Xylella Fastidiosa

Xylella fastidiosa is a harmful bacterial pathogen affecting a variety of plants, causing significant economic losses in agriculture. In Alabama, the pathogen’s presence has been steadily increasing, impacting fruit crops like blueberries, grapes, and peaches. This blog post delves into the research findings on Xylella fastidiosa in Alabama, highlighting the diseases it causes, its primary insect vectors, and essential strategies for managing its spread.

 

Xylella Fastidiosa in Alabama: A Growing Concern for Agriculture

Xylella fastidiosa, responsible for a range of plant diseases, has been identified as a significant threat to crops across Alabama. Research conducted in various agricultural regions of Alabama, including the Gulf Coast, Central, and North Alabama, has confirmed the presence of the pathogen in key fruit crops such as blueberries, grapes, peaches, and plums.

The pathogen is transmitted by sharpshooter insects, which feed on the xylem of plants, allowing the bacteria to spread from one plant to another. Xylella fastidiosa causes several plant diseases, including bacterial leaf scorch, Pierce's disease, and phoney peach disease. These diseases result in symptoms such as leaf necrosis, stunted growth, premature leaf drop, and reduced fruit production. The impact of these diseases on Alabama's agriculture cannot be overstated, as they affect both the health of crops and the state's agricultural economy.

 

Key Research Findings on Xylella Fastidiosa in Alabama

Study 1: Rabbiteye Blueberry Cultivation in Alabama

A study conducted at Auburn University investigated the performance of various rabbiteye blueberry cultivars in North Alabama, focusing on disease resistance and the presence of pathogens such as Xylella fastidiosa. The research highlighted that blueberries are particularly susceptible to bacterial leaf scorch, a condition caused by Xylella fastidiosa. The disease leads to premature leaf drop, which reduces the plant’s ability to photosynthesize and negatively impacts fruit yield. The study emphasized the importance of selecting disease-resistant blueberry cultivars to mitigate the spread of Xylella in the region.

Study 2: Sharpshooter Leafhopper Abundance and Distribution in Alabama

A study on the seasonal abundance of sharpshooter leafhoppers across Alabama revealed that these insects are the primary vectors of Xylella fastidiosa. The study found that Homalodisca vitripennis (glassy-winged sharpshooter) and Graphocephala versuta (blue-green sharpshooter) are the most common sharpshooters in Alabama, with the highest populations found in the Gulf Coast region. These sharpshooters feed on plant xylem, transmitting Xylella fastidiosa to healthy plants, facilitating the spread of bacterial diseases in orchards and vineyards .

Study 3: Spread of Xylella Fastidiosa in Alabama’s Orchards and Vineyards

A comprehensive study in Alabama’s orchards and vineyards confirmed the widespread presence of Xylella fastidiosa across several fruit crops. The study showed that Xylella infection caused significant damage to crops such as muscadine grapes, blueberries, peaches, and plums, with symptoms ranging from leaf necrosis to stunted plant growth. Researchers identified various sharpshooter species that contribute to the spread of the bacteria, including Homalodisca vitripennis and Oncometopia orbona, with each species exhibiting different seasonal patterns of abundance. This research underscores the importance of timely monitoring and vector control to reduce the risk of Xylella transmission .

 

Impact of Xylella Fastidiosa on Alabama’s Agriculture

The spread of Xylella fastidiosa in Alabama poses a significant threat to agriculture, particularly in areas with high concentrations of fruit crops. The pathogen affects a wide variety of plants, but its impact on crops like blueberries, muscadine grapes, and peaches is particularly concerning. For instance, bacterial leaf scorch in blueberries leads to premature leaf drop and diminished fruit quality, making the crop less viable for farmers. Similarly, Pierce’s disease in grapes causes vine death, which severely affects grape production.

As Alabama’s agricultural landscape continues to be impacted by this pathogen, managing its spread is crucial for the state’s economy. Integrated pest management (IPM) strategies, including controlling sharpshooter populations and selecting disease-resistant plant cultivars, are essential steps in mitigating the risks posed by Xylella fastidiosa.

