From

Location

Message

Date Posted

Salem, OR

I would appreciate any help on this. Several of my plants are showing yellowing on the leaves. I have just posted a couple pictures. The leaves turn yellow, then tend to burn. I am seeing a little of this on all my plants, but some more severe than others. No other problems, plant is showing no wilting and pumpkins are still growing. I have sent off soil sample and tissue samples, but would appreciate any help, while I "impatiently" wait for the results. Thanks everyone!!

9/7/2009 9:18:15 PM

Ohio

s jeff, I havnt seen the pics yet , but usally this time of year you start seeing Downy Mildew, it will turn the leaves yellow in a hurry and then turn them brown.

9/8/2009 4:25:14 AM

Ohio

http://www.bigpumpkins.com/Diary/DiaryViewOne.asp?eid=118087

http://www.bigpumpkins.com/Diary/DiaryViewOne.asp?eid=71345

9/8/2009 4:30:20 AM

Ctpumpkin@optonline.net

Looks like the start of Powdery Mildew which will not be revealed in a soil test.

9/8/2009 10:01:56 AM

Salem, OR

Thanks everyone. I have been spraying religiously for Powdery mildew, because I saw signs of that very early in the season. Is Downy Mildew and Powdery Mildew the same thing? If not, I'll need to check and see if the fungicides I have been using address Downy.

9/8/2009 11:10:55 AM

Colorado Springs, CO

The yellowing of leaves can also be signs of the progressive loss of available (new) nitrogen for the entire plant. Are these leaves perhaps the older leaves on the plant and thus furthest away from the leading end of the vine ? The older leaves can "give away" their nitrogen as the newer tissue takes (demands) it more readily, and thus the old leaves sacrifice their green-ness and will wither first.

This happens on tomato plants and many other plants, for that matter. The season is waning, the plants have worked hard to grow and produce. Resources immediately available in the soil can become depleted by this time of the season.

Watering practices and relative humidity can contribute to the powdery mildew problem. Some plant varieties are simply more susceptible to PM than others, be they flowers or veggies. The squash/cuke/pumpkin family is one of these. Take a sharp clean knife and cut off the PM'd leaves and begin watering at ground level from here on out. Stop any overhead watering practices now.

9/19/2009 10:20:11 AM