Yes you do.

Dave

Ok, thank you. I will spray them again tomorrow. It looks like it is going to rain again tonight.

Actually it looks like showers and possible T-storms for you and me most of this week since I'm not that far from you in upstate NY and am a weather maven who checks four weather sites several times a day.

I just can't help it and it harkens back to my being raised on a farm where we grew many acres of tomatoes and lots more. Weather could and can make or break a commercial farmer moneywise in any single season, as well I know.

Carolyn

Always pays to check the weather forecast before wasting the time applying garden sprays. Even if the forecast isn't perfect it sure improves your odds for success.

Dave

Does the same hold for liquid copper? I've been trying to get my plants sprayed, it really does look like LB on my potatoes, but it rained most of the day yesterday and we're supposed to have more T-storms this afternoon and tomorrow too. I just don't want it to spread to my tomatoes!

The source of Late Blight (P. infestans) spores is via wind and embedded in rain droplets, so if you feel that your potatoes have LB it would seem to me that the spores would have landed on your tomatoes as well.

Rain will wash off anything that's been sprayed, even if spreader/stickers are used, and that includes Daconil and copper as well, and it's been that way forever and forever.

We all deal with it as best we can with fingers crossed as I'm doing here since LB is reported in many areas of NYS as well. My special problem is that someone else does all my gardening for me since I'm kind of chained to this walker, and that person can't always get here in time to do the sprayings that I think are necessary.

Carolyn

So, no matter what you're spraying, is it better to wait until you know you'll have at least a couple of clear days to spray, or should you spray ASAP if you know you have a problem, even if you have to reapply 2 days later?

I did see a couple of leaves on 1 big CP plant that looked suspicious - I pulled them last night. That plant (and 2/3 of my tomatoes) are about 25 ft from the worst potatoes (I have 1.5 rows of each, with peppers in between). Should I just pull the worst potatoes (15 plants in that half row closest to tomatoes)?

Hard to know what to do when 30% chance of rain is "scattered T-storms" and 20% is only "partly cloudy".

Most, (all?) fungicides need to be applied before it rains to protect the plant. I don't think any of them work to "cure" an already infected plant.

So spray before the rains come for protection and reapply if needed after the rain goes.

I know they won't cure it - extension office told me if stems weren't affected, just cut off all the affected foliage and spray, I may be able to hold off the disease a couple of weeks until harvest. And of course spray the tomatoes as a preventive measure.

if you mulch with straw,thats the best preventive for leaf disease, just spray again after you mulch. it might help to give the plants a little more fertilizer higher in potash, 5-10-10 or 10-10-10 or organicly a good drench of liquid seaweed followed bi a little bit of sulfate of potash magnesium. this helps the plants fight disease.

Never knew Dragons were a problem for veggie gardens. Now if this was a livestock forum I could see needing to spray THEM with Draconil. You must have some new Vegetarian type Dragons down there on the island.

Also I'm not so sure simple sprays would be all that effective anyways. Generally you would need a wizard, a ballista, or several large foreign speaking men weilding large exotic weapons and wearing fur and scale armour. Or of course a Dragon of your own.

CH

if you mulch with straw,thats the best preventive for leaf disease

*****

It is if you're talking about splashback reinfection as I think I posted about above, but not for any NEW infections where the foliage disease pathogens are spread by wind and rain.

And since we've been talking about Daconil here, that would refer to any new infections by either Early Blight ( A. solani), or Septoria Leaf Spot, or both, b'c both can be present on tomato plants at the same time.

Carolyn

Well, I sprayed the tomatoes about 9Am, picked more foliage off the potatoes, then went to pick my great-uncle's blueberries. His potatoes look the same and he says he thinks they just got a little dry at one point - but my blotches keep showing up every few days. he said if it was LB they'd be pretty much dead after a week. So who do I believe, the PhD (who didn't call back to tell me if it sporulated), or my 99-yr old uncle who has a lifetime of experience?

It might have rained here a little (I went to grocery store), have to check if tomatoes are still covered, guess there's no harm in spraying the potatoes - it's a little windy, but it looks like only Partly Cloudy tonight.

(BTW, my potatoes - and tomatoes, peppers - are mulched with hay and only the upper leaves of the potatoes are affected, so definitely airborne)

You don't indicate your zone or location so it is impossible to determine if LB is even an issue in your area. Have you asked the county ag if other cases have been reported? Have you taken leaves to them for examination? They need to know.

As your uncle said late blight destruction of plants is pretty fast - a week to 10 days max is common and "blotches showing up every few days" isn't characteristic of LB. Are there exceptions? A few depending on how aggressive the treatment is and soon it is caught. Otherwise it is there one day and the whole plant - leaves and stems - is down soon after.

Can we prevent the infection in the first place? To a degree by spraying from day one of planting. If you don't do that then you take your chances and if you get it you pull the plants.

Should we even try to salvage LB infected plants? No. It only causes it to spread to others, magnifies the problem for a county exponentially, and can result in an epidemic as in 2009. It is the price we pay if we don't take the precautions. So IF it is officially LB why haven't you pulled and disposed of the plants already? If it isn't then you spray and if it rains you spray again.

Dave

Oh, sorry, I posted on the LB in New Haven county thread - I'm in CT, I did take leaves in on Thursday and they said it looked like late blight. Now I am inclined to believe them (or at least it's gray mold or something) and not my uncle b/c I could have sworn I got every single leaf that had a spot this AM and this PM there were more.

I haven't pulled the plants b/c PhD at extension told me on Friday to pull the leaves and spray and I could possibly get a few weeks out of them so I could harvest. I did email this AM and ask if they got them to sporulate and whether I should pull the plants, they have not updated the map on USA Blight to show my county, so I asked if that meant they haven't confirmed that's what my potatoes have. No reply yet so I don't know if it's official, or if I'm "clean" (he did say my blueberries looked like gray mold took after frost damage, took samples of those in Thurs too, so maybe it's the same thing though he didn't think so?). Really don't know what to do besides pull leaves and spray - but at some point either the plants are going to die of LB, or run out of leaves since I've been pulling them for 5 days now (and gave them a severe trim on Sat).

I mulched all my tomato plants heavily with straw today so that is all I got acomplished besides adding another layer of weave on the plants supported by Florida Weave. But the staw is on their heavily, no way is there gonna be any splashback.

I kept thinking it was gonna rain so I didn't spray again but I will be respraying tomorrow.

Ha, the mulching looks so good. I was admiring it again today! More important, it protects the tomato plants.

It is lovely today so I did get the tomatoes sprayed. So all is good. I see lots of green tomatoes here so I can't wait for ripe ones to come along.

At least it did not rain again today and wash off my spray.

First, I would like to ask everyone: when you spray with Daconil, what sort of mask do you use?

===

And secondly ... Coconut Head, when I look at them in my mind's eye ... well, at the moment they are arguing tactics. And arguing. I don't understand the languages, but the mutual insults are unmistakable. The Wizard looks disgusted. Some of the ballista underlings have their slide rules out.

Hope the dragons don't take advantage and ambush them before they come to a consensus.

As far as vegetarianism is concerned: these are obviously canny dragons with the good sense to enjoy broiled beefsteak tomatoes with their beef. None of our plants are safe.

I spoke too soon. We had a thundershower at about 5:30 Am and it rained pretty good. But honestly they have been giving about 20% chance of thunderstorms all week so you can't plan by that as the rain might not come.