 

Strategies for Managing Xylella Fastidiosa in Alabama

To address the growing issue of Xylella fastidiosa in Alabama, researchers recommend a combination of monitoring, pest control, and the use of disease-resistant cultivars. Early detection of the disease is crucial, as it allows farmers to implement control measures before the infection spreads. Regular monitoring of sharpshooter populations using yellow sticky traps is a key strategy to track vector abundance and predict the timing of Xylella transmission.

Additionally, farmers should focus on selecting cultivars that are resistant or tolerant to Xylella infection. For example, certain grape cultivars, such as muscadine grapes, have shown some resistance to Pierce’s disease, though mild symptoms may still occur under high disease pressure. The use of insecticides to control sharpshooter populations can also reduce the risk of Xylella transmission, although the effectiveness of chemical treatments can vary depending on environmental conditions and insect population density.

Table: Summary of Xylella fastidiosa Presence in Alabama

Region	Study Outcome	Impact on Crops	Sharpshooter Vectors
Gulf Coast	High prevalence of Xylella fastidiosa in muscadine grapes, peaches, and blueberries	Significant damage in blueberries, grapes, and citrus	Homalodisca vitripennis (Glassy-winged sharpshooter)
Central Alabama	Moderate infection rates in peaches and grapes	Reduced fruit yield and quality	Graphocephala versuta (Blue-green sharpshooter)
North Alabama	Lower infection rates, but presence in blueberries	Minor symptoms in blueberries and grapes	Homalodisca vitripennis, Oncometopia orbona

Final Thoughts

The spread of Xylella fastidiosa in Alabama is a growing concern that threatens the state’s agricultural crops. Research has confirmed the presence of the pathogen in several fruit crops, with sharpshooter insects playing a key role in its transmission. Through integrated pest management, early detection, and the use of disease-resistant cultivars, farmers in Alabama can take proactive measures to reduce the impact of Xylella fastidiosa on their crops. Continued research and monitoring will be crucial to managing the spread of this pathogen and ensuring the sustainability of Alabama’s agricultural industry.

 

References:

• Ma, X. (2010). The Occurrence of Xylella fastidiosa and Its Sharpshooter Vectors in Selected Alabama Orchards and Vineyards. Master's thesis, Auburn University.
• Ma, X., Coneva, E., Fadamiro, H., Murphy, J. F., Ray, C., & Dane, F. (2010). Seasonal Occurrence and Abundance of Sharpshooter Leafhoppers in Alabama Orchards and Vineyards. International Journal of Fruit Science, 10(3), 341-354. DOI: 10.1080/15538362.2010.510428.
• Potter, R. J. (2010). Performance of Newly Released and Well-Established Rabbiteye Blueberry (Vaccinium ashei) Cultivars in North Alabama. Master's thesis, Auburn University.

Xylella Fastidiosa in Arizona

Xylella fastidiosa (Xf) is a bacterial pathogen that affects plants by clogging their vascular system, leading to a variety of diseases. In Arizona, this pathogen has emerged as a significant concern for local agriculture, particularly in pecan orchards and vineyards. Over the years, Xf has been found to cause diseases like Pecan Bacterial Leaf Scorch (PBLS) and Pierce’s Disease (PD) in various crops. Recent studies reveal alarming insights into the spread of X. fastidiosa in Arizona, making it crucial for farmers and researchers to understand the pathogen's behavior and impact.

Infection due to Xylella fastidiosa leads to symptoms such as leaf scorch, branch dieback, and, in severe cases, plant death. X. fastidiosa is primarily spread by xylem-feeding insect vectors, such as sharpshooters and leafhoppers. While certain strains of X. fastidiosa are benign in native plants, others cause significant damage to crops and ornamental plants.

This pathogen has been responsible for devastating agricultural diseases, including:

·         Pierce’s Disease in grapevines

·         Citrus Variegated Chlorosis in citrus

·         Pecan Bacterial Leaf Scorch (PBLS) in pecans, as observed in Arizona and New Mexico .

