Michigan Potato Diseases - News

Late blight in tomatoes and potatoes in 2009

2009-10-13T00:43:00.006-04:00

The first report in Michigan of potato late blight caused by Phytophthora infestans was on potatoes in southwest Michigan. The Kirk Lab at MSU confirmed the disease on tomatoes from home gardens in Lansing, East Lansing, Sturgis, Traverse City and Cass City in the following few days. Reports of late blight on tomatoes and potatoes in Montcalm and Mecosta Counties quickly followed and it was clear that an epidemic had broken out in many areas in Michigan. Home gardeners, organic and small growers were particularly badly affected. In 2009, an uncommon strain appeared on both tomatoes and potatoes. The strain is similar to US-14 (the established strain in most of the US is US-8). The disease is normally managed by preventing survival of its over-wintering stages in potato tubers by crop management and waste potato management and use of herbicides in rotational crops followed by regular applications of fungicides. Such management restricts epidemic development and usually excludes the disease from urban and rural areas.

At Michigan State University the Department of Plant Pathology runs a website that addresses the risk of this disease and describes measures for controlling initial sources of the pathogen and for controlling the disease should it appear during the season (www.lateblight.org). Late blight has caused considerable loss to growers in areas where the disease is uncommon, and to home gardeners. In Michigan, damage to tomatoes increased as the season progressed and put commercial potato producers at increased risk resulting in an increase in the application of crop protection products. Base-maintenance for potato late blight control for commercial growers would normally be about $100/A/season, but in 2009 this cost rose by about 50% due to increased frequency of applications and more use of expensive late blight containment fungicides. This is effectively an increase of about $2 million. In addition, growers have to protect tubers going into long-term storage with disinfectant-type products.

Whatever the source of the disease, at MSU we are developing educational programs for growers to help them manage this disease in both tomatoes and potatoes. Growers may be asking "Did I do something wrong and what can I learn from this to become a better manager/grower?" Fungicides are available but that does little to help organic tomato and potato producers as they have very little other than cultivar resistance to rely on, and little is know about this resistance with this new strain of late blight.

During August an educational pamphlet was developed in conjunction with the Michigan Potato Industry Commission and distributed by MSU extension and Bedford Farm Supply Services to Amish growers throughout mid-western Michigan who were severely affected by the disease. The pamphlet and further information can be found at your local MSU extension office orat the Michigan Potato Diseases website (www.potatodiseases.org).

APS 2009 Posters now available on-line

2009-08-27T11:46:00.003-04:00

The posters presented by the lab at this years American Phytopathological Society Annual Meeting in Portland, OR, are now available for download on the recent publications webpage. This year we presented four posters at the meeting along with several oral presentations.

Late blight on tomatoes

2009-08-22T14:58:00.006-04:00

Check out the video below showing the devastation caused by late blight on tomatoes in west Michigan.

More discoveries of Late Blight in tomatoes

2009-08-01T14:30:00.002-04:00

Late blight has now been found in a further 2 locations, the Greater Lansing area (Ingham county) and Lapeer (Lapeer county). Please note that in both these locations late blight was found on tomatoes. Late blight has not been found on potatoes in either of these locations.

Late Blight found on Tomato in Gratiot county

2009-07-30T02:11:00.004-04:00

Today (July 29, 2009) the plant disease diagnostic center at MSU received a tomato plant that had late blight on both the fruit and foliage. This sample was from a home gardener in Gratiot county. There has been a severe outbreak of late blight on tomatoes in the Northeast, in states including New York. Potato growers in Gratiot county should be on alert as in the Hudson Valley region of New York, the disease has jumped from tomatoes to potatoes and is wreaking havoc in both. The source of the outbreak in the Northeast is being investigated by pathologists and it is thought that home gardens likely helped spread the infection: Lowe's, Home Depot, Kmart and Wal-Mart all sold tomato seedlings with late blight in their garden centers from April to June. As such this find in Gratiot county may also be from a similar source. The New York Times has published several articles on the subject. Click here and here for more information.

Late blight discovered in SW Michigan

2009-07-28T17:15:00.004-04:00

A late blight outbreak was reported and has been confirmed in St. Joseph county. So far a single outbreak has been confirmed in a field near Sturgis. With the thunder storms and heavy rains that have swept across the state in recent days it is important to be extra vigilant when scouting fields for late blight. Particular attention should be paid to pivot tracks and other such lanes created by farm machinery. For further information on measures that should be taken when late blight is observed refer to the Late Blight extension bulletin. This bulletin is also available as a high quality downloadable .pdf file.

New Publications for 2009

2009-05-20T15:19:00.004-04:00

Two new research publications are now available for download on the website. The first publication deals with the impact of different US genotypes of Phytophthora infestans on potato seed tuber rot and plant emergence in a range of cultivars and advanced breeding lines. The second publication discusses recent advances in screening potato cultivars for increased tolerance to common scab (Streptomyces scabies).

