Plastic Biodegradable Mulches Reduce Weeds and Promote Crop Growth in Day-neutral Strawberry in Western Washington

Abstract

<jats:p>Day-neutral strawberry (<jats:italic>Fragaria ×ananassa</jats:italic>) is typically grown in plasticulture production systems that use black polyethylene (PE) mulch for weed management and promotion of crop growth and yield. The objectives of this research were to evaluate several commercial plastic and paper biodegradable mulch (BDM) products [Bio360, Experimental Prototype (Exp. Prototype), and WeedGuardPlus] in comparison with standard black PE mulch and bare ground cultivation in day-neutral strawberry grown in an annual system in northwestern Washington. Mulch performance [as percent visual cover (PVC)], weed suppression, marketable yield, plant biomass, and fruit quality were evaluated in ‘Albion’ and ‘Seascape’ strawberry grown in 2014 and 2015. PVC measured at the end of the production season was lowest for the Exp. Prototype (8%) in 2014 and was greatest for Bio360 (90%), WeedGuardPlus (90%), and PE (98%). In 2015, PVC at the end of the production season was again lowest for Exp. Prototype (62%), followed by WeedGuardPlus (64%), Bio360 (93%), and PE mulch (97%). Overall, weed pressure was higher in 2015 relative to 2014 and was greatest in the bare ground treatment in both years of the study. By the end of the 2015 season, weed cover in the bare ground treatment was 95%, followed by WeedGuardPlus (50%), Exp. Prototype (34%), PE (25%), and Bio360 (15%). Yield showed year and cultivar effects and was higher in mulched treatments. Plant biomass showed varying effects; root biomass was lowest in ‘Seascape’ in 2015 under the bare ground treatment and greatest under Bio360, which was similar to PE mulch and WeedGuardPlus. Leaf biomass was lowest in the bare ground treatment and highest in mulched treatments (except in 2015, when leaf biomass was intermediate for plants grown with WeedGuardPlus). Crown biomass showed a similar trend and was overall greater for plants grown in mulched treatments except for Bio360 in 2014, which was the same as the bare ground treatment. Overall, fruit quality was maintained among strawberry grown with BDMs, with soluble solids concentration (SSC, %) and titratable acidity (TA) being the only variables to show treatment effects. SCC tended to be lower in fruit from bare ground plots. TA was different for ‘Seascape’ in 2015 with fruit from bare ground and Exp. Prototype treatments having higher TA than the PE treatment. This study demonstrates that BDMs can be comparable to PE mulch in terms of performance and impacts on crop productivity in day-neutral strawberry, suggesting that BDMs could be a viable alternative to PE mulch for strawberry growers in the Pacific Northwest.</jats:p>

The Status and Future of the Strawberry Industry in the United States

“…Labor availability and cost are the biggest challenges for the processing and fresh-market industries. To remain competitive with the inexpensively priced, processed fruit from California, Pacific Northwest growers must produce a high-quality product, particularly for fresh markets, that can command a premium price and keep the costs of production low (DeVetter et al, 2017;Hokanson and Finn, 2000). The future is strong for local fresh production whether it be for on-farm or farmers' markets sales or sales through high-value, generally smaller, grocery chains (e.g., market of choice).…”

“…China's recent ban on imported recycled plastic (Brooks et al, 2018) and challenges associated with the disposal of field-used plastic could influence production costs and fumigation possibilities under plastic in the future. Biodegradable mulches may have a greater role in the future of strawberry production (DeVetter et al, 2017).…”

Polyethylene and Biodegradable Plastic Mulches for Strawberry Production in the United States: Experiences and Opinions of Growers in Three Regions

“…For example, most California strawberries are annual plantings for fresh market (Fennimore, 2017); the Pacific Northwest is known for the production of highquality processing fruit in a perennial matted row system (Finn, 2017); and the Northeast and Mid-Atlantic states exhibit a combination of perennial matted rows and raised-bed plasticulture for fresh-market strawberries (Pritts, 2017). Plastic mulch is increasingly popular across all U.S. strawberry production regions because of its ability to suppress weeds, moderate soil temperature, conserve water, and protect plants (DeVetter et al, 2017;Fernandez et al, 2001;Freeman and Gnayem, 2005). Biodegradable plastic mulch has been shown to perform comparably to PE mulch for strawberry production in terms of weed suppression (Andrade et al, 2014), soil moisture retention (Costa et al, 2014), fruit quality (Bilck et al, 2010), crop yield (DeVetter et al, 2017), and material functionality from planting to harvesting (Kapanen et al, 2008).…”

Structural and Functional Responses of Soil Microbial Communities to Biodegradable Plastic Film Mulching in Two Agroecosystems

“…Biodegradable mulch films (BDMs) are a potential alternative: BDMs are made of polymers that can be degraded by microbial action (21–24). In the field, BDMs perform like other plastic films by altering the soil microclimate and improving crop yields (25). However, unlike PE plastics, which require removal and disposal, BDMs are designed to be tilled into the soil where resident soil microbes are expected to degrade them over time.…”