Ulmus 'Lobel'

Ulmus 'Lobel' is a Dutch hybrid cultivar raised at Wageningen, derived from a crossing of clone '202' (U. 'Exoniensis' × U. wallichiana) with '336' ('Bea Schwarz', selfed), cloned in 1962 and released for sale in 1973.

Description

'Lobel' is a fastigiate, small-crowned, tree not unlike the pyramidal Hornbeam Carpinus betulus 'Fastigiata'. The typically acuminate leaves are < 11 cm long × < 7 cm broad, and notably late to flush, rarely before mid-May.

Pests and diseases

'Lobel' was rated 4 out of 5 ("good") in the Netherlands for its resistance to Dutch elm disease. However, in trials conducted by the Istituto per la Protezione delle Piante, Italy, 'Lobel' suffered 50% defoliation and 35.5% dieback when inoculated with unnaturally high concentrations of the fungal pathogen, compared with 2.8% and 1.2% resp. for 'Sapporo Autumn Gold'.

Owing to the U. wallichiana in its ancestry, young specimens of 'Lobel' proved particularly susceptible to elm yellows (phloem necrosis) in trials in Italy.