Fungal Blights and Organic Sprays

blog etsy and spring 2013 185 Hi folks- I have been, and am, really busy with the spring garden as well as life so I have a lot backed up to write about!

What was really urgent for me today was saving the plums. If you follow me you know this tree, because I wrote about pruning it earlier. I went ahead and cut down the Santa Rosa, by the way, after it finished blooming. I have planted another plum which should be big enough to pollinate the Methley next spring.

We have had the coldest, wettest spring anyone remembers, – I still have radishes and the first ever Michili (Napa) cabbages! Now that it is warming up, and continuing to rain, the brown rot is hitting my plums hard. Actually, it loves warm humidity even more, but since it is now endemic, it just attacks when the fruit starts to ripen. Brown rot is pretty self descriptive. First you see a small dark bruise on the fruit, then it becomes a brown spot, then the spot spreads, and finally it creates little powdery bumps all over the rotten fruit. That’s when it is sporulating and contaminating more fruit.

signs of brown rot in fruit

Brown rot spreads through affected fruit

Plums often grow in clusters so it spreads that way too. It creates a stickiness so that it can stay in the tree and mess up your crop next year too. Diabolical! I do collect the damaged fruit as much as I can, but so much is hiding in the grass that I can’t get it all. Of course the sprays do drip on the fallen fruit. Still, it stands to reason that if I see brown rot spreading from one fruit to another, if I remove any plums I see with signs of rot, that may save some fruit. It seems to work.

Surround crop protectant

25 lb bag of Surround

I have two chemical free weapons for this; Serenade and Surround. Serenade is a bacillus subtilis product which seems to stop the brown rot enough to save the crop. I mix 1/3 c. per gallon in my backpack sprayer. It smells a bit yeasty and looks like brown slime. The package says to cover up, use safety glasses and a mask. I tend to think that’s because that’s what people do when they spray chemicals. Perhaps it would be bad to breathe in b.subtilis. I cover up anyway, but I can tell you that I feel a whole lot less nervous getting Serenade on me than Captan or some such toxin.

Other great things to use for fungus are wettable sulfur, or Bordeaux mixture. Bordeaux mixture is best used as a preventative, so it is applied once a year in winter. It is not good to use too much copper as it will eventually build to toxic levels. Sulfur is safer, but not as strong. Neem is good too, although I generally sing its praises as a preventative for plum curculio, the evil beetle that makes those little crescent shaped scars at the top or base of the plum which usually make them drop off prematurely. However it is also reportedly a fungicide, and it is made from a tree in India which also is used in toothpaste.

Surround is completely inert and safe to use

Surround is completely inert and safe to use

When you spray, make sure you are getting under the leaves as well and are spraying until the leaves drip. The best cheap sprayer I have had so far is a 4 gallon plastic backpack sprayer. I honestly forget the brand, and the label fell off last year. I think it is a Chapin or a Hudson.

4 gal backpack sprayer
I’m not sure what brand this is; maybe Chapin or Hudson.

 They don’t generally last. Make sure you flush them out after every use.

 

You sling it onto your back and pressurize it with a handy lever arm on the left side. You have to keep pumping to keep the pressure up while you are spraying though. (There are battery powered ones. )To get up high the best sprayer is a trombone sprayer. Low tech and works. You mix up your product in a pail and put the sucker end in, then start sliding the tube up and down like a trombone. You can get up 30 feet. They are well made, but you will have to take the tip off a lot because if something falls in your bucket it will clog the sprayer tip.

Surround on plums

Surround on plums

I love Surround. It is totally inert; made of finely milled (15 microns) kaolin clay. You could eat it. It works as a particle film barrier to control both pests and fungal diseases. You mix up 3 cups to a gallon of water and pour it through a strainer into your sprayer. For me 2 gallons is enough for a big fruit tree. You can combine Neem with it. The nice folks at Bayer (hiss) don’t recommend mixing Serenade with it, although the guy who sold it to me in Floyd County, VA said he didn’t see why not. (At the time, Seven Springs Farm had the best price for Surround.) Anyway, when you spray a tree or plant with Surround, it looks like it has been slightly whitewashed, although this does not prevent photosynthesis. It confuses flying pests, and chokes the mouth parts and other apertures on crawling insects. It prevents sunscald. I am not sure how it prevents fungus, but it does. Perhaps the pH does it, or it makes the leaves dry faster. A man I heard at one of our MOFFA meetings said it prevents early blight on his Yellow Brandywine Tomatoes. That made me sit up- Yellow Brandywine is my absolute favorite tomato, as you will know if you follow this blog, but she is a bit finicky about dampness and I am always clipping off her bottom leaves. Of course the thing is you have to stay on it. Spray every 10 days is the norm, but if it rains you might have to respray, depending on how well the tree got washed. The gully washer we had last night was definitely a reason. The Surround does cling pretty well though.

Mulberries

Just give up and eat mulberries

Deciding whether I am going to grow something difficult is an emotional choice, and it probably shouldn’t be. Maryland’s Eastern Shore is a paradise, but our warm, humid climate does make growing many fruit trees a challenge. Our winters don’t really freeze the bugs, and fungus thrives. Southern fruits like figs, which enjoy moisture, do very well, especially Brown Turkey and Celeste. Many old houses have nameless ancient fig trees that people try to propagate from, because they are historical as well as trouble free. The solution, really, is to grow what does well in your climate, and to look for disease resistant cultivars, like the Freedom apples that came out in the 80’s- Jonafree, Macfree, Liberty and Freedom, to name a few. My Liberty apple produces large red blemish free fruit with zero spraying so far. And it is very tart and tasty.  But gardeners long to grow the fantasy- a wonderful antique apple, a tender plum. I long for the crisp, silvery, magical Albemarle Pippin of my childhood. Our 2 Albemarle Pippins have not produced one decent apple in 18 years- they are longing for the Blue Ridge Mountains and have fireblight. I need to get on them with copper sulfate this winter. The moral of the story is, decide how much you want to twist yourself into knots to grow something, and know when you are not getting a good return on your investment.

In the meantime, I spray the safe stuff.

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