Tag Archives: powdery mildew

Welcome to our Demonstration Garden!

May 14, 2019                                                                                                      DONATIONS PAGE LINK

The fruit trees in the orchard this year would amaze anyone. They are striking and flush …
with pests. It’s true. Come and allow us to demonstrate all manner of pest infestation plus other unsightly disorders.

Last year was a record bounty but, this year, we are counting on one hand the number of fruits from most of the trees.

Why, on one small branch of the Mirabelle plum (photo) you can view tip dieback from brown rot, scale, aphids and leaf roller damage. The pear, just after the height of the leaf roller infestation, has now been chewed to smithereens by the California pear sawfly (photo).

Wander over to the Fuji and notice apple blister mite. Then, check out the powdery mildew on the William’s Pride.

This situation takes me back to coaching where you had to make sure you didn’t spend all of your energy on the one high-maintenance kid and take for granted the other 14 well-behaved teammates. So, yesterday, I coddled our precious persimmon. The persimmon, like the mulberry, sits and watches the devastation and only asks for a drink of water now and then. I composted-in-place its weeds, fed it some nice compost and leaf litter, and laid out a coat of chips on top. Namaste.

Sun, May 19, 2-4, Work Party
Sat, Jun 1, 10-12, Work Party
Sun, Jun 16, 2-4, Work Party
Sat, Jul 6, 10-12, Work Party

Back in February, Allison and I thought we had the winter moth larvae in check. We had banded the trunks then flattened the eggs below the band. The problem was, while we were focused down on that trunk, the winter moth larvae soon would be sailing through the air, landing on whichever fruit or nut tree was within striking distance. Much like a skilled parachutist, I think they tug a certain way on that silken thread to ensure they make it to the canopy. In April, they were landing on our sweaters and hats faster than we could squish them off the leaves and blossoms. We had kept our own trees from propagating larvae but we were defenseless against tall neighboring trees that spit out the little buggers like factories.

Yesterday, I sighed as I cleaned off more dead material from Liberty branches (photo). Oh, but then I looked closely. Was that a little speck of green? Sure enough, the tree is pushing out a new leaf where the others had been eaten.(photo) The Liberty is willing and ready to try again. OK then! We will also find energy to grow and prepare for the next obstacle.

Ruth

Guarding the Grapes

September 23, 2018

neem

The predictable announcement was, “Yum!” from anyone who tasted our Interlaken table grapes. One taster cocked her head and let her eyes drift upward, savoring the sweet with a little tart sensation.

We were thankful to have a few grapes this year! Last year was a bust due to powdery mildew. In 2017, the grape clusters shriveled and dropped. We knew we needed a plan for the 2018 season.

Our first step was to sign up for another class from the grape guru Michelle Moyer (WSU – Prosser).

Michelle explained: Powdery mildew (Erysiphe necator) comes in many forms. A vine is most susceptible when temperatures are 68F to 86F and humidity is moderate (40-75%), conditions that are quite common in Western Washington during the growing season.

Sat, Oct 6, 2-5, CIDER FEST!
Bring your tools for sharpening
Bring your appetite for tasting
Bring your wallet for homemade goodies

In cool climates, powdery mildew typically shows up one month after bud break – approx. May 30. Weather During Critical Epidemiological Periods and Subsequent Severity of Powdery Mildew on Grape Berries. Plant Disease 100:116-124.   Moyer, M.M., D.M. Gadoury, W.F. Wilcox, and R.C. Seem. 2016.

control

Proper pruning, including fruit-zone leaf removal and shoot thinning, to facilitate air circulation and sun light penetration is critical to aid in the control of powdery mildew. UV exposure and air circulation are both effective against this fungal problem.

Sadly, our most mature set of three vines rest along the sound wall where air circulation is compromised.

Michelle referred to a study by Matthew DeBacco (2011)  wherein compost tea and milk spray were used to combat powdery mildew.

Well! These materials were easy to find and certainly organic so we began our own experiment. The left vine we treated with neem oil, the middle was the control where we did nothing and the right vine received powdered milk spray (1/4 C non-fat dry milk, 1-T baking soda and a few drops of dishwashing soap to a gallon of water.)

We were not absolutely consistent in our applications but we tried to spray about every week to 10 days.

pow. milk

Our results (see photos) were convincing; the powdery milk spray was the most effective. All clusters dropped on the control and all but one on the vine sprayed with neem oil but we did have clusters ripen completely on the milk treated vine.

Next year we plan again to spray using an improved milk recipe per the studies we’ve read. We’ll use a backpack sprayer to make the process more efficient. We’ll also prune more effectively in February and remove fruit zone leaves a bit earlier than we did this year. We may try compost tea as a test spray against the milk spray. However, making the tea every other week is quite a process so we shall see.

 

Nancy

P.S. On a recent visit to Carnation Farms, the garden supervisor mentioned that she has had luck treating basil with powdered milk spray.

More reading: Crisp P, Wicks TJ, Troup G, Scott ES (2006) Mode of action of milk and whey in the control of grapevine powdery mildew. Australasian Plant Pathology 35, 487–493. http://www.publish.csiro.au/ap/ExportCitation/AP06052