Good experiences with everbearing strawberries cultivated in running tunnels

Area yields are of decisive importance for the economic efficiency of strawberry production. The amount of those yields depends on how many weeks during the growing season ripe fruits are available for harvest. June-bearing cultivars, for example, have a short harvest period of about four weeks. Everbearing cultivars, which are in the local region cultivated traditionally in open field, have a harvest period of ten to 12 weeks from mid-July to early October. To extend the harvest time for everbearer even further, the question comes up whether it is possible to shift the picking period into spring by planting in autumn and tunnelling in spring. In order to achieve this goal, corresponding experiments were carried out over several years. The results show that high early yields in spring can be achieved by different everbearing cultivars. The earliness was comparable to the earliness of June-bearing cultivars cultivated under the same growing conditions. About 45% of the total yield of the everbearer was usually harvested in the first four weeks after picking start in early May. This corresponds to a yield performance of 70 to 80% compared to the standard cultivar 'Clery' in the same time. The first harvest peak in May was followed by a long extended lower second harvest period, that usually ends in September. The total yields varied between 5 and 7 kg m^‑1 (40-56 t ha^‑1), depending on the year and cultivar. In conclusion, the trials have shown that this new cultivation method makes it possible to extend the harvest period and increase the total yield. Especially the high early yields are interesting for growers due to higher sales prices in spring. In spite of many positive aspects, it should be noted that there are significant costs of picking and cultivation during the summer harvest.