7.13.2013

Downy Mildew and Striped Cucumber Beetles

We have had rain for the past 2 weeks and cooler weather and it has felt like spring outside.   Earlier this week it warmed up again to very humid and hot air and was very uncomfortable.  Then the past 2 days it has cooled down again.  I started noticing some yellow and white spots with some brown on the leaves of the cucumbers last week.  I should have researched it right away but have finally gotten around to it.  I have discovered that the cucumbers have Downy Mildew.  
Downy Mildew patches on our Cucumber leaves
From my research this disease occurs mostly in moist cool weather (normally occurring in spring and fall).  You discover it most of the time after rain or lots of dew.  Sometimes it goes away after the weather becomes warmer and the sun is out more often.
BED #4 with Cucumber vines in back (July 9th)
I have removed most of the diseased leaves in hopes of stopping the spread of the infection.   I could choose to use a copper fungicide, which is an organic fungicide but I have decided against that.  I have read that the copper can be toxic to worms and microbes if it builds up in your soil.  If I have enough time I may try aerated compost tea which can prevent the spread of the disease.  I did save some compost just to do this!
Striped Cucumber Beetle
I have also spotted another type of beetle in the garden!  The Striped Cucumber Beetle is on our Cucumbers and Winter Squash!  I went out tonight and using my glass jar filled with water and soap I knocked them into the jar with a Q-tip.  They fly away if you try to use your fingers so I found that this method worked well.  I found many of them in the yellow flowers on the Cucumbers and the orange flowers on the Winter Squash.  I am going to be on the lookout for them each day!  The best thing you can do is to keep preventative measures in place and continue to trap them before they do harm!
June 15th Row Covers still on


June 20th Row Covers removed on Beds #3 & #4
The good news is that we did keep our row covers on the Cucumbers long enough so that the plants had time to mature.

Cucumber seeds started indoors: May 1st
Cucumber seedlings planted outdoors: May 18th
Row Covers removed: June 20th  (plants 7 weeks old)

Hopefully this extra time the plants had to grow and develop will allow them to withstand some beetles.  I am going to be on the lookout because I read that the Striped Cucumber Beetle can transmit Bacterial Wilt, Squash Mosaic Virus and increase Powdery Mildew (which we already have on the Zucchini) and Black Rot.  Yikes!!
Yellow Zinnia
On a more helpful note I am going to start to read up on the different harmful insects so that I have a more educated understanding and a visual picture for the future.  I think I saw this Cucumber Beetle a couple of weeks ago, but I was too busy to look it up!  Here is a helpful link to Identifying Harmful Insects


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