Effects of Hail on Potatoes

By Harlene Hatterman-Valenti from Focus on Potato. Published on Oct 10, 2018.

While issues related to weather seem to always concern growers due to their unpredictability, hail injury is a weather issue that can greatly reduce marketable yield depending on the cultivar grown, the seriousness of the hail storm, and plant growth stage when the hail occurs.

Remote Scouting in Agricultural Systems

By Ian MacRae from Focus on Potato. Published on Apr 23, 2018.

Recent advances in the size and efficiency of remote sensing cameras and systems and in unmanned aircraft systems (UAS or 'drones') have been driving a rising interest in using these technologies in pest management. Remote sensing of plant disease has tremendous potential in agriculture, but research is needed to develop these diagnostic tools. This presentation will discuss the background and techniques of remotely scouting plant disease with small UAS and some of the benefits and limitations of the technology.

Stubby-Root Nematodes and Corky Ring Spot of Potato

By George W. Bird from Focus on Potato. Published on Aug 31, 2017.

Corky Ringspot is a serious infectious disease of potato. When present, tuber losses can be as high as 50%. The primary symptoms are characteristic concentric rings on tuber skin and internal tissues. The disease is caused by the Tobacco Rattle Virus and vectored by Stubby-Root Nematodes. The virus has a wide host range and stubby-root nematodes are often found at soil depths greater than 12 inches. This presentation is designed to assist potato growers, professional consultants and other practitioners, throughout all potato growing regions, in understanding and managing Corky Ring Spot. It contains information about symptoms of the disease, Tobacco Rattle Virus, Stubby-Root Nematodes and how to sample for this nematode, in addition to the management strategies of containment, exclusion and nematode population control. Special reference is given to chemical and biological control options and the topic of soil health. After hearing this presentation, members of the potato growing community should have a general overall understanding of the nature of Corky Ring Spot and options for managing this key disease.

Enlarged Lenticels

By Andy Robinson from Focus on Potato. Published on Aug 31, 2017.

This presentation will assist growers, consultants, and other practitioners involved in all regions of the potato industry to better understand and manage enlarged lenticels. The presentation provides information on the development of lenticels, effects of lenticel infections and how to management lenticel spot.

Seed Potato Certification

By Robert D. Davidson from Focus on Potato. Published on Jul 31, 2017.

This presentation will help consultants, growers and other practitioners in the U.S. and Canada learn about the basics of seed potato certification. Specifically, in this presentation, the basis for seed potato certification and the current process being followed will be described. Additionally, discussion will center on which diseases and conditions are the focus of inspections and how these problems are managed, or not, through the use of clean, high quality seed potatoes. Finally, viewers will learn the certification process and what the use of clean seed means for other seed growers and the commercial industry.

What Is the Source of Potato Psyllids Colonizing Potato Fields in the Pacific Northwest?

By David Horton from Focus on Potato. Published on May 31, 2017.

The outbreak of zebra chip disease in potato fields of Washington, Oregon, and Idaho in 2011 has led to substantial disruption of established IPM programs in potatoes. Managing zebra chip disease requires controlling potato psyllid, the insect which vectors the bacterium causing the disease, and uncertainties in understanding biology of potato psyllid in the Pacific Northwest has forced growers to rely on calendar-based applications of insecticides to prevent establishment of infective psyllids in their fields. This presentation will examine the possible role of two non-crop host plants of potato psyllid - bittersweet nightshade and matrimony vine - as possible "bridge" hosts between late winter emergence of potato psyllid from overwintering quarters and late spring emergence of the potato crop. Understanding psyllid biology on non-crop plants in the Pacific Northwest will allow growers to better predict when seasonally and in what fields potato psyllid is likely to first arrive.

Potato Growth and Development

By Mike Thornton from Focus on Potato. Published on Apr 28, 2017.

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.

Helping Growers Manage Potato Psyllids and Zebra Chip in the Columbia Basin of Washington State

By Carrie H. Wohleb from Focus on Potato. Published on Mar 31, 2017.

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.

Fungicide Management of Rhizoctonia Canker and Black Scurf

By Jeff Miller from Focus on Potato. Published on Feb 27, 2017.

Rhizoctonia canker and black scurf causes economic loss to potato growers by decreasing tuber quality, and yield in severe cases. This webinar will focus on how fungicides can be used effectively to manage this disease.

Practical Management of Powdery Scab

By Robert D. Davidson from Focus on Potato. Published on Feb 09, 2017.

This presentation will aid consultants and growers in understanding how to identify powdery scab of potato and manage this disease using an integrated approach to control. Key symptoms used to identify the various stages of the disease will be described and contrasted with other similar problems. Details of the pathogen, host, disease cycle, and environmental factors affecting symptom development, will be discussed. Much attention will be given to management options for this disease including avoiding the disease, measuring the inoculum load in soil, making the appropriate cultivar selections based upon the field history, resistance of a given cultivar, inoculum levels, and environment, and utilizing specific chemical control when warranted. Understanding the full integration of several different strategies for the producer are key to managing this potentially devastating and hard to control disease.

Epidemiology and Management of Potato White Mold

By Dennis A. Johnson from Focus on Potato. Published on Nov 16, 2016.

White mold is one of several important foliar diseases that potentially affect potato production due to reductions in tuber yield and increase disease management costs. This presentation will help potato growers and field managers in potato production regions understand how the fungus that cause white mold colonizes host substrates to initiate disease, infects healthy potato foliage, and is most efficiently managed. Environmental and host factors that affect disease spread and progression will be discussed. The rolls of sclerotia in overwintering of the pathogen, of apothecia and ascospores in disease spread, senescent host tissue for initial infection and how they all relate to disease management will be presented. By the end of the presentation, those that listen will know more about the epidemiology of white mold and will be well equipped to manage the disease.

Late Blight Management Under Semi-Arid Conditions

By Jeff Miller from Focus on Potato. Published on Oct 13, 2016.

