Common Walnut Provenence / Progeny Trial
The aims of the provenance/progeny trials are to test the performance of the sampled genotypes in environmental conditions typical of suitable forestry sites in southern England, and to assess their suitability for producing quality hardwood timber. Most of this genetic material is being tested in Britain for the first time and these trials provide a unique opportunity for the long-term assessment of the species' future potential as an economic crop.
Material
Walnut genetic material was collected across both the natural and introduced ranges of Juglans regia and propagated during 1998, was planted-out in three field trials sited in southern England during December 1998. Twenty-five provenances and 375 half-sib progenies are distributed across three provenance trials located on different sites, the largest of which also acts as a combined provenance/progeny trial.
Over 250 progenies were sourced from Kyrgyzstan in central Asia during a seed collecting expedition in 1997. The natural and extensive walnut forests of Kyrgyzstan are at the northern of the species' natural range and contain many excellent phenotypes (see picture).
See below for a map showing the Natural Range of the Common Walnut.
Trial design
The provenance field trials are a randomised complete block (RCB) design incorporating non-contiguous multiple-tree plots distributed in twenty two 100-tree blocks, located across three sites. The largest trial, sited in Paradise Wood contains 14 blocks of the 22 (1400 trees), whilst two external trials, sited in Gloucestershire and Somerset, each contain four blocks (400 trees). Three trial sites were selected for planting to permit the assessment of genotype x environment interaction (GEI). They were selected according to their suitability for walnut cultivation and for their contrasting environmental conditions.
Hemery, G. E. (1998). Walnut (Juglans regia) seed-collecting expedition to Kyrgyzstan in Central Asia.
Hemery, G. E., and Popov, S. I. (1998). The walnut (Juglans regia L.) forests of Kyrgyzstan and their importance as a genetic resource.
Hemery, G. E. (2000). Juglans regia L: genetic variation and provenance performance.
The Common Walnut's Natural Range
Provenance collections have made from the Fergana and Chatkal mountains.