Late Blight Risk Monitoring 2009

2009-05-04T00:09:00.010-04:00

The Late Blight Risk Monitoring system is now up and running for the 2009 growing season. Five new locations have been added to the network since last year. These are Cassopolis, Charlotte, Hastings, Kalamazoo and Leslie. In addition, the station at Saginaw Bean & Beet Farm has moved to a new location at Richville.

2008 Late Blight Trials

2008-08-12T17:49:00.004-04:00

The regular users of the late blight risk monitoring website may have noticed that late blight has been reported in Bath Township. This change of status is just to indicate that we now have a good epidemic of late blight going at the MSU Muck Soils Research Farm in the late blight research trials. For more information, or to view the epidemic at the Muck farm contact Willie Kirk or Rob Schafer to arrange a visit. If you don't have their phone number you can email webmaster@lateblight.org.

New publications available on potato diseases

2008-05-08T13:57:00.003-04:00

I have updated our research and extension publications for the latter part of 2007 and the first quarter of 2008. Most of the publications are available as .pdf files for download.

New weather station added to MAWN

2008-05-08T13:50:00.002-04:00

A new weather station in Coldwater has been added to the MAWN. This station is now available on the Late Blight Resistance Management Network for those of you who live in the Coldwater area.

Physiologically Induced Heat Stress Posing Problems in Seed Potatoes.

2008-05-07T07:00:00.001-04:00

A heat-induced problem affecting seed tubers produced in MI during 2007 may have manifested itself in reduced seed quality for 2008. Tests conducted at MSU have shown that seed tubers are failing to completely suberize after cutting (Fig. 1). This has been seen mainly in the variety Snowden although may be present in other varieties. For more information on this problem and recommendations on how to manage seed from MI in 2008 please refer to the Disease Update: Physiologically Induced Heat Stress Posing Problems in Seed Potatoes.

Fusarium Dry Rot Posing Problems in Potatoes

2008-05-06T23:15:00.001-04:00

Fusarium dry rot is one of the most important diseases of potato, affecting tubers in storage and seed pieces after planting. Fusarium dry rot of seed tubers can reduce crop establishment by killing developing potato sprouts. This year there have been reports of Snowden seed lots affected although other seed lots may also be affected. For more information on how to combat this problem please refer to the Disease Update: Fusarium dry rot Posing Problems in Potatoes.

Late Blight Risk Monitoring 2008

2008-05-02T15:52:00.002-04:00

The Late Blight Risk Monitoring system is now up and running for the 2008 growing season. Six new locations have been added to the network since last year. These are Arlene, Berrien Springs, East Lansing/MSUHTRC, Hickory Corners/MSUKBS, Keeler/South Hartford and Romeo.

MSU Montcalm Research Farm Field Day 26 July, 2007

2007-07-24T16:30:00.000-04:00

The MSU Montcalm Research Farm Field Day will be held this coming Thursday (July 26). Proceedings will start at 11am with the MPIC Research Committee meeting (11am - 2.30pm) in the Douglas Township hall, Entrican. All growers are invited. Lunch will be served at 11.30am. Potato Wagon tours of the research plots will start at 3pm. A catered dinner will be served between 5.30 -6.30pm. For further information contact Chris Long (5 17) 355-0271 Ext.193; email: longch@msu.edu. The new potato diseases scouting guide and disease bulletins will also be available for purchase. The bulletins cost $1 each and the scouting guide will cost $10.

Pocket scouting guide for potato diseases available

2007-07-19T19:33:00.000-04:00

The new potato diseases scouting guide "A Pocket Guide to Disease Scouting in Michigan Potatoes" is now available for purchase from the MSU Extension Bulletin office. This is a comprehensive pocket reference text for use in disease scouting in Michigan potato fields. It provides information on the disease cycles and biology of common potato pathogens and on management options for their control. For more information call 517-353-6740.

Late Blight Meeting, June 13, 2007

2007-06-04T19:44:00.000-04:00

There will be a meeting on late blight held on Wednesday June 13 at the St. Joseph County Intermediate School District Building in Centerville (62445 Shimmel Rd). Click here to get directions. The meeting starts at 10 am and a free lunch, sponsored by DuPont, will be served at 12pm.

Michigan Potato Diseases Series Updated

2007-06-04T19:26:00.000-04:00

Seven new high resolution potato diseases extension bulletins are now available for purchase from the MSU Extension Bulletin Office for $1.50 each. For more information call 517-353-6740. You can also download these bulletins from the Extension publications page as .pdf files.

