The Influence of Inducing Agents Applied by Soil Drenches on Disease Severity of Apple and Pear Scab

2020 ◽  
Vol 46 (5) ◽  
pp. 358-370
Author(s):  
Glynn Percival
Keyword(s):  
Field Trials ◽  
Preventative Measure ◽  
Leaf Chlorophyll ◽  
Limited Efficacy ◽  
Pear Scab ◽  
Scab Control ◽  
Potassium Phosphite ◽  
Pear Trees ◽  
The Uk ◽  
Inducing Resistance

Apple and pear scab are foliar diseases of ornamental and fruiting apple and pear trees. Unmanaged, yield and aesthetic losses can be severe. Overreliance on synthetic fungicides means novel means of disease management are required. Field trials were conducted using apple (Malus cv. Crown Gold) and pear (Pyrus communis ‘Williams Bon Chrétien’) to assess the efficacy of a range of commercially available inducing resistance (IR) agents (harpin protein, potassium phosphite, salicylic acid derivative, and chitosan) as root drenches against both scab diseases. A synthetic fungicide (penconazole) spray program used within the UK for apple and pear scab control was included for comparison. Each IR agent was applied four times, (i) before the visible appearance of scab (April through June, i.e., preventatively) or (ii) after symptoms of scab were visibly observed (June through August, i.e., curatively). Limited efficacy as scab protectants was demonstrated when IR agents were applied curatively. Likewise, limited efficacy was recorded when IR agents were applied once or twice as a preventative measure. However, when IR agents were applied as root drenches greater or equal to three times, efficacy as scab protectants was confirmed (increased leaf chlorophyll content, increased fruit yield, reduced leaf and fruit scab severity). A synthetic fungicide penconazole spray program provided the greatest protection against apple and pear scab in all trials when sprayed preventatively rather than curatively. Results suggest application of at least three root drenches from April through June with an appropriate IR agent provides a useful addition to existing methods of apple and pear scab management under field conditions.

Evaluation of Electrolysed Oxidizing Water for European Pear Rust Management on Pear (Pyrus cv. Conference)

2021 ◽  
Vol 47 (3) ◽  
pp. 116-122
Author(s):  
Glynn Percival
Keyword(s):  
Leaf Rust ◽  
Chlorophyll Content ◽  
Field Trials ◽  
Field Conditions ◽  
Compound A ◽  
Leaf Chlorophyll ◽  
Foliar Pathogen ◽  
Rust Severity ◽  
Pear Trees ◽  
Foliar Pathogens

Pear rust is a foliar pathogen of ornamental and fruiting pear trees. Unmanaged, yield and aesthetic losses can be severe. Over-reliance on synthetic fungicides means novel means of pathogen management are required. Field trials were conducted using pear (Pyrus cv. Conference) to assess the efficacy of electrolysed oxidizing water (EO water) as a rust protective compound. A synthetic fungicide (boscalid + pyraclostrobin) spray program used for pear rust management was included for comparison. Each treatment was applied 4 times prior to the visible appearance of rust (April through June, i.e., preventatively). Studies were conducted in 2017 and repeated in 2018. Efficacy of EO water as a rust protectant compound was confirmed (increased leaf chlorophyll content, reduced leaf rust incidence and severity). The degree of leaf rust severity protection conferred was not statistically different from a boscalid + pyraclostrobin spray program. Results suggest 4 spray applications of EO water provides a useful addition to existing methods of pear rust management under field conditions that may have applicability against other foliar pathogens.

scholarly journals Improving a pest management tool for scenario analysis of economic populations of Globodera pallida

Nematology ◽  
2021 ◽  
pp. 1-11
Author(s):  
Ann-Kristin Koehler ◽  
Christopher A. Bell ◽  
Matthew A. Back ◽  
Peter E. Urwin ◽  
Howard J. Atkinson
Keyword(s):  
Scenario Analysis ◽  
Yield Loss ◽  
Meta Analysis ◽  
Field Trials ◽  
Globodera Pallida ◽  
Management Tool ◽  
Analysis Tool ◽  
The Individual ◽  
The Uk ◽  
Annual Decline

