Rowcover Material and Time of Application and Removal Affect Ripening and Yield of Strawberries

Abstract

Abstract Effects of time of application and removal of straw, clear polyethylene, black polyethylene, polypropylene, and polypropylene–polyamid rowcovers were measured for ‘Earliglow’ and ‘Allstar’ strawberries ( Fragaria × ananassa Duch.). There was no consistent effect of date of autumn application on yield or fruit size for the polypropylene cover. All winter-applied rowcovers resulted in improved yields relative to uncovered plots, although this difference was not always significant. When applied during early spring, opaque materials reduced yields up to 46% and delayed fruiting as much as 3 days, while some translucent materials enhanced yields as much as 94% and accelerated harvest by 8 days compared to uncovered strawberries. Covering with translucent materials during both winter and spring had even stronger positive effects, with ‘Earliglow’ being more responsive. With translucent rowcovers, the time of removal had a greater effect on production and fruit size than rowcover type. Optimal removal dates differed for rowcover type and cultivar. For a short period of time in early spring, rowcovers apparently provide an environment favorable for flower development.