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 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.

Evaluation of Inducing Agents and Synthetic Fungicide Combinations for Management of Foliar Pathogens of Urban Trees

2021 ◽  
Vol 47 (2) ◽  
pp. 85-95
Author(s):  
Glynn Percival ◽  
Sean Graham
Keyword(s):  
Symptom Severity ◽  
Field Studies ◽  
Urban Trees ◽  
Horse Chestnut ◽  
Full Strength ◽  
Leaf Chlorophyll ◽  
Foliar Pathogen ◽  
Alternative Means ◽  
Pathogen Control ◽  
Foliar Pathogens

Unmanaged, foliar pathogens of urban trees can be detrimental to tree health and aesthetics. Overreliance on synthetic fungicides increasingly means alternative means of pathogen management are now required. The purpose of these studies was to investigate the efficacy of 3 commercially available agents, harpin protein, salicylic acid derivative, and liquid chitosan, which can initiate induced resistance (IR) in plants. IR agents were applied independently and in combination with a synthetic fungicide (boscalid + pyraclostrobin) against 2 foliar pathogens (Venturia pirina and Guignardia aesculi) under field conditions with Pyrus communis ‘Williams’ Bon Chrétien’ and horse chestnut (Aesculus hippocastanum) acting as tree hosts. These agents were tested over 3 consecutive years. In 4 of 5 field studies, the use of an IR agent alone reduced pathogen symptom severity, increased fruit/seed yield, and enhanced leaf chlorophyll content. In virtually all studies, application of boscalid + pyraclostrobin at 2/3 strength plus an IR agent provided the same degree of pathogen control as boscalid + pyraclostrobin at full strength. Application of boscalid + pyraclostrobin at 1/3 strength plus an IR agent provided a reasonable degree of foliar pathogen control. Results showed that a combined mix of an IR agent with a 1/3 reduced dose of boscalid + pyraclostrobin was as effective at reducing symptom severity of 2 foliar pathogens as boscalid + pyraclostrobin applied at full strength, provided at least 4 sprays were applied during a growing season.

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.

scholarly journals Morpho-physiology of wheat genotypes under different sowing dates as affected by Helminthosporium leaf blight and leaf rust in Chiwan, Nepal

2013 ◽  
Vol 3 ◽  
pp. 109-116
Author(s):  
SP Neupane ◽  
BR Ojha ◽  
SK Ghimire ◽  
SK Sah ◽  
SM Shrestha ◽  
...  
Keyword(s):  
Leaf Rust ◽  
Chlorophyll Content ◽  
Flag Leaf ◽  
Leaf Blight ◽  
Animal Science ◽  
Wheat Genotypes ◽  
Sowing Dates ◽  
Rust Severity ◽  
Helminthosporium Leaf Blight ◽  
Late Sowing

An experiment was conducted at the Agronomy farm of the Institute of Agriculture and Animal Science (IAAS), Rampur, Nepal in 2008/09. The experiment was laid out in factorial design in spit plot arrangement consisting of date of sowing as main factor and wheat genotypes as sub factor. Wheat genotypes were sown in 22 November for normal sowing and 29 December for late sowing condition. These were assessed against Helminthosporium leaf blight and leaf rust severity in a naturally inoculated environment. Result showed that wheat genotypes differed significantly with respect to flag leaf area, flag leaf duration and plant height. Genotype BL-3064 showed the lower decline (624.9 to 615.1) in chlorophyll content whereas RR-21 showed highest decline (471.2 to 360.4) in chlorophyll content from normal to late sowing, possibly contributing to resistant to the disease. The AUDPC value revealed that genotypes BL-3625 and BL-3623 had increased level of resistance due to lower AUDPC value and higher flag leaf duration. The results of this study suggest that genotypes BL-3623, BL-3625, BL-3063 and BL-3064 could be the option in warm and humid regions of Terai condition so far as resistant to Helminthosporium leaf blight and leaf rust are concerned. Agronomy Journal of Nepal (Agron JN) Vol. 3. 2013, Page 109-116 DOI: http://dx.doi.org/10.3126/ajn.v3i0.9012

scholarly journals Resistance to Leaf and Yellow Rust in a Collection of Spanish Bread Wheat Landraces and Association with Ecogeographical Variables

Agronomy ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 187
Author(s):  
Fernando Martínez-Moreno ◽  
Patricia Giraldo ◽  
Cristina Nieto ◽  
Magdalena Ruiz
Keyword(s):  
Leaf Rust ◽  
Bread Wheat ◽  
Yellow Rust ◽  
Latency Period ◽  
Field Trials ◽  
Seedling Stage ◽  
North West ◽  
The North ◽  
Rust Severity ◽  
High Precipitation