Late blight has the potential to be one of the most destructive diseases for potato growers. Late blight is influenced largely by environmental conditions. Management under semi-arid conditions can be quite different than managing the disease under wet, humid conditions. This presentation outlines effective control practices for growers who raise potatoes under semi-arid conditions. This presentation addresses the effect of irrigation on late blight, fungicide efficacy against late blight, the impact of weather, timing of fungicide applications, the effect of application method on fungicide residue, and the role of post-harvest products.

Integrated Late Blight Management

By Amanda Gevens from Focus on Potato. Published on Apr 29, 2016.

Late blight is a potentially destructive disease of potato and tomato crops worldwide. While the disease has been studied by many for over a century, changes within the Phytophthora infestans pathogen population have required further in depth investigation for management. From 2009 to the current, a group of newly identified genotypes/clonal lineages/strains of the pathogen were identified, with US-23 becoming most predominant in both tomato and potato production areas of the continental U.S. This presentation will offer new information on the characterization of US-23 and other newer clonal lineages as it pertains to pathogen persistence and management. Further, a process for integrated late blight management, established for Wisconsin, will be shared to aid practitioners in understanding critical concepts of the pathogen and fungicides to enhance overall disease management.

Dickeya: A Scottish, UK and European Perspective

By Gerry Saddler from Focus on Potato. Published on Apr 29, 2016.

Blackleg, a disease that has had little impact on potato production in North America over the years is showing worrying signs in recent times that it's on the move. It's a disease that has plagued potato production in Europe for decades and can be caused by a number of different bacteria Dickeya and Pectobacterium species. Potatoes producers up and down the East Coast are rightly concerned and this presentation should give practitioners and growers an overview of the European experience of the disease, update them on ongoing research and explain what the European authorities and industry are doing to combat the problem. By the end of this presentation, the practitioner should have a better understanding of the disease, the pathogens involved and current advice on disease management practice.

Blemishes of Table Potatoes: Common Biotic Causes

By Jacquie van der Waals from Focus on Potato. Published on Mar 01, 2016.

Potato tubers are affected by a number of blemishes, which can cause severe economic losses, in terms of rejection of seed batches, yield losses, downgrading of potatoes on the market, or rejection of processing potatoes. Despite the fact that many blemishes are merely cosmetic in nature, the demand by consumers for washed potatoes has exacerbated the problem of rejection of blemished tubers. Tuber blemishes are broadly classified as typical or atypical. Typical blemishes have known causes, for example pests, pathogens or specific abiotic factors; while the cause(s) of atypical blemishes have yet to be determined. Correct diagnosis of a tuber blemish is important in management of the disease and prevention of future occurrences of the blemish. This presentation covers the causal agents, symptoms and management of the most common typical tuber blemishes with biotic causes, and can serve as a guide for growers and others in the potato industry to help with identification of these blemishes.

Pythium Leak of Potato

By Lyndon Porter from Focus on Potato. Published on Dec 14, 2015.

This presentation provides a synopsis of Pythium leak of potato. Growers, consultants, students and people interested in the potato industry will come to understand the pathogen, disease symptoms, epidemiology and management strategies associated with this worldwide disease of potato. Pythium leak can be a major storage disease and this presentation will discuss practices to limit issues in storage facilities. Development of resistance by the pathogen in the US to the fungicide metalaxyl will be discussed and its implications.

"It's Significant to Me!" The Purpose of Using Statistics in Agricultural Research

By Jeff Miller from Focus on Potato. Published on Oct 28, 2015.

Have you ever listened to a scientific presentation and heard the phrase, "but the differences were not significant"? Or have you ever wondered why researchers put letters next to number in tables or on graphs? This presentation will answer these questions. Additionally, this presentation will help viewers make sense of how information is used in relation to making claims about performance of products used in crop production. Specifically we will present examples of how data are collected from small plot and large scale research trials, show how those data should be presented, and answer the question, "is it really significant to me?"

Optimizing Shank Injection Fumigation Using Metam Sodium

By Neil C. Gudmestad from Focus on Potato. Published on .

The soil fumigant metam sodium continues to play an important role in the management of soil borne pests of potato such as Verticillium dahliae, the primary cause of early dying, and the root lesion nematode, Pratylenchus penetrans. Recent label changes resulting from the re-registration of metam sodium by the EPA have made the application of the fumigant through water applications very difficult due to the requirement of large buffer zones to reduce human and animal exposure to the chemical. As a result, there has been a dramatic increase in the application of metam sodium via shank injection. This method of application is not as efficacious as water applications of metam sodium. This presentation will discuss the most recent research conducted at North Dakota State University directed at improving the efficacy of shank injection metam sodium.

Managing Diseases with Biopesticides in Potato Production

By Amanda Gevens from Focus on Potato. Published on Jun 26, 2015.

Potato diseases account for a significant portion of crop production costs and yield losses each year. A broad range of plant pathogens can impact quality and yield of potato plants both in the field and post-harvest in transit or storage. For some chronic diseases, fungicides are essential to protect yield and quality. Growers, now more than ever, have an increasing number of biopesticide options available to integrate into their overall disease management programs. Understanding the modes of action of biopesticides is critical in making such products work for successful disease management. This presentation will address some of the basics of biopesticides including product categories, modes of action, and efficacy as they pertain to conventional potato systems.

Best Management Tactics and Fungicide Resistance in Alternaria Populations (Early Blight and Brown Spot)

By Lydia Tymon from Focus on Potato. Published on May 29, 2015.

Broad-spectrum fungicides are the primary products used for the management of Alternaria. However, a shift to include narrow spectrum fungicides in rotation was made in order to minimize the impacts on mammal toxicity and alleviate environmental concerns due to chemical residues. Fungicide resistance must be taken into account when the chemical affects a single site and is repeatedly used. This presentation will provide consultants and growers with the best practices to manage early blight on potato. It will review fungicide basics, exhibit how quickly fungicide resistance develops, will briefly compare pathogenicity and aggressiveness of the early blight pathogen, A. solani, to the brown spot pathogen, A. alternata, and review best management tactics for early blight.

