Pest pressures challenge organics future

  • May 1st, 2013

The favorable climate and relatively low pest and disease pressure in the arid West have been blessings for organic tree fruit growers. Those conditions explain why more than 95 percent of the nation’s organic apple production comes from Washington, California, Arizona, Colorado, and Oregon. But increasing pest challenges and [...]

  • New grape disease reduces yields, quality

New grape disease reduces yields, quality

  • April 1st, 2013

Left: A Merlot grapevine shows redleaf symptoms on mature leaves in the lower portions of the canopy. Symptoms are easily confused with grapevine leafroll disease. Right: Cabernet Franc clusters from a single vine show infection on the left, nonsymptomatic cluster on the right.

A new disease that threatens the health [...]

  • Developing a disease management program

Developing a disease management program

  • March 15th, 2013

Washington State University viticulture extension specialist Dr. Michelle Moyer suggests growers consider the following when developing a ­disease management program:

•    Reproductive rate of the pathogen. How fast can the disease reproduce in your vineyard? Is weather conducive to reproduction?
•    Speed of your reaction time. Do you have enough [...]

  • Living with cherry diseases

Living with cherry diseases

  • March 15th, 2013

Little cherry disease made a dramatic resurgence in Washington in 2010 and has since spread rapidly. These Sweetheart cherries show symptoms of small and puny fruit.
PHOTO BY KEN EASTWELL

With no cure for cherry trees infected with most viruses—short of cutting them out of the orchard—Washington State University researchers [...]

Preventing mildew

  • March 15th, 2013

Guide for grape pest management available
Washington State University’s 2013 Grape Pest Management Guide includes recommendations for controlling insects, weeds, diseases, and other pests. The guide also includes results of 2012 fungicide efficacy trials, a table with Fungicide Resistance Action Committee (FRAC) codes for resistance management, and suggestions of [...]

  • Working with copper

Working with copper

  • March 15th, 2013

Copper is a potent spray chemical, useful on many stone and pome fruits. It is active against bacterial diseases like fireblight, bacterial canker, and bacterial spot, and fungal diseases like cherry leaf spot, peach leaf curl, and apple scab as well.

Used correctly, copper sprays, especially very early in the [...]

  • Kill the pathogen

Kill the pathogen

  • March 15th, 2013

Apple scab is a serious problem in humid climates, and McIntosh is very susceptible. Lesions occur on both leaves and fruit.
PHOTO COURTESY OF GEORGE SUNDIN

Apple growers have three new fungicides they can use to control apple scab, and Dr. George Sundin would like to see growers keep them.

“Use [...]

  • Bacterial canker

Bacterial canker

  • March 1st, 2013

The weather turned hot and dry—­conditions conducive to healing the cuts without making the canker situation worse. Then, the recommended approach was to make two fall sprays of copper, with two more copper sprays recommended before bud break this spring.
12 STEPS TO MANAGE BACTERIAL CANKER
In Oregon, bacterial [...]

  • Last Bite

Last Bite

  • February 15th, 2013

1  Which of the following is not a fruit symptom of little cherry disease?
a.    Small size
b.    Poor color
c.    High acids
d.    Poor shape

2    Which of the following rootstocks is not resistant to fireblight?
a.    Geneva 41
b.    Budagovsky 9
c.    PiAu-56-83
d.    Malling 26

3     What [...]

  • Fireblight-resistant apple

Fireblight-resistant apple

  • February 15th, 2013

Ladina, a new high-quality apple variety with low susceptibility to fireblight and mildew, has been developed by a Swiss research station. The variety is also scab resistant. Ladina, bred at the Swiss federal research institute Agroscope­ ­Changins-Wädenswil, comes from a cross of Topaz and Fuji made in 1999. The [...]

  • An expensive disorder

An expensive disorder

  • February 15th, 2013

Photos courtesy of Bhaskar Bondada

A shrivel is not just a shrivel.

Of the various types of shrivel impacting grape quality, sour shrivel is especially unwanted because it renders the fruit unsuitable for winemaking.

The disorder, found in vineyards around the world, is known by several names. In California, researchers have begun [...]

  • Identifying grape shrivels

Identifying grape shrivels

  • February 15th, 2013

In the past, grape growers have mistaken any shrivel in their fruit for grape berry shrivel, also known as sour shrivel, says Washington State University’s Dr. Bhaskar Bondada. In a panic, some were needlessly thinning clusters to remove what they thought were berries afflicted with sour shrivel.

It’s important to [...]