Like the Chinese juniper, the sallow tree (Juniperus sabina) is also attacked by pear rust. The fungal spores infect the leaves of pear trees. The fruit trees are attacked in summer. The fungus survives the winter in the wood of juniper bushes.
Pear rust often affects sallow trees
life cycle
A rust fungus with the scientific name Gymnosporangium sabinae hides behind the pear grate. This fungus goes through two stages of development on different trees. The sallow tree is one of the main hosts, in whose wood the fungus spreads and lives for many years.
Each spring, it develops orange-colored fruiting bodies that shrink in drought and swell in humid weather conditions. These spore stores develop spores that spread more than 500 meters upwind. They infect the leaves of wild and cultivated pears.
Fight
Since 2010 there has been a fungicide that is used specifically against pear rust. However, the remedy is intended to combat the fungal disease on pear trees. When used immediately after the first symptoms, the universal fungus-free agent stops the further spread of the spores. The active ingredient has a depot effect, so that the effect lasts even after the injection.
Prevent
Regularly check juniper bushes for clubby thickenings that occur between March and April. The affected branches should be cut back far into the healthy wood. However, it is not certain that the fungus was completely removed. Its mycelium often extends well into the wood without you noticing. Heavily infested shrubs should be removed completely to stop further spread.
If you have pear trees in the garden, you should pick off and discard infested leaves. Dead shoots are regularly removed. To promote the vitality of the trees, you can regularly spray plant strengtheners.
This strengthens Sade tree and pear:
- nettle brew
- horsetail extract
- organic mineral PK fertilizer
Hardy species
The varieties Juniperus sabina 'Blaue Donau', 'Blue Haven' and 'Tamariscifolia' are particularly susceptible to the rust fungus. Instead of the sallow tree, choose other juniper species that are less susceptible to pear rust infestation.
Species and varieties not susceptible:
- Juniperus horizontalis: 'Blue Chip' and 'Prince of Wales'
- Juniperus x pfitzeriana: 'Mint Julep' and 'Pfitzeriana Glauca'
- Juniperus squamata: 'Blue Carpet', 'Meyeri', 'Blue Star' and 'Holger'