Management of Aphid-Borne Viruses andBemisia argentifolii(Homoptera: Aleyrodidae) in Zucchini Squash by Using Uv Reflective Plastic and Wheat Straw Mulches

Abstract

Plastic UV resective mulch (metalized mulch) and wheat straw mulch delayed colo- nization by Bemisia argentifolii Bellows & Perring and the incidence of aphid-borne viruses 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 of marketable 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 both mulched 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 plastic mulch and the straw mulch grew more 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 sux from the plastic averaged between 80 and 90% of ambient spectral quantum sux values in the UV (300 Ð 400-nm) range. Spectral quantum sux values of wheat straw were similar to those of the resective mulch and ambient near 300 nm but were virtually identical to bare soil beyond 320 nm. The metalized mulch resected 94% of the incoming photosynthetically active radiation (PAR) in the 400 Ð700-nm range compared with ambient, whereas the straw mulch resected 85%. Bare soil resected only 41% of incoming PAR compared with ambient.