Preventing the Spread of Potato Viruses: What Insecticides Can and Cannot Do

By Andrei Alyokhin from Focus on Potato. Published on Apr 24, 2015.

Potato Leaf Roll Virus (PLRV) and Potato Virus Y (PVY) are the two most serious viral diseases affecting potato growers in North America. Each virus is characterized by its own distinct epidemiology, and should be treated accordingly. This presentation will help consultants, growers, and other practitioners in North America to optimize insecticide use for controlling aphid vectors of PLRV and PVY in their crops. Practitioners will learn the differences between persistently and non-persistently transmitted viruses, between colonizing and non-colonizing aphid species, and their implications for making proper decisions on using insecticides.

Genetics of Late Blight Real World Implications

By Bill Fry from Focus on Potato. Published on Mar 27, 2015.

This presentation explains many of the genetic characteristics (general and unique) of Phytophthora infestans. It starts with a chronological description of the gradually increasingly accurate understanding of the genetics of this oomycete. It emphasizes the population genetics worldwide, but with special emphasis on the United States. A major theme is that "migration" has played a huge role in the diversity of populations in the USA and worldwide. An accurate understanding of the simple population genetic structure of this organism in the USA can be used to improve efforts to mitigate the harmful effects of this pathogen.

Sanitation for Bacterial Ring Rot

By Gary Secor from Focus on Potato. Published on Dec 26, 2014.

This presentation will help consultants, growers, and other practitioners in potato producing areas throughout the U.S. implement proper sanitation and disinfectant procedures for bacterial ring rot, a zero tolerance disease in the seed potato industry. Periodic outbreaks of this disease require vigilant testing and sanitation to prevent and manage additional spread and infection. This presentation explains how the Cms bacteria survive, proper disinfection procedures to prevent ring rot, suggestions for cleaning facilities and equipment if you have ring rot, and characteristics of frequently used disinfectants. By the end of this presentation, practitioners and potato growers should understand proper sanitation and disinfection procedures to reduce the risk of bacterial ring rot in potato operations and farms.

Update on Potato Sprout Control

By Nora Olsen from Focus on Potato. Published on Oct 24, 2014.

This presentation will update growers and industry personnel in the US on potato sprout control options. Specifically, advances in technology, development of new products and formulations, and coordination of control programs have allowed flexibility and fine-tuning of sprout control in the industry. Variety differences, storage management practices, and consumer expectations have necessitated an integration of ways to minimize sprout development in storage, through the cold chain, and/or in retail displays. General background and specific program options will be discussed. Information provided will help in the development of an individualized integrated program based upon variety, storage conditions, and market.

Root Lesion Nematode on Potato

By Ann MacGuidwin from Focus on Potato. Published on Sep 26, 2014.

This presentation will help consultants, growers, and other practioners scout and manage root lesion nematodes, the most common nematode pest in most potato fields. This presentation will explain when to be concerned about root lesion nematodes, the interaction of root lesion and Verticillium dahliae for the potato early dying disease, and the options available to maintain population densities of root lesion nematodes below damaging levels. The life cycle of root lesion nematodes will be covered including their remarkable ability to persist without feeding. By the end of this presentation, the practitioner should know more about the root lesion nematode life cycle, be aware of their patchy distribution in the field, understand the importance of managing nematodes throughout the entire rotation, and have a general knowledge of the tools available to do so.

Managing Fungicide Resistance in Potato

By Barry J. Jacobsen from Focus on Potato. Published on Aug 11, 2014.

This presentation will help potato growers, consultants, agribusiness personnel and others associated with the potato industry in North America understand and manage problems associated with fungicide resistance. This presentation will discuss the different modes of action of fungicides currently registered for use on potatoes in the USA, the risks of developing fungicide resistance and practices to minimize the development of fungicide resistance problems in production fields.

Phosphorous Acid and its use in Potato Post-Harvest Situations

By Steven B. Johnson from Focus on Potato. Published on Jul 30, 2014.

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.

Factors That Cause Sugar Ends in Potatoes

By Mike Thornton from Focus on Potato. Published on May 30, 2014.

This presentation will help consultants, growers and other practitioners in North America understand the development of the physiological disorder called "sugar ends" in processing potatoes. Specifically, this presentation will focus on key stress factors associated with the development of sugar ends, and the management practices that help reduce this disorder.

Hairy Nightshade Control, Biology and Competition in Potatoes

By Pamela J.S. Hutchinson from Focus on Potato. Published on Apr 30, 2014.

This two-part presentation will help consultants, growers, and other practitioners in United States potato production areas understand the hairy nightshade's biology, how it competes with various potato varieties, and controlling this weed with cultural and herbicide methods. Included in part one, titled Nightshade Control in Potatoes, is information about control of hairy nightshade and other weeds problematic in potato, including cutleaf, black, and eastern black nightshade. Hairy nightshade has proved troublesome in potatoes for reasons such as 1. same family as potato so control methods safe to the crop and detrimental to the weed may be limited, 2. can germinate the entire potato growing season, therefore, control must last season-long, and 3. even if controlled early to avoid competition with resulting yield losses, later germinating hairy nightshade can host insects, diseases, or nematodes which are detrimental to potato. Part two discusses the biology of hairy nightshade. When a practitioner fully understands the biology of hairy nightshade, then putting together effective integrated weed management strategies to target this weed is possible.

Building an IPM Approach for Managing the Potato Tuberworm

By Silvia I. Rondon from Focus on Potato. Published on Apr 30, 2014.

This presentation will help consultants, growers, and other practitioners in potato production regions in the U.S. to understand the biology, ecological distribution and management of the potato tuberworm (a.k.a. potato tuber moth). Specifically in this presentation, practitioners will learn: how to ID the problem, how to establish integrated pest management programs gathering the most relevant up-to-date information. By the end of this presentation, the practitioner should know more about the potato tuberworm, a worldwide potato pest.

Phytoplasmas in Potatoes

By Ian MacRae from Focus on Potato. Published on Feb 04, 2014.

