Field trials of foliar sprays of 3,5-dichlorophenoxyacetic acid (3,5-D) against common scab on potatoes

Prior studies have shown that applications of the synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D) to the foliage of potato plants can reduce common scab. Here field and glasshouse trials suggest that 2,4-D foliar treatments may also reduce the biologically distinct tuber disease, powdery scab. Significant correlations between suppression of common and powdery scab from the field trials suggested an interaction between the two diseases or possible additional broad spectrum mechanisms of enhanced defence against pathogen invasion provided by 2,4-D treatment.

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Field trials of chemicals for control of common scab by soil treatment

Potato Research ◽

10.1007/bf02418683 ◽

1977 ◽

Vol 20 (3) ◽

pp. 225-229 ◽

Cited By ~ 2

Author(s):

A. H. McIntosh

Keyword(s):

Common Scab ◽

Field Trials ◽

Soil Treatment

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FIELD MEASUREMENT OF DROPLET DRIFT FROM GROUND SPRAYERS. I. SAMPLING, ANALYTICAL, AND DATA INTEGRATION TECHNIQUES

Canadian Journal of Plant Science ◽

10.4141/cjps78-096 ◽

1978 ◽

Vol 58 (3) ◽

pp. 611-622 ◽

Cited By ~ 25

Author(s):

R. GROVER ◽

L. A. KERR ◽

J. MAYBANK ◽

K. YOSHIDA

Keyword(s):

Meteorological Parameters ◽

Field Trials ◽

Application Rate ◽

Meteorological Station ◽

Dichlorophenoxyacetic Acid ◽

Target Area ◽

Spray Solution ◽

Integration Techniques ◽

Actual Field ◽

2,4 Dichlorophenoxyacetic Acid

A procedure for the evaluation of ground deposits and droplet drift characteristics from a typical farm sprayer under actual field conditions is described. It involves sampling both the ground deposits on the swath and the air-borne cloud mass, the latter at various heights and distances downwind from the target area. The system was evaluated with the commonly used 65° flat-fan nozzles operated at 280 kPa which provided an application rate of 0.56 kg/ha of 2,4-D amine (2,4-dichlorophenoxyacetic acid) in 56 ℓ water/ha. The spray solution also contained a fluorescent dye as a tracer. A portable meteorological station, where a number of meteorological parameters can be measured or recorded during the course of a field trial, is also described. Results of four field trials are presented with discussion regarding on-swath deposit density and its distribution over the swath, off-swath drifting cloud mass and its deposition and decay as a function of distance, and mass balance.

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Relationship Between the Application of Foliar Chemicals to Reduce Common Scab Disease of Potato and Correlation with Thaxtomin A Toxicity

Plant Disease ◽

10.1094/pdis-05-11-0397 ◽

2012 ◽

Vol 96 (1) ◽

pp. 97-103 ◽

Cited By ~ 10

Author(s):

Robert S. Tegg ◽

Ross Corkrey ◽

Calum R. Wilson

Keyword(s):

Measurement Error ◽

Common Scab ◽

Russet Burbank Potato ◽

Disease Suppression ◽

Tuber Initiation ◽

Strongly Correlated ◽

Symptom Development ◽

Thaxtomin A ◽

Foliar Sprays ◽

Streptomyces Spp

Production of the phytotoxin thaxtomin A by pathogenic Streptomyces spp. is essential for induction of common scab disease in potato. The disease can be significantly reduced by a range of chemicals applied as foliar sprays before tuber initiation. We tested a range of chemicals that had previously demonstrated varying capacities to reduce common scab for both disease suppression and their ability to inhibit thaxtomin A toxicity in both ‘Desiree’ and ‘Russet Burbank’ potato. Our results for disease suppression generally supported previous studies. Our tuber slice assays with thaxtomin A showed a strong correlation between the ability of the chemical to suppress common scab symptom development and the ability of the chemical to inhibit thaxtomin A toxicity. A Bayesian measurement error linear regression model was derived for each cultivar and trial and demonstrated a clear positive relationship between disease and thaxtomin-A-induced necrosis. The relationships obtained were much stronger than would have been obtained without adjustment for measurement error. This demonstrates that disease mitigation using chemical foliar sprays is strongly correlated with the ability of the chemical to inhibit thaxtomin A toxicity, suggesting this mechanism as a key mode of action for understanding this novel disease control strategy.

