Selecting Strawberry Cultivars for Winter Greenhouse Production

Costs of transportation and food safety concerns have spawned an increase in public support of locally grown produce and fruit. With this in mind, a two-phase investigation was planned with the goal of incorporating low start up costs for sustainable greenhouse production with selection of strawberry cultivars that would provide the greatest benefit in terms of number and size of berries as well as nutraceutical properties.  Twelve strawberry cultivars, some day neutral and some short day responsive, were grown from September through late April.  In phase I, all plants were potted in a soil-lite mix in 6-inch pots, watered as needed and grown in a glass greenhouse as part of a student laboratory experience.  By mid December, at least one plant per cultivar had flowered and produced fruit.  Some cultivars such as ‘Sweet Charlie’ and ‘Albion’ were highly prone to spider mite infestation, but still fruited.  In phase II, 24 plants of each cultivar were selected based on similar leaf number and uniform plant size.  All runners, flowers and fruit were removed and plants were replanted in new soil-lite mix and placed across two benches in a poly-covered greenhouse.  The phase II experiment was set up as a randomized complete block design with 6 replications of four plants per cultivar, 3 replications running north-south on each bench. Data taken included: date of first flower, total fruit number and berry weight per plant.  Berries were deemed ripe based on color comparison between berries in the grocery store and those on the bench standardized by using the RHS color chart. Bees (Bombus impatiens) were introduced when the first flowers started to open. Within four weeks, some cultivars, e.g. ‘Albion’ and ‘Strawberry Festival’, resumed flowering and fruiting.  Other cultivars were slower to respond, e.g. ‘Darselect’, ‘Evie-2’, ‘Honeoye’ and ‘KRS-10’. This was different than phase I observations with ‘Darselect’, ‘Evie-2’, ‘Honeoye’, ‘AC Wendy’ and ‘Seascape’ among the cultivars showing good flowering/fruiting. Mite infestations once again occurred and were curtailed by spot spraying using organic-approved oil.  In addition to total yield, nutraceutical properties including total phenols will be presented.