Summer is upon us once again and now I start to worry about Curly Top Virus. Curly Top can devastate several plants or even your entire crop. It is transmitted by the sugar beet leafhopper. They are very small and hard to detect in the garden. Only one-tenth of inch long, pale green, gray, or brown in color. They are winged and wedge-shaped.
The interesting thing about the nasty little bugger is that tomatoes are not their favorite crops. It just comes in looking for what it wants, hops around, infects the plant and moves on. Tomatoes aren’t the only thing that can be affected by Curly Top. Peppers and bean plants can also be infected.
Curly Top is just what the name implies. Curling leaves. It kinda looks like your tomato plant is wilting. To be sure that wilting is not what the problem , water and wait to see if the wilted look goes away in an hour or so. Leaflets roll and develop a purplish color, especially along the veins. Leaves and stems become stiff; fruit ripens prematurely. Leaves may remain green or turn yellow. Yellowing will generally begin at the bottom of the plant first. The virus spreads in a random fashion. You can have a healthy plant right next to an infected plant.
There is no cure for curly top, but there are prevention steps you can take. The beet leaf hopper prefers to feed in sunny spots. Providing some shade for tomatoes and peppers will discourage leafhopper feeding. Row cover can be used to offer shade. Not only will it discourage the beet leaf hopper, it will also help tomato and pepper plants grow better and produce more fruit during the hottest summer months giving them some relief. The beet leaf hopper also likes dry conditions. Keeping the soil evenly moist will raise the humidity level around the plants. Apply a good layer of organic matter to reduce evaporation. Areas that the humidity level is 50% or higher there will be little or no beet leaf hoppers. Areas of 30% humidity there is a large increase of hoppers. Of course our area that is often time 10% or lower during the summer months we seem to be affected heavily. Another option to help keep these hoppers at bay is spraying with neem. Neem is an organic spray from the neem tree. Spraying should be done weekly and ONLY in the evening times. If you spray during the heat of the day you will cause burning! NEVER use more than the label tells you when using concentrate. This can also cause burn. More is not always better. I also try not to spray the blossoms. If your plant shows all the tell tell signs of curly top,
stunting, curly leaves, ect. it should be removed. Leaving the disease plant in place will provide a source of virus for feeding leafhoppers to pick up and carry to healthy plants. Put the disease plant in a garbage bag, seal and toss or burn. DO NOT COMPOST the diseased plant either.