Downy Mildew

[B-Hoppy]

Finally got around to training a Chinook today and found a Downy Mildew infected shoot. Kinda odd because we haven't had any rain to speak of in a few weeks and the humidities have been relatively low. The number of shoots and the density of foliage on this particular crown most likely added to the disease manifesting itself. The first two pictures show the way the disease creates a mottled appearance on the leaves (lime green=infected portion).

The last picture shows how the disease compresses the shoot and the distance between internodes is drastically shortened compared to the unaffected shoot. Haven't had enough time to get anything preventative on up to this point but may have to make some time real soon. Hope the pictures help.

 

[johngaltsmotor]

I'm surprised. I've been trying for years to grow cucumbers to make pickles and downy mildew around here makes it darn near impossible. But my hops have never had a single leaf affected by it. I simply assumed they were too resilient to be susceptible.

 

[B-Hoppy]

In a really ingenious move, Ma Nature stacked the deck in her favor by creating a bunch of different kinds of downy mildew. That old gal has all the bases covered

You might consider looking around your growing area for 'weedy' hosts for that particular type of mildew. Possibly by identifying and removing them you might be able to lessen the chances of mildew to occur on your cucumbers?

forgot the link: http://www.extension.purdue.edu/extmedia/BP/BP-68-W.pdf

 

[theredben]

Just to be clear, what B-Hoppy was trying to say in colourful language is that the Downy Mildew that infects Cucumbers is a different species than the Downy Mildew that infects Hops. You could grow hops in the middle of a field of diseased cucumbers and your hop plant would never get Downy from the cucumber.

 

[brewerelated]

Towards the end of the growing season last year I think my plant became infected by Downy Mildew as well. I saw lesions on some of the leaf and some browning on the leaves and cones. I don't have pictures from last season, but I have pictures of my new growth from this season.

I've done some research on the internet and I read that Downy Mildew overwinters in the crown. One of the signs of an overwintered infection is the emergence of "basal spikes" at the beginning of following season. I looked on the internet for pictures of the basal spikes, but I have trouble comparing them to my pictures.

My hops have broken grown this season already and here are some pictures of my hops. Do these look like basal spikes? I also want to note that these are Centennial hops and they are susceptible to downy mildew.