2018 ASHS Annual Conference

The current open field strawberry propagation method in the US has intrinsic problems such as seasonal scarcity, low productivity, and plants have a high risk for contamination with soil borne pathogens. A potential alternative is precision indoor propagation (PIP). The overall objective of this project is to maximize strawberry tip production (reduce flower initiation) by precisely controlling all the environmental factors to provide affordable and clean propagation material. The objective of the present experiment is to find the optimal light intensity to maximize strawberry propagation efficiency (tips per mother plant). ‘Albion’ (day-neutral) strawberry plugs (27) with two expanded leaves and crown diameter of 7.3 ± 0.8 mm were transplanted in one-gallon pots filled with a substrate mixed of 50% perlite, 25% peat moss and 25% coconut coir. Potted plants were placed in a custom designed indoor strawberry propagation system. Plants were subject to three different light intensity treatments: 250PPF (251 ± 11), 350PPF (345 ± 13), and 450PPF (446 ± 14) photosynthetic photon flux (mmol m^-2 s^-1) at 12 h photoperiod provided by cool white fluorescent lamps. The canopy air temperature was maintained at 27.6 ± 0.3°C / 23.9 ± 0.2°C during the day/dark period, relative humidity of 63.1 ± 4.4 % and ambient CO₂. The plants were watered through electronic irrigation system with modified Yamazaki recipe. Preliminary data shows that after three weeks of growth, there is no significant difference between the three treatments in leaf count and flower development, treatments have produced 5.7 ± 1.6 flowers and the canopy has 5.4 ± 0.6 leaves. Plants under 450PPF have 16% and 12% greater crown diameter (14.3 ± 1.2 mm) than plants under 250PPF and 350PPF treatments, respectively. Runners will be harvested when the first tip has two expanded leaves, and the third tip starts developing. Number of tips per mother plant and tip growth rate and morphology will be recorded. In addition, mother plant growth rate and morphology will also be recorded.