Last season, curly top virus caused a significant decline in the quality of sugar beets grown in my garden as well as tomato. The steps I have taken so far include spraying with a preventative insecticide, (neem oil), removing affected plant materials, and practicing good weed control to eliminate sheltering locations for the leaf hopper vector.
The steps do not appear to work adequately as some of my plants are starting to show purple leaf vein discoloration, an early sign of infection. Yellowing is also present.
In addition to the control methods mentioned above, what other methods can I use? Can anything be done to the plants showing symptoms to preserve fruiting?