This presentation will help producers, agricultural professionals and others in the North Central region and other potato producing areas recognize and manage the phytoplasma disease, Purple Top in potatoes. In this presentation, the biology of the phytoplasma causing Purple Top and its insect vector, the aster leafhopper, are discussed as well as potential management of the disease in potato production. The disease, its symptoms and impacts are reviewed and the epidemiology resulting from the life history, distribution and movement of the vector/pathogen complex is presented.

Potato Mop-Top Virus: An Emerging Problem in Potato Production

By Jim Crosslin from Focus on Potato. Published on Dec 30, 2013.

This presentation will provide consultants, growers, and other practitioners in the potato growing regions of the US with important information on Potato mop top virus. This virus has traditionally been most important in Northern Europe and parts of South America. However, it has been reported relatively recently in several areas of Canada and the US, including Maine, North Dakota, Washington, and most recently in Idaho. Anecdotal reports from growers and processors suggest that the virus is increasing in importance in several potato-growing regions. This presentation will illustrate the various types of symptoms produced by PMTV and provide some guidelines for management of this soil-borne virus.

The Value of Pesticides

By Jeff Miller from Focus on Potato. Published on Nov 25, 2013.

Pesticides are an important component in the production of a healthy potato crop. Unfortunately, the general public does not understand the value of pesticides. Much of the information available on the internet focuses on the perceived risk of pesticides and largely ignores the benefits. This presentation provided a general overview of the regulation and benefits of pesticides and the value they add to our society.

Managing Weed Resistance to Herbicides in the Potato Rotation

By Jed Colquhoun from Focus on Potato. Published on Oct 30, 2013.

This presentation will help U.S. potato consultants, growers, and other practitioners manage weeds across the crop rotation in a way that minimizes the risk for herbicide resistance development. Herbicide-resistant weeds pose significant economic and production challenges, particularly in specialty crops such as potatoes where weed control options are already limited. This presentation will provide an update on herbicide-resistant weeds and a systematic way to assign herbicides to crops across the rotation in a manner that maintains weed control while utilizing multiple herbicide modes of action.

Ammonia Volatilization

By Donald A. Horneck from Focus on Potato. Published on Sep 25, 2013.

This presentation will help growers and consultants use nitrogen more efficiently and reduce nitrogen emissions into the atmosphere. Loss of nitrogen from our agriculture systems is costly to both a growers economics as well as to us environmentally. Ammonia volatilization is one of the principle ways that nitrogen is lost to the air. Knowing how to manage nitrogen to minimize this loss is key to making growers more efficient and reducing our environmental impact.

Chemical Control of Foliar Plant Diseases in Potato: Application of Fungicides

By Philip B. Hamm from Focus on Potato. Published on Aug 30, 2013.

This presentation will help consultants, growers, and other practitioners where ever potatoes are produced. Foliar fungicides are commonly used to protect potatoes from a number of devastating foliar diseases, particularly late blight. Knowing the factors that contribute to the best application (most product applied) regardless of method (air, ground or chemigation) will help to ensure the best protection, for the longest time period, and save money. Information will be presented detailing where fungicides can be found in the potato canopy following application by the different methods, how much of the material applied still remains by canopy level nearly a week later, and what are the results of repeated applications related to fungicide amount through time. Information is shared provided on how fungicide amounts can be increased by some application methods, what increasing or decreasing water amounts used during application impact or not, fungicide deposition, and why timing of application is important to get the best disease control possible.

Potato Psyllid Trapping and Management

By Don Henne and Erik J. Wenninger from Focus on Potato. Published on Jul 30, 2013.

Potato Psyllid Monitoring and Management in Texas will help consultants, growers, and other practitioners in the potato growing regions of the U.S. to better understand zebra chip disease symptoms, monitoring potato psyllid populations, and advice on effective management of potato psyllids. More specifically, the audience will learn about the history of zebra chip disease and states affected, disease symptoms above and below ground, the potato psyllid and potato psyllid research, sampling and monitoring of potato psyllid populations, challenges to psyllid management, useful management approaches, and resistance management. Although much of the presentation contains information obtained from research in Texas, there is much to be learned by practitioners from other potato growing regions. Potato Psyllid and Zebra Chip in Idaho will help growers, consultants, and other practitioners involved in the potato industry in the Pacific Northwest to understand more about potato psyllids and zebra chip in our growing region, particularly in Idaho. Specifically in this presentation, practitioners will learn about: the recent emergence of zebra chip in the Pacific Northwest, results of the monitoring efforts for potato psyllids in Idaho during 2012, and current research at the University of Idaho aimed at understanding the biology and management of potato psyllids and zebra chip in our area. After viewing this presentation, one should know more about the ongoing efforts at University of Idaho aimed at understanding the distribution and abundance of potato psyllids across our state and at developing management strategies for this vector of the zebra chip pathogen.

Rotating New Chemistries in Potato Pest Management

By Russell L. Groves from Focus on Potato. Published on Jun 18, 2013.

This presentation will help consultants, growers, and other pest management practitioners in the upper Midwest potato growing region(s) to better understand the need for effective rotation of insecticide chemistries to gain adequate and longer-term control of problematic insect pests like the Colorado potato beetle. This insect pest has a long history of rapidly generating resistance to most pesticides in the Eastern and Midwestern US. Over the past 15 years, the principal form of control used to management populations of the Colorado potato beetle has been centered on the use of the neonicotinoid class of insecticides (IRAC 2013, Mode of Action Class 4A). This reliance has lead to the development of localized resistance and novel, reduced-risk insecticides are now required to offset these losses in control. An improved understanding of how effective insecticide rotations, using different MoA classes, is a key component of effective insecticide resistance management planning.

Petiole Analysis as a Diagnostic Tool for Improving Potato Nutrition

By Carl Rosen from Focus on Potato. Published on Jun 18, 2013.