The Spread of Xylella Fastidiosa in Arizona

Arizona has witnessed several outbreaks of Xylella fastidiosa, particularly in pecan trees, ornamental plants like Chitalpa tashkentensis, and grapevines. The pathogen's presence in these plants is concerning for Arizona’s agricultural industries.

Key Findings from Arizona Studies

1.      Pecan Bacterial Leaf Scorch (PBLS): PBLS, caused by X. fastidiosa, was first detected in Arizona in 2015. Symptoms such as leaf scorch, necrosis, and branch dieback have been observed in several pecan orchards across the state. The disease has severely affected the pecan industry, which contributes significantly to Arizona’s economy. The pathogen is primarily spread by insect vectors such as sharpshooters, with some studies indicating that grafting of infected plant material also contributes to its spread.

2.      Chitalpa and Other Ornamental Plants: X. fastidiosa has also been detected in Chitalpa trees, a popular ornamental species in Arizona. Chitalpa trees exhibit leaf scorch symptoms, which were initially thought to be due to environmental stress but were later linked to X. fastidiosa infection. This pathogen was also found in nursery stock, suggesting that it can spread through commercial plant trade .

3.      Genetic Analysis and Subspecies of Xylella Fastidiosa: Recent genetic studies have uncovered a novel subspecies of X. fastidiosa, known as X. fastidiosa subsp. tashke, which has been identified in Chitalpa trees in Arizona. This new subspecies is genetically distinct from other known strains and has been linked specifically to the southwestern U.S., including Arizona .

Impact on Arizona's Agriculture

The impact of Xylella fastidiosa in Arizona is far-reaching:

·         Economic Losses in Pecan Orchards: PBLS has led to declining yields and increased management costs in pecan orchards. The disease causes trees to suffer from poor water and nutrient transport, ultimately affecting tree health and productivity .

·         Threat to Vineyards: Pierce’s Disease, caused by X. fastidiosa, is a major threat to Arizona’s grape industry. The pathogen affects grapevines by blocking water transport, causing vine death, and reducing the quality of the grapes .

·         Spread through Nursery Stock: The discovery of X. fastidiosa in nursery stock emphasizes the risk of pathogen spread through the trade of plants. This can lead to the introduction of the disease into new areas, exacerbating the problem.

Table: Summary of Xylella Fastidiosa in Arizona

Region/Plant	Presence of X. fastidiosa	Disease Caused	Impact	Study Reference
Pecan Orchards	Positive for X. fastidiosa	Pecan Bacterial Leaf Scorch	Reduced tree growth, yield loss, economic impact	Study 2, Study 5
Chitalpa Trees	Positive for X. fastidiosa	Leaf scorch, dieback	Aesthetic and functional damage in landscapes	Study 3, Study 7
Vineyards	Positive for X. fastidiosa	Pierce’s Disease	Potential for grapevine death, loss of quality yield	Study 6

Prevention and Management Strategies

Managing Xylella fastidiosa in Arizona requires a multifaceted approach:

1.      Vector Control: Sharpshooters and other insect vectors play a key role in spreading X. fastidiosa. Using insecticides and implementing monitoring systems like sticky traps can help control vector populations .

2.      Improved Diagnostic Tools: Researchers are working on developing more reliable diagnostic methods, such as PCR-based tests, to detect X. fastidiosa early in infected plants .

3.      Tree Removal and Grafting Practices: Infected trees should be removed to limit the spread, and nurseries should ensure their stock is free from the pathogen. Additionally, using healthy scion wood for tree propagation can help prevent the introduction of X. fastidiosa .

The Pathogen’s Growing Threat in Arizona

Xylella fastidiosa presents a growing threat to Arizona's agriculture, particularly affecting pecan orchards and vineyards. The novel subspecies X. fastidiosa subsp. tashke, found in ornamental plants like Chitalpa, further complicates efforts to manage the pathogen. Ongoing research and proactive management strategies will be crucial in mitigating the impact of X. fastidiosa in Arizona and preventing its spread across the southwestern United States.

