BiomeMakers Blog

The Top 5 Potato Diseases in Pacific Northwest

Written by Jamie Nix | 22/May/24

Potato farmers face a wide range of challenges in their efforts to consistently produce high-quality yields, and diseases are typically among the most imperative factors they manage.

Soilborne diseases can cause substantial economic losses and are a significant concern for potato farmers. Late Blight, in particular, is one of the most serious diseases of potatoes worldwide. It can destroy complete crop cultivation and lead to as much as 85% yield loss. Yet, armed with the right knowledge and tools, you can turn the tide and protect your crops from these relentless diseases. 

Through the power of BeCrop technology, we've identified some of the most common soilborne diseases affecting potatoes in the Pacific Northwest. This article will equip you with the microbiological insights needed to recognize the symptoms, understand the underlying causes, and implement effective management strategies to keep your crops thriving. Understanding these diseases, symptoms, and management is crucial for preserving potato crops.

Top 5 Potato Diseases

  1. Verticillium Wilt: Caused by Verticillium dahliae, this soilborne fungus affects potatoes, leading to wilting and reduced yield.
  2. Common Scab: Caused by Streptomyces scabiei, this disease leads to the development of scab-like lesions on potato tubers, reducing their market value.
  3. Fusarium Dry Rot/Wilt: Caused by various Fusarium species, this disease affects potatoes, leading to tuber rot and wilting.
  4. Early Blight: Caused by Alternaria solani, this disease leads to the development of dark lesions on potato foliage, potentially impacting photosynthesis.
  5. Late Blight: This devastating disease is caused by the oomycete Phytophthora infestans, leading to foliar lesions and tuber rot.

Controlling Bacterial and Fungal Diseases in Potatoes

Dealing with each disease threatening the potato crop in the Pacific Northwest requires specific strategies tailored to combat its unique characteristics. 

Verticillium Wilt:

To combat Verticillium Wilt, it is recommended to use certified disease-free seed potatoes when planting. Practicing crop rotation with non-susceptible crops can also help reduce the build-up of Verticillium dahliae in the soil.

Maintaining soil health through proper irrigation and drainage practices is essential to minimize the impact of this soilborne fungus on potato crops. Applications of organic soil amendments such as composts and certain biofungicide products containing beneficial biocontrol agent microbes like Bacillus or Trichoderma, have been shown to suppress Verticillium. However, results of these soil health focused treatments seem to vary heavily depending on site history and soil properties.

Common Scab:

To address Common Scab, plant scab-resistant potato varieties that are less susceptible to the disease. Additionally, practice crop rotation by avoiding planting potatoes in the same soil consecutively, as this can help reduce scab development. Maintaining proper soil pH levels and avoiding excessive irrigation, which can create conditions favorable for scab development, are also essential strategies. Like with Verticillium Wilt, biofungicides and compost applications have shown the ability to reduce Common scab prevalence, with results varying across locations and specific input employed.

Fusarium Dry Rot/Wilt:

Managing Fusarium Dry Rot/Wilt includes planting resistant potato varieties that are less susceptible to various Fusarium species causing tuber rot and wilting. Crop rotation with non-host crops can help reduce the presence of Fusarium pathogens in the soil.

Ensuring proper soil drainage and using certified disease-free seed potatoes are vital strategies to minimize the impact of Fusarium diseases on potato health and yield.

Early Blight:

Controlling Early Blight involves applying biocontrols and other crop protection products preventatively to protect potato foliage from dark lesions caused by Alternaria solani.

Proper irrigation management to avoid wet foliage and removing infected plant material are crucial steps in managing Early Blight effectively. 

Late Blight (Phytophthora infestans):

Managing Late Blight may involve implementing biocontrol applications to control the spread of the disease. Regularly monitoring crops for early signs of late blight, such as foliar lesions and tuber rot, is crucial for timely intervention and disease management. Selecting early and faster growing varieties of potato can also help mitigate Late Blight impacts on yield and marketability. 

BeCrop Biological Soil Analysis for Disease Treatment and Prevention

BeCrop biological soil analysis offers a valuable data-driven approach for disease treatment and prevention in potatoes, similar to its benefits in vineyards, corn, and soybean. By using BeCrop soil biology analyses, potato farmers can identify soil-borne diseases early and implement timely preventative measures. 

Understanding the microbial communities in potato fields through BeCrop biological soil analysis can help farmers manage soil health effectively, fostering a balanced microbial community that supports healthy soil, potato health and resilience. 

See below a sample report where several diseases above were detected early from a single soil sample.


Protecting potato crops from these diseases requires a proactive approach that combines preventive measures with effective management strategies. By leveraging the insights provided by BeCrop, potato growers can make informed decisions on disease prevention strategies, and ensure the long-term health and productivity of their potato crops.


Note: Biome Makers agronomists have identified some of the top soilborne bacterial and fungal diseases affecting crops in the US. These diseases are found in the soil. While not all soilborne diseases are included, the selected ones are among some of the most impactful, with variability by region. It's important to note that the diseases are not listed in order of impact, and they do not include viruses. The detection of these diseases is made possible by BeCrop technology and soil database, offering valuable insights for crop management and disease prevention.