This presentation will help consultants, county agents, growers, and other practitioners in potato-producing states to understand how petiole analysis can be used as a diagnostic tool to help improve nutrition of the potato crop. Specifically in this presentation, practitioners will learn: the principles behind using tissue nutrient analysis for crop production, the proper procedures for taking a petiole sample, how to interpret the results following analysis, and use of petiole nitrate analysis as a guide for in-season nitrogen fertilizer application. By the end of this presentation, the practitioner should know more about appropriate use of petiole analysis for potato production.

Verticillium Wilt: Potato Early Dying

By Dennis A. Johnson from Focus on Potato. Published on Jun 03, 2013.

This presentation provides an overview of Verticillium wilt of potato. It is intended to help growers, consultants, and students to better understand the epidemiology and management of the disease. The presentation shows representative color images of disease symptoms, describes the disease cycle, and discusses disease management strategies. Sources of initial inoculum, development of the pathogen within plants and development of the disease in fields are discussed. A distinction is made between Verticillium wilt and potato early dying.

Effect of Glyphosate on Potatoes

By Andrew P. Robinson from Focus on Potato. Published on May 01, 2013.

This presentation will assist growers, consultants, and other practitioners involved in all regions of the potato industry to better understand and identify the effects of glyphosate in potatoes and how it can be managed. The presentation provides a short background on glyphosate, describes injury symptoms of glyphosate in potatoes, and details symptoms of glyphosate residues that remain in seed through storage and are planted the following year. Strategies to manage glyphosate in potato are discussed.

Late Blight Forecasting

By Bill Fry from Focus on Potato. Published on Apr 01, 2013.

This presentation will help consultants, practitioner, and growers to understand late blight forecasts and to more manage late blight more effectively. First, the epidemiological basis for (potato) late blight forecasts is described. In the potato production system in most temperate regions where sexual reproduction does not occur, survival from one season to the next is in association with an infected host (typically potato tubers). Most forecasts allow a period of time early in the season before which fungicide sprays are not necessary and the presentation describes the most popular systems in the USA. The presentation then describes a Decision Support System (DSS) that can be used in "real time" as an aid in scheduling fungicide sprays. The DSS integrates the effect of weather, host resistance and fungicide to assure adequate disease suppression.

Metam Sodium: Implementation of Phase II Labeling

By Kyle Coleman from Focus on Potato. Published on Feb 28, 2013.

For decades, growers of high value crops have relied heavily upon metam sodium and metam potassium products to control weeds, disease and nematodes. Soil fumigation is one of the most costly inputs for crop production, but without it, many crops such as potatoes, onions and carrots would fail. In order to comply with EPA registration eligibility standards, numerous studies and label changes are underway. Label changes and required activities designed to address stewardship of the product are contained with the Phase I and II label requirements. Phase II changes took place in December of 2012, and will be discussed in this presentation.

Brown Spot of Potato

By Dennis A. Johnson from Focus on Potato. Published on Jan 31, 2013.

This presentation provides an overview of brown spot of potato. It is intended to help growers, consultants, and students to better understand the epidemiology of the disease and how it can be managed. The presentation shows representative color images of disease symptoms, the pathogen on potential overwintering substrates, and defines environmental and plant growth factors that lead to the development of the disease. The aggressiveness of the brown spot (Alternaria alternata) and early bight (Alternaria solani) pathogens are compared. Brown spot management tactics are discussed.

Early Generation Seed Potato Production

By Amy Charkowski from Focus on Potato. Published on Dec 20, 2012.

This presentation will help consultants, growers, and other practitioners understand the fundamentals of early generation seed potato production, from tissue culture to minituber production. Early generation potato production relies on development of disease-free tissue culture plantlet banks, careful production of minitubers, which includes close monitoring of the crop for pests, diseases, and variety mixtures. By the end of the presentation should understand the process of producing a large crop of potato tubers from a single disease-tested tissue culture plantlet and should be able to use this knowledge to help evaluate the health of a seed potato crop.

Soft Rot and Blackleg Diseases of Potato

By Amy Charkowski from Focus on Potato. Published on Nov 29, 2012.

This presentation will help consultants, growers, and other practitioners control bacterial blackleg, soft rot, and stem rot in potato by providing information on how to interfere with these diseases at planting, during the growing season and at harvest. Some fundamentals of the biology and ecology of these bacterial pathogens that are related to the control of these diseases is also presented. There are no curative treatments for these bacterial diseases and no resistant potato varieties, so appropriate production practices are required to combat losses faced by these diseases. By the end of the presentation should understand why the recommended cultural practices work to control these diseases.

Seed Potato Certification

By Robert D. Davidson from Focus on Potato. Published on Nov 06, 2012.

This presentation will help consultants, growers, and other practitioners in the U.S. and Canada learn about the basics of seed potato certification. Specifically, in this presentation, the basis for seed potato certification and the current process being followed will be described. Additionally, discussion will focus on which diseases and conditions are the focus of inspections and how these problems are managed through the use of clean, high quality seed potatoes. Finally, viewers will learn how certification is conducted and what clean seed brings to the table for both other seed growers and the commercial industry.

Aging of Seed Potatoes: Physiological Process and Consequences for Production

By N. Richard Knowles from Focus on Potato. Published on Sep 28, 2012.

This presentation will help consultants, growers, researchers and other practitioners to identify production, postharvest handling and storage factors that influence the physiological age and productivity of seed potatoes. Understanding the physiology of aging and how it affects crop growth and yield will enable the adoption of management practices to control the aging process to optimize tuber set and size distribution for various markets. Effects of seed age on plant growth and development and the utilization of key age-induced growth responses as indicators of the relative physiological age of seed lots will be discussed. The sensitivity of cultivars to environmental conditions that accelerate aging will also be reviewed. By the end of this presentation, the practitioner should have a solid understanding of the physiological basis of aging of seed potatoes and its consequences for production.

Using Pathogen Detection Test Kits for Rapid Potato Disease Diagnosis

By Nora Olsen from Focus on Potato. Published on Aug 24, 2012.