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Effects of foliar sprays of daminozide on the incidence of potato common scab

Annals of Applied Biology ◽

10.1111/j.1744-7348.1979.tb02955.x ◽

1979 ◽

Vol 92 (1) ◽

pp. 29-38 ◽

Cited By ~ 6

Author(s):

A. H. MCINTOSH ◽

G. L. BATEMAN

Keyword(s):

Common Scab ◽

Foliar Sprays ◽

Potato Common Scab

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Dehydrated pork manure by-product: effect of a chitosan amendment on bacterial community and common scab incidence

Phytoprotection ◽

10.7202/045779ar ◽

2011 ◽

Vol 90 (3) ◽

pp. 107-115

Author(s):

Julie Roy ◽

Pierre J. Lafontaine ◽

Rock Chabot ◽

Carole Beaulieu

Keyword(s):

Bacterial Community ◽

16S Rrna ◽

16S Rrna Gene ◽

Seed Treatment ◽

Common Scab ◽

Disease Incidence ◽

Anaerobic Bacteria ◽

Field Trials ◽

Potato Seed ◽

Rrna Gene

Chitosan amendment modified the composition of a microbial community associated with dehydrated pork manure by-product. The amended product (biosolid PC) contained a lower number of anaerobic bacteria than the non-amended product (biosolid P). Chitosan also significantly reduced the fungal population. A 16S rRNA gene bank constructed from DNA extracted from the bacterial community associated with both P and PC biosolids revealed that bacterial ordersXanthomonodales,Pseudomonadales,Enterobacteriales,Burkholderiales,Actinomycetales,Bacillales,ClostridialesandLactobacillaleswere found in both biosolids. Bacteria from theStenotrophomonasgenus were abundant in both biosolids. However, the addition of chitosan appeared to induce changes in the population of some bacterial genera. For example, clones carrying a 16S rRNA gene corresponding to theBacillusgenus were doubled in biosolid PC. In field trials carried out to test their effect on common scab incidence, biosolids P and PC were applied as potato seed treatment. Biosolid P increased disease incidence by a factor of 1.33 and 2.85 in two independent experiments. However, when chitosan was added to the seed treatment, the stimulating effect of biosolid P on common scab was cancelled out.

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Response of Woody Species to 2,4-D, 2,4,5-T, and Picloram as a Function of Treatment Method

Weed Science ◽

10.1017/s004317450003085x ◽

1969 ◽

Vol 17 (1) ◽

pp. 40-46 ◽

Cited By ~ 6

Author(s):

H. D. Coble ◽

R. P. Upchurch ◽

J. A. Keaton

Keyword(s):

Propylene Glycol ◽

Woody Species ◽

Treatment Method ◽

Dichlorophenoxyacetic Acid ◽

Butyl Ether ◽

Shoot Height ◽

White Ash ◽

Foliar Sprays ◽

2,4 Dichlorophenoxyacetic Acid ◽

Ether Ester

Naturally-established individual specimens of 12 woody plant species occurring in North Carolina were treated with foliar, dormant stem, and basal applications of the propylene glycol butyl ether ester formulation of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), the propylene glycol butyl ether ester of 2,4-dichlorophenoxyacetic acid (2,4-D), and the potassium salt of 4-amino-3,5,6-trichloropicolinic acid (picloram). The triethanolamine salt of 2,4,5-T also was applied as a foliar treatment. Three rates of each herbicide were used. Responses measured were percent control of original shoots, percent regrowth, shoot height, and number of live stems per plant. No differences were observed between the amine and ester formulations of 2,4,5-T applied as foliar sprays except on rhododendron (Rhododendron maximum L.) where the ester produced 86% control compared to 28% for the amine salt. Foliar sprays of picloram were effective in controlling all species except white ash (Fraxinus americana L.), sweet gum (Liquidambar styraciflua L.), sweet bay (Magnolia virginiana L.), and rhododendron. Control of these species averaged only 45% compared to 96% on all other species studied. No species was effectively controlled by dormant stem or basal applications of picloram. All species considered, the propylene glycol butyl ether ester of 2,4,5-T applied as a dormant stem or basal application provided the most consistent results, giving 89% and 91% control, respectively.

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Organic materials applied as seed treatments or foliar sprays fail to increase grain yield of wheat

Australian Journal of Experimental Agriculture ◽

10.1071/ea9860367 ◽

1986 ◽

Vol 26 (3) ◽

pp. 367 ◽

Cited By ~ 5

Author(s):

DJ Miers ◽

MW Perry

Keyword(s):

Grain Yield ◽

Crop Production ◽

Organic Materials ◽

Wheat Yield ◽

Field Trials ◽

Cereal Crops ◽

Seed Treatments ◽

Foliar Sprays ◽

Commercial Cultivation ◽

Application Rates

Organic materials derived from fish, seaweed or bacterial cultures, and being sold as 'natural' aids to crop production, were tested for their effects on wheat yield in Western Australia. Six products based on seaweed (Seasol powder and liquid, Kelpak 66), fish (Eco, 10.8.8, Crop Booster) or bacterial culture (Cytozyme Seed Plus), and Complesal, an inorganic nutrient spray, were tested as seed treatments or foliar sprays. Thirty-two replicated field trials (plot size 100 m2) were conducted over 3 years using recommended rates of fertiliser and 'commercial' weed and pest control practices. No statistically significant increases in grain yield were detected from the use of any product in any trial. Average treatment grain yields in 18 trials in 1982 ranged from 99.4 to 10 1.2% of the control and in 12 trials in 1983 from 96.2 to 99.3% of the control. The results give no indication that, at the application rates used, organic materials applied as seed dressings or foliar sprays can increase the grain yield of cereal crops in commercial cultivation.

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