American plum line pattern virus
American plum line pattern virus (APLPV) affects plums and other species of Prunus, such as apricot, peach, nectarine and ornamental cherry. APLPV can directly reduce the marketability of ornamental cherry trees, but otherwise may only have an economic impact when it is found with certain other viruses.Originally from North America, APLPV has been detected in Queensland and Victoria. This fact sheet outlines how to identify infected trees and provides suggested management options.
In Japanese plum (Prunus salicina), symptoms usually commence in spring with green and then yellow mottling (Figure 1), which often include 'oak-leaf' patterns (Figure 2). By summer, the yellow mottling increases and fades to creamy-white (Figure 3).
Figure 1 (left): Early symptoms of APLPV on Japanese plum (image from EPPO)
Figure 2 (middle): 'Oak-leaf' shapes on Japanese plum caused by APLPV (image from EPPO)
Figure 3 (right): Advanced symptoms of APLPV on Japanese plum. (image from EPPO)
Most cultivars of peach (Prunus persica), exhibit light-green and wavy lines during the spring and early summer (Figure 4A). Later, the lines form various shapes, rings, confluent rings, nets or "oak-leaf" patterns (Figure 4B).
Symptoms in Japanese ornamental cherry (Prunus serrulata) often include formation of "oak leaf" patterns, although symptoms may also include chlorotic, golden or white rings. Additionally, yellowish discoloured areas can appear in conjunction with vein banding (Figure 5). Discoloured areas can also be golden or pinkish.
Figure 4A (left) and 4B (right): Symptoms of APLPV on peach (images from EPPO)
Figure 5: Chlorotic areas on ornamental cherry typically caused by APLPV (image from Oregon State University)
Impact, spread and management
Symptoms do not cause any appreciable loss of productivity. In plum and peach signs of disease often disappear by late summer. Thus control measures many not be required. However, disease symptoms in ornamental cherry (Figure 5) may reduce aesthetic value. Also, APLPV may induce greater impact when co-infecting with other viruses such as the Prune dwarf virus.
Diseases caused by viruses cannot be directly controlled via spraying. Thus the use of planting material certified or tested to be free of the virus is recommended. The means of natural spread is unknown, but APLPV can be transmitted mechanically, through grafting and possibly pruning. The virus is probably not seed-borne and international spread is most probably by movement of infected planting material. To prevent the spread of APLPV in your property:
- Consider removing diseased trees
- Ensure staff and visitors adhere to on farm biosecurity and hygiene practices
- Keep records of disease histories to enable pest and disease impacts to be monitored and traced.
Also, with suitable personnel protective equipment: -
- Disinfect tools and equipment with sodium hypochlorite (1% solution of a 12% concentrate of pool chlorine)
- Clean farm machinery, remove dirt and plant material with a high pressure hose, if possible spray machinery with 1% chlorine.
Note chlorine will rust equipment and needs to be washed off after application.
For further information phone 136 186 for your local Plant Biosecurity Officer or email email@example.com. To arrange for virus testing, phone Crop Health Services on (03) 9032 7515.
Image sources and references
CABI (2016) American plum line pattern virus (American line pattern of plum) In Crop Protection Compendium. Wallingford, UK: CAB International.
Agriculture Victoria (2016) PIDS, American plum line pattern virus (APLPV) – 03/11/2016, CCEPP Secretariat.
EPPO, European and Mediterranean Plant Protection Organization, (2016) American plum line pattern virus (APLPV0), retrieved from EPPO (Accessed 30 November 2016).
CABI & EPPO (n.d.) Data sheets quarantine pests, Plum American line pattern ilarvirus (PDF 28 KB), retrieved from EPPO (Accessed on 24 November 2016).
Oregon State University (n.d.) Cherry (Prunusspp.), Virus-induced Cherry Decline (Accessed 5 December 2016).