Winter cover affecting freezing injury in strawberries in a coastal and continental climate

The study was conducted in two continental and two coastal experiments on field-grown strawberries on high beds. It was shown that use Of winter cover reduced freezing injury in plants without snow cover during winter. Cover positively affected development of flower stalks, increasing the number and the proportion of flower stalks that were large. Also, it reduced injury in flower primordia and thus the number of misshapen fruits, and made the plants produce larger fruits. As a sum, these effects increased the yields up to 9% in the continental and 45% in the coastal fields. The yield differences of the coastal vs. the continental experiments were partly due to more freezing and thawing at the coastal than at the continental fields, and partly influenced by a snow roof to keep the snow off the plants in the continental experiments. Generally. covering with fleece, bubble plastic and brown-paper-laminated bubble plastic gave a better result than straw for winter covering. When straw was used it was essential to remove it in early spring. Using fleece and bubble plastic as winter covers, there was no difference in yield by removal of the cover in the first week of April or May for the cvs 'Bounty' and 'Senga Sengana', but cv. 'Korona' reacted generally positively to prolonging the covering period. Covering from 1 September to 1 November only, had a negative effect on yield compared with no cover, while covering in April only was equal to no covering.