Misdiagnosing a disease can be very costly if unnecessary or ineffective control measures are made. There are many real-life examples where proper identification of a disease was not made until after avoidable inputs were applied, management changed, or rumors started. It would be beneficial to growers, fieldmen and extension personnel to have rapid and simple disease identification test kits available to make accurate initial disease diagnoses in the field. These test kits can also be helpful in eliminating disease misdiagnoses and identifying whether the issue is physiological or chemical and not due to a pathogen. A research and extension program was developed to evaluate the use of commercially available pathogen test kits and determine the accuracy of each test kit. Using potatoes as a test model, multiple test kits for numerous diseases were used, assessed and compared to results from traditional diagnostic methods. Results indicated the kits tested were reliable, easy to use, and accurate. Some limitations were observed but they were not restricting. Overall, the use of disease diagnostic test kits will provide an additional tool for greater accuracy, efficiency and sustainability.

Potato Growth and Development

By Mike Thornton, Ph.D. from Focus on Potato. Published on Jul 26, 2012.

This presentation will help consultants, growers and other practitioners throughout North America better understand the key growth stages in potato plant development. It will specifically focus on some of the key factors that influence plant development at each stage of growth, and identify how they impact crop yield. By the end of this presentation, practitioners should be better able to understand how environment and management impact potato growth and yield.

The Identification and Management of Silver Scurf

By Philip B. Hamm, Ph.D. from Focus on Potato. Published on Jun 22, 2012.

This presentation will help consultants, growers, and other practitioners in the US and Canada to identify and manage the fungus that causes silver scurf on potatoes. This disease causes wide spread losses in fresh marketed potatoes throughout North America, and can be particularly damaging on smooth skin potatoes and/or potatoes stored for long periods. Management options are discussed, beginning at planting , at harvest and during storage.

Potato Economics

By Joe Guenthner, Ph.D. from Focus on Potato. Published on May 07, 2012.

This presentation will help growers and other potato industry people understand the economics of potato production, consumption and markets. The first of two presentations to deal with this topic, it lays a foundation of economic principles that apply to potato markets. Viewers will learn about domestic and international issues that can affect the profitability of potato growing, packing, processing and marketing.

Potato Economic Issues 2012

By Joe Guenthner, Ph.D. from Focus on Potato. Published on May 07, 2012.

This presentation will cover four economic issues that affect the potato industry in 2012. Viewers will learn about market power in the potato marketing chain. The second issue is potato production costs. Crop protection and the influence of pests, such as zebra chip, on the competitive position of potato production regions is discussed next. The fourth topic, marketing, includes discussion of a rapidly growing restaurant chain - Five Guys - that buys a large volume of fresh potatoes.

Internal Heat Necrosis of Potato

By Craig Yencho, Ph.D. from Focus on Potato. Published on Apr 12, 2012.

This presentation is on internal heat necrosis of potato. Internal heat necrosis (IHN) is a non-pathogenic physiological disorder of potato tubers. It was originally described in the early 1900s and has also been called internal brown spot, physiological internal necrosis, internal browning, internal brown fleck, and chocolate spot. Potatoes with IHN have light brown to reddish brown necrotic patches in the parenchyma (flesh) of the tuber. There are no aboveground symptoms and no external symptoms on the tubers. IHN is generally a significant problem in the mid-Atlantic and southeastern US, but it can also a problem in other regions of the country when high temperatures and drought prevail. In this talk, Dr. Craig Yencho from NC State University will cover various aspects of IHN including symptoms and control, when a crop is at risk of developing IHN, models to predict the occurrence of IHN, varietal resistance to IHN, and current research efforts to develop IHN resistant potato varieties.

Sugar Management in Storage

By Alvin J. Bussan, Ph.D. from Focus on Potato. Published on Mar 29, 2012.

Sugar management is an important factor for potato crops, particularly those that end up as potato chips or French fries. This talk will help growers, consultants, and researchers--as well as others involved in pre-harvest and post-harvest management--develop potatoes with desirable sugar levels. In this presentation, we will discuss sugar management in various stages of crop management and storage. These stages cover in-season practices, particularly in relation to potato crop maturity and stress; best practices and timing during potato harvest; managing preconditioning in storage, and storage management.

Insecticide Resistance Management Colorado Potato Beetle: a Case Study on Potatoes

By Russell L. Groves, Ph.D. from Focus on Potato. Published on Mar 29, 2012.

The story of insecticide resistance is again taking place with the battle against the Colorado potato beetle (CPB) in Wisconsin and the upper Midwest. This beetle has a long history of rapid development of insecticide resistance to nearly all classes of insecticides and this fact has been well documented in portions of the northeastern US and specifically Long Island, NY. It has been documented that the CPB has now developed resistance to virtually every insecticide used for its control and this includes over 40 active ingredients across several chemical classes which now, unfortunately, has begun to include the neonicotinoid class of insecticides. Potato growers rely heavily on neonicotinoid insecticides for the control of damaging populations of this insect. Although this resistance has been discrete in its distribution, it stresses the need for continued vigilance in the management of insecticide resistance and strict adherence to integrated pest management strategies which reduce the likelihood and onset of resistance development.

Bacterial Ring Rot of Potato

By Neil C. Gudmestad, Ph.D. from Focus on Potato. Published on Mar 29, 2012.

Bacterial ring rot of potato is one of the most feared tuber borne diseases of potato. On an annual basis economic losses due to ring rot are low, however, it is the constant threat of severe and devastating losses that warrants the continued vigilance of the potato industry. Although the bacterium that causes ring rot is primarily disseminated by seed potatoes, the bacterium is also capable of surviving outside its host for extended periods. Disease management is dependent on an integrated approach using high quality seed, modern pathogen detection technologies and sanitation.

Biology and Management of the Potato Psyllid and Zebra Chip Disease

By Joseph E. Munyaneza, Ph.D. from Focus on Potato. Published on Mar 29, 2012.

