Actual situation and prospect of walnut production in the Netherlands.

摘要

Walnut (Juglans regia) cultivation is of minor importance in The Netherlands. Actual production is estimated at 300 t dried unshelled nuts with an average yield level of 1,000 kg/ha. Due to varying climatological conditions (absence/presence of late night-frost (May) and/or cool/warm summers) yield varies considerably from year to year. Most walnut trees are still grown as isolated trees (seedlings) at homestead of farms or along dikes or avenues. Approximately 40 ha, at ten farms, is cultivated for commercial purposes, where Broadview is the dominating variety. There are two commercial nurseries, yearly producing some 8,000 grafted plants (seedlings of different origin being used as rootstock) of which only 30% for the Dutch market. Only limited quantities of harvested nuts are sold outside the region of production. Most nuts are sold as unshelled nuts. Preparation and sale of Dutch walnuts containing products like liqueur, gin, cake, pastry, oil, marmalade, pate, ice cream, cheese, muesli, nougat, honey and bread still is nearly completely absent. The results of a study about the possibilities to promote a municipality (Gorssel) as walnut municipality of The Netherlands are described. To strengthen the specificity of Gorssel walnut products a selection of local walnut has been started in 2003. Evaluation of characteristics of nuts of 35 seedling trees in the municipality of Gorssel resulted in a preliminary selection of five accessions (JOP 2, ALM 7, EEF 6, GOR 2 and GOR 5), which will be propagated by grafting on seedling rootstock and tested, together with the varieties Broadview and Cyril, at seven sites in the municipality..