The BCTVCP also encourages communication between growers and their neighbors; Find out when they plan to disk/mow the middles, and ask if they can add an insecticide for BLH into their mix when mowing or before disking.
Fallow fields typically harbor adult BLH and will produce a generation or two during the summer on the weeds. Goosefoot has been a favored host weed, sometimes producing BLH counts ranging from 20-100+ per sweep! Other host weeds include London rocket, saltbush, and Russian thistle. Weeds within fallow fields should ALWAYS be sprayed first to knock down the BLH, prior to disking.
Almond and pistachio orchards are increasing in the valley. Young orchards and vineyards where there is plenty of sunlight, usually have a lot of BLH host weeds in the middles of each row. Typical host weeds include London rocket, saltbush, goosefoot, pigweed, and Russian thistle. BLH counts range from 3-5 per 10 sweeps to 30+ per single sweep, depending on location.
Disking, mowing, plowing, grazing, and using an herbicide on any weedy areas that harbor BLH will disturb the beet leafhopper, which typically results in the movement through a nearby tomato field. Subsequent Curly Top infection can then be seen a couple of weeks later.
Within the last week, the BCTV program has noticed an increase in the late onset of curly top virus infection within tomato fields. Such infections can usually be traced back to a cultural practice that occurred within a couple of weeks, such as disking and mowing, and are not attributed to the BLH spring migration.