"new bottle"

Read the label. Usually, liquid formulations contain "petrolium distillate." It is like spraying your plants with emulsified gasoline.

1. Switch to a wettable powder.

2. Use a good surfactant made for plant sprays to distribute the spray evenly. If you don't, large beads of spray will dry leaving a concentrated residue which will turn into brown dead spots.

Both of those are chemicals that can burn plants if the concentration is wrong; they may also have interacted in a nasty fashion. The rule of thumb is to never mix sprays unless they say specifically that they can be combined, or unless they are both gentle foliar feeds.

The damage is finite, and they should grow out of it shortly. Do take care not to spray in the heat of the day, either; do it when the day is cool and relatively windless, like early morning or evening.

--Alison

I just sprayed my six plants with malathion a few days ago, and have one plant with newest growth (leaves, stems, flowers) that have brown lesions, particularly at the base of the leaves and the tips of the growth, looks sort of like late blight (see photos on problem solver 2), but I don't think it's late blight. I too think I've burned the foliage with the chemical. And I think a couple of real hot days in the mid-high 90's exacerbated the plant's reaction. Strange though that none of the other 5 plants have any of these lesions. I overreacted to hornworms and decided to use the malathion on an impulse. Wish I hadn't. Found out later that other, much less toxic substances can do the same job. Not happy to hear of your similar experience, but am relieved to hear that my problem is very likely the same as yours, with the cause being chemical reaction rather than disease. Also, this is my second year growing heirloom tomatoes, and I have found that they are really very resilient overall, and I expect that they will recover from this setback. I'm just going to watch the plant closely, particularly the new growth.

Hope this helps.

I sprayed my tomato plants with liquid sevin mixed according to instruction. I also have burnt looking leaves and brown on tomato skin. Are these tomatoes safe to eat? They will be ripe in two weeks and were sprayed last week.