I'm in the mts of AZ at 6900 foot so tomato growing is a challenge. Using season extenders, however, I've had decent results until the arrival of migrating leafhoppers three years ago. They carry a disease called curley top. Leaves curl, veins turn purple, branches get stiff and fruit stops growing and ripens prematurely. Horrible. The only treatment I have discovered from my online research is to cover completely to prevent the deadly bite which is a bit awkward with 5-6 foot plants. Have any of your resoureful growers found anything that works once the plants are infected? On another matter: anyone familiar with Mexico heirloom variety? I have a 7ft plant with absolutely no fruit. Other varieties doing fine on same regimen.