References

1.      Randall, J. J., Goldberg, N. P., Kemp, J. D., et al. (2009). "Genetic Analysis of a Novel Xylella fastidiosa Subspecies Found in the Southwestern United States." Applied and Environmental Microbiology, 75(17), 5631–5638.

2.      Hilton, A.E., Jo, Y-K., Cervantes, K., et al. (2017). "First Report of Pecan Bacterial Leaf Scorch Caused by Xylella fastidiosa in Pecan (Carya illinoinensis) in Arizona, New Mexico, California, and Texas." Plant Disease, 101(6), 1027. https://doi.org/10.1094/PDIS-02-17-0298-PDN.

3.      "Prevalence and strain characterization of Xylella fastidiosa causing grapevine and pecan diseases in Arizona." University of Arizona.

Xylella fastidiosa (XF) is a bacterium that has emerged as a major threat to Arkansas’ agricultural landscape. Known for causing severe plant diseases, this pathogen affects a wide range of crops and ornamental trees across the state. In Arkansas, the effects of Xylella fastidiosa are evident in various plant species, with symptoms ranging from marginal leaf scorch to the death of trees. This post delves into the ongoing research on Xylella fastidiosa, its spread in Arkansas, and the significant impact it has on local agriculture, particularly in terms of the diseases it causes.

 

The Spread of Xylella Fastidiosa in Arkansas

Xylella Fastidiosa in Arkansas has been closely studied, as researchers aim to understand its spread, impact, and management. According to the Arkansas Plant Health Clinic (Smith, 2013), the presence of Xylella fastidiosa is well-documented, with infections found in various host species such as redbud, oak, maple, and grapevines, to name a few. This bacterium is primarily spread by sap-sucking insects like leafhoppers and spittlebugs, which transfer the bacteria from infected plants to healthy ones.

Key Studies and Findings:

1. Plant Species Affected: Various ornamental trees such as oaks, maples, and elms, as well as fruit-bearing crops like grapes, peaches, and citrus, are vulnerable to the bacterium. Xylella fastidiosa causes Bacterial Leaf Scorch (BLS) in these plants, leading to browning of leaves, stunted growth, and eventual plant death if left unmanaged.
2. Pierce’s Disease and Other Symptoms: In Arkansas, the grape industry is particularly vulnerable to Pierce's Disease, a form of Xylella fastidiosa infection that causes severe vine decline. Researchers have noted that the disease significantly impacts grape yields, especially in regions with warmer climates.
3. Early Detection and Management: The Plant Health Clinic has underscored the importance of early detection and accurate diagnosis to manage the spread of Xylella fastidiosa. Early identification allows for targeted management strategies such as trunk injections of antibiotics to suppress symptoms.

 

Xylella Fastidiosa Research in Arkansas

Research on Xylella fastidiosa is ongoing in Arkansas, with various studies aiming to understand its behavior and impact better. One of the critical studies conducted by the University of Arkansas and Texas A&M University focuses on the development of grape varieties resistant to Pierce’s Disease.

Southern Sensation Seedless Grapes are one of the successes from this research. This grape variety was developed specifically to resist Pierce’s Disease, making it a promising solution for local farmers battling the effects of Xylella fastidiosa. As reported in American Vineyard Magazine (2025), these grapes have shown resilience even in regions heavily affected by Pierce’s Disease, offering hope to grape growers in Arkansas. Despite several setbacks, including severe winter temperatures, the Southern Sensation Seedless has demonstrated remarkable resistance, growing successfully in both Texas and Arkansas.

Outcomes and Impacts:

1. Resistance to Pierce’s Disease: The Southern Sensation Seedless grape is particularly resilient to Pierce's Disease, showing minimal symptoms even in areas severely affected by Xylella fastidiosa. This advancement holds great promise for Arkansas' grape industry.
2. Testing and Trials: Trials conducted in both Texas and Arkansas have highlighted the variety’s durability and fruit quality, making it a valuable asset for growers in regions prone to disease outbreaks.
3. Other Disease Resistance: Apart from Pierce's Disease, this grape variety also exhibits resistance to other common grapevine diseases, such as downy mildew.

