The use of reflective mulch to reduce the incidence of watermelon mosaic virus in Western Australia

Watermelon mosaic virus has caused losses in cucurbits in the last 8 years in the Gascoyne River district of Western Australia. Neither insecticides nor oil sprays have reduced the incidence of this disease. In three trials, plants mulched with reflective (aluminium) polythene were less infected (by 21%, 30% and 72%) than were those given a control treatment; yield increases of watermelons ranged from 77% to 270%. Black polythene mulch also reduced the incidence of virus and increased yield, but to a lesser degree. In all experiments the disease incidence rose more slowly in the mulch plots: this effect contributed greatly to the observed increase in yield.