Preventing Curly Top in Tomatoes

Tomatoes are the one crop I look forward to the most in my garden.  I know I'm not alone in loving homegrown tomatoes.  Tragically tomatoes are disease prone and at the mercy of many pests. Curly top is a disease transmitted by and insects so you are dealing with both pest and disease.

  

To deal with curly top you need to understand how the disease is transmitted to the tomato plant.  As the grasses in surround areas dry up leafhoppers, who are the lovely little vector for curly top virus, leave the fields and come to your much greener garden to feed.  They feed on the juices of a plant and can infect your tomatoes with curly top. So leafhoppers vector the virus we call curly top.

Curly top is a virus that spreads throughout the whole plant and unfortunately there is no cure.  You must ruthlessly remove the plant.  Leaving it in the garden will allow other insects to feed on the infected plant and spread the virus to other plants.

Leaves of infected plants twist and curl upwards.  They become stiff and leathery.  Sadly they eventually turn turn yellow, then brown and die.  Curly top can also effect melons, spinach, beets, and beans. 

To help prevent curly top remove weeds around your garden and control pests. 

Since most of my tomatoes are heirlooms that I start from seeds, it is very discouraging to have to tear out a plant.  I do usually start 2 or 3 of every variety.  I plant one or two in the garden depending on the variety and keep one the potting shed incase I lose one to curly top.  Generally I only lose 2 or 3 plants out the the 30+ tomatoes I plant to curly top.

Caging and Covering Tomatoes

After tomatoes are in the ground, prepare a cage to cover the tomato.  I use a light to medium weight floating row cover cloth to make shades for the tomatoes. Floating row covers allow a % of light to penetrate and are used to protect from insect damage and frost damage. Cut the row cover cloth a couple inches bigger than your cage.  Use clothes pins to secure.  Start with the shade cloth as close to the tomato plant as possible.  Move the cloth up as the plants grow.  Remove completely when the tomato is growing out of the cage.

I do use a preventative spray to discourage leaf hoppers and various diseases. The sprays are organic and safe for beneficial insects if used properly.  If you don't want to spray you can cover your tomatoes with a row cover.  Some studies have shown that putting a shade cloth over the tomatoes makes it more difficult for the leafhoppers to find them.

Disease preventing strategies

Today I weeded around the tomatoes gave each plant a drink of fish emulsion, and spread a layer of mulch around each plant. Prune off any lower leaves that don't look good. Put them in a plastic bag in the trash just in case they have a fungal or bacterial disease. I did my first spray this morning which will ward off leafhoppers, tomato horn worms, and prevent some diseases if done relgularly.

In a 1 gallon sprayer I add the following depending on what problem you are having.  For example if you don't have horn worms don't add Spinosad if blight is not a problem don't add Serenade.  The neem and kaolin clay are deterrents for the leaf hopper that spreads the curly top virus:

•  1/2 cups of Kaolin Clay  this is a deterrent for any chewing or sucking insect. Add this first with half the water and shake. Then add the remainder of the water and the following.  If you do not have all these that's fine.  Use what you have.

•   2 Tbsp of Neem/ gallon-  Neem is an insecticide and fungicide.  It is systemic and taken up by the plant an spread throughout the plant tissues.  When insects feed on the plant, they are inhibited from molting and laying eggs.  It is also a repellent.  It kills a wide range of insects and is not harmful to beneficial insects because they must ingest it in order to be affected.

•   4 Tbsp of Spinosad-  Spinosad is bacteria that is very effective on caterpillars, thrips, aphids and other pests. Good for tomato hornworms so only use if you have hornworms

•  4 Tbsp of Serenade- Serenade is a bacterium,, bacillus subtilis, that prevents fungal diseases.  It must be used prior to the pathogen being present. Fungus diseases include mildews, blights, wilts, and anthracnose. Only use if blight is a problem

     2 Tbsp of Kelp  a great foliar spray

Mix all this and you are ready.  I also use this on potatoes, cucumbers, squash, pumpkins, melons and corn. 

These are the organic options for disease and pest control. Please do not buy the Pyrethrin brand shown it has an additive that makes it not approved for organic gardens.  Garden's alive and Peaceful Valley have one that is only Pyrethrin.