• Fungicide tools and resistance management guidelines

Fungicide tools and resistance management guidelines

  • May 15th, 2011

As of spring 2011, growers in eastern Washington have several new fungicides at their disposal for managing powdery mildew.

For cherry growers, new products include Adament ­(tebuconazole + trifloxystrobin), Quash (metconazole), and Unicorn (tebuconazole + sulfur).

Four new materials are available for grape growers: Adament, Inspire Super ­(difenoconazole + cyprodinil), Unicorn, [...]

  • Clean plant center has new manager

Clean plant center has new manager

  • April 1st, 2011

James Susaimuthu inspects plant material in the Fruit Tree Clean Plant Center’s greenhouse.

One of the goals of Dr. James Susaimuthu, new program manager of the Fruit Tree Clean Plant Center, is to use his diagnostic skills to find ways to improve virus testing of plant material.

Susaimuthu, with a background [...]

  • How to manage scab and mildew

How to manage scab and mildew

  • April 1st, 2011

Powdery mildew appears as superficial, white powdery growth on leaves and shoots that results in the stunting and distortion of young growth. Right: ruit like this Jonathan apple, when infected with powdery mildew, are stunted and russetted, and fruit set may be reduced.
BRITISH COLUMBIA MINISTRY OF AGRICULTURE

A good [...]

Good Stuff

  • March 15th, 2011

Sweet success
A new series of scab-resistant apples called “Sweet Resistants” developed by the Consorzio Italiano Vivaisti (CIV) in Italy was among the ten finalists for the Fruit Logistica Innovation Award during the Fruit Logistica trade fair in February. The five varieties in the series are Gaia, Gemini, Renoir, [...]

  • A primer on Botrytis cinerea

A primer on Botrytis cinerea

  • March 1st, 2011

Dr. Wayne Wilcox of Cornell University says Botrytis cinerea as a weak pathogen that prefers injured, senescent tissue, such as old blossom parts and ripening fruit. The more ripe the fruit, the more susceptible it becomes, an added consideration when rains delay harvest.

Botrytis thrives where there’s low evaporative water [...]

  • Bunch rot strategy for 2011

Bunch rot strategy for 2011

  • March 1st, 2011

PHOTO COURTESY OF CORNELL UNIVERSITY

For Washington grape growers who had a bunch rot problem in 2010, efforts to get rid of any carryover crop are worthwhile, says a New York plant pathologist. Growers should also be prepared to spray a botrytis-specific fungicide during bloom, if weather conditions are favorable [...]

  • Botrytis comes to dry Washington

Botrytis comes to dry Washington

  • March 1st, 2011

Latent infections inside a cluster can take over the bunch by harvest time.
PHOTO COURTESY OF CORNELL UNIVERSITY

Last year’s cool season not only challenged growers and winemakers with slow fruit ripening, it also brought bunch rot to some vineyards, causing significant damage from a lack of disease awareness.

The 2010 [...]

  • Cougarblight model updated

Cougarblight model updated

  • March 1st, 2011

Washington State University is working to help growers be better prepared to fight fireblight.

Washington State University’s Cougarblight model is being updated to improve its ability to predict when conditions are conducive to fireblight.

The model uses information on temperature, wetness, and presence of fireblight bacteria to predict infections and was [...]

Tackling scab resistance

  • February 15th, 2011

Apple growers in the Midwest who stuck by the “old ways” of applying fungicides have not faced the problem of apple scab becoming resistant to fungicides. The old ways employed protectant fungicides like captan and ­mancozeb; the new ways used curative chemistries.

Now what should growers do? Dr. Janna Beckerman, [...]

Scab-resistant varieties need protection, too

  • February 15th, 2011

When apple breeders in New Jersey, Indiana, and Illinois came together in 1926 to form the Purdue-Rutgers-Illinois university collaboration called PRI, their ­number-one goal was to create new apple varieties that were scab resistant.

They did it, too, and about 20 resistant varieties have been released. While several varieties have [...]

  • Opportunistic fungi

Opportunistic fungi

  • February 15th, 2011

Disease organisms invade injured tissue and develop cankers that release spores. Some red strains of McIntosh are susceptible, for reasons unknown, to opportunistic diseases that kill branches.
Photos courtesy of george sundin, Michigan State University

Starting in 2006, an epidemic of sorts started in apple orchards in Michigan. It was [...]

Watch for crown gall and vine decline

  • February 15th, 2011

Vineyardists in the Pacific Northwest have been relatively lucky regarding the number of grape diseases they have to worry about. But recent experiences indicate that Washington growers should also watch for diseases associated with vine decline, and crown gall could again be a problem in the state.

In the mid-1990s, [...]