The risk of Neonectria fruit rot in store can be estimated pre-harvest based on:
- The incidence of cankered trees in the orchard
- The rot history taken from packhouse records
- The rainfall between blossom and harvest.
Inspect orchards in spring for cankered trees and estimate the % cankered trees.
| Canker incidence | Risk |
|---|---|
| (% cankered trees) | |
| No canker | No risk |
| <5% | Low |
| 5-25% | Moderate |
| >25% | High |
- In orchards with more than 5% of trees with canker, where long term storage of the fruit is planned, apply fungicide sprays for control of Neonectria fruit rot during blossom and at petal fall.
- Monitor rainfall from blossom to harvest
- Decisions on the need for early marketing of fruit can be made as follows:
Guidelines for decisions based on orchard canker risk
| Orchard canker risk | Rain blossom-harvest | Action |
|---|---|---|
| High | Low | Market pre-Christmas if no sprays applied in blossom |
| Average | ||
| High | ||
| Moderate | Low | Low risk - no special action needed |
| Average | Market pre-Christmas if no sprays applied in blossom | |
| High | ||
| Low | Low | Low risk - no special action needed |
| Average | ||
| High | Market pre-Christmas if no sprays applied in blossom |