Pests, Diseases and Other Problems
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Subject: Leaf problem - need advice
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From
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Location
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Message
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Date Posted
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Mr. Orange |
Hilpoltstein, Bavaria, Germany
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Please check out this link and the following two gallery pictures!
http://www.bigpumpkins.com/DisplayPhoto.asp?pid=3653&gid=-25075
Thanks, Martin
MartinReiss83@t-online.de
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6/5/2005 12:52:30 PM
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Indana Grower |
New Salisbury IN
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Martin i cant say what is i can say what it is not it is not a lack of water.wish i could be more help
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6/5/2005 1:56:44 PM
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BenDB |
Key West, FL
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looks like burn from too strong of fert to me
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6/5/2005 3:06:52 PM
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Mr. Orange |
Hilpoltstein, Bavaria, Germany
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So far I haven't used any fertilizer this season...
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6/5/2005 4:36:32 PM
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Indana Grower |
New Salisbury IN
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looks like a burn to me to did you put on anything is your water ok
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6/5/2005 5:35:50 PM
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Mr. Orange |
Hilpoltstein, Bavaria, Germany
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Like I mentioned, so far I haven't used any fertilizer this season and I also haven't sprayed any pesticide. The plants have been watered either by rain or with collected rain water. There is nothing I can think of that could have caused burn other than the sudden 90°F heat we got last week.
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6/5/2005 6:22:55 PM
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Indana Grower |
New Salisbury IN
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ok if that is the problum put on as many new leaves as you can befor pumpkin set to help with bad leaves
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6/5/2005 6:56:54 PM
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Tremor |
Ctpumpkin@optonline.net
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I think you hit the nail on the head Martin. Young AGs hate going into high heat while wet. Like many plants, AGs seem to posess hormone that help them rid their rootzones of surplus water. Many plants do this by regulating the opening of the stomates. I think a hormone alters guard cell potassium salts into supressing closure. So the stomates open further & have trouble closing for a short period following a high moisture incident. I suppose this would be triggered by a lack of soil oxygen but cannot say for sure.
Anyway, the plant loses mositure at a rate greater than the roots can re-supply just long enough to cause some necrosis.
More research has been done on turf & other high value agriculture crops. So once again, the Giant Pumpkin grower is left using recycled data from other growing diciplines.
Of course there is still the outside chance you really have a serious pest problem too. Did you check the undersides of the leaves for mites?
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6/5/2005 7:51:47 PM
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Mr. Orange |
Hilpoltstein, Bavaria, Germany
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Hi all,
thanks for all your help.... appreciated a lot!
Steve,
yes, I did check the underside of the leaves! After having had serious problems with spider mites on my cucumbers in another patch in recent years I am really in alert!
But there was nothing, no aphids, no spider mites, no netting, nothing, under the leaves in question.
But I must say I am feeling a lot better after you somehow confirmed my theory. It was really cold and wet (water was standing on a nearby meadow for weeks!) for several weeks and then, out of nothing, it switched to HOT and dry. That’s why I figured it to be some form of heat related wilt.
The only strange thing is that it has now been back to cooler for two days and still a few new leaves were affected during these two days. But I think the leaves could already have been damaged when it was hot and it was just not visible yet. Like if the leaves need a few days from the moment the damage is caused until they dry out enough for the human eye to realize it. Does that make any sense??? We are supposed to get more cold weather until mid week. I will closely observe the leaves and if no more new leaves will be affected in the next few days maybe the heat really was the problem.
Let me know....
Martin
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6/6/2005 2:15:37 AM
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LIpumpkin |
Long Island,New York
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Its those finicky orange ones again....geez
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6/6/2005 8:19:52 PM
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Mr. Orange |
Hilpoltstein, Bavaria, Germany
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HA HA HA, G! But my plants are still alive whereas a 980 Razo squash plant that I gave to a local grower has already died! It couldn't stand the wet and cold spell we had during most of May!
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6/7/2005 4:39:56 AM
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gordon |
Utah
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Martin, to me it looks like sunburn ... or something along those lines ...
so what do you do for spider mites ?
thanks gordon
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6/7/2005 10:30:24 AM
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LIpumpkin |
Long Island,New York
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I suspect if you gave the orange one to the friend it would be dead too.
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6/7/2005 7:06:04 PM
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Mr. Orange |
Hilpoltstein, Bavaria, Germany
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I suspect the same but we don't know :-)
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6/8/2005 8:34:22 AM
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Dr Nevus |
Springfield, MO
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Martin -- this actually looks like chilling or cold injury, which occurs at low but ABOVE freezing temperatures, and in some cases may become more apparent when the plant rewarms. Cucumbers are more susceptible than pumpkins, and I used to see it when I grew in South Dakota. Apparently the tendency to this is inherited in cucumbers. However, my impression was that it was usually less severe in direct seeded plants than in transplanted seedlings. Maybe that is because I was starting the transplants early and putting them out when it was still to cold, though?
Here is a link to a bad picture of it: http://aggie-horticulture.tamu.edu/cucurbit/leaf/38.3.html. I have a better picture in my Compendium of Cucurbit Diseases. A book I highly recommend if you don't already have it, published by APS Press.
-- Chris
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6/8/2005 8:43:20 PM
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Mr. Orange |
Hilpoltstein, Bavaria, Germany
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Chris,
You might very well be right on that one... we had a few nights in a row with lows between 2 and 4°C, close to freezing. The day I posted the pics was the last day the problem did spread. The next day no more leaves got affected. By now, all the affected leaves look more or less like the leaves in the "after about four days" picture.
However, I now have a new leaf issue... the last two nights were below freezing and the new growth of the plants doesn't look good at all. The weather we are getting lately is hilarious...
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6/9/2005 9:57:24 AM
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Dr Nevus |
Springfield, MO
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I wondered about you when I saw a picture of new snow in the Austrian Alps day before yesterday, Martin. Were you able to protect your garden from freezing?
By the way, I have several of your tall sunflowers going!
-- Chris
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6/11/2005 9:07:06 AM
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Mr. Orange |
Hilpoltstein, Bavaria, Germany
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Chris,
Yes, I was able to protect the most important things. I only lost a few cucumber plants and some flowers. Other plants, among them the AGs, only received minor damage.
Keep me posted on the progress of your sunflower plants!
Martin
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6/11/2005 12:51:12 PM
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Brooks B |
Ohio
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Martin, I have one of your ski rocket plants that just wont die,lol(Not that im trying to kill it on purpose,lol) But I started about 10 of the sky rockets inside and this one is the only one that didnt die from dampning off. I planted it outside in the cold with no protection and forgot about it,I thought it was dead because it was all brown and laying flat on the ground.Then about Three days later I notice it trying to stand up with just a little green leaf starting,so I watered it and it started to come back! I then forgot about it again,lol, for about another week and it looked like a plant in the desert,dirt was dry and hard,plant looked like toast,I thought what the hell,Ill water it,guess what it came back and is starting to look good at 4 inches tall, is still alive!
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6/11/2005 11:29:10 PM
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Total Posts: 19 |
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