Asian citrus psyllid and mites will move into groves as trees bloom and go into their first big flush of the season, notes Bill Sheffield, manager of the United Agri Products branch in Waverly, FL. At the same time, beneficial insects and predators are entering the groves, and bees are abuzz.
“Pollination is a crucial time for growers,” says Sheffield. “A good fruit set and good leaf flush early sets a grower on the right path for the entire growing season.”
The situation is complicated by the emergence of Asian citrus psyllid, which is the vector for greening.
Sheffield takes an IPM approach to insect control. He says growers need to know the field history of their groves, they should scout for insects and disease if possible before treating, and they should rotate chemical controls.
Temik (aldicarb, Bayer CropScience) is available to most growers as a psyllid control option pre-bloom, and Sheffield recommends applying it in January or February, when possible. However, there are restrictions with Temik around groundwater. “Plus, some growers just can’t get over their entire acreage before bloom,” he says.
At bloom, Portal (fenpyroximate, Nichino America) is the only insecticide labeled for contact and residual control of both mites and psyllid and that is non-toxic to bees. Portal is a new chemistry, and 2008 will be the first year it is available at pre-bloom and bloom time.
“It received its registration just last summer,” explains Sheffield. “We did some field trials with it, and it did really well. We got about 60 to 70 days of control for mites, so I think it’s going to be a very valuable tool for us early because it’s safe on bees and soft on beneficial insects as well.”
Otherwise, growers can spray oil if their insect populations are low. “Oil will give you some short-term control if all you want to do is get through bloom, but it might take two or more applications,” says Sheffield. “In the past, that’s about all we had.”
Post-bloom and in the summer, several miticides are available for mites, and several of them also control psyllid. “Controlling the psyllid is going to be a very difficult thing to do,” says Sheffield. “We really don’t have anything that lasts very long — three to four weeks of control is about all we can expect. But greening is such a concern that growers will do their best to treat every major flush, when possible, to protect themselves.
“Plus, disease becomes a problem about then, so if a grower sees canker in his trees, he’s going to want to treat for it, plus he’s going to want to get mites and psyllid at the same time. That’s why I think Portal will be especially useful. It tank-mixes well, it gives you enough mite control to get you to the summer oil spray, and it controls psyllids during bloom. Growers are limited to just two applications of Portal a year, so they can put it on at bloom, then rotate into other psyllid controls later.”