A collection of 84 bread wheat Spanish landraces were inoculated with three isolates of leaf rust and one of yellow rust at the seedling stage in controlled conditions. The latency period of leaf rust on the susceptible landraces was also assessed. An extended collection of 149 landraces was planted in three locations in field trials to evaluate the naturally occurring leaf and yellow rust severity. Several landraces (36) were resistant to one leaf rust isolate at the seedling stage, but only one was resistant to all three isolates. Landraces resistant to PG14 leaf rust isolate originated from areas with higher precipitation and more uniform temperatures. Many resistant landraces were from the north-west zone of Spain, a region with high precipitation and uniform temperatures. Results from the field trials also confirmed this trend. Landraces from the north-west also possessed a longer latency period of leaf rust, an important component of partial resistance. Regarding yellow rust, 16 landraces showed a lower disease severity in the seedling tests. Again, the resistant landraces mostly originated from areas with higher precipitation (especially in winter) and more uniform temperature.

scholarly journals Response of wheat genotypes against leaf rust (Puccinia triticina) under field conditions

2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Muhammad Jamshed Anwar ◽  
Muhammad Aslam Javed ◽  
Muhammad Waqas Jamil ◽  
Imran Habib ◽  
Shahid Nazir ◽  
...  
Keyword(s):  
Leaf Rust ◽  
Agricultural Research ◽  
Puccinia Triticina ◽  
Leaf Rust Resistance ◽  
Research Area ◽  
Field Conditions ◽  
Biotechnology Research ◽  
Rust Severity ◽  
Wheat Lines ◽  
Research Institute

Leaf rust occurs worldwide wherever wheat is grown. The current research was planned to evaluate the response of 37 wheat (Triticum aestivum) genotypes against leaf rust resistance under field conditions during crop season 2017-18.These genotypes were sown in augmented design with two meter long line sowing method with 30 cm row to row distance at research area of Agricultural Biotechnology Research Institute (ABRI), Ayub Agricultural Research Institute (AARI), Faisalabad, Pakistan. After every five genotypes, a line of rust spreader “Morocco” was sown. Moreover, the trial was also surrounded by planting two rows of spreader to increase the inoculum pressure. Data was recorded on the basis of leaf rust severity scale. Leaf rust severity response was variable among tested genotypes. Out of thirty-seven genotypes, five wheat lines were immune (no disease symptoms) i.e. 17BT007, 17BT013, 16BT008, 16BT010 and 16BT011. Seven lines were found to be resistant with AUDPC vales ranged 1-199. Response of ten lines was moderately resistant while five lines were categorized as moderately susceptible. Ten genotypes exhibited susceptible response against leaf rust with more than 600 AUDPC value. High values above 600 of AUDPC showed greater incidence of leaf rust on wheat plants while lower AUDPC values indicated resistance to leaf rust. Present research provided the resistant wheat lines to the breeders to incorporate them in their breeding program against leaf rust.

scholarly journals Wheat Leaf Rust Severity as Affected by Plant Density and Species Proportion in Simple Communities of Wheat and Wild Oats

1998 ◽  
Vol 88 (7) ◽  
pp. 708-714 ◽  
Author(s):  
Thomas G. Pfleeger ◽  
Christopher C. Mundt
Keyword(s):  
Leaf Rust ◽  
Plant Density ◽  
Seeding Density ◽  
Wheat Leaf Rust ◽  
Wild Oats ◽  
Regression Parameters ◽  
Wheat Leaf ◽  
Rust Severity ◽  
Tiller Density ◽  
Foliar Pathogens

While it is generally accepted that dense stands of plants exacerbate epidemics caused by foliar pathogens, there is little experimental evidence to support this view. We grew model plant communities consisting of wheat and wild oats at different densities and proportions and exposed these communities to Puccinia recondita to induce wheat leaf rust. Wild oats was included because it is a common competitor of wheat and may act as a barrier to the dispersal of P. recondita spores among wheat plants. Disease severity was estimated as percentage of wheat flag leaves covered by rust lesions. Seeding density rarely had a significant influence on rust severity, probably because of compensation due to increased tillering at low seeding densities. In contrast, increasing the proportion of wheat in mixtures with wild oats consistently increased wheat leaf rust severity. Regression parameters describing wheat leaf rust severity as a function of wheat seeding density did not differ significantly between pure wheat stands and wheat-wild oat mixtures and, thus, failed to support an effect of wild oats on wheat leaf rust other than through its competitive impact on wheat tiller density.

