News
Blightline August 28, 2014
Late blight has been reported in Benton County, MN, in commercial potatoes and been moving into additional fields in this area as a result of rains, high dew points, and cool weather. Growers in central MN should be scouting fields, applying fungicides to reduce tuber infection and killing fields to prevent further movement. Recommended fungicides to reduce tuber infection include Gavel, Omega and Ranman. Late blight is an explosive disease that can spread quickly in cool wet weather so it is important to keep the foliage protected with fungicides late in the season. We would appreciate receiving samples of late blight for genotype identification.
Blightline August 25, 2014
The late blight reported in Becker County was negative after laboratory testing. Growers should continue to apply protectant fungicides for both late blight and early blight and continue to scout for late blight. Morning dews that form this time of the year provide free moisture necessary for late blight infection. Late blight is an explosive disease that can spread quickly in cool wet weather so it is important to keep the foliage protected with fungicides late in the season.
Aphid Alert for Week Ending August 22
Aphid vector numbers were up for A THIRD WEEK IN A ROW! Probably because the temperatures last week were excellent for aphid reproduction and numbers were increasing. This may well have led to an increase in winged aphids, resulting in higher trap catches. Trap catches increased at a number of locations over last week and decreased in some others. Numbers were up in Ada, Erskine, Hallock, Hoople, Langdon, Linton I, Perham, Staples, Stephen and Walhalla and down at other sites. Approximately 80 more aphids were recovered overall from all traps compared to last week.
Late Blight Found in Becker County, MN - Blightline August 22
Late blight has been found in a second county in Minnesota. Today a sample was found in Becker County.
Late Blight reported! Blightling Aug 20, 2014
Late blight has been reported in a field of Russet Burbank processing potatoes in Sherburne County, MN by a local consultant. Disease is confined to one field and incidence is limited. The genotype has not yet been identified. This is the first report of late bight in our region. Growers should continue to apply protectant fungicides for both late blight and early blight and continue to scout for late blight. Morning dews that form this time of the year provide free moisture necessary for late blight infection.
NPPGA Field Day set for August 21, 2014
The annual potato field day tour will travel to three locations - Larimore, Inkster and Hoople - on Aug. 21. The field day begins at 7 a.m. with breakfast at Hoverson Farms near Larimore. Research presentations will begin after breakfast. Lunch and research presentations will be given at the Forest River Colony near Inkster starting at noon. Following lunch, a field tour will highlight irrigated research trials. The twilight tour will be at Oberg Farms near Hoople starting at 5 p.m. This will include a barbecue and research presentations by North Dakota State University and University of Minnesota potato researchers and Extension specialists.
Blightline August 18, 2014
Late blight has not been reported in our region of ND, MN or MB. Growers should be applying protectant fungicides for both late blight and early blight and continue to scout for late blight. Morning dews that form this time of the year provide free moisture necessary for late blight infection.
Aphid Alert II
Aphid Alert II trap catches for the week ending Aug 15 are now available. Aphid vector numbers in seed potatoes took a huge jump this past week with capture numbers doubling at most locations! Vector species captured include lots of small grain aphids (not surprising given maturing small grains), green peach aphid from two locations, and soybean aphid from multiple locations. Aphid scouting and management should be well underway! If you're in a position to kill vines early, consider it. Most of our PVY is transmitted in the late season.
Blightline Aug 11
Late blight has not been reported in our region of ND, MN or MB. The late blight severity threshold value of 15 has been reached at all locations. For our conditions, application of a protectant fungicide such as mancozeb or chlorothalonil on a 7-10 day schedule is recommended.
Christian Thill
It is with great sadness that I have to tell you Christian Thill passed away unexpectedly on Friday morning of an irregular heart beat.
Aphid Alert II: Aug 8. Aphid number are increasing rapidly!
Trap catches from the Aphid Alert II suction trap network are in for the week ending Aug 8. This has been one of the biggest capture weeks so far this summer. We had large increases in almost all trap locations over last week. If you have not started aphid management, it's time to start!
Blightline August 7, 2014
Late blight has not been reported in our region of ND, MN or MB. The late blight severity threshold value of 15 has been reached at all locations. For our conditions, application of a protectant fungicide such as mancozeb or chlorothalonil on a 7-10 day schedule is recommended.
Focus on Potato: Phosphorous Acid and its use in Potato Post-Harvest Situations
Dr. Steven Johnson from the University of Maine. This presentation will help consultants, extension agents, growers, and other practitioners in the potato-producing states to understand more about phosphorous acid and its use in potato post-harvest situations. Specifically in this presentation, practitioners will learn the differences between phosphorus containing compound used in agriculture, what pathogens are controlled by phosphorous acid, and how to apply the material onto potatoes entering storages. By the end of this presentation, the practitioner should increase their knowledge of phosphorous acid and how to best use it in potato post-harvest situations for optimal disease control.
Blightline August 4, 2014
Late blight has not been reported in our region of ND, MN or MB. The late blight severity threshold value of 15 has been reached at all locations except Williston. For our conditions, application of a protectant fungicide such as mancozeb or chlorothalonil on a 7-10 day schedule is recommended.
Aphid Alert up to August 1
Aphid counts were down this week over last with only the Ada site reporting more than 10 vector species individuals. Even numbers of non-vector aphid species were down this week, indicating that aphid flights were suppressed but warmer temps, especially nights, may well drive numbers higher (or then again, maybe autumn is coming - nothing would surprise me about this summer!). Bird cherry oat aphids were again the most numerous vector species and was recovered from 13 of the 18 sites reporting. No green peach aphids or soybean aphids were recovered in any trap but green peach aphids were found in our greenhouse on potted potato plants. We suspect they were already present in low numbers and the warmer days increased their reproductive rate in the greenhouse.
Blightline July 28, 2014
Late blight has not been reported in our region of ND, MN or MB. The late blight severity threshold value of 15 has been reached at all locations except Beach, Leonard, and Williston, which are at 13, 10 and 14 respectively. Weather conditions at all sites except these three have accumulated sufficiently for late blight to occur if inoculum is present, and application of a protectant fungicide such as mancozeb or chlorothalonil should be applied on a 7-10 day schedule is recommended.
Aphid Alert
A new Aphid Alert is now available at aphidalert.blogspot.com or aphidalert.umn.edu. This includes trap catches from sites up to July 18th. Aphid numbers are increasing, but most are bird cherry oat aphid and green bug. Please go to Dr. MacRae's webpage for more information.
Blightline July 24, 2014
No late blight has been reported in our region. The recent storm caused late blight severity values to increase quickly the past three days. The threshold value of 15 has been reached at all locations except Beach, Leonard, Williston, Grand Forks and St. Thomas. At the severity value threshold of 15, weather conditions have accumulated sufficiently for late blight to occur if inoculum is present. Application of a protectant fungicide such as mancozeb or chlorothalonil on a 7-10 day schedule is recommended.
Blightline July 21, 2014
No late blight has been reported in our region. Late blight has been reported in potatoes Portage County, Wisconsin; the late blight is not widespread. Late blight severity values generally did not increase over weekend. If severity values in your area have accumulated to 15, application of a protectant fungicide such as mancozeb or chlorothalonil on a 7-10 day schedule is recommended. Many sites have reached this threshold.
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