 

The Impact of Xylella Fastidiosa on Arkansas Agriculture

Xylella fastidiosa has profound effects on Arkansas agriculture, particularly affecting crops like grapes, peaches, and ornamental trees. The bacterium’s ability to clog the water-conducting tissues of plants leads to a host of issues, including leaf scorch, reduced growth, and tree death.

Affected Regions in Arkansas:

• Northwest Arkansas: Grapevines in this area, particularly in Benton and Washington counties, are heavily impacted by Pierce’s Disease.
• Central Arkansas: Ornamental trees in this region, especially those in urban settings, show signs of Bacterial Leaf Scorch.
• Other Agricultural Areas: Other crops such as peaches and almonds are also vulnerable, with the bacterium leading to reduced yields and weakened plant health.

Management Strategies:

• Antibiotic Injections: One of the primary methods for controlling Xylella fastidiosa in infected trees is the use of trunk injections of oxytetracycline, a treatment that helps suppress symptoms, though it does not cure the infection.
• Monitoring and Early Detection: Continuous monitoring by agricultural extension services and the Plant Health Clinic has proven effective in identifying outbreaks early and controlling their spread.
• Insect Control: Managing the insect vectors, such as leafhoppers and spittlebugs, is also crucial in preventing the spread of Xylella fastidiosa.

Table: Summary of Xylella Fastidiosa's Impact in Arkansas

Region	Plant Species Affected	Symptom	Management Outcome
Northwest Arkansas	Grapevines, Oak	Pierce’s Disease, BLS	Grapevine decline, Tree death
Central Arkansas	Maple, Redbud, Elm	Bacterial Leaf Scorch	Trunk injections, Disease suppression
Statewide (General)	Grape, Peach, Citrus	Bacterial Leaf Scorch	Limited progress in disease control

The presence of Xylella fastidiosa in Arkansas has become a critical concern for local agriculture. Its ability to cause diseases like Pierce’s Disease and Bacterial Leaf Scorch continues to affect a wide range of plant species, particularly grapevines and ornamental trees. Research into resistant plant varieties, like the Southern Sensation Seedless grape, offers hope for mitigating the impact of this pathogen. However, ongoing efforts are necessary to control its spread, particularly through early detection, insect control, and management practices.

As Arkansas continues to grapple with the impact of Xylella fastidiosa, collaboration between local farmers, researchers, and agricultural extension services will be paramount in finding lasting solutions to combat this growing threat.

References

• Smith, S. (2013, June 25). Plant Health Clinic Newsletter - Issue 17. University of Arkansas Cooperative Extension.
• "Southern Sensation Seedless: New Table Grape for the Mid-South." American Vineyard Magazine, April 2025.

 

 

Xylella fastidiosa is a dangerous plant pathogen responsible for a wide array of plant diseases, including some of the most harmful to California’s agricultural landscape. From almond orchards to grapevine fields, this bacterium has embedded itself in the very fabric of the state's farming industry, impacting both local economies and crop health. Understanding the spread of Xylella fastidiosa, particularly in California, is crucial for protecting these valuable crops. This blog post takes a closer look at the presence of Xylella fastidiosa in California, the diseases it causes, and the ongoing research efforts to manage its spread.

 

Xylella fastidiosa (Xf) is a bacterial pathogen that thrives in the xylem vessels of plants. This bacterium disrupts the plant’s ability to transport water and nutrients, leading to severe symptoms such as leaf scorch, stunted growth, and in extreme cases, the death of the plant. Xylella fastidiosa is transmitted primarily through insect vectors, particularly sharpshooters like the glassy-winged sharpshooter (Homalodisca vitripennis) and other leafhoppers.

In California, Xf has caused significant damage to crops such as grapevines, almonds, and olives, as well as a range of ornamental plants. It is particularly notable for causing Pierce’s disease in grapevines and almond leaf scorch disease (ALSD) in almond trees, among other diseases.