scholarly journals COR/LEA Proteins as Indicators of Frost Tolerance in Triticeae: A Comparison of Controlled versus Field Conditions

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 789
Author(s):  
Klára Kosová ◽  
Miroslav Klíma ◽  
Ilja Tom Prášil ◽  
Pavel Vítámvás
Keyword(s):  
Cold Acclimation ◽  
Field Experiments ◽  
Quantitative Relationship ◽  
Field Trials ◽  
Frost Tolerance ◽  
Late Embryogenesis Abundant ◽  
Field Conditions ◽  
Lea Proteins ◽  
Winter Cereals ◽  
Vernalisation Requirement

Low temperatures in the autumn induce enhanced expression/relative accumulation of several cold-inducible transcripts/proteins with protective functions from Late-embryogenesis-abundant (LEA) superfamily including dehydrins. Several studies dealing with plants grown under controlled conditions revealed a correlation (significant quantitative relationship) between dehydrin transcript/protein relative accumulation and plant frost tolerance. However, to apply these results in breeding, field experiments are necessary. The aim of the review is to provide a summary of the studies dealing with the relationships between plant acquired frost tolerance and COR/LEA transcripts/proteins relative accumulation in cereals grown in controlled and field conditions. The impacts of cold acclimation and vernalisation processes on the ability of winter-type Triticeae to accumulate COR/LEA proteins are discussed. The factors determining dehydrin relative accumulation under controlled cold acclimation treatments versus field trials during winter seasons are discussed. In conclusion, it can be stated that dehydrins could be used as suitable indicators of winter survival in field-grown winter cereals but only in plant prior to the fulfilment of vernalisation requirement.

scholarly journals Identification of leaf rust resistance genes Lr34 and Lr46 in common wheat (Triticum aestivum L. ssp. aestivum) lines of different origin using multiplex PCR

2021 ◽  
Vol 16 (1) ◽  
pp. 172-183
Author(s):  
Agnieszka Tomkowiak ◽  
Roksana Skowrońska ◽  
Michał Kwiatek ◽  
Julia Spychała ◽  
Dorota Weigt ◽  
...  
Keyword(s):  
Multiplex Pcr ◽  
Leaf Rust ◽  
Common Wheat ◽  
Fungal Pathogens ◽  
Rust Resistance ◽  
Leaf Rust Resistance ◽  
Field Conditions ◽  
Pcr Marker ◽  
Specific Sequence ◽  
Cereal Species

Abstract Leaf rust caused by the fungus Puccinia recondita f. sp. tritici is one of the most dangerous diseases of common wheat. Infections caused by fungal pathogens reduce the quantity and quality of yields of many cereal species. The most effective method to limit plant infection is to use cultivars that show rust resistance. Genetically conditioned horizontal-type resistance (racial-nonspecific) is a desirable trait because it is characterized by more stable expression compared to major (R) genes that induce racially specific resistance, often overcome by pathogens. Horizontal resistance is conditioned by the presence of slow rust genes, which include genes Lr34 and Lr46. This study aimed to identify markers linked to both genes in 64 common wheat lines and to develop multiplex PCR reaction conditions that were applied to identify both genes simultaneously. The degree of infestation of the analyzed lines was also assessed in field conditions during the growing season of 2017 and 2018. Simple sequence repeat anchored-polymerase chain reaction (SSR-PCR) marker csLV was identified during analysis in line PHR 4947. The presence of a specific sequence has also been confirmed in multiplex PCR analyses. In addition to gene Lr34, gene Lr46 was identified in this genotype. Lines PHR 4947 and PHR 4819 were characterized by the highest leaf rust resistance in field conditions. During STS-PCR analyses, the marker wmc44 of gene Lr46 was identified in most of the analyzed lines. This marker was not present in the following genotypes: PHR 4670, PHR 4800, PHR 4859, PHR 4907, PHR 4922, PHR 4949, PHR 4957, PHR 4995, and PHR 4997. The presence of a specific sequence has also been confirmed in multiplex PCR analyses. Genotypes carrying the markers of the analyzed gene showed good resistance to leaf rust in field conditions in both 2017 and 2018. Research has demonstrated that marker assisted selection (MAS) and multiplex PCR techniques are excellent tools for selecting genotypes resistant to leaf rust.

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