Zebra chip, a new and damaging disease of potato is causing millions of dollars in losses to the potato industry in the United States, Mexico, Central America, and New Zealand. The disease is associated with a new species of the bacterium liberibacter, transmitted to potato by the potato psyllid. This presentation will help consultants, growers, and other practitioners in affected areas recognize zebra chip symptoms and understand the disease epidemiology, the biology and behavior of the potato psyllid, and ways to control this insect pest in order to effectively manage zebra chip.

Zebra Chip Disease of Potatoes

By Gary Secor, Ph.D. from Focus on Potato. Published on Mar 29, 2012.

This presentation will provide an overview of this new disease of potatoes that has become important in the southwestern and midwest regions of the US since its discovery in the mid-1990s. The presentation is intended to help educate growers, consultants, practitioners and allied industry personnel identify and understand the basic aspects of zebra chip. The presentation shows numerous color photos of disease symptoms, explains the field aspects including host range, pathogen and vector, and management practices that will help manage this disease.

Common Scab of Potato

By Thomas A. Zitter, Ph.D. from Focus on Potato. Published on Mar 29, 2012.

This presentation on Common Scab of Potatoes was developed to help consultants, growers, and other practitioners in all regions of the country on all of the major aspects that need to be addressed to successfully manage this disease. I have divided my presentation into the following major themes: 1.) A general introduction to the disease; 2.) Development and a description of the symptomatology associated with Common Scab; 3.) Illustrations of another disease of potato called Powdery Scab, since it does have some features in common with Common Scab; 4.) Specific characteristics of the organisms involved; 5.) Some specific in-field features of this disease; and 6.) The best management practices necessary for dealing with this disease.

Integrated Management of Storage Diseases

By Barry Jacobsen, Ph.D. from Focus on Potato. Published on Mar 29, 2012.

This presentation will help growers, consultants and others understand management of diseases that occur during potato storage. This presentation is most applicable to temperate production areas of North America but does address a few diseases that do not yet occur in North America. Understanding pathogen biology, how they infect and how they can be managed are critical to reducing storage losses.

Mid to Late Season Irrigation Management

By Howard Neibling, Ph.D. from Focus on Potato. Published on Mar 29, 2012.

This presentation will help growers, consultants, and other practitoners in the potato industry with mid to late season irrigation management. Recent weather patterns have resulted in more frequent occurrence of above-normal crop water use years. As a result, it appears that the probability of higher than normal water use this year has increased. If this situation develops after planting, options for using a marginal-capacity irrigation system to maintain low water stress conditions for the rest of the year are significantly reduced. This presentation provides suggestions for in-season equipment modification, and additional water management options to obtain the highest yield and quality of potatoes with less than adequate water.

Practical Management of Powdery Scab

By Robert D. Davidson, Ph.D. from Focus on Potato. Published on Mar 29, 2012.

This presentation will aid consultants and growers in understanding how to identify powdery scab of potato and manage this disease using an integrated approach to control. Key symptoms used to identify the various stages of the disease will be described and contrasted with other similar problems. Details of the pathogen, host, disease cycle, and environmental factors affecting symptom development, will be discussed. Much attention will be given to management options for this disease including avoiding the disease, measuring the inoculum load in soil, making the appropriate cultivar selections based upon the field history, resistance of a given cultivar, inoculum levels, and environment, and utilizing specific chemical control when warranted. Understanding the full integration of several different strategies for the producer are key to managing this potentially devastating and hard to control disease.

White Mold of Potato: Epidemiology and Management

By Dennis Johnson, Ph.D. from Focus on Potato. Published on Mar 29, 2012.

This presentation provides an overview of white mold or Sclerotinia stem rot of potato. It is intended to help growers, consultants, and students understand how white mold can be better managed by modifying the canopy environment and by timing control tactics based on the disease cycle. The presentation shows representative color images of the disease, explains the cause, and defines environmental and plant developmental factors that lead to the development of the disease. White mold management tactics are discussed.

Pink Rot of Potato

By Jeff Miller, Ph.D. from Focus on Potato. Published on Mar 29, 2012.

This presentation will help consultants, growers, and other practitioners in North American potato production understand the pink rot disease cycle on potato. The presentation will show the various symptoms of pink rot and then focus on pink rot management. The strengths and weakness of different management recommendations will be discussed, including in-season and post-harvest options.

Early Blight: A Global Management Issue on Potatoes

By Walter R. Stevenson, Ph.D. from Focus on Potato. Published on Mar 29, 2012.

This presentation will aid consultants, growers and practitioners understand how to identify and manage early blight of potato in the field and storage. Key symptoms are described that help to differentiate this disease from other common diseases. Important details of the pathogen, host and disease cycle are discussed. Managing early blight in the field requires the careful integration of cultural and chemical methods including rotation, choice of cultivar, plant nutrition and fungicide application. Understanding how these elements play a role in managing early blight helps to reduce losses in yield and tuber quality as well as reducing the reliance on weekly application of fungicides.

Early Season Irrigation Management

By Howard Neibling, Ph.D. from Focus on Potato. Published on Mar 29, 2012.

Production of high-yielding, high quality potatoes requires careful irrigation to avoid crop water stress throughout the growing season. This presentation outlines a method of pre-season irrigation planning to evaluate the adequacy of irrigation system capacity under your specific climate and soil conditions for normal and unusually high water-use years. For systems flagged as marginal or inadequate, suggestions are given for pre-season equipment changes and water management strategies to produce a high yield and quality potato crop.

Corky Ringspot Disease of Potato

By Nick David, Ph.D. from Focus on Potato. Published on Mar 29, 2012.

This presentation will provide an overview of Corky Ringspot Disease in potato. It is intended to help educate growers, consultants, and industry personnel identify and manage this costly disease. This presentation discusses the causal agent and vector of Corky Ringspot Disease, illustrates symptoms, and identifies management practices to minimize this disease.

Managing Nitrogen for Irrigated Potato Production in the Upper Midwest

By Carl Rosen, Ph.D. from Focus on Potato. Published on Mar 29, 2012.

