Division VI.2 Frequency and timing

Level I + Level II: assessment of damage causes shall be carried out during normal crown condition assessment in summer.

In Level II plots where the complete programme is carried out, the so-called ‘key-plots’’, an additional visit for damage assessment shall be made if important damage is observed outside the period of crown condition assessment. The observations of the staff responsible for deposition sampling or phenological observations may act as an early warning system. This additional visit shall be made at the time when the main damage cause is supposed to be at its maximum (e.g. spring for defoliators).