 

The Spread of Xylella fastidiosa in California: A Growing Concern

The spread of Xylella fastidiosa in California has been well-documented across multiple studies. Its presence has been confirmed in a variety of crops, highlighting the vulnerability of California’s agricultural systems. Below, we explore the research findings and the areas affected by Xylella fastidiosa.

Study 1: Pecan Bacterial Leaf Scorch (PBLS)

In 2017, a significant study confirmed the presence of Xylella fastidiosa in pecan trees across Arizona, New Mexico, California, and Texas. The pathogen caused Pecan Bacterial Leaf Scorch (PBLS), which led to tan to light brown necrotic lesions on leaf margins, eventually causing leaf abscission. In California, 15 pecan cultivars, including popular varieties like 'Cape Fear' and 'Pawnee', were found to be infected. The discovery of Xylella fastidiosa in California’s pecan orchards underscores the pathogen’s expanding reach across the state.

Reference: Hilton, A.E., Jo, Y.K., Cervantes, K., et al. (2017). First Report of Pecan Bacterial Leaf Scorch Caused by Xylella fastidiosa in Pecan (Carya illinoinensis) in Arizona, New Mexico, California, and Texas. Plant Disease.

Study 2: Xylella fastidiosa in Olive Trees

Another pivotal study focused on California’s olive trees, specifically in Southern California, where symptoms of leaf scorch and branch dieback were observed. From 2008 to 2012, researchers tested 198 symptomatic olive trees and found that 17% tested positive for Xylella fastidiosa. However, while olive trees served as hosts for the pathogen, the study concluded that they did not contribute significantly to the disease’s spread, despite the presence of the bacterium in some trees.

Reference: Krugner, R., Sisterson, M.S., Chen, J., et al. (2014). Evaluation of Olive as a Host of Xylella fastidiosa and Associated Sharpshooter Vectors. Plant Disease.

Study 3: Mulberry Leaf Scorch in Southern California

The discovery of Mulberry Leaf Scorch (MLS) caused by Xylella fastidiosa in Southern California further expands the list of host plants affected by the bacterium. The study found that Xf was present in both white mulberry trees and ornamental species in urban areas, with strains genetically similar to those causing diseases in other regions. Although MLS was a new disease in California, it was clear that Xf’s impact on the state's plants was becoming more widespread.

Reference: Hernandez-Martinez, R., Cooksey, D.A., Wong, F.P. (2006). Discovery and Characterization of Xylella fastidiosa Strains in Southern California Causing Mulberry Leaf Scorch. Plant Disease.

 

Impact on California's Agriculture and Economy

The spread of Xylella fastidiosa has profound implications for California’s agricultural industry, which relies heavily on crops such as almonds, grapevines, and olives. The presence of Xf in these high-value crops threatens not only the health of these plants but also the livelihoods of farmers and the state's economy.

Pierce’s Disease in Grapevines

Perhaps the most well-known effect of Xylella fastidiosa in California is Pierce’s Disease in grapevines. This disease has led to significant yield losses in Napa Valley and other wine-growing regions. The glassy-winged sharpshooter, which feeds on the xylem sap of grapevines, spreads Xf, causing symptoms like leaf scorch and stunted growth. The economic impact of Pierce’s Disease is substantial, as vineyards face both loss of production and the costs of managing and replacing infected vines.

Almond Leaf Scorch Disease (ALSD)

Almond Leaf Scorch Disease (ALSD) is another major concern. The bacterium’s ability to infect almond trees has led to decreased yields and the weakening of tree health. As the almond industry in California is worth billions of dollars, the presence of Xylella fastidiosa poses a severe risk to this crop, further underscoring the need for effective management strategies.

 

Managing the Spread of Xylella fastidiosa

Research on Xylella fastidiosa in California has led to a better understanding of the pathogen’s transmission dynamics and spread. The role of sharpshooters as vectors of Xf is well-documented, and controlling these insect populations is a key component of disease management. Several strategies are being developed, including:

• Insecticide treatments to reduce vector populations.
• Removal of infected plants to prevent the spread of the bacterium to healthy crops.
• Development of resistant plant varieties to withstand Xf infections.
• Monitoring programs to detect the pathogen early and track its spread across the state.

