Optimization of Microenvironments by Multi-colored Plastic Mulch Improves Earliness and Total Yield ofStrawberry

摘要

Although soil warming by black plastic mulch is beneficial for winter strawberry (Fragaria xananassaDuch.) production in Florida, it can cause heat stress during transplant establishment, especially when growers advance planting dates from October toSeptember to improve earliness. This problem may be overcome by using plastic mulch that is white in the center and black on the shoulders. It can be expected that a white center stripe will cool the root-zone during establishment while black shoulders warm soils during the colder mouths of production. We evaluated entirely black plastic mulch (black mulch) and black plastic mulch with a 51-cm wide white center stripe (white-striped mulch), using two cultivars: the current major cultivar, Florida Radiance, and a newly developed early-yielding cultivar, Florida Beauty. Bare-root transplants were planted in the field on 26 Sepember 2015, and harvests were performed twice weekly between 6 November 2015 and 10 March 2016. Early season root-zone temperatures were 4.4 °C cooler under white-striped mulch during the hot afternoon hours. Fruit earliness and total yield were both improved by white-striped mulch. Increases in the early (November and December) yield were 57% for 'Florida Radiance' [3.7 versus 5.8 t/ha] and 27% for 'Florida Beauty' [8.3 versus 10.5 t/ha]. By contrast, the late season (January-March) yield was less affected by plastic mulch color. As such, white-striped mulch resulted in total yield increases of only 6% for 'Florida Radiance' [20.1 versus 21.4 t/ha] and 9% for 'Florida Beauty' [25.7 versus 28.1 t/ha]. These results suggest that using white-striped mulch is an effective strategy to improve earliness for winter strawberry production in Florida.