This presentation will help consultants, growers, and other practitioners manage nitrogen (N) for irrigated potato production in the Upper Midwest. Of the essential elements required for potatoes, N is the one that often has the most important impacts tuber yield and quality. The topics addressed in this presentation include a brief review of potato N needs and the N cycle; N requirements in relation to specific potato growth stages; factors to consider when developing an N management plan; and potato responses to N from various research trials. From this presentation, the practitioner should learn how to make N rate and timing recommendations for optimal potato yield and quality.

Potassium and Chloride in Potatoes

By Don Horneck, Ph.D. from Focus on Potato. Published on Mar 29, 2012.

This presentation will help consultants, growers, and other practitioners in most potato growing regions make a decision on when a chloride or sulfate based fertilizer is appropriate for fertilization. This presentation will discuss both the role of potassium and chloride in potatoes. The misconception that potatoes are "chlorophobes" will be addressed as well as the benefits of potassium fertilization. Historical and recent research will demonstrate potassium effects on petioles and specific gravity.

Maximizing Seed Performance: Wound Healing and Disease Management

By Phil Nolte, Ph.D. from Focus on Potato. Published on Mar 29, 2012.

This presentation will help consultants, growers, practitioners and allied industries in all regions that produce potatoes to better understand and manage some of the risks associated with the use of cut potato seed. The presentation discusses vegetative propagation, the importance of certified seed, the processes of suberization and wound periderm formation, the effect of temperature and other environmental factors on potato emergence, the interaction between dry rot and soft rot seed decay and provides guidelines on how to properly heal cut seed before planting.

Black Dot Root Rot of Potato

By Barry Jacobsen, Ph.D. from Focus on Potato. Published on Mar 29, 2012.

Black dot has been proven to be both a widespread and important disease of potatoes. The causal fungus, Colletotrichum coccodes, is found worldwide, has a broad host range and can survive as sclerotia in soils for long periods. Yield losses of up to 40% have been shown for some cultivars in inoculated experiments with many commonly grown cultivars showing yield losses of 10-20%. Yield losses occur both through root rot and premature dying and from tuber blemishes that resemble Silver Scurf. Black dot is commonly involved in the early dying complex with Verticillium wilt and nematodes. Control of this disease can involve soil fumigation with Vapam or KPam, use of seed treatments such as Dynasty to prevent spread by seed, in furrow fungicide applications followed by post emergence fungicide applications, long rotations and production practices that reduce stress. While no cultivars are immune, cultivars with less than 5% yield losses have been identified.

Aphid Management in Potatoes

By Juan Manuel Alvarez, Ph.D. from Focus on Potato. Published on Mar 29, 2012.

This presentation will help consultants, growers, and other practitioners in the United States to develop a better understanding about aphids, which are considered major potato pests in the U.S. Aphids cause direct damage to potatoes by feeding on the phloem of the plant and occasionally high densities can kill plants. More importantly, aphids transmit viruses that cause serious diseases on potato plants that reduce the yield and quality of potatoes. This presentation introduces concepts that help identifying the most important potato colonizing and non-colonizing aphid species in several parts of the U.S. The information presented on the management of aphids includes cultural, biological and chemical control methods. Managing aphids successfully, using any method, depends on being able to reliably monitoring aphid populations in the field. The presentation includes recommendations on how to scout for aphids. This presentation also includes brief explanations about the two most economically important viruses that affect potatoes, the potato leafroll virus, PLRV and the potato virus Y, PVY. Understanding how aphids transmit the two viruses is critical in the management of this pest to prevent virus infections. Even the most intense aphid control may not prevent spread of viruses unless measures are also taken to keep virus-source plants at a minimum. Information is presented about an omnipresent weed plant in the Pacific Northwest of the U.S. that is in the same family as the potato, the hairy nightshade, which is not only a preferred host for potato colonizing aphids but also an additional inoculum source for PLRV and PVY. Research in Idaho has demonstrated that hairy nightshade might play a major role in the epidemiology of potato viruses. The presentation includes a section on this important weed plant that is currently present in many potato-growing regions of the US. Since at this time most of the aphid management in potatoes is done with insecticides, the final part of the presentation is dedicated to chemical control and includes recommended chemistries that not only kill the aphids but also prevent virus transmission. To obtain specific recommendations on insecticide compounds, formulations, or rates, viewers will need to refer to the product labels. Finally, the recommendations presented here are not to be used exclusively; the agricultural clientele mentioned above should adapt them to their own needs and improve upon them while incorporating their own experience and creativity.

The Changing Face of Potato Virus Y

By Stewart Gray, Ph.D. from Focus on Potato. Published on Mar 29, 2012.

This presentation will help growers, seed certification and regulatory officials, consultants, and other practitioners in the United States understand how and why Potato virus Y (PVY) is affecting the seed potato crop and if left unchecked why it will become a major disease issue for the food sector of the potato industry. Specifically we address the reemergence of PVY as a disease problem in seed potatoes, how regulatory, business and science-based activities have addressed the problem, and finally what steps can and are being taken to manage the disease and prevent the newly introduced tuber necrotic strains of the virus from becoming a major quality issue for potato growers. By the end of this presentation, the practitioner should understand the emerging PVY problem and know more about the existing and developing strategies that seed certification programs and growers, especially seed growers, can use to control PVY.

Potato Late Blight

By Steve Johnson, Ph.D. from Focus on Potato. Published on Mar 29, 2012.

This presentation will help consultants, growers, practitioners and allied industries in all regions that deal with potatoes understand the devastating disease of late blight. The presentation shows representative color photos of the all aspects of the disease, explains the cause and disease cycle, defines the factors leading to disease, and presents management practices that will reduce losses owing to late blight.

Fusarium Dry Rot of Potatoes

By Gary Secor, Ph.D. from Focus on Potato. Published on Mar 29, 2012.

This presentation will help consultants, growers, practitioners and allied industries in all regions that grow and store potatoes understand this common and widespread disease, Fusarium dry rot. The presentation shows representative color photos of the all aspects of the disease, explains the cause and disease cycle, defines the factors leading to disease, and presents harvest and storage management practices that will reduce losses due to dry rot.