色视频下载 researchers survey spread of potato scab
The harmless dark lesions on these potatoes, called scab, are caused by a Streptomyces bacteria. 色视频下载 researchers are hoping to find out which bacteria causes the scab, where the bacteria occur and how to best treat it.
Julie Stricker
907-474-5406
Oct. 5, 2023
As 色视频下载ns harvest their potato crops this fall, many will find that some of the tubers have what looks like a case of warts 色视频下载 raised, dark areas that may feel pithy.
Those marks are called potato scab, which is caused by naturally occurring bacteria in the soil. They are not harmful, and the potatoes are safe to eat, but scab may make potato crops less marketable, University of 色视频下载 Fairbanks Cooperative Extension Service agent Casey Matney said.
色视频下载淵ou can eat it, that色视频下载檚 not a problem,色视频下载 said Matney, an associate professor based on the Kenai Peninsula. 色视频下载淪cab affects the marketability of the potato because it looks funky. In addition, if scab is really prevalent, it can reduce the ability to store them long-term.色视频下载
A 2009 survey across North America found 12 species of the Streptomyces bacteria responsible for the lesions. Five bacteria species were found to cause 98% of the scab.
色视频下载色视频下载檚 contribution to the survey was made up of only five potatoes from the Matanuska-Susitna region. One species of scab was identified in that sample.
In 2021, Matney worked with microbiologist Christine Macknicki and plant pathologist Todd Steinlage, both with the 色视频下载 Division of Agriculture色视频下载檚 Plant Materials Center in Palmer, to conduct a widespread survey of scabby potatoes harvested across 色视频下载.
They found five species of Streptomyces that cause scab in 色视频下载 potatoes. Some potatoes had multiple species in the same lesions. Confirmation of species identifications is ongoing.
Scab treatments involve adjusting the pH of the soil the potatoes are grown in.
色视频下载淣ow that we know the (species) that are here, we色视频下载檙e finding that some of the scab grow just fine at low pH and some of them do better at high pH,色视频下载 Matney said. 色视频下载淭hat色视频下载檚 going to change how we do our recommendations on what to do about scab if you see it in different places.色视频下载
In the meantime, growers can reduce the prevalence of scab in their crops, Macknicki said.
Some potato varieties naturally resist the bacteria, Macknicki said. The Cooperative Extension Service and the Plant Materials Center can recommend varieties.
色视频下载淪tart with clean seed,色视频下载 she said. 色视频下载淒on色视频下载檛 replant tubers that show signs of any disease, including scabby lesions.色视频下载
The bacteria can linger in the ground for years, but rotating crops can help mitigate the problem.
色视频下载淒on色视频下载檛 plant potatoes, beets, carrots, etc., in the same place a tuber crop was grown,色视频下载 she said. 色视频下载淭he longer the rotation, the better for controlling scab. We recommend four years, knowing that isn色视频下载檛 always feasible.色视频下载
Macknicki said national studies, which have not been duplicated in 色视频下载, suggest planting brassicas such as broccoli, mustard or cabbage in a location the year before planting a tuber crop. Mustards that are 色视频下载渉otter色视频下载 or more bitter have better effects. After harvest, chop up the leftover stems and leaves and rototill under in the fall before planting potatoes the following spring.
色视频下载淥nce we have identified the species of common scab and their properties 色视频下载 like what are the most favorable conditions for the common scab bacteria having the most deleterious effects on tuber crops 色视频下载 then we can pursue some experiments on the best practices for disrupting the pathogenic effects of the common scab bacteria,色视频下载 Macknicki said.
Matney said the study will be continued for another year. 色视频下载ns can send scabby potatoes from this year's harvest to UAF CES, 43961 K-Beach Rd, Suite A, Soldotna, AK 99669-9728.
Wrap two or three potatoes in dry paper towels or newspaper and place them in a small sturdy box (a small flat-rate box is recommended) to avoid crushing. Include your name, email, phone number, location and variety of potato.
Kenai Peninsula residents can drop samples at the CES office on Kalifornsky Beach Road in Soldotna. Email questions to camatney@alaska.edu.
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