TMV or No?

coolbythecoast · June 20, 2015

I have been reading that TMV infection is rare, perhaps even more rare among us amateur growers. I am posting a pic of one of my tomato leaves, several of my plants have rather suddenly come down with this symptom. If not TMV, then what? I do not see the kind of shoestring leaves that are common with CMV.

Particulars are:

Grown in screen room, have a few whitefly and fungus gnat. Spraying with Pyrethrin to eliminate. Symptoms appeared some time after first spraying. Also using Gnatrol bio control, but can't imagine that this would cause symptoms.

Soil is pine bark fines, peat and perlite. Lilly Miller 5-10-10 added while mixing. Last season I added hydro-tomato fertilizer after 1 month or so, but none so far this year.

Approximately 5% of plants presently exhibiting symptoms.

Have grown 1 yr previous with all particulars identical. Had perhaps 20% of plants exhibiting same symptoms by mid-season. Removed all plants upon discovery and this year re-used only pots from plants asymptomatic. Sterilized pots with 20% chlorine bleach for 10-20 minutes.

So what do you think, too much fertilizer, too little? Effects of the Pyrethrin? Some contamination from the fines? Blisters and mottling seem to resemble TMV pictures I find on the web.

Ignore the date on the pic, my VCR flashes 12:00 as well (grin). And don't ask "What's a VCR?, it will really make me feel old!"

Thanks

digsdirt · June 20, 2015

Are you familiar with a condition called Tomato Leaf Edema? That is what I think I see in your photo.

It can be caused by a number of things that cause an abnormal increase in the size and number of a group of leaf cells. Have you sprayed the plant with anything? Yes. Are there any signs of sucking pests? Yes. Both are contributing factors.

Other contributing factors - Are you perhaps using any high intensity lights on the plant? Do you perhaps water the plant with warm water? What is the humidity like in your growing area? When the soil is overly warm and the surrounding air cool and moist the roots can absorb water fater than the plant leaves can lose it by transpiration. That causes the cells in the leaves to swell and rupture or divide to store that excess. You end up with raised pattern and discoloration like seen in your leaves.

Control - in the greenhouse (similar to your set up) we have to substantially reduce the humidity by either venting or raising the air temp slightly, increase the air circulation around the plants (fans), cut back on fertilization, and reduce watering. The damaged areas usually don't return to a normal appearance and some may brown and die when damage is severe. Just remove those leaves. New growth should be normal.

Hope this helps.

Dave

PS: and no Turkish imported tobacco allowed in the house

It is the primary source of any TMV seen nowdays.

PSS: for the fungus gnats pick up a pack of Mosquito Dunks or Mosquito Bits, dissolve small amt. in water and water the soil with it a couple of times. It is just BtI (Bacillus thuringiensis israelensis). Whiteflies - yellow sticky traps.

coolbythecoast · June 21, 2015

Thanks a bunch, Dave! Although I have a few whitefly, I kinda assumed it was not a disease as I have been so careful with isolation and disinfection. Yes I have most of the factors that you list as contributing to edema. The nights cool off fast around here so I suppose the pots are warm, the air is cool. We are next to the ocean, so we have plenty of humidity.

How much to water? Is it OK to wait until the plants begin to faint?

How much to fertilize? Last year I used tomato hydroponic fertilizer regularly, alternating it with a water flush to keep fertilizer/salts from building up. Most of the plants seemed to tolerate this well.

Speaking of the hydroponic fertilizer, the Calcium Nitrate doesn't dissolve well, is it OK to apply to the plants while the particles are suspended in agitated water, or should I pre-dissolve in warm water and allow to cool? Troublesome to do, but will attempt it if needed.

June 20, 2015	#2
digsdirt Tomatovillian™ Join Date: Jun 2015 Location: No.Central Arkansas - 6b/7a Posts: 179	Are you familiar with a condition called Tomato Leaf Edema? That is what I think I see in your photo. It can be caused by a number of things that cause an abnormal increase in the size and number of a group of leaf cells. Have you sprayed the plant with anything? Yes. Are there any signs of sucking pests? Yes. Both are contributing factors. Other contributing factors - Are you perhaps using any high intensity lights on the plant? Do you perhaps water the plant with warm water? What is the humidity like in your growing area? When the soil is overly warm and the surrounding air cool and moist the roots can absorb water fater than the plant leaves can lose it by transpiration. That causes the cells in the leaves to swell and rupture or divide to store that excess. You end up with raised pattern and discoloration like seen in your leaves. Control - in the greenhouse (similar to your set up) we have to substantially reduce the humidity by either venting or raising the air temp slightly, increase the air circulation around the plants (fans), cut back on fertilization, and reduce watering. The damaged areas usually don't return to a normal appearance and some may brown and die when damage is severe. Just remove those leaves. New growth should be normal. Hope this helps. Dave PS: and no Turkish imported tobacco allowed in the house It is the primary source of any TMV seen nowdays. PSS: for the fungus gnats pick up a pack of Mosquito Dunks or Mosquito Bits, dissolve small amt. in water and water the soil with it a couple of times. It is just BtI (Bacillus thuringiensis israelensis). Whiteflies - yellow sticky traps. __________________ Dave Last edited by digsdirt; June 20, 2015 at 10:26 PM. Reason: to add text

June 21, 2015	#3
coolbythecoast Tomatovillian™ Join Date: May 2007 Location: SoCal Posts: 39	Thanks a bunch, Dave! Although I have a few whitefly, I kinda assumed it was not a disease as I have been so careful with isolation and disinfection. Yes I have most of the factors that you list as contributing to edema. The nights cool off fast around here so I suppose the pots are warm, the air is cool. We are next to the ocean, so we have plenty of humidity. How much to water? Is it OK to wait until the plants begin to faint? How much to fertilize? Last year I used tomato hydroponic fertilizer regularly, alternating it with a water flush to keep fertilizer/salts from building up. Most of the plants seemed to tolerate this well. Speaking of the hydroponic fertilizer, the Calcium Nitrate doesn't dissolve well, is it OK to apply to the plants while the particles are suspended in agitated water, or should I pre-dissolve in warm water and allow to cool? Troublesome to do, but will attempt it if needed.