A Study Undertaken in Southern Britain to Investigate the Late-Flushing of Hedgerow Ash in Spring 1987

1991

S. 189-197

3 Abb., 2 Tab., 13 Lit. Ang.

Unselbständiges Werk

200101953

Following the abnormally late flushing of many ash (Fraxinus excelsior) in 1987 a study on their conditon was initiated. An investigation of 19 trees at 12 sites in England and Wales was carried out in June with a second inspection later in the summer. For comparison, another full survey of the same trees was undertaken the following year. Information collected on more than 4000 bud positions showed that in 1987 significantly fewer buds flushed to produce healthy shoots than in 1988 (18 per cent compared with 34 per cent respectively). Although no difference was detected between the two years in the numbers of buds killed or damaged by ash bud moth (Prays fraxinella) or invaded by fungi (principally Fusarium lateritium) there were significantly more buds killed by unknown causes in 1987 than in 1988 (13 per cent and 4 per cent respectiely). The trees were fully recovered by mid- summer 1987 and went on to foliate normally in 1988. There was thus no reason to consider that the late flushing marked the onset of any serious dieback.