symptom Expression ◽  
Apple Trees ◽  
Leaf Scar ◽  
Tree Disease ◽  
Control Option ◽  
Canker Development

European canker, Neonectria ditissima, is a worldwide apple tree disease killing shoots, branches and trees, and treatment with phosphorous acid is a possible control option. The effect of six postharvest phosphorous acid (PA) treatments on fruit residues the following season was studied in Tasman on two trial sites growing ‘Scifresh’ or ‘Scilate’ apple trees. Spray treatments consisted of number (0–3) and timing (early, mid and/or late) of PA applications. Additionally, leaf-scar wounds were artificially inoculated with N. ditissima spores at the ‘Scilate’ site on 1 and 8 June 2017 to determine disease control. Symptom expression was checked regularly between October 2017 and February 2018. None of the treatments caused a statistically significant reduction in the incidence of canker development compared with the control. Two or more PA applications resulted in PA residues in fruit, at harvest, the following season. Higher PA residues were found in fruit following early applications than with late applications. More applications of PA resulted in higher residues. This finding has important implications for exporting fruit to markets that have no tolerance for PA residues.

scholarly journals EU financial accounts reports

10.5912/jcb96 ◽  
2004 ◽  
Vol 10 (4) ◽  
Author(s):  
Colin Aaronson
Keyword(s):  
Research And Development ◽  
Disease Control ◽  
Smallpox Vaccine ◽  
Biotechnology Company ◽  
Stages Of Development ◽  
The Third ◽  
The Us ◽  
Development Expenditure ◽  
Control And Prevention ◽  
Centers For Disease Control

Acambis is a profitable and cash-generative biotechnology company that is focused on building a substantial franchise in the vaccine space. Its results for the period have benefited significantly from its contract to supply 155 million doses of its ACAM2000 smallpox vaccine to the US Centers for Disease Control and Prevention (CDC). During the year ended 31st December, 2003, Acambis generated profit before taxation (before exceptional items) of £46.8m on sales of £169.1m compared with a profit of £9.6m on sales of £79.7m for the whole of 2002. The pre-tax profit for the year was £39.4m, after taking account of an exceptional cost of £7.4m following a settlement with BTG International Limited to discharge all rights and obligations under a technology licence agreement established in 1994. The profit was earned mainly in the third quarter, with £22.2m earned during the three months ended 30th September, 2003, the company having earned £20.6m for the six months ended 30th June, 2003. Research and development expenditure increased from £16.5m in 2002 to £19.1m in 2003, the result of the progression of the company's products to the later stages of development.

Field evaluation of a derivative of 1,4-oxathiin for control of cereal smuts

1968 ◽  
Vol 8 (35) ◽  
pp. 756 ◽  
Author(s):  
J Kuiper
Keyword(s):  
Disease Control ◽  
Field Evaluation ◽  
Field Trials ◽  
Loose Smut ◽  
Common Bunt ◽  
The Third ◽  
Excellent Control ◽  
Cereal Seed ◽  
Better Than ◽  
Commercial Field

In semi-commercial field trials, the systemic cereal seed fungicide Vitavax (2,3-dihydro-5- carboxanilido-6-methyl-1,4-oxathiin) gave excellent control of natural loose smut infections of wheat and barley; combining it with phenylmercuric acetate reduced its efficacy on loose smut of wheat. In an irrigated row-plot trial, using wheat artificially inoculated with loose smut, Vitavax at the recommended rate was only moderately effective ; at half rate disease control was unsatisfactory. Vitavax was tested on three collections of common bunt of wheat. On all three it was better than Ceresan. It was inferior to hexachlorobenzene on two collections, but on the third, resistant to hexachlorobenzene, it was much superior. Vitavax gave excellent control of covered smut of oats whereas Panogen and Ceresan were much less effective.

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