New bulletin on Common Scab of Potato available

2006-12-19T00:59:00.000-05:00

The new webpage on Common scab of potato is now online. The webpage covers the symptoms of the disease, disease cycle and current control options available in Michigan. A printed version of the webpage will be available from the MSU Extension Bulletin Office in the new year, and when that is published a .pdf version will be made available online. To receive a .pdf version before then contact webmaster@potatodiseases.org and I will send you one via e-mail.

New Dry Rot webpage online

2006-10-12T16:25:00.000-04:00

The new webpage on Dry rot of potato is now online. The webpage covers the symptoms of the disease, disease cycle and current control options available in Michigan. A printed version of the webpage will be available from the MSU Extension Bulletin Office later in the year, and when that is published a .pdf version will be made available online. To receive a .pdf version before then contact webmaster@potatodiseases.org and I will send you one via e-mail.

Two new publications available for download

2006-10-10T22:02:00.000-04:00

Two new publications have just been posted to our publications page and are available for immediate download. The first publication is on Phytophthora infestans, the causal agent of late blight, and the second is a First Report on a new disease of potatoes called Fusarium sprout rot, which is caused by the Fusarium dry rot pathogen Fusarium sambucinum.

New publication on resistance to late blight available

2006-09-11T12:13:00.000-04:00

A new publication on the effect of photoperiod and temperature on resistance to Phytophthora infestans is now available for download in .pdf format on the publications page. The abstract is summarized below:

"Deposition of phenolic compounds before and after inoculation with Phytophthora infestans was evaluated in two Mexican cultivars (Malinche and Tollocan) with major unknown R genes for resistance to potato late blight, two cultivars (CIP1 and CIP2) without R genes from the International Potato Center (CIP) and the susceptible cultivar Atlantic. Before inoculation, plants were grown in growth chambers at two temperatures (16 or 24 C) and two photoperiods (PPD 12 or 16 h day length). Forty-eight hours after inoculation, the number of penetrations was recorded and depositions of phenolic compounds were classified according to detection and location in (a) the anticlinal cell wall, (b) the whole cell, (c) the stomatal cells, and (d) without detectable depositions of phenolic compounds. The concentration of phenolic compounds in the epidermal cells was slightly increased at 16 C and 16 h PPD and penetration frequency was lower at 16 C (12 h PPD). Concentration of phenolic compounds was not correlated with penetration frequency, but was correlated with the resistance level of the different potato cultivars. Atlantic had the highest number of penetrations followed by Tollocan, CIP1, CIP2, and Malinche. The cytological observations indicated that four types of deposition of phenolic compounds occurred in all five potato cultivars irrespective of their type and level of resistance. These results suggest that deposition of phenolic compounds on epidermal cells is a general resistance mechanism in potato leaves that does not have a specific relation with resistance to the penetration of P. infestans. Phenolic depositions were intrinsically similar in potato cultivars with and without R genes, which stresses the difficulty in differentiating between horizontal and vertical resistance."

GM potatoes for UK 'in 10 years'?

2006-08-24T13:12:00.000-04:00

The BBC news website is running a story today on BASF requesting permission to grow GM potatoes in the United Kingdom. According to the article:

"BASF says it hopes GM potatoes could be sold in the UK within 10 years. It says they would be resistant to late blight disease, meaning no need for spraying fields with fungicides, and could save millions in damaged crops."

However, they face opposition from environmentalists who say "consumers do not want GM potatoes even if it means cutting back on chemicals." Claire Oxborough, from Friends of the Earth said:

"Consumers have already made that choice and that's why all the supermarkets and food companies have stopped using GM ingredients in their foods."

However, an earlier story on the BBC website reavealed the potential value of such research as it emerged that the Soil Association, which promotes organic farming as being free of artificial chemicals has admitted that copper-based (copper oxychloride) sprays were being used to control late blight. From the article:

Tom Gilbert, who runs Ballylaggan organic farm in Northern Ireland, questions whether organic potato production should even be attempted in the British isles because of a climate which almost invariably results in blight infection.

He said: "If you have to spray things to make them succeed, it's not really what the organic ideal is about. I do it with a heavy heart spraying them because I don't really approve of it."

Montcalm Research Farm Field Day this Thursday (Aug 17)

2006-08-11T19:18:00.000-04:00

Just a note to remind everyone that the Montcalm Research Farm Field Day is this coming Thursday (Aug 17). Events will start at 11:00 am at the Douglass Township Hall, in Entrican. See the attached flyer for further details, or contact Chris Long by phone at (517) 355-0271 Ext. 193, or e-mail: longch@msu.edu.

New Pink Rot Bulletin online

2006-08-07T15:52:00.000-04:00

The new webpage on Pink rot of potato is now online. The webpage covers the symptoms of the disease, disease cycle and current control options available in Michigan. A printed version of the webpage will be available from the MSU Extension Bulletin Office later in the Fall, and when that is published a .pdf version will be made available online. To receive a .pdf version before then contact webmaster@potatodiseases.org and I will send you one via e-mail.