|GABRIEL, MAGDALENA - University Of California|
|LEGARD, DAN - California Strawberry Commission|
|SJULIN, TOM - Horticultural Consulting|
Submitted to: Scientia Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/13/2015
Publication Date: 12/17/2015
Citation: Wang, D., Gabriel, M., Legard, D., Sjulin, T. 2016. Characteristics of growing media mixes and application for open-field production of strawberry (Fragaria ananassa). Scientia Horticulturae. 198:294-303.
Interpretive Summary: Growing strawberries in soilless substrate media is considered an option for not having to fumigate the soil but the approach has not been tested in open field systems. Laboratory and field experiments were carried out to evaluate the water holding properties of selected growing media and tested in open fields for producing strawberry fruits. Compared to the grower standard soil beds, coconut coir and a peat-perlite mix produced similar or slightly lower (95%) marketable fruit yield based on two-year field studies. Questions remain on the initial cost of the media and if they could be reused and for how long, but the study demonstrated that it was possible to produce viable fruit yield with the growing media.
Technical Abstract: Pathogen-free growing media are widely used for strawberry production in protected structures in Europe but not common in the United States. There is a need to investigate the feasibility of producing strawberry fruits in open fields with the pathogen-free media in the U.S. The objective of the study was to evaluate water holding properties of a number of selected growing media and apply them as substrates for strawberry production in open fields. The growing media reported in this paper included coconut coir, a peat-perlite (PP) mix, a peat-rice hull (PR) mix, and a peat-coir-rice hull (PCR) mix. Water retention functions of these media were measured in the laboratory. To monitor the apparent water content of the media in field applications, time domain reflectometry (TDR) probes were calibrated in the laboratory. A two-year field experiment was conducted, on a commercial strawberry farm, to evaluate the strawberry fruit yield under these growing media. Results indicated that the water retention curves and TDR calibration of these media were well described with equations developed for field mineral soils (R2 > 0.8). In year 1, marketable strawberry fruit yields from Coir, PP, and PR treatments averaged about 41,000 kg/ha which was not significantly different from the soil beds. Because of a longer harvesting season in year 2, marketable strawberry yields from Coir and PP treatments averaged about 50,000 kg/ha which was approximately 95% of the yield from the grower standard soil beds. Therefore the two-year field experiment demonstrated that compared to the field soil, 95-100% yield could be achieved with coconut coir or peat-perlite mix as the growing media in an open field production system.