Folks, what is this mold on my squash leaves?

ScottinAtlanta · June 22, 2012

It is on squash and cucumbers (delicata), and is progressing at a moderate pace.

kath · June 22, 2012

Looks like powdery mildew.

tjg911 · June 22, 2012

scott if you want to try a safe organic cure use fish milk.

fish milk is easy to make, use this as a foliar spray:

o 2 cups of milk i prefer whole milk but low fat is ok
o 1 teaspoon dish detergent NOT ANTIBACTERIAL as it'll kill beneficial bacteria on the plant
o fish emulsion or fish and seaweed emulsion concentrate use the amount specified for 2 quarts of water. i use neptune's harvest and i use 1/2 tablespoon
o 2 quarts of water

spray plants every 5 days when it rains or every 3 weeks when it is dry. spray in the morning on a sunny day as the sun activates the protective properties. do not store this, mix it fresh each time. if i have any left over i spray cukes and squashes. tomatoes also seem to like fish milk, the calcium no doubts is beneficial. there is very little research about this. i don't drink milk so i buy a gallon and let it sit in the basement fridge. it can go beyond the expire date so long as it is not turning to yogurt! if you drink milk, then you'll have a fresh supply all the time.

tom

**mdvpc** · June 22, 2012

You can also use greencure which works great for me on zuccini, squash and cukes.

b54red · June 22, 2012

If the humidity stays high or it rains then your plants will be totally wrapped up in the stuff. It is already starting on mine. I treat with my bleach solution; but many of the worse infected leaves will die but if you don't stop it the stuff will get on all the new growth under those leaves. It looks like the powdery mildew is pretty widespread on the leaves and the speed with which it spreads will increase quickly in our high humidity.

Cole_Robbie · July 1, 2012

Check out my gardenweb thread about it, with pics: http://forums2.gardenweb.com/forums/...420528.html?10

It is powdery mildew, but not the kind you are used to. It's Podosphaera Xanthi, and it's a special gift from our drought. It actually likes hot and dry weather, and is typically found in the desert southwest. It actually hates rain and water touching it, which is the opposite of the other kind of powdery mildew that is actually caused by wet conditions. Plus it like low humidity, again the opposite of the typical kind of powdery mildew. I don't know if hosing the plant down would help; you could just end up trading one problem for another. It is so hot and dry lately that at least the plant would dry quickly.

Everyone seems to have a different philosophy regarding chemicals. Mine is to use as many as possible, because I have 2 1/2 acres planted and very much need it to not die. I sprayed daconil first. Now I'm going to wait five days and spray with sulphur, then wait five more days and spray with a copper-based fungicide. If you don't rotate different fungicides, resistance can develop. Sulphur is (afaik) organic and has been used for over a hundred years. The guy who is credited with discovering powdery mildew in the 1800's used sulphur to treat it. I don't think any of those fungicides fix the damage, they just protect what healthy growth you have left.

chancethegardener · July 3, 2012

Quote:

Originally Posted by mdvpc

You can also use greencure which works great for me on zuccini, squash and cukes.

Greencure works very well for me, too.

royceag · July 14, 2012

I just received Actinovate for my planting out cocktail (MycoGrow, BiotaMax & Actinovate) and I'm going to apply it as a fungicide today. Fingers crossed it gets rid of this terrible PM we're suffering due to rain & humidity galore. If not, Greencure is next on my list.

ScottinAtlanta · July 14, 2012

Folks, I could not find Greencure, and I did nothing. The plants grew out of the problem. But thanks for all the advice - I have some Greencure on order, and will hit it fast next time. I guess I lost about 2 weeks of growth to that mold.