Table: Summary of Xylella fastidiosa’s Presence in California

Study	Region	Disease	Key Findings	Impact on Agriculture
Study 1	Arizona, New Mexico, California, Texas	Pecan Bacterial Leaf Scorch (PBLS)	79 pecan trees infected across multiple states	Affects pecan trees, potential yield losses
Study 2	Southern California	Olive Tree Infection	17% of symptomatic trees tested positive for Xf	Olive trees act as secondary hosts
Study 3	Southern California	Mulberry Leaf Scorch (MLS)	Xf found in mulberry trees, new disease in California	Further spread of Xf to urban and agricultural areas
Study 4	Central Valley, California	Almond Leaf Scorch Disease (ALSD)	Detection of Xf in almond orchards	Risk to almond crop health and productivity
Study 5	Napa Valley, California	Pierce’s Disease in Grapevines	Xf spread by glassy-winged sharpshooters	Significant yield loss in grapevines

Conclusion: The Path Forward

As the presence of Xylella fastidiosa continues to expand across California, it is crucial for farmers, researchers, and policymakers to work together to mitigate the pathogen's impact on the state’s agricultural landscape. The research presented in this post emphasizes the need for proactive management strategies and ongoing surveillance to protect crops from this devastating disease. By staying informed and embracing new technological solutions, California’s agriculture can better navigate the challenges posed by Xylella fastidiosa and continue to thrive in the face of this growing threat.

 

References:

1. Hilton, A.E., Jo, Y.K., Cervantes, K., et al. 2017. "First Report of Pecan Bacterial Leaf Scorch Caused by Xylella fastidiosa in Pecan (Carya illinoinensis) in Arizona, New Mexico, California, and Texas." Plant Disease.
2. Krugner, R., Sisterson, M.S., Chen, J., et al. 2014. "Evaluation of Olive as a Host of Xylella fastidiosa and Associated Sharpshooter Vectors." Plant Disease.
3. Hernandez-Martinez, R., Cooksey, D.A., Wong, F.P. 2006. "Discovery and Characterization of Xylella fastidiosa Strains in Southern California Causing Mulberry Leaf Scorch." Plant Disease.
4. Krugner, R., Ledbetter, C.A., Chen, J., & Shrestha, A. 2012. "Phenology of Xylella fastidiosa and Its Vector Around California Almond Nurseries: An Assessment of Plant Vulnerability to Almond Leaf Scorch Disease." Plant Disease.
5. Beal, Dylan Joseph. 2021. "Assessing Vectors of Xylella fastidiosa in California: From Ecology to Transmission Dynamics." Doctoral dissertation, University of California, Berkeley.
6. Shapland, E.B., Daane, K.M., Yokota, G.Y., et al. 2006. "Ground Vegetation Survey for Xylella fastidiosa in California Almond Orchards." Plant Disease.
7. Raju, B.C., Goheen, A.C., & Frazier, N.W. 1983. "Occurrence of Pierce's Disease Bacteria in Plants and Vectors in California." Phytopathology.
8. Uyemoto, J.K., & Seoft, S. 1992. "Important Diseases of Prunus Caused by Viruses and Other Graft-Transmissible Pathogens in California and South Carolina." Plant Disease.
9. Kahn, A.K., Sicard, A., Cooper, M.L., et al. 2023. "Progression of Xylella fastidiosa Infection in Grapevines Under Field Conditions." Phytopathology.
10. Krugner, R., Sisterson, M.S., Chen, J., & Johnson, M.W. 2014. "Evaluation of Olive as a Host of Xylella fastidiosa and Associated Sharpshooter Vectors." Plant Disease.
11. Beal, Dylan Joseph. 2021. "Assessing Vectors of Xylella fastidiosa in California." University of California, Berkeley.
12. Krugner, R., Ledbetter, C.A., Shrestha, A., & Chen, J. 2012. "Evaluation of Almond Tree Susceptibility to Xylella fastidiosa." Plant Disease.