Effect of the fungicide phosphite on pollen fertility of perennial species of the Eucalyptus marginata forest and northern sandplains of Western Australia.

Abstract

The fungicide phosphite was shown to affect pollen fertility in a range of perennial species from the south-west of Western Australia. Phosphite was applied to perennial species of the jarrah (Eucalyptus marginata) forest by spraying to run-off with 2.5, 5 and 10 g L^–1 phosphite in either autumn or spring. Pollen fertility of Dryandra sessilis was reduced by phosphite for up to 35 and 60 weeks after spraying in spring or autumn, respectively. Trymalium ledifolium pollen fertility was reduced by phosphite 38 and 61 weeks after spraying in spring or autumn, respectively. Lasiopetalum floribundum was less affected with a reduction in pollen fertility being observed for up to 3 weeks after spraying in spring. Other perennial understorey species of the jarrah forest, Adenanthos barbiger, Boronia cymosa, Hovea elliptica and Phyllanthus calycinus were also shown to have reduced pollen fertility after treatment in autumn or spring, as did Comesperma calymega, Eremaea astrocarpa and Hibbertia hypericoides, species of the northern sandplains when sprayed in summer.