Dry matter partitioning in a nursery and a plasticulture fruit field of strawberry cultivars 'Sweet Charlie' and 'Camarosa' as affected by prohexadione-calcium and partial leaf removal

Strawberry plants ( Fragaria × ananassa Duch.) are planted in Canadian nurseries in spring to be dug in autumn as bare-root transplants for winter annual plasticulture fruit production in the south-eastern U.S.A.. A series of whole plant harvests were performed on 'Sweet Charlie' and 'Camarosa' strawberry plants in a nursery and a plasticulture fruit field to study their pattern of dry matter partitioning. Plants were either treated with prohexadione-calcium or mowed, or treated with prohexadione-calcium and mowed in the nursery and compared to untreated plants. All treatments caused a reduction in plant height at the time bare-roots transplants were dug in the nursery. Treated plants allocated more dry matter to root and less to leaves, resulting in an increase in root to shoot ratio and this effect lasted until plants were well established after transplantation into the plasticulture system. By fruiting, treated plants allocated more biomass to fruits, and this difference was due to increased fruit number and not increased fruit size. Untreated plants allocated more to leaves, both in number and percentage, and to stems. Prohexadione-calcium increased root allocation, and mowing (alone or combined with prohexadione-calcium) decreased it. Plants that were prohexadione-calcium-treated and mowed had the highest harvest index and untreated plants had the lowest. 'Camarosa' developed many more leaves and proportionally less fruits than 'Sweet Charlie' during the fruiting phase