June 22, 2012	#3
tjg911 Tomatovillian™ Join Date: Feb 2006 Location: zone 5b northwest connecticut Posts: 2,570	scott if you want to try a safe organic cure use fish milk. fish milk is easy to make, use this as a foliar spray: o 2 cups of milk i prefer whole milk but low fat is ok o 1 teaspoon dish detergent NOT ANTIBACTERIAL as it'll kill beneficial bacteria on the plant o fish emulsion or fish and seaweed emulsion concentrate use the amount specified for 2 quarts of water. i use neptune's harvest and i use 1/2 tablespoon o 2 quarts of water spray plants every 5 days when it rains or every 3 weeks when it is dry. spray in the morning on a sunny day as the sun activates the protective properties. do not store this, mix it fresh each time. if i have any left over i spray cukes and squashes. tomatoes also seem to like fish milk, the calcium no doubts is beneficial. there is very little research about this. i don't drink milk so i buy a gallon and let it sit in the basement fridge. it can go beyond the expire date so long as it is not turning to yogurt! if you drink milk, then you'll have a fresh supply all the time. tom __________________ I need a hero I’m holding out for a hero ‘til the end of the night He’s gotta be strong And he’s gotta be fast And he’s gotta be fresh from the fight I need a hero I’m holding out for a hero ‘til the morning light He’s gotta be sure And it’s gotta be soon And he’s gotta be larger than life

June 22, 2012	#4
mdvpc Tomatoville® Moderator Join Date: Jan 2006 Location: San Antonio, Texas Posts: 4,386	You can also use greencure which works great for me on zuccini, squash and cukes. __________________ Michael

July 14, 2012	#8
royceag Tomatovillian™ Join Date: Jun 2012 Location: Charlotte, NC 7b Posts: 42	I just received Actinovate for my planting out cocktail (MycoGrow, BiotaMax & Actinovate) and I'm going to apply it as a fungicide today. Fingers crossed it gets rid of this terrible PM we're suffering due to rain & humidity galore. If not, Greencure is next on my list. __________________ All the best, Royce

June 22, 2012	#2
kath Tomatovillian™ Join Date: Jan 2010 Location: zone 6b, PA Posts: 5,664	Looks like powdery mildew.

June 22, 2012	#5
b54red Tomatovillian™ Join Date: Sep 2009 Location: Alabama Posts: 7,068	If the humidity stays high or it rains then your plants will be totally wrapped up in the stuff. It is already starting on mine. I treat with my bleach solution; but many of the worse infected leaves will die but if you don't stop it the stuff will get on all the new growth under those leaves. It looks like the powdery mildew is pretty widespread on the leaves and the speed with which it spreads will increase quickly in our high humidity.

July 1, 2012	#6
Cole_Robbie Tomatovillian™ Join Date: Jun 2012 Location: Illinois, zone 6 Posts: 8,407	Check out my gardenweb thread about it, with pics: http://forums2.gardenweb.com/forums/...420528.html?10 It is powdery mildew, but not the kind you are used to. It's Podosphaera Xanthi, and it's a special gift from our drought. It actually likes hot and dry weather, and is typically found in the desert southwest. It actually hates rain and water touching it, which is the opposite of the other kind of powdery mildew that is actually caused by wet conditions. Plus it like low humidity, again the opposite of the typical kind of powdery mildew. I don't know if hosing the plant down would help; you could just end up trading one problem for another. It is so hot and dry lately that at least the plant would dry quickly. Everyone seems to have a different philosophy regarding chemicals. Mine is to use as many as possible, because I have 2 1/2 acres planted and very much need it to not die. I sprayed daconil first. Now I'm going to wait five days and spray with sulphur, then wait five more days and spray with a copper-based fungicide. If you don't rotate different fungicides, resistance can develop. Sulphur is (afaik) organic and has been used for over a hundred years. The guy who is credited with discovering powdery mildew in the 1800's used sulphur to treat it. I don't think any of those fungicides fix the damage, they just protect what healthy growth you have left.

July 14, 2012	#9
ScottinAtlanta Tomatovillian™ Join Date: Jul 2011 Location: Atlanta, Georgia Posts: 2,593	Folks, I could not find Greencure, and I did nothing. The plants grew out of the problem. But thanks for all the advice - I have some Greencure on order, and will hit it fast next time. I guess I lost about 2 weeks of growth to that mold.