[[(U. glabra var Exoniensis x U. wallichiana) x (U. minor 1 x U. minor 28)] x [(U. glabra var Exoniensis x U. wallichiana) x (U. minor 1 x U. minor 28) selfed]
Institut National de la Recherche Agronomique, France
Vada, like the better-known clone Lutece, was developed by the Netherlands elm breeding programme but later acquired by the French agency INRA and released in 2006 after lengthy trials. It arose from the crossing of the Dutch clone Plantyn with another self-pollinated specimen of Plantyn. It is therefore one quarter Himalayan and three quarters European elm. Within the European elm ancestry is U. glabra “Exoniensis” which has contributed strongly to the character of the tree.
In inoculation trials carried out in France, Vada outperformed all other clones being tested (including Lutece). Precise statistics are not available, but the tree’s resilience is said to be on the elite level of Sapporo Autumn Gold. That clone exhibited 2.78% defoliation and 1.22% dieback in the inoculation trials at Antella, Italy, in 2000
Vada is a fairly fastigiate tree showing pronounced apical dominance, but it is not yet clear whether it is truly monopodial or merely very upright. The stem tends to weave, but the rootstock seems impressively wind-firm. In the French trials, Vada achieved 14 m at 20 years of age. A height increment of over 150cm is possible in ideal circumstances when the plant is at its most vigorous. Equally, growth can be very limited if a young tree is ever allowed to become pot-bound which, like several other elm clones, Vada readily does. Its wood, assessed against that of other one year old elm whips (Patriot, Pioneer, Accolade and Lutece) is remarkably tough. One wonders what the properties of Vada timber might be.
In common with Lutece and Columella, the Vada leaf has acquired character from U. glabra “Exoniensis”. While that inheritance is subtle in Lutece, and so exaggerated as to verge on the unacceptable in Columella, for Vada it works well (certainly better than in “Exoniensis” itself). Leaves on vigorous shoots are positively flamboyant – large, strongly curved, glossy and very dark – and can expose leading shoots to contortion from high winds early in the year. On non-vigorous growth the “Exoniensis” character yields to that of field elm. Interestingly, Vada seems to be the only modern elm clone to share the native elms’ susceptibility to the pimpling caused by leaf gall mites, though to a far lesser extent. Towards the end of the season, however, the Vada leaf seems to suffer from other attacks so that it can appear shabby. Leafing is late, but not quite as late as Lutece. Many minor buds fail to burst, so that young plants are rather sparsely furnished. In combination with the tree’s limited lateral development this can lead to a skeletal appearance.
Vada is a difficult clone to appraise, not least because INRA has published no photographs of older trees. It has obvious virtues – excellent disease resistance, tough upright growth, and rich colour. On the other hand its ultimate form is impossible to predict, its silhouette is stark, leafing is late, its growth can slow abruptly, and its foliage tends to suffer in the course of the season. Only time and further observation will show whether the advantages or the failings come out on top.