Potato Extension
Aphid Alert - 9 Aug 17
This is officially a high aphid year! PVY Vector Risk INdex values are much higher than last year's totals at almost all locations. With the increasing numbers of vectors, we strongly recommend scouting and the use of crop oils. Anti-feeding insecticides should be applied if required. We continue to see high aphid numbers as well as an increasing PVY risk index. High capture numbers are widespread across the region with 11 of 16 trap locations reporting close to or over 100 aphid vectors.
Blightline August 3, 2017
Late blight has been confirmed in two commercial potato fields southeast of Perham in Ottertail County, MN. Late blight has also been reported near Veseleyville in Walsh County. We recommend that all potato fields in these areas should be thoroughly scouted for the presence of late blight. Growers in areas where late blight is present should apply a specialty fungicide with strong activity against late blight, such as Orondis, Revus Top or Ranman, Omega or Gavel. Curzate is recommended after a rain because it will kill late blight infections that are less than two days old.
Blightline July 31, 2017
Late blight has been confirmed in a commercial potato field in Pembina County, ND. The genotype is US23. Additional late blight has been reported in Walsh County, ND and Nelson County, ND. Because of the widespread findings of late blight, we recommend that all potato fields in northeastern ND should be thoroughly scouted for the presence of late blight. Growers in areas where late blight is present should apply a specialty fungicide with strong activity against late blight, such as Orondis, Revus Top or Ranman, Omega or Gavel.
Aphid Alert
Trap catch did vary slightly this week. Vector numbers were up at Brooks (81), Gully (35), Moran (25), McVille (84), Hoople (92), Staples (39) and Humboldt (183) vectors. This year continues to be a very high vector year. Soybean aphids are still on the rise throughout much of MN. Some of these populations continue to show pyrethroid resistance. Due to another week of high vector catch numbers, crop oils are again highly recommended
Late Blight Confirmed in North Dakota
Late blight was confirmed in a potato sample on Thursday July 27 from Pembina County, North Dakota. The genotype is not yet known. Conditions have been favorable for late blight spread and infection, and growers in this area should apply a late blight specialty fungicide immediately. All growers in northeast North Dakota and northwest Minnesota should scout potato fields for late blight and be ready to apply late blight fungicides.
The Impact of Dicamba Herbicide on Potato Yield, Quality, and Seed Viability
The presentation explains the effects dicamba has on potato leaves, tubers, and seed when planted back. Dicamba is a translocating herbicide that will express injury in the growing points of plants. When a low dose of unintended herbicide comes in contact with a sensitive crop, such as potato, the results can be devastating for the potato plant and tubers. New leaves become twisted, cupped and malformed, while tuber number can be reduced and malformed.
Aphid Alert (July 14)
Looks like it might be turning into an aphid year. We saw high trp catches at some locations this week and we're seeing a lot of diversity in the species being captured. Six sites this week had trap catches containing more than 20 vectors of varying efficiencies: Humboldt (35), Ada (41), Crookston (49), Sabin (25), and Brooks (39) in MN and Hoople (26) in ND. However, Green peach aphid (the most efficient vector) was recovered from traps in Perham, Crookston, Sabin, and Brooks.
Blightline July 17, 2017
No late blight has been reported in ND, MN or MB. Late blight has been reported in central WA (US8) and in MI (US23). Late blight severity values accumulated in the northern half of the Red River Valley in both MN and ND. Many areas have reached or exceeded the late blight threshold value of 15. This indicates that conditions have been favorable for late blight infection if inoculum is present. A protectant fungicide should be applied when the threshold value reaches 15 or just prior to row closure, whichever occurs first. It continues to be important to scout for late blight in those areas where the threshold has been reached concentrating on areas of the field that stay wet longer such as along tree lines and low areas where water accumulates.
Helping Growers Manage Potato Psyllids & Zebra Chip in the Columbia Basin of Washington State
This presentation explains efforts to help Washington’s potato industry manage potato psyllids and zebra chip disease. It describes a regional insect monitoring program and pest alert system in the Columbia Basin of Washington. Viewers from all potato-growing regions will learn more about zebra chip disease and its vector, the potato psyllid. This includes descriptions of 1) psyllid life stages and how each can be monitored in potato fields; 2) how zebra chip is spread by psyllids; and 3) psyllid yellows disorder caused by potato psyllid nymph feeding. The presentation includes a review of zebra chip incidence in the Columbia Basin in the six years since it was first detected in the region. It also explains what has been learned about psyllid overwintering in the region and seasonal dispersal. Insecticide recommendations for managing potato psyllids and zebra chip in the Columbia Basin are described.
Potato Growth and Development
This presentation will help consultants, growers and other practitioners in North America understand potato growth and development as it impacts yield and quality. Specifically, this presentation will focus on key growth stages in crop development, and how management practices can impact each of those stages.
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