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

1977 ◽  
Vol 20 (3) ◽  
pp. 225-229 ◽  
Author(s):  
A. H. McIntosh
Keyword(s):  
Common Scab ◽  
Field Trials ◽  
Soil Treatment

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

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.

Influence of growth regulators on skin colour and scab diseases of red-skinned potatoes

2010 ◽  
Vol 90 (5) ◽  
pp. 745-753 ◽  
Author(s):  
D. Waterer
Keyword(s):  
Abscisic Acid ◽  
Growth Regulators ◽  
Common Scab ◽  
Foliar Application ◽  
Colour Change ◽  
Field Trials ◽  
Streptomyces Scabies ◽  
Powdery Scab ◽  
Skin Colour ◽  
Spongospora Subterranea

A uniform dark red skin colour is desirable in table potatoes; however, the colour of the popular red-skinned cultivar Norland is variable and tends to fade during storage. This study evaluated the potential to enhance skin colour of red potatoes by foliar application of the auxin-type herbicide 2,4-D or long-lasting analogs of the naturally occuring hormone abscisic acid (ABA). In field trials conducted from 2007 to 2009, the plant growth regulators (PGR) were applied to the foliage of Norland and AC Peregrine Red (a new dark red variety) potato plants when the crop was at the tuber set stage. Although the 2,4-D treatments altered the appearance of the foliage they had no consistent impact on yields or tuber shape, but did reduce the average tuber size. Objective and subjective assessments indicated that the 2,4-D treatments altered the skin colour of the tubers both immediately after harvest and after extended cold storage. The degree and nature of the colour change was somewhat dependent on the year, the rate of 2,4-D applied and the cultivar. The change in tuber appearance arising from the 2,4-D treatments was not always considered desirable by consumer panellists. The 2,4-D treatments also reduced tuber damage by common scab (Streptomyces scabies), but tended to increase grade out to powdery scab (Spongospora subterranea). The ABA analogs had no consistent impact on yields, skin colour or disease reaction. Key words: 2,4-dichlorophenoxyacetic acid, abscisic acid, common scab, powdery scab, Streptomyces scabies, Spongospora subterranea

scholarly journals Soil Fumigation and Runner Plant Production: A Synthesis of Four Years of Strawberry Nursery Field Trials

HortScience ◽  
2000 ◽  
Vol 35 (4) ◽  
pp. 642-646 ◽  
Author(s):  
Kirk D. Larson ◽  
Douglas V. Shaw
Keyword(s):  
Field Trials ◽  
Soil Fumigation ◽  
Soil Treatment ◽  
Plant Production ◽  
Soil Productivity ◽  
Fragaria Ananassa ◽  
Planting Stock ◽  
Treated Soil ◽  
Meta Analyses ◽  
Nursery Field

Strawberry (Fragaria ×ananassa L.) runner plant production during a 4-year period was compared on nursery soils treated with methyl bromide (MB) and chloropicrin (CP) mixtures (MB:CP) and three alternative soil treatments: CP, mixtures of 1,3-dichloropropene (Telone®) and CP (DP:CP), and no fumigation (NF). The effect of soil treatment on runner plant production for a single nursery propagation cycle was determined in all 4 years. In 2 years, runner production in a final propagation cycle was also determined as a function of soil treatment in previous cycles. A single propagation cycle in NF soil decreased runner production relative to all other treatments. Treatments with CP at rates of 140 to 191 kg·ha–1 generally decreased runner production significantly (P ≤ 0.05) in comparison with treatment with MB:CP; use of CP at rates ≥303 kg·ha–1 resulted in statistically equivalent runner production. In one trial, use of two DP:CP formulations (516 kg·ha–1 of a 7:3 DP:CP mixture, and 448 kg·ha–1 of a 3:7 DP:CP mixture) significantly reduced and did not affect runner production, respectively, relative to the use of MB:CP. Use of MB:CP in the previous propagation cycle also increased runner productivity in comparison with NF. Runner productivity of planting stock produced with 314 kg·ha–1 of CP did not differ statistically from that of stock produced with MB:CP, but productivity of planting stock on soil treated with 157 kg·ha–1 of CP was intermediate between that on NF and MB:CP-treated soil. Planting stock grown on nontreated soil in two previous propagation cycles produced 25% fewer runner plants than did similar stock grown on MB:CP-treated soil. Productivity of planting stock produced with CP at rates of 280 to 314 kg·ha–1 in two previous propagation cycles did not differ statistically from that of stock produced with MB:CP. Results of meta-analyses indicated that fumigation with MB:CP was more effective in increasing runner production than was CP or NF, regardless of the propagation cycle or rate of application. For mixtures of 1,3-dichloropropene and CP, nursery productivity was maximized by using at least 280 kg·ha–1 of CP.

scholarly journals A Novel Streptomyces sp. Strain PBSH9 for Controlling Potato Common Scab Caused by Streptomyces galilaeus

Plant Disease ◽  
2020 ◽  
Vol 104 (7) ◽  
pp. 1986-1993
Author(s):  
Xiao-yu Zhang ◽  
Chi Li ◽  
Jian-jun Hao ◽  
Yu-chen Li ◽  
De-zhou Li ◽  
...  
Keyword(s):  
Common Scab ◽  
Inhibition Zone ◽  
Field Trials ◽  
Potential Candidate ◽  
Streptomyces Sp ◽  
Soilborne Disease ◽  
Effective Strategies ◽  
Potato Common Scab ◽  
Multiple Species ◽  
Potato Growth

