Question
QUESTION: I have 350 fall mums in our greenhouse that I planted into 8" pans from cuttings on 05/19/09.  I've seen some thrips, but am keeping them under control with Conserve.  Now several varieties have browning around the leaf edge.  Not just the leaves on the bottom, but the top as well.  I realize this could be many things; too much water, too little water, mineral deficiency, etc.  I can tell you that I water pot-to-pot (not overhead), keeping them moist but not soaked, and I fertilize every few days.  They are also treated with Medallion every 20 days.  This is only my 4th year growing mums.  The first 2 years I had no pests, no diseases, they turned out huge and gorgeous!  Last year was my first experience with thrips and the leaf-edge browning...I lost 3/4 of my crop.  Since I'm already seeing the same issues now as last year, I need to try and solve this problem fast.  Any advice would be greatly appreciated.  Thank you!

ANSWER: Ok  good information Jen.  Mums are beautiful  I have a couple Iam managing for my wife.  The browning may be from the conserve or Medallion.  These products are fantastic at controlling the insects but do nothing for the health of the plants which is where the true problem lies.  Each time the pesticides are applied there is a destructive effect to the plant cells.  I would try to go with an all natural product called Atomic Grow.  I have used it on my wifes plants and it works good.  I have used it on Thrips, aphids, sooty mold, ants, leaf miner etc..  It also stimulates the plants as it enters through the stomata.  Each leaf will then produce more sucrose resulting in more blooms better root systems etc.  I think it works on Nematodes too but Ive never tested.

www.atomicgrow.com


Good luck Jen

James

---------- FOLLOW-UP ----------

QUESTION: Thanks so much for the great info!  Now you've really got me thinking!  I didn't use Conserve or Medallion last year (couldn't afford them :)  But I did use an Acephate systemic spray from Ortho AND I also used it on the mums twice already this year (they suggest you alternate insecticides for better control of thrips).  Since I had the exact same problem last year with the leaf-edge browning, do you think it could be from the acephate?  Also, the grower I purchased the mum cuttings from felt it could be getting too hot in the greenhouse, since I don't have any shade cloths, thereby causing the leaf scorch.  We've already had some temps in the 90's here in MN, so the GH definitely is a cooker!  But the fans are constantly running and the windows are always down, plus I didn't have this problem the first two years so am curious what your thoughts are on that as well.  Thanks again!

Answer
You will get phytotoxicity on the leaf if your applying pesticides in a very hot area for sure.  You may want to re-evaluate your fertilzer schedule.  May be too much for the plants to process.  When the plants cant process the fertilizer fast enough amino acids will start to build up.  Insects will also sense this and move in.  Its there job to attack anything unbalanced in nature.  Your schedule just needs a little tweaking.

Also the systemic product I recommended Atomic grow.  It works by cleaning the stomata of each leaf to the micron.  It also immediately cleanses any insects thrips or otherwise.  When the stomates are cleansed the leaves will produce more sucrose resulting in higher Brix levels.  This is the root of your problems.  The plants will rebalance and unclog the nutrient tie up your having.  I would seriously take a close look at this product.  If you want a second opinion you can go to www.crowleynursery.net.  Kathy owns a 22 acre Botanical garden and can help you even more.

James