If pollinating varieties, either standard fruit varieties or ornamental Malus, are to flower consistently, abundantly and produce good pollen, it is essential that they are well-managed within the main orchard. Unfortunately, their management is often neglected or forgotten.
- It is essential that their tree size is maintained within the space allotted to them and excessive fruit set is avoided if biennial bearing is not to be a problem.
- A trial conducted at Long Ashton Research Station in 1979 examined the influence on return bloom of either fruit thinning or summer pruning of pollinating varieties.
- Fruitlet thinning produced most significant benefits with Golden Delicious.
- Although stripping all the fruits off most of the other varieties produced increases in flowering, it is questionable whether these increases warranted the time and effort involved.
- It is possible, of course, that earlier thinning might have given more benefits and that pollen quality (not measured here) may have been improved by the thinning treatments.
- Thinning fruits is probably only warranted with pollinating varieties which regularly set excessive numbers of fruits with high seed numbers, or with varieties known to have biennial bearing tendencies.
- Summer pruning, which is sometimes necessary to control the size of pollinating trees, severely reduced return bloom on Egremont Russet, and Golden Delicious, but effects on the other pollinating varieties were insufficient to cause concern.
Flower bud numbers per tree (1980) as influenced by fruitlet thinning and summer pruning treatments
| Variety | Fruitlet thinning treatments | Summer pruned | ||
|---|---|---|---|---|
| None | To 1 fruit/cluster | All fruit removed | ||
| Egremont Russet | 207 | 248 | 349 | 77 |
| Discovery | 525 | 217 | 330 | 180 |
| G. Delicious | 137 | 257 | 643 | 12 |
| James Grieve | 261 | 233 | 368 | 212 |
| L. Lambourne | 286 | 276 | 303 | 238 |
| Worcester Pearman | 140 | 116 | 123 | 129 |
| M. Aldenhamensis | 337 | 429 | 521 | 316 |
| M. Golden Hornet | 689 | 955 | 1059 | 742 |
| M. Hillieri | 379 | 838 | 1189 | 841 |
| M. Winter Gold | 1428 | 1480 | 1611 | 754 |
(from Church, 1981 see Further reading)
Prune and train pollinating varieties so as to stimulate renewal growth and adequate production of quality flowers.
Apply water and nutrients to pollinating varieties so as to sustain their growth and flowering.