Potato common scab is an important soilborne disease worldwide that can significantly reduce the quality and economic values of potato. The disease is caused by multiple species of Streptomyces, which are not well controlled due to lack of effective strategies. Streptomyces galilaeus has been recently identified as a dominant species causing potato common scab in Inner Mongolia, China. This study was focused on screening and characterizing antagonists for biological control against pathogenic S. galilaeus. Bacterial strain PBSH9 was isolated from a potato tuber. PBSH9 was identified as a Streptomyces sp. on the basis of morphological, physiological, and biochemical characteristics, as well as DNA sequence analysis. PBSH9 inhibited S. galilaeus with a diameter of inhibitory zone of 19.8 mm on agar plates. The extracellular filtrate of PBSH9 also inhibited S. galilaeus growth with a diameter of inhibition zone of 10.0 mm. Furthermore, PBSH9 promoted potato sprouting and emergence. Disease control was up to 81.88% in greenhouse trials, and from 47.64 to 73.97% in 3-year field trials. Among the tested inoculation methods, seed treatment was more effective than soil drenching for PBSH9 application. PBSH9 not only effectively controlled potato common scab but also increased potato growth. Thus, it can be a potential candidate for biocontrol agent.

scholarly journals Stable and Extreme Resistance to Common Scab of Potato Obtained Through Somatic Cell Selection

2010 ◽  
Vol 100 (5) ◽  
pp. 460-467 ◽  
Author(s):  
Calum R. Wilson ◽  
Robert S. Tegg ◽  
Annabel J. Wilson ◽  
Gregory A. Luckman ◽  
Alieta Eyles ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Somatic Cell ◽  
Common Scab ◽  
Disease Incidence ◽  
Field Trials ◽  
Cell Selection ◽  
Extreme Resistance ◽  
Genetic Changes ◽  
Thaxtomin A ◽  
Disease Resistant

Somatic cell selection with thaxtomin A as a positive selection agent was used to isolate variants of potato cv. Russet Burbank with strong to extreme resistance to common scab. Glasshouse and field trials identified 51 variants with significantly reduced disease incidence (frequency of infected tubers) and severity (tuber lesion coverage) compared with the parent cultivar. The most promising variants exhibited extreme disease resistance, rarely showing lesions, which were invariably superficial and shallower than those on the parent. Resistance traits were consistently expressed both in 10 glasshouse and two field trials at different locations, with varied inoculum and disease pressure. Disease-resistant variants differed in their response to thaxtomin A in tuber slice bioassays. Of 23 variants tested, 10 showed reduced thaxtomin A susceptibility, with the remaining 13 responding similar to that of the parent. Thus, toxin tolerance was not the only factor responsible for observed disease resistance; however, four of the five most disease-resistant variants had enhanced thaxtomin A tolerance, suggesting that this factor is important in the expression of strong disease resistance. Pathogenicity and toxin tolerance remained stable over a 6-year period, demonstrating that selected phenotypes were robust and genetic changes stable. The majority of disease-resistant variants had tuber yields equivalent to the parent cultivar in glasshouse trials. This suggests that selection for disease resistance was not associated with negative tuber attributes and that certain variants may have commercial merit, worthy of further agronomic testing.

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

1982 ◽  
Vol 25 (4) ◽  
pp. 347-350 ◽  
Author(s):  
A. H. McIntosh ◽  
M. M. Burrell ◽  
J. H. Hawkins
Keyword(s):  
Common Scab ◽  
Field Trials ◽  
Dichlorophenoxyacetic Acid ◽  
Foliar Sprays

scholarly journals Foliar Treatments of 2,4-Dichlorophenoxyacetic Acid for Control of Common Scab in Potato Have Beneficial Effects on Powdery Scab Control

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Hannah Katherine Thompson ◽  
Robert Stephen Tegg ◽  
Ross Corkrey ◽  
Calum Rae Wilson
Keyword(s):  
Common Scab ◽  
Field Trials ◽  
Powdery Scab ◽  
Dichlorophenoxyacetic Acid ◽  
Beneficial Effects ◽  
Pathogen Invasion ◽  
Potato Plants ◽  
Scab Control ◽  
Tuber Disease ◽  
2,4 Dichlorophenoxyacetic Acid

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.

Subtypes of Attention Deficit Hyperactivity Disorder: Evidence From DSM-IV Field Trials

1995 ◽  
Author(s):  
B. B. Lahey ◽  
B. Applegate ◽  
K. McBurnett ◽  
J. Biederman ◽  
L. Greenhill ◽  
...  
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Attention Deficit ◽  
Field Trials ◽  
Hyperactivity Disorder ◽  
Dsm Iv

Designing and Implementing Randomized Field Trials of Interventions in Schools

2007 ◽  
Author(s):  
George Bohrnstedt ◽  
Jeanne Poduska ◽  
Mike Garet ◽  
Sheppard Kellam ◽  
David Myers
Keyword(s):  
Field Trials ◽  
Randomized Field Trials
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