Coalition tests IPM in California cut flower production

Researchers from University of California and North Carolina State University developed an integrated pest management (IPM) program for cut roses. The program has been tested at eight California cut flower growers since 2000. The results were released this spring.

The study revealed the predatory mite Phytoseiulus persimilis effectively and economically controls twospotted spider mites. Growers applied P. persimilis when sampled rose leaves were between 10 percent and  25 percent infested.

Chemical controls, including azadirachtin, bifenazate and insecticidal soap, were applied when sampled leaves were more than 25 percent infested. The chemical controls tested provide “some level of compatibility with P. persimilis,” according to the study.

To control western flower thrips, growers applied commercial reduced-risk pesticides and targeted lower-volume sprays to the upper canopy of the hedge instead of conventional full-volume wet sprays. Growers also implemented cultural controls such as removing fully open flowers, where thrips lay eggs.

At two test sites, the citrus mealybug infested greenhouses after the IPM program began. The pest is generally a problem only at sites where roses are or were grown adjacent to other flower crops, such as stephanotis, according to the study.

{sidebar id=1}

For more: Christine Casey, NCSU, (919) 515-8880; chris_casey@ncsu.edu; http://californiaagriculture.ucop.edu/0702AMJ/pdfs/IPMroses.pdf.