Low-Tunnel Strawberry Production: Comparison of Cultivars and Films

Abstract

Growing repeat-fruiting strawberries (Fragaria ×ananassa Duchesne ex Rozier) under low tunnels can extend a strawberry harvest season from a few weeks to several months. Yields from multiple dayneutral cultivars have been compared under a single film, and yields from single cultivars have been compared under multiple films, but a study of possible cultivar and film interaction effects in low tunnels has not been reported. From 2014-2018, six cultivars were compared under low tunnels covered with a standard polyethylene film and three other films purported to improve growing conditions. Traits analyzed included total yield, percent rotted yield, berry weight, percent marketable yield, and average market score. 'Monterey' performed above average for all traits and better under TIII TES/IR 0.102 mm thick film (TES film) or Kool Lite Plus 0.152 mm thick polyethylene film (KL film). 'Albion' performed above average for all traits except yield and better under TES film or Clear TIII 0.102 mm thick polyethylene film ("standard clear" or SC film). 'Portola' performed above average for all traits except percent rotted yield, better under SC, KL, and TES films, and had lower percent rotted yield under TES film. Because TES film was helpful to the three betterperforming cultivars evaluated, it was considered a good choice for growers to try in on-farm evaluations of available repeatfruiting cultivars. Generally, yield, berry weight, market score, and percent marketable yield were correlated positively with each other.

Albion Strawberry Responds to Mulch Treatments and Low Tunnels Covered with Photoselective Films

“…(2020) reported that 'Albion' performed best under KLP and under a relatively transparent film that had transmission properties similar to those of TRP. While there were no statistically significant differences in yield on white mulch among films in the present study, which aligns with other work (Willden et al, 2021), the average yields on white mulch were greatest under KLP, UVO, and TRP, indicating that our findings related to the best film for 'Albion' on white mulch are strikingly similar to those of Lewers et al (2020). Also on white mulch, Willden et al (2021) observed that yield tended to increase with the level of UV reduction.…”

“…However, when plants were grown on white mulch, yields were consistently highest under the UVreducing films KLP and UVO (the former also reduced NIR transmission). One-off exceptions to this trend were white mulch/ UVT, white mulch/TRP, and black mulch/ KLP, which each performed very well during one of two years [above average plant performance under KLP has also been reported by (Lewers et al 2020)]. This trend may suggest an interaction between the reflectance and absorption properties of the mulches and the transmission profiles of films.…”

“…With several recent exceptions (Anderson et al, 2019;Lewers et al, 2020;Willden et al, 2021), low tunnel research in North America has primarily focused on cultivar evaluation, not on the spectral transmission and effects of the films covering low tunnels. Yet, the current selection of agricultural films for protected culture is quite diverse and includes photoselective films, which can selectively block, reduce, or transmit specific wavelengths of the electromagnetic spectrum.…”

“…In Quebec, Canada, 'Seascape' largely produced comparable yields under different films, with the exception of one year when higher yield under a particular film was attributed to 3% greater PAR transmission (Van Sterthem et al, 2017). In Maryland, Lewers et al (2020) investigated the performance of multiple cultivars and photoselective films and reported that Albion tended to have above-average performance (compared with other films) under two films that blocked UV-B and had high PAR transmission. Interestingly, these films differed in their UV-A and NIR transmission substantially.…”

“…Interestingly, all published low tunnel studies with strawberry have used white (or white-on-black) plastic as the ground mulch (Anderson et al, 2019;Lewers et al, 2017Lewers et al, , 2020Petran et al, 2016;Willden et al, 2021), but black plastic mulch is the dominant mulch used for vegetable production in New Hampshire. Since northeastern growers have largely continued to rely on the perennial matted row system (Samtani et al, 2019), there has been limited research comparing black and white plastic mulches for plasticulture strawberry production.…”