Refining Management of Apple Powdery Mildew in New York State with Weather-Based Fungicide Application Timing Programs

Strickland, David A.; Ayer, Katrin M.; Olmstead, Daniel; Cox, Kerik D.

doi:10.1094/pdis-08-22-1825-re

Cited by 3 publications

(1 citation statement)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Once non-crop hosts for specific plant pathogens are discovered, management implications arise. Removing non-crop host plants could reduce the incidence of that pathogen in crops (Peterson, 2018;Strickland, Carroll, & Cox, 2020). In other systems, management of weeds may reduce pest populations in crops (Norris & Kogan, 2005).…”

Section: Discussionmentioning

confidence: 99%

Risk assessment for non‐crop hosts of pea enation mosaic virus and the aphid vector Acyrthosiphon pisum

Clark

Basu

Eigenbrode

et al. 2023

Agri and Forest Entomology

View full text Add to dashboard Cite

1. Viral insect-borne plant pathogens have devastating impacts in agroecosystems.Vector-borne pathogens are often transmitted by generalist insects that move between non-crop and crop hosts. Insect vectors can have wide diet breadths, but it is often unknown which hosts serve as pathogen reservoirs and which non-crop host harbours the highest density of vectors.2. In the Pacific Northwest USA, the pea aphid (Acyrthosiphon pisum) is a key virus vector in pulse crops. Despite pea aphid having a large number of potential noncrop plant hosts occuring in the region, no reservoir has yet been identified for the economically-costly pathogen Pea Enation Mosaic Virus (PEMV).3. We addressed these issues by linking field surveys of an aphid vector and plant virus with statistical models to develop risk assessments for common non-crop legumes; in 2018, we completed a 65-site survey where aphids were surveyed in weedy legumes within and outside dry pea fields.4. We quantified the abundance of pea aphids on 17 hosts, and plant tissue was tested for PEMV. Relatively high densities of A. pisum were found in habitats dominated by hairy vetch (Vicia villosa), which was the only legume other than cultivated dry pea where PEMV was detected. 5. Our results indicate that V. villosa is a key alternative host for PEMV, and that pest management practices in this region should consider the distribution and abundance of this weedy host in viral disease mitigation efforts for pulses.

show abstract

Section: Discussionmentioning

confidence: 99%

Risk assessment for non‐crop hosts of pea enation mosaic virus and the aphid vector Acyrthosiphon pisum

Clark

Basu

Eigenbrode

et al. 2023

Agri and Forest Entomology

View full text Add to dashboard Cite

show abstract

Effects of Temperature, Moisture, and Ultraviolet Light on Germination, Infection, and Survival of Gymnosporangium yamadae Teliospores and Basidiospores

Zhang

et al. 2023

Plant Disease

View full text Add to dashboard Cite

Apple rust caused by Gymnosporangium yamadae is a significant disease in China’s main apple production areas. We evaluated the effects of temperature, moisture, and ultraviolet (UV) light on the germination, infection, and survival of teliospore horns and basidiospores under artificially controlled environmental conditions. The temperature required for the germination and infection by G. yamadae teliospores and basidiospores ranged from 5°C to 25°C, with an optimum of approximately 17°C. The teliospore horn germinated when soaking in distilled water for 5 min and required at least 2.3 h of development to produce basidiospores under the most favorable conditions. Basidiospores could only germinate in free water and produced germ tubes 0.8 h after being placed in the water. The half-life of the basidiospore was 72.5 h in the dark and only 9.5 h when exposed to intense UV light. The basidiospores inoculated on the host leaves required at least 2.3 h of water exposure to cause rust lesions. A revised Weibull model could describe the relationships between the germination and infection of teliospore horns and basidiospores with temperature and wetness duration. Collectively, these results can serve as a valuable guide for developing a model to predict future apple rust epidemics and establish a method for effective control strategies.

show abstract

Assessment of Fungicide Resistance via Molecular Assay in Populations of Podosphaera leucotricha, Causal Agent of Apple Powdery Mildew, in New York

et al. 2023

View full text Add to dashboard Cite

Podosphaera leucotricha, causal agent of apple powdery mildew, is a pathogen endemic worldwide where apples are produced. In the absence of durable host resistance, the disease is most effectively managed in conventional orchards with single-site fungicides. In New York State, increasingly erratic precipitation patterns and warmer temperatures due to climate change may create a regional environment more conducive to apple powdery mildew development and spread. In this scenario, outbreaks of apple powdery mildew may supplant the apple diseases of current management concern – apple scab and fire blight. Presently, there have been no reports from producers of fungicide control failures for apple powdery mildew, though increased disease incidence has been reported to and observed by the authors. As such, action was needed to assess the fungicide resistance status of populations of P. leucotricha to ensure key classes of single-site fungicides (FRAC 3, demethylation inhibitors, DMI; FRAC 11, quinone outside inhibitors, QoI; FRAC 7, succinate dehydrogenase inhibitors, SDHI) remain effective. In a two-year survey (2021-2022), we collected 160 samples of P. leucotricha from 43 orchards, representing conventional, organic, low-input, and unmanaged orchards from New York’s primary production regions. Samples were screened for mutations in the target genes (CYP51, cytb, and sdhB) historically known to confer fungicide resistance in other fungal pathogens to the DMI, QoI, and SDHI fungicide classes, respectively. Across all samples, no nucleotide sequence mutations that translated into problematic amino acid substitutions were found in the target genes, suggesting that New York populations of P. leucotricha remain sensitive to the DMI, QoI, and SDHI fungicide classes, provided no other fungicide resistance mechanism is at play in the population.

show abstract

Refining Management of Apple Powdery Mildew in New York State with Weather-Based Fungicide Application Timing Programs

Cited by 3 publications

References 45 publications

Risk assessment for non‐crop hosts of pea enation mosaic virus and the aphid vector Acyrthosiphon pisum

Risk assessment for non‐crop hosts of pea enation mosaic virus and the aphid vector Acyrthosiphon pisum

Effects of Temperature, Moisture, and Ultraviolet Light on Germination, Infection, and Survival of Gymnosporangium yamadae Teliospores and Basidiospores

Assessment of Fungicide Resistance via Molecular Assay in Populations of Podosphaera leucotricha, Causal Agent of Apple Powdery Mildew, in New York

Contact Info

Product

Resources

About