Last week Arash in Iran left the following comment:
Hello to all
I am a researcher in iran.I and my cooperator have collected 22 accessions from region of Tarom (one of areas of Zanjan province). We want to research taht how many genotypes are being farm in this area and also study resistance to puccinia alli. please gide me how I operate thate conclude best.
on this post.
He actually doesn’t say it’s specifically on garlic, rather alliums in general, but since my original post was on garlic I assume that’s what he meant.
Does anyone have any information for him?
I can say that in the last few years since I’ve been making posts about garlic rust, I first read that it was present in on the US west coast, specifically in California in the region around Gilroy and a few isolated places in Oregon. I also knew it was present in northern Europe because it was in my garden and those of fellow gardeners in the UK, Denmark and Sweden.
In the years that followed I had reports from readers that it was present in the entire Willamette Valley area of Oregon, and later British Columbia in Canada and Los Angeles, in southern California. Two years ago someone reported it appeared in Ethiopia. I see mentioned on the Internet it’s also appeared this year on the east coast of the US in Maine. It seems to be spreading now, almost all over the world.
Following a suggestion from Søren, a fellow blogger in Denmark I’ve been experimenting with spraying dilute milk on my plants. I have not done this in any sort of scientific way, but my feeling is it’s of significant benefit. It seems to slow the rust down and manage it, to the extent it’s no longer a serious problem. I spray this on the plants about once a week or after rain, during the last 2-3 months or when I think rust infection is likely to occur. It’s benefit seems to be much greater if applied before the plants are infected. I use a ratio of 3-10 parts water to one part milk.
In the last several years I have grown more than 120 varieties of garlic in my garden, and a friend of mine more than 300. We have not really noticed significant signs of resistance to garlic rust on any of them, except a few of the more vigorous varieties like Susan Delafield and Estonian Red (a purple stripe type) seem to stand up a little longer to the rust probably because of the strength of the plants, and some silverskin varieties like Chilean Silver seemed to get infected a little later than the others.
The other thing a number of people observed was the application of high nitrogen fertilizer, in particular animal manure, caused the rust problem to become much worse.