Monday, December 10, 2007 - 9:41 AM

Evaluation of barrier plants for protecting zucchini from non-persistently aphid-transmitted virus

Roshan Manandhar, and Cerruti Hooks, University of Hawaii, Plant and Environmental Protection, 3500 Maile Way, Honolulu, HI

Barrier plants have been successfully used as an effective cultural control strategies for reducing the spread of non-persistently aphid-transmitted virus. Field and laboratory experiments were carried out to evaluate the potential of barrier plants to reduce the spread of Papaya ring spot virus-watermelon strain (PRSV-w) in zucchini. Two cover crops, buckwheat Fagopyrum esculentum and sunnhemp Crotolaria juncea and an intercropped vegetable, okra Abelmonchus esculentus, were evaluated as barrier plants. Results from water pan trap indicated that population densities of alatae aphids in zucchini plots grown with barrier crops did not significantly differ from bare-ground zucchini. But, foliar counts of alatae aphids showed significant lower number of aphids on zucchini with barrier plants as compared to zucchini bare-ground. The percentage plants displaying virus symptoms significantly lower in zucchini grown with barrier plants compared to bare-ground. It is believed the barrier crop acted as a natural sink for non-persistent virus and thus delayed virus spread resulting in higher percentage of marketable yield.

Species 1: Hemiptera Aphididae Aphis gossypii (cotton aphid)