Tomato pesticides, anything better than Malathion?

R

Real.Dale.Benjamin 18 years ago

Hi, I'm growing tomatoes on my apartment porch, got maybe a dozen plants going not too bad. Got a severe problem with bugs and bacteria pest because I recirculate excess water. Yup, the plant's saucer has a little hole in it with a quarter inch barb and tube which leads to an overflow collector. Half a day later I pour it back into the plant's pot. Recirculate the excess water, bacteria, bugs, whatever. Not the ideal situation to produce prize winning tomatoes, I fear, but a step in the direction of water conservation, probably taken a million times before.

This year is my first endeavor to raise tomatoes, and I'm pleased so far. I'm in San Diego county California a bit east. My porch is overhung on the north and west sides, so the tomatoes only get a few hours of direct sunshine a day. No rain, so I water them twice daily, and spray with tap water after dark. I also flood the pots with tap water, so I get some overflow, which I use next watering.

Pests encountered so far include caterpillars, leaf eating bugs, and something (bacteria?) which turns leaves and stems black in places.

Caterpillar/worms seem easily defeated by applications of Ortho Bug-Be- Gone, but it must be replaced monthly.

The leaf eating bugs are not so easily defeated. A little Malathion every other night slows them down a lot, but too heavy an application seems to destroy the foliage. I reckon I'm using about a teaspoon of Malathion per gallon of water now. First I heavily spray my victims with straight tap water, then lightly spray them with the Malathion solution. After a quarter hour, I again spray heavily with straight tap water. Seems to reduce the damage, but my principal question at the moment is what can be done to improve the results? Another insecticide, or another proportion?

The black growth mostly on the stalks and a few leaves I attribute to some bacterial infestation, but the Malathion don't seem to help. A few hours spent examining labels of pesticides at the Home Depot and Lowes seems to suggest I am SOL. The growth puts me out of competition for the Better Homes and Gardens competition, but don't seem to be hurting the plants a lot; it's just ugly. Any ideas?

Vote

V

vert20 18 years ago

Excess moisture on the leafs will cause a mold and fungus growth. All that spraying, more so at night, is giving the molds a chance to really grow. On occation spray the leaves otherwise just water the soil. Also try using a spay made up with garlic oil, hotpepper juice and a little dish soap mixed with water. What that will do is change the tast of the leaf and the bugs won't eat it as much.

Vote

G

George.com 18 years ago

or another alternative to try is a neem oil spray.

rob

Vote

O

Omelet 18 years ago

Seconded.

I would personally never use Malathion on anything I expected to eat.

Vote

M

Max Wright 18 years ago

In message , Omelet writes

Me neither! But that black growth sounds suspiciously like blight - which no amount of insecticide - or fungicide, for that matter - is going to cure. If that's really what it is, there isn't much you can do except remove affected leaves and fruit and hope it only spreads slowly. However, since blight thrives in humid conditions you should probably cut down on the spraying too.

Vote

O

Omelet 18 years ago

I wonder if a sulfur treatment would help?

Vote

Z

zxcvbob 18 years ago

Bordeaux mixture should work, and it even sticks pretty well through rains.

Bob

Vote

O

Omelet 18 years ago

I'm not familiar with that. I'll have to google it...

Vote

Z

zxcvbob 18 years ago

Copper sulfate and slaked lime. I think it's even "organic" approved.

Bob

Vote

O

Omelet 18 years ago

It makes sense.

I may have to try some of that for the ivy out front.

Vote

Z

zxcvbob 18 years ago

Your ivy has a fungus? Bordeaux mixture is a fungicide; it sounded like OP's tomatoes have a blight. Fungicide will help.

BTW, my one tomato plant that's downhill from the compost pile (where among other things I've been dumping the cat box) is big and robust and

3 times the size of the other tomato plants. It's also the only one that doesn't have any blight at all. Coincidence?

Bob

Vote

G

Glenna Rose 18 years ago

snipped-for-privacy@charter.net writes: [snip]

Or maybe healthy soil?

(though cat and dog feces are definitely not recommended for compost)

Glenna

Vote

G

George.com 18 years ago

what role does the lime play? We have copper sulfate spray which I use from time to time, but not with lime.

rob

Vote

O

Omelet 18 years ago

It was suffering from root rot. Some of it still does from time to time. It kills whole sections before I catch it. :-(

I can use topical fungicides for my Peruvian torches. They came in with a blight and I've been fighting it ever since.

Good nitrogen in that cat litter. ;-) It used to be beneficial here too, but I quit dumping used kitty litter in garden beds when I switched to scoopable. That stuff is nasty.

Vote

O

Omelet 18 years ago

They are if you COMPOST them first.

Vote

J

Jim Kingdon 18 years ago

A somewhat complicated issue...

See for example

formatting link

we do is have a separate compost bin (buried trash can, with the bottom cut out) for the dog waste. It will be a while before we need to worry about what to do with the compost (it reduces in volume with time), but probably we'll eventually rotate the fresh waste to a different can and let the old one sit for a year or so and use it on the garden. Despite the lack of high temperatures in this kind of bin, I'm not persuaded that it is particularly likely to transmit disease, especially compared with other activities like picking up the dog doo in the first place (hand-washing after dog walks strikes me as being at least as important as any composting protocol here).

Vote

Z

zxcvbob 18 years ago

That's part of it, although the plant looks like maybe it got too much nitrogen because it doesn't have many blooms nor tomatoes yet. I think those will just come later than on the plants that aren't doing so well.

I think next year when I do the "spring cleaning" in my back yard, I will follow that umn.edu page's advice about burying dog waste at least

6" deep in the soil. I'll bury it about 10" deep under my tomato plants. ;-)

Bob

Vote

O

Omelet 18 years ago

I don't worry much about disease with well composted stuff. I also compost for up to two years. Those heavy construction bags are good for that as they hold up well. I've got some wild grape vines started composting this year after I had Lynn' ruthlessly prune them. ;-)

Doggy doo goes into 5 gallon buckets. It's pretty rich stuff tho' and needs to be liberally mixed with sand and other organic compost that is not so high in Nitrogen. Dog doo compost is why those grapes needed pruning.

Vote

O

Omelet 18 years ago

Make sure you compost it first. ;-) One nice thing about black bag composting, leaving it (the bags) in the sun heats it to high temps so kills any parasites.

Vote

O

Omelet 18 years ago

I saw an earlier post that showed the dangers of parasites harbored in the manure. Long term composting is supposed to take care of it. I compost most stuff for two years minimum.

I did not finish that sentence anyway. It only starts off in 5 gallon buckets. From there it gets mixed with leaf or weed compost and placed into those large construction grade (heavy mil) trash bags and placed out along the back fence in a corner of the yard.

I've not actually used dog manure compost on crop plants (I had plenty of chicken and emu manure for that). It's been being used on the fence border for the honeysuckle vines and wild muscadine grape vines. We used to use used cat litter for the flower beds. The Cannas are heavy feeders and it did them a lot of good.

I had to quit doing that when we switched to scooping litter. That stuff turns into a heavy, slick clay. Not a good idea at all!

Vote

Tomato pesticides, anything better than Malathion?

Join the Discussion

Didn't find your answer?