Summary Globodera pallida is the most damaging pest of potato in the UK. This work underpins enhancement of a well-established, web-based scenario analysis tool for its management by recommending additions and modifications of its required inputs and a change in the basis of yield loss estimates. The required annual decline rate of the dormant egg population is determined at the individual field sample level to help define the required rotation length by comparing the viable egg content of recovered cysts to that of newly formed cysts for the same projected area. The mean annual decline was 20.4 ± 1.4% but ranged from 4.0 to 39.7% annum−1 at the field level. Further changes were based on meta-analysis of previous field trials. Spring rainfall in the region where a field is located and cultivar tolerance influence yield loss. Tolerance has proved difficult to define for many UK potato cultivars in field trials but uncertainty can be avoided without detriment by replacing it with determinacy integers. They are already determined to support optimisation of nitrogen application rates. Multiple linear regression estimates that loss caused by pre-plant populations of up to 20 viable eggs (g soil)−1 varies from ca 0.2 to 2.0% (viable egg)−1 (g soil)−1 depending on cultivar determinacy and spring rainfall. Reliability of the outcomes from scenario analysis requires validation in field trials with population densities over which planting is advisable.

scholarly journals Controlling Brown Spot of Pear by a Synthetic Antimicrobial Peptide Under Field Conditions

Plant Disease ◽  
2015 ◽  
Vol 99 (12) ◽  
pp. 1816-1822 ◽  
Author(s):  
Mireia Puig ◽  
Concepció Moragrega ◽  
Lídia Ruz ◽  
Emilio Montesinos ◽  
Isidre Llorente
Keyword(s):  
Fungicidal Activity ◽  
Field Trials ◽  
Control Measures ◽  
Field Conditions ◽  
Brown Spot ◽  
Potted Plants ◽  
Detached Leaf ◽  
Brown Spot Disease ◽  
Pear Trees

Brown spot of pear, caused by Stemphylium vesicarium, is a fungal disease of increasing importance in several pear-growing areas of Europe. Disease control measures include the application of fungicides and sanitation methods. Antimicrobial peptides may be a complement or alternative to conventional fungicides used to manage brown spot disease. In a previous study, the synthetic peptide BP15 showed postinfection fungicidal activity against S. vesicarium in in vitro and detached-leaf assays. In the present study, the efficacy of BP15 (KKLFKKILKVL-NH2) in controlling brown spot of pear was evaluated under field conditions using potted plants and pear trees in orchards. In field trials, the treatments with BP15 or with the fungicide thiram were scheduled according to the infection risk predicted by the BSPcast model. Potted pear plants treated with BP15 showed a disease reduction of about 42 to 60% in five of seven trials. In three of four tree trials, the disease severity on shoots treated with BP15 was significantly lower than in the nontreated controls, with a mean efficacy of 38.2%. It was concluded that BP15 is a good candidate to be further developed as a fungicide for controlling brown spot of pear.

The significance of proleg disruption by chlordimeform to sublethal control of larvae of Pieris brassicae (L.) (Lepidoptera: Pieridae) in the field

1988 ◽  
Vol 78 (4) ◽  
pp. 613-621 ◽  
Author(s):  
Alison Blackwell
Keyword(s):  
Control Mechanism ◽  
Field Trials ◽  
Pieris Brassicae ◽  
Initial Population ◽  
Behavioural Symptoms ◽  
Delayed Effects ◽  
Lepidopteran Larvae ◽  
Effect Of Treatment ◽  
Sublethal Doses ◽  
The Uk

AbstractThe results of field trials in the UK are reported, investigating the hypothesis that the disruption of proleg clasping in lepidopteran larvae by sublethal doses of the formamidine pesticide chlordimeform contributes significantly to a control mechanism. Pieris brassicae (L.) was used as a model pest. Topically dosed third-instar larvae, placed on cabbage plants, became excited and many fell. Although the behavioural symptoms were reversible within 24 h, fallen larvae rarely re-established themselves on the plants. The ED50 halving the initial population was similar to the ED50 for proleg disruption, emphasizing the importance of the latter as a major cause of the former. Arthropod or bird predation was not shown to increase following chlordimeform treatment. However, inclement weather did enhance the detaching effect of treatment and also its delayed effects on larval development and survival.

