Strange Leaf Curl

The biggest problem I faced this year with my tomatoes was a strange leaf curl that started on the youngest, tender leaves at the top of the plants.  As it turned out, I don't think that the leaf curl affect blossom set or fruit production but here some stuff I learned about it.  Let me know if you found out anything different!

Strange Leaf Curl at Top of Plants

I searched the web for hours and most of the expert sites agreed that leaf curl on the tops of the plants was either pesticide drift damage or stress.  Since there were several folks around town with the same problem, I determined that it was not pesticide drift.  I thought it could be stress as it showed up right after a 7 inch rain but it persisted (and continued to spread) even after it dried out.

Finally I heard from the local extension agent.  An extension specialist from College Station said that it was most likely a microscopic mite that cause the problem.  It feeds on the chlorophyll in the plant and causes the damaged leaf to curl.  There is not visible damage to the leaf other than the curl and you can only confirm the presence of the mite by sending off a sample which takes time and money.  He suggest a foliar spray of liquid sulfur or pyrethrin.  Sevin dust does not work.  Since I don't use chemicals, I decided to try neem oil which is an excellent miticide, at least on red spider mites.  However, these seemed a little tougher than their more common cousin (assuming that the mite was the problem).  I did spray once with neem and the progression seemed to slow and eventually stop, I'm not sure that it was the answer.  I'm also not sure if the the little critters did enough damage to slow the plants down.  For a couple of weeks, I was harvesting around 10 lbs. of tomatoes a day!

At any rate, if you have this problem, you can give the liquid sulfur or the neem oil a try.  They are both very safe.