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6 EUFORGEN: Quercus suberNErWORK _more than one year or prolonged nursery production will be discussed at the nextmeeting, when the results of the seed collections in 1996 are known.Nursery and establishment of field trialsIf acorn production follows the patterns now visible for flowering, it will bepossible to collect all seed lots during Autumn 1996, sowing will be carried out inFebruary 1997 and trials will be established during Autumn 1997. As the ConcertedAction does not include any financial support for the establishment of field trials,the participants will seek additional financial resources as soon as possible.4.2 Discussion of experimental design of field trialsCountries offered to host the following numbers of trials: Portugal (3), Spain (2),Italy (2), France (2) and Morocco (1). The involvement of North African countries inthe Concerted Action project, financed by the EU in general, and the problematicsupport for the establishment of field trials in particular, were discussed. Allparticipants expressed their wish for a stronger and doser collaboration.The discussion at the meeting first focused on the establishment itself of the trialsbecause it is not easy to have areas of required size (up to 24 ha) suitable forgrowing cork oak and with an acceptable level of environmental homogeneity. Areliable appraisal of genetic parameters might then become questionable.The final spacing of the trials was unanimously accepted to be 5 x 5 m. Thedecision was based on taking into consideration that, in many countries, cork oakstands are managed in densities of 300 to 400 trees/ha (correspop.ding to 5.S x 5.S mand 5 x 5 m, respectively), and that in new afforestations there is a tendency forcloser spacing.•Size of the trials was, therefore, reduced by four times. The .possibilities offinding areas of around 6 ha and diminishing block variability are clearly higher.Consequently, the statistical power of the experimental results can be improved.Several proposals for the experimental design of the field trials were discussedand should be used as background information for the preparation of theexperiments in individual countries. The choice of any trial design depends on thepossibly different objectives of the scheme in each country. The differencesbetween trial sites and between the objectives in individual countries should befully taken into account.The decision on objectives of the field experiments and on details of theexperimental design will thus be made under the responsibility of eachparticipating country. Two proposals of the experimental design were initiallydiscussed at the meeting and are briefly summarized below. Proposal A (H. Muhs)is relevant whenever- high priority is given to the progeny testing part, andProposal B (G. Eriksson) if the main objective is provenance testing.Proposal AProvenance and progeny trials:• 34 provenances x 20 mother trees = 6S0 mother trees• Initial spacing 2.5 x 5 m=12.5 m"/tree (one thinning procedure after 10/15 years)• 2 tree plots (within row)• 6S0 mother trees x 2 trees/plot x 4 replications = 5440 trees/trial• Seed requirements: 2 trees x 4 replications x 10 trials = SO seedlings/mothertree.