scholarly journals Effects of Foliar Sulfur Sprays on Pecan Independent of Pecan Scab Control

HortScience ◽  
2014 ◽  
Vol 49 (4) ◽  
pp. 434-437 ◽  
Author(s):  
Lenny Wells ◽  
Jason Brock ◽  
Tim Brenneman
Keyword(s):  
Foliar Application ◽  
Leaf Tissue ◽  
Leaf Chlorophyll ◽  
Scab Control ◽  
Pecan Scab ◽  
Chlorophyll Index ◽  
S Application ◽  
Tissue Nitrogen ◽  
Foliar S ◽  
Foliar Urea

Many commercial pecan [Carya illinoinensis (Wangenh.) K. Koch] producers routinely spray foliar urea and sulfur (S) in combination with their fungicide sprays, despite very little information available in the scientific literature regarding the effects of these practices on pecan production. The objectives of this study were to investigate the effects of foliar application of elemental S and urea, alone and in combination, on pecan leaf tissue nitrogen (N) and S concentration, pecan nut quality, leaf chlorophyll index (LCI), and pecan scab control. Foliar S sprays increased pecan nut weight over the control in 2 of 3 years of study. Pecan nut weight was unaffected by foliar urea sprays compared with the control, but nut weight was lower for foliar urea sprays compared with foliar S sprays in the first 2 years of study. Neither foliar S nor urea sprays affected pecan scab incidence or severity. Foliar S sprays failed to increase leaf S concentration throughout the study. Pecan leaf N and leaf S concentrations were lower in the foliar urea treatment than in the control and foliar S treatments during the initial year of study; however, no treatment differences were observed for urea after Year 1. Foliar S application enhanced LCI in 2011 and 2012. Leaf chlorophyll index was also increased by the combination of foliar urea and S in 2012. These results suggest that foliar S sprays may provide pecan producers with a tool with which to maximize nut size and increase the profitability of their crop.

scholarly journals Hygienic rationing of flupyradifurone and justification of safe use regulations of flupyradifurone-based insecticide to protect vineyards, apple, pear trees and cabbage

2019 ◽  
Vol 87 (3) ◽  
pp. 5-17
Author(s):  
O.P. Kravchuk ◽  
V.I. Medvedev ◽  
P.G. Zhminko ◽  
A.P. Grinko ◽  
S.G. Serheiev ◽  
...  
Keyword(s):  
Developmental Toxicity ◽  
Daily Intake ◽  
Field Trials ◽  
Population Exposure ◽  
Long Term Effects ◽  
Hazard Class ◽  
Environmental Objects ◽  
Standards And Regulations ◽  
Pear Trees ◽  
State Registration

ABSTRACT. Flupyradifurone is an insecticide recommended to protect vineyards, apple, pear trees and cabbage in agriculture. For the state registration in Ukraine, toxicological and hygienic assessment of flupyradifurone and its insecticidal product Sivanto Prime 200 SL was performed. Acceptable daily intake of flupyradifurone for human was justified at the level of 0.02 mg/kg; hygienic standards for flupyradifurone and regulations for the safe use of insecticide Sivanto Prime 200 SL, in agriculture were developed. Objective. Toxicological and hygienic assessment of flupyradifurone and its insecticidal preparation, evaluation of the risk of rural labourers and population exposure. Methods. Expert and analytical, toxicological, physical and chemical, statistical and hygienic. Results. Based on acute toxicity parameters for different ways of exposure, flupyradifurone and Sivanto Prime 200 SL are rated as hazard class II. Long-term effects (carcinogenicity, mutagenicity and teratogenicity, reproductive and developmental toxicity) are not limiting criteria when assessing flupyradifurone hazard. Field trials have shown that residual flupyradifurone was not detectable in grapes, apples, pears and cabbage during harvesting. Occupational risk degree under inhalation and cutaneous exposure of labours to flupyradifurone was within the acceptable level. Conclusion. Use of flupyradifurone-based insecticide Sivanto Prime 200 SL for the protection of vineyards, apple, pear trees and cabbage as per agricultural and hygienic standards and regulations will not lead to contamination of agricultural products and environmental objects and will be safe for the population. Keywords: insecticide, flupyradifurone, toxicological properties, hygienic standards and regulations, hazard assessment.

scholarly journals Graft incompatibility in Prunus spp. preceded by SPAD index reduction

2017 ◽  
Vol 38 (2) ◽  
pp. 635 ◽  
Author(s):  
Tainá Rodrigues das Neves ◽  
Newton Alex Mayer ◽  
Bernardo Ueno
Keyword(s):  
No Reduction ◽  
Field Trials ◽  
The Other ◽  
Single Plant ◽  
Index Reduction ◽  
Leaf Chlorophyll ◽  
Chlorophyll Index ◽  
Graft Compatibility ◽  
Graft Incompatibility ◽  
Prunus Spp

This study aimed to measure the leaf chlorophyll index (SPAD 502 Plus) in three peach cultivars grafted on different clonal rootstocks, totaling 68 scion/rootstock combinations, between five and nine months after planting in the field to determine possible graft incompatibility symptoms in Prunus spp. Three field trials with peach scion cultivars ‘BRS-Kampai’, ‘Jade’, and ‘Maciel’ grafted on 18, 25, and 25 clonal rootstocks, respectively, were established in July and August 2014. Own-rooted scion trees (without rootstock) were used as controls in each trial and all rootstocks were propagated from herbaceous cuttings. The experimental design was a randomized block with four replications and each plot consisting of a single plant. Three SPAD measurements were taken between January and April 2015. SPAD index values for rootstocks ‘Mirabolano 29C’ (P. cerasifera) and ‘Marianna 2624’ (P. cerasifera x P. munsoniana) were significantly lower in the three scion cultivars, culminating with tree death from graft incompatibility. Rootstocks ‘Mirabolano 29C’ and ‘Marianna 2624’ showed translocated graft incompatibility with scion cultivars BRS-Kampai, Jade, and Maciel and tree death was preceded by a reduction in SPAD index values five months after field planting. No reduction in SPAD index values was observed in the other scion/rootstock combinations nine months after planting, but these combinations should be monitored for a longer period to confirm their graft compatibility.

scholarly journals Response of Yield, Growth and Iron Deficiency Chlorosis of 'Santa Maria' Pear Trees on Four Rootstocks

2016 ◽  
Vol 44 (2) ◽  
pp. 563-567 ◽  
Author(s):  
Ali IKINCI ◽  
Ibrahim BOLAT ◽  
Sezai ERCISLI ◽  
Ahmet ESITKEN
Keyword(s):  
Titratable Acidity ◽  
Fruit Weight ◽  
Pyrus Communis ◽  
Cumulative Yield ◽  
Cydonia Oblonga ◽  
Iron Deficiency Chlorosis ◽  
Leaf Chlorophyll ◽  
Pyrus Communis L ◽  
Pear Trees ◽  
Santa Maria

This study was conducted on the 'Santa Maria' pear (Pyrus communis L.) budded on various rootstocks [pear seedling (Pyrus communis L.) and quince (Cydonia oblonga Mill.) (BA 29, QA and QC) rootstocks] under calcareous soil and semi-arid conditions during 2004-2012. The results showed that the highest cumulative yield per ha (53.1 t ha-1), fruit weight (304.1 g), fruit volume (337.2 cm³), fruit flesh firmness (22.3 lb.) and titratable acidity (0.21%) was obtained from trees on BA 29 rootstock. The highest SSC (15.8 %), cumulative yield per tree (78.08 kg tree-1), TCSA (79.03 cm²) and the lowest titratable acidity (0.18 %) were obtained from pear seedling. The most vigorous trees were grown on pear seedling, followed by 'BA 29', 'QA' and 'QC' rootstocks. The 'Santa Maria' pear variety's leaf chlorophyll content on all rootstocks fell during the study period up to 60 DAFB compared with 30 DAFB. It was found that leaf chlorophyll and Fe contents were higher in trees on pear seedling and BA 29 rootstocks and lower in those on 'QA'.

scholarly journals Field comparison of sterol-biosynthesis-inhibiting fungicides used alone and in combination with protectant fungicides for apple scab control

2005 ◽  
Vol 71 (1) ◽  
pp. 1-8 ◽  
Author(s):  
J. Warner
Keyword(s):  
Disease Control ◽  
Broad Spectrum ◽  
Venturia Inaequalis ◽  
Apple Scab ◽  
Field Trials ◽  
Sterol Biosynthesis ◽  
Scab Control

Several sterol-biosynthesis-inhibiting (SBI) fungicides were tested alone and in combination with a broad-spectrum protectant material in field trials for control of Venturia inaequalis. When used in a 10-day spray schedule, SBI fungicides, whether used alone or in a mixture, provided improved scab control as compared to the protectant material used alone. With bitertanol, diniconazole, and penconazole, the mixture also provided better scab control than when the SBI fungicide was used alone. However, with flusilazole and myclobutanil, no improvement in disease control occurred with the mixture as compared to the SBI fungicide alone. Fruit russeting was observed after a post-bloom application of hexaconazole and growth-regulating effects on the foliage were observed following cyproconazole and hexaconazole use. The use of SBI fungicides in mixtures to avoid or delay the development of fungus resistance is discussed.

scholarly journals Asian Pear: A Potential Alternative Fruit Crop for Growers in the Mid-Atlantic Region

HortScience ◽  
2016 ◽  
Vol 51 (11) ◽  
pp. 1325-1328
Author(s):  
Christopher S. Walsh ◽  
Julia M. Harshman ◽  
Anna E. Wallis ◽  
Amy Barton Williams ◽  
Michael J. Newell ◽  
...  
Keyword(s):  
Fire Blight ◽  
Field Trials ◽  
Pyrus Pyrifolia ◽  
Eastern United States ◽  
Good Opportunity ◽  
European Pear ◽  
Asian Pear ◽  
Pear Trees ◽  
Research And Education

Production of european pears (Pyrus communis L.) in the eastern United States is limited by a number of physiological and pathological problems. In an attempt to expand sustainable pear production in that region, a series of long-term field trials of asian pear [Pyrus pyrifolia (Burm. F) Nak. (syn. Pyrus serotina L.)] were established at two sites in Maryland. To compare precocity, productivity, and survival, nine asian pear cultivars and three European cultivars were planted in a replicated trial in 2010 at the Wye Research and Education Center (Wye REC). The asian pears were precocious and productive and many trees flowered and fruited in the second leaf. After the fourth leaf, survival of ‘Isi’iwasi’, ‘Shinsui’, ‘Kosui’, and ‘Olympic’ was good, while many ‘Hosui’ and ‘Ya Li’ (asian pear) trees as well as ‘Bartlett’ and ‘Golden Russett’ (european pear) trees had died at that point, following bloom infections of fire blight (Erwinia amylovora). At Keedysville (WMREC), 18 asian pear cultivars in two established plantings were evaluated for their field tolerance to fire blight following a severe hailstorm. The cultivars Shin Li, Daisu Li, Shinsui, and Olympic fared as well as Magness, a fire blight–tolerant european pear cultivar that served as a benchmark in that evaluation. Conversely, ‘Hosui’, ‘Choju’, ‘Kosui’, ‘Seigyoku’, ‘Ya Li’, and ‘Ts’e Li’ were severely damaged. Three consumer tastings were conducted using fruit from the Wye REC trial. ‘Yoinashi’, ‘Atago’, ‘Shinko’, and ‘Olympic’ were well received by consumers. After tasting asian pears, most people, even those less familiar with the crop, reported they would consider purchasing the fruit and requested the names of local producers. Based on our long-term research results, there appears to be a good opportunity for locally produced asian pear fruit. With the correct cultivar selection for fire blight management, local growers should be able to produce this alternative crop sustainably and market their fruit profitably.

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