Apple sucker is generally a minor pest of modern desert and culinary apple orchards where it is controlled well by insecticide spray programmes. It is troublesome in unsprayed orchards, especially in organic orchards and on older trees.
It is an important and damaging pest in cider apple orchards.
The life cycle involves sucker eggs overwintering on bark before hatching at or shortly after bud burst when they invade the trusses.
The presence of the pest is indicated by blobs of waxy honeydew in the base of the trusses where the flower stalks join. Most damage is done by nymphs during the pre-blossom period.
They suck the sap from green tissue of blossom trusses and leaf buds causing brown discoloration of petals and blossom buds and, where damage is severe, buds may be killed. The discoloration resembles, and is sometimes mistaken for, frost injury.
Populations of apple sucker should be assessed along with other pests at the pre-blossom pest assessment. Examine trusses for signs of infestation or damage. The treatment threshold is 30% or more of trusses infested.
Control
Spray with an approved insecticide before blossom.
Insecticides approved for use on apple which are recommended by the manufacturer to be effective or partially effective for control of apple sucker when applied to control other pests
| Choice of insecticides - efficacy factors | |||||
|---|---|---|---|---|---|
| Active ingredient | Trade name (examples) | Class | Selectivity | Approved for control of | Safety to Typhs |
| deltamethrin | Decis Forte etc. | pyrethroid | broad spectrum | Aphids, apple sucker, capsids, codling & tortrix moths, sawflies | harmful |
| fatty acids | Flipper (EAMU 3419/19) | bioinsecticide | broad spectrum | Aphids, blossom weevil, two-spotted spider mite | unspecified but generally safe in IPDM programmes |
| spirotetramat | Batavia | tetramic acid derivative | selective | Sucking insect pests | unclassified |
|
Choice of insecticides - safety factors Read and follow the label before applying any sprays |
|||||||
|---|---|---|---|---|---|---|---|
| Hazards | Harvest interval (days) | Max. no. sprays | Buffer zone width (m) | ||||
| Anticholin-esterase? | Humans | Fish & aquatic life | Bees | ||||
| deltamethrin | no | h, i | ed | d | 7 | u | 50 |
| fatty acids | no | h, i | h | u | 0 | 8 | 20 |
| spirotetramat | no | h, i | t | d | Start of ripening | 2 | sm |
| h=harmful, i=irritant, d=dangerous, ed=extremely dangerous, c=closed cab required for air assisted sprayers,u=uncategorised/unclassified/unspecified, sm -= statutory minimum (= 5 m buffer zone width) | |||||||
Control in organic orchards
Generally, there are no satisfactory controls for apple sucker in organic orchards. Cultural control approaches should be given priority.Though not specifically recommended for control of apple sucker, it is probable that early season sprays of fatty acids will give some control.
- The sprays have to be applied early at the green cluster growth stage (after the overwintered eggs have hatched in spring but before reproduction occurs is best) and in high volumes so that the suckers are thoroughly wetted by the spray.
- Application is sometimes made during gentle rain.