Undetermined Hop MaladyBy
I have had healthy/disease free hops until this year. This year my Magnum hops is suffering from some
sort of hop malady (disorder or disease of the plant, especially one that is chronic or deepseated). I have been unable to determine the culprit here. I have researched many books and websites and have not come across any disease whether bacterial, viral, fungal or deficiency or pest that causes these symptoms. One fairly thorough hop disease resource I checked did not have pictures of the symptoms I am seeing.
The symptoms are, crumpled/misshaped leaves and shoot tips. The closest I have come symptom-wise is a boron deficiency. I only found one product that contained any boron in it – it is Bonide Liquid Iron + micronutrients. It contains magnesium, boron, copper, iron, manganese, zinc which should cover a few different possible deficiencies. I had to try something.
I sprayed all three of my plants (lost a Fuggle container hop over the winter) Nugget, Magnum and Cascade. This seemed to help the Magnum somewhat. There are sideshoots (laterals) coming out with what appear to be normal leaves (so far) – only time will tell. The Nugget and Cascade hops have darkened leaves and the leaves are larger than they have been in the past – must have been at least partially deficient in iron or one of the other minerals.
I also added kelp meal to the soil and top-dressed with compost from my composter hoping to address any and all possible deficiencies. It may be too late – It is still growing (10 feet tall) but does not look healthy. I am going to see how things turn out. I may have to dig it up and start with a new hop rhizome next year – hoping there is no pathogen in the soil.
The only thing that has been done out of the ordinary was a hop rhizome trimming this year. That was a good month before any signs of trouble. I did trim back all the shoots except 5 that I am training up the rope about a week prior to any signs of trouble. The Magnum was about 5 feet tall and healthy before the leaves started to crumple (no discoloration of any kind). Whether the rhizome trimming, the hop shoot trimming allowed a virus, bacteria or fungus into the plant, I don’t know. It also has been cold and lots of rain (Black Root Rot?) before this happened. I would need to dig up the crown to check for black root rot or pests possibly eating away at the root stock – I am not at that point yet. There are no visible pests on the bines or leaves, if it is a pest issue, it would be underground with the crown/root stock.
I will keep you all posted and any remote diagnosis from the pictures and history here would be appreciated.