Evaluating the effect of temperature and light during cold storage of strawberry transplants and runner tips

Abstract The objective of this study was to characterize the effect of temperature and light during cold-storage (CS) of ‘Albion’ strawberry transplants and runner tips, aiming to identify conditions that would minimize negative effects on quality, growth, and productivity. In the first experiment, transplants with two crown diameters (small ≤ 10 mm or large > 10 mm) propagated indoors under either 24 or 16 h·d –1 were placed in three CS temperatures under darkness or provided with 5 µmol·m –2 ·s –1 . For transplants propagated under 24 h·d –1 , low, medium, or high CS temperature ranges included − 2.6 to -0.8 °C, 0.3 to 3.0 °C, or 3.3 to 8.9 °C, respectively, whereas transplants propagated under 16 h·d –1 were exposed to -2.2 to 0.0 °C, 0.2 to 3.0 °C, or 3.1 to 6.6 °C, respectively. Overall, transplant quality decreased after 30 d of CS, particularly at low temperatures. Petiole elongation occurred during CS, but this negative response was most pronounced at higher temperatures. In general, there were few growth differences in response to temperature or light during CS, but as expected, transplants with large crowns had higher shoot and root dry mass (DM). Decreases in root DM were measured in transplants propagated under 24 h·d –1 following CS exposure. However, those propagated under 16 h·d –1 maintained growth comparable to plants that were never exposed to CS. After a carryover finishing phase, growth differences in response to CS temperature, light, and crown diameter were minimal, but transplants with large crowns propagated under 16 h·d –1 produced a greater fruit yield than those with small crowns. In the second experiment, unrooted runner tips were placed in CS for 30 d under darkness at -1.5, 2.0, or 4.7 °C. Quality decreased across all temperature treatments, regardless of crown diameter, but was particularly low under − 1.5 °C. Despite this, growth of runner tips was generally maintained during CS, as indicated by the absence of temperature response differences in petiole length, leaf area, and shoot DM, and by a lack of differences in these variables with plants that were never exposed to CS. Nonetheless, runner tips showed signs of stress during the finishing phase, suggesting that additional research is needed to optimize propagation strategies following exposure to CS. Overall, our results suggest that although quality was negatively affected immediately after CS, most of the treatments evaluated in this study are suitable for storing strawberry transplants and runner tips for 30 d. Therefore, conditions for CS should be optimized for cost efficiency, which may be achieved by maintaining temperatures near or slightly above the base temperature of strawberry, or by providing darkness. Additionally, our results suggest that using runner tips with larger crowns may provide benefits during post-storage establishment, as they generally produced more growth than those started from small crowns.