Autumn brings reports of Psa-V
With autumn weather firmly settled in, reports of Psa-V symptoms are on the rise in some orchards. Mostly from sites where the disease has been challenging in the past.
- Young Gold3 scions girdled in early March were showing exudate at the girdle points. Infection in the trunks and leaders were also common in these plants.
- Exudate from trunk lenticels on young scions.
- A Gold3 block, which recovered strongly after ongoing spring cut-out of Psa-V, showed indications of infection beginning to move back through some plants. Symptoms included dieback from leader cut points, dehydrated strung laterals and blackened canes.
- New spotting was seen on Bruno suckers and/or young plants, particularly where a comprehensive spray programme had not been maintained.
- On some Gold3 blocks, cane die-back and fruit shrivel was seen during harvest.
- Monitor orchard areas where Psa-V infection has been present in the past and remove infected material as soon as possible. Removal and disposal of infected material outside the production area remains a key tool in Psa-V management and a key component of the industry management strategy to minimise the build-up and spread of any resistant Psa strains that may have developed.
- Maintain excellent tool hygiene and protect pruning cuts to avoid infection transfer.
- Trim high male growth, particularly in sites prone to frost. Warm temperatures have led to growth flushes, creating tissue that will be vulnerable to frost damage and Psa-V infection when temperatures turn colder.