PEST MANAGEMENT Management of Aphid-Borne Viruses and Bemisia argentifolii (Homoptera: Aleyrodidae) in Zucchini Squash by Using UV Reflective Plastic and Wheat Straw Mulches

Plastic UV reßective mulch (metalized mulch) and wheat straw mulch delayed colonizationbyBemisia argentifoliiBellows&Perring and the incidenceof aphid-borneviruses in zucchini squash. No insecticides were used in either mulch treatment. The mulches were compared with a preplant treatment of imidacloprid and an untreated, unmulched control. In 2000, yield ofmarketable fruit in the plastic and straw mulched plots was approximately twice that from the imidacloprid plot. In 2001, yield from the straw mulch plots was twice that of the imidacloprid and plastic mulch plots. Yields from bothmulched plots and from the imidacloprid plots ranged from 3 to 12 times higher than those from the control plots. The mulches were more effective than a preplant application of imidacloprid in reducing the incidence of both B. argentifolii and aphid-borne viruses. Plants growing over the plasticmulch and the strawmulch grewmore rapidly and reached a larger size, as determined by plant dry weight, than did those growing over bare soil, with or without imidacloprid. The spectral quantum ßux from the plastic averaged between 80 and 90% of ambient spectral quantum ßux values in the UV (300Ð400-nm) range. Spectral quantum ßux values of wheat straw were similar to those of the reßectivemulch and ambient near 300 nm but were virtually identical to bare soil beyond 320 nm. The metalized mulch reßected 94% of the incoming photosynthetically active radiation (PAR) in the 400Ð700-nm range comparedwith ambient,whereas the strawmulch reßected 85%.Bare soil reßected only 41% of incoming PAR compared with ambient.