In Ohio, fresh local strawberries are typically produced in open fields from late spring to early fall. During the off-season, controlled environment facilities, such as tunnels, greenhouses, and indoor vertical farms, can be used to extend the production season and help growers produce strawberries year-round. The increasing interest in local foods and the continuous expansion of controlled environment production in Ohio have empowered strawberry growers to produce locally grown strawberries competitively.
A major challenge faced by strawberry growers is locating a source of clean planting materials. Most strawberry planting materials are propagated vegetatively at large scales, suffering a higher risk of diseases compared to seed propagation methods. For example, an emerging strawberry fungal disease, Neopestalotiopsis, spreading through transplants has caused severe crop losses in both open-field and greenhouse strawberry farms. Although seed-propagated strawberry plants are less commonly used as commercial planting materials, they provide an opportunity for strawberry growers to access or produce their own clean planting materials at a relatively lower cost than other methods such as tissue culture.
Another advantage of seed-propagated strawberries is that they allow more flexibility in planting times. Common commercial strawberry planting materials include field-propagated bare roots (frigo or fresh-dug) and field- or greenhouse-propagated runner tip plants (unrooted, plug, or tray plants). In springtime, strawberry frigo bare-roots are typically used for open-field planting. Rooted plug plants are available for greenhouse planting and plasticulture in fall. During other times of the year, the availability of strawberry planting materials is relatively limited. Strawberry seeds can be started anytime and grown into transplants the same size as plug plants in 7–9 weeks under indoor conditions.
Seed-propagated strawberries also produce a more uniform transplant size. Vegetative strawberry transplants are produced from runners. This results in larger and more mature daughter plants growing closer to the base of the runners than the daughter plants growing farther from the base (Fig. 1). The inconsistent size and developmental stage of transplants can cause variations in growth rate, flowering time, and harvest time. Seed-propagated strawberry planting materials germinating at the same time, however, can produce more consistent transplants (Fig. 2).
Most seed-propagated strawberries are F1 hybrids of selected parent lines. Therefore, they technically display greater plant vigor and extended production time compared to traditional vegetatively propagated planting materials. However, actual performances are cultivar specific and also affected by the parental genotypes used for developing hybrid cultivars. Breeding seed-propagated strawberries is not an easy task. Usable germplasms for hybrid breeding are limited because existing strawberry cultivars are highly heterozygous. Nevertheless, due to the potential evolutional changes in propagation methods and distribution of planting materials, many global seed companies have been making significant efforts to develop seed-propagated strawberry cultivars.
Several challenges still need to be overcome to expand the use of seed-propagated strawberries. Currently, only a few seed-propagated strawberry varieties are commercially available in the United States, and information on yield, fruit quality, stress tolerance, and disease resistance is largely unknown. Therefore, it is difficult for growers to choose cultivars based on growing conditions and market preferences. Additionally, cultivation practices for strawberry seed germination and seedling production are not well understood. The germination rates of currently available strawberry seeds are much lower compared to most vegetable seeds. As interest in growing strawberries from seeds is increasing, seed companies, such as ABZ Seeds (abzseeds.abzstrawberry.nl/en), Sakata (global-sakata.com/news/20231031.html), Miyoshi (miyoshi-strawberry.jp), and Limgroup (en.limgroup.eu/f1-hybrid-strawberries) have put forward efforts to breed, evaluate, and promote seed-propagated strawberries around the globe. To overcome the challenges of growing seed-propagated strawberries and promote local strawberry production, universities can provide additional support to seed-propagated strawberry research and education by collaborating with strawberry breeders, transplant producers, and strawberry growers.
Additional Resources
- ABZ seeds: Strawberry F1 hybrids from seed
(abzseeds.abzstrawberry.nl/en) - Sakata seed corporation makes full-scale entry into F1 seed strawberry business
(global-sakata.com/news/20231031.html) - Miyoshi F1 seed strawberry project
(miyoshi-strawberry.jp) - Limgroup F1 hybrid strawberries
(en.limgroup.eu/f1-hybrid-strawberries)