Also agronomic characteristics and period of plantation should be chosen to reduce the risk of weakness in the first years after plantation.
For the choice of training and pruning systems, IP guidelines have to recommend those options facilitating the following objectives:
- Manageable uniform size,
- Balance between growth and regular yields,
- Optimal distribution of solar radiation,
- Production of high quality fruits,
- Reduction of conditions favourable for the development of insect pests and diseases,
- More efficient application of pesticides in the canopy and fertilisers,
- Planting systems must allow safer, more efficient spraying practices to be adopted,
- Reduction of the amount of pesticides applied.
Planting distances should allow enough space for the tree throughout its expected life span without the use of synthetic plant growth regulators. The use of growth regulators is not permitted.
The use of non-naturally occurring, synthetic plant growth regulators, as fruit finishing or ripening agents, chemical thinning and crop setting agents is also not permitted.
The use of antibiotics is not permitted.
Where excessive numbers of flowers have pollinated and set during blossom and an excessive crop is likely to result, the young fruitlets must be thinned to the optimum number to ensure adequate fruit size and quality. To get these results, a multi-step approach is strongly recommended, based on: early and late summer pruning, pre-bloom pruning, mechanical and hand thinning.
IP guidelines must set out which chemicals are permitted, clearly specifying the aim and the restrictions of their use.