NGI Updates

American serpentine leafminer, Liriomyza trifolii, has been found infesting plant hosts in Kununurra, Western Australia in March 2021, and more recently on Thursday Island in the Torres Strait, Queensland in May 2021.

As a National Priority Plant Pest, the American serpentine leafminer poses a serious threat to Australia’s horticulture, nursery production, and agricultural plant industries. Severe infestations of American serpentine leafminer may result in premature leaf drop, poor growth, and reduced crop yields.    More

Powdery mildew causes disease on a large number of common nursery stock lines including many vegetable and ornamental species, e.g. tomato, cucurbit crops, rose, begonia, gerbera, zinnia, poinsettia, and many others.

Young new growth or soft, lush foliage tends to be most susceptible. Small white powdery spots occur on most host tissues including upper and lower leaves, stems and fruit. More

Downy mildew causes disease on a large number of common ornamental nursery plants including Cissus, lisianthus, poppy, ranunculus, rose, snapdragon, stock, pansy, alyssum, impatiens, sweet pea, cucurbits, helichrysum basil and brassica seedlings. Each species of downy mildew only infects a small number of closely related plants.

Common leaf symptoms include white to grey or lavender fluffy growth on the underside of leaves. Pale yellow or necrotic spots appear on the upper surface that can be angular and vein delimited. As disease becomes more severe the entire leaf can become infected and may drop off. Downy mildew can also become systemic, particularly in small plants causing wilt and death of the entire plant. Infection of growing tips can cause leaf distortion, stunting and stem cracking.

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Thursday, 17 June 2021

The Tomato potato psyllid (TPP) is an exotic pest that was first detected in Perth, Western Australia in February 2017, and has more recently been detected across regional areas of WA, with the exception of the Kimberley region in the north.

The tiny sap-sucking insect poses a significant risk to the nursery industry as it reduces crop yield and spreads the bacterial plant disease ‘zebra chip’ in potato, caused by Candidatus Liberibacter solanacearum (CLso) bacterium. More