Row Cover and Planting Date Interaction in High Tunnel Strawberry Production

The objective of this study was to determine how late strawberries could be transplanted without adversely affecting yield following high tunnel tomato production.  In this two-year study, ‘Chandler’ strawberry transplants were set on four different dates in high tunnels and outside in a field immediately adjacent to the tunnels.  Planting dates were randomly allocated to the beds and row cover usage was randomized and applied as a strip across all rows on one half of the plots.  Plants were spaced 14 inches apart in double rows, 12 inches apart on black plastic mulch-covered beds, spaced 42 inches center to center.  White spun-bonded polypropylene row cover (1.25 oz/yd, 70% transparency) was applied in late November and removed in late March both years.  Harvest began in late April in the tunnels and late May outside.  Yield was determined by weighing marketable fruit from each 10 ft plot at 2–5 day intervals.  The data was analyzed as a strip-split plot with each year analyzed separately.  High tunnels were the whole-plot, row cover the strip-plot and planting date was the sub-plot factor. There was no significant interaction among tunnels, row cover and planting dates for total yield in 2007.  High tunnels increased total yield from 15.70 lbs/plot (outside) to 38.04 lbs/plot (in tunnel) and row covers increased total yield from 24.32 lbs/plot to 29.43 lbs/plot, but planting date had no effect.  In 2008, there was a significant three-way interaction and a significant tunnel by row cover interaction.  Overall the latest planting date had lower total yield except when grown inside a high tunnel and covered with a row cover.  Tunnel interacted with row covers for the three early planting dates in that outside row covers increased total yield from 9.23 lbs/plot to 17.96 lbs/plot, while in the high tunnels row covers decreased yield from 19.98 lbs/plot to 14.75 lbs/plot. In 2007, the median harvest occurred nine days earlier in the high tunnels than outside (DOY 150 vs. 141) and row cover median harvest date was four days earlier than without cover (DOY 144 vs. 148).  Median harvest date was earlier in 2008 with row cover outside (DOY 152 vs. 154), but later in the tunnels (DOY 143 vs. 140).  The latest planting date had an earlier median harvest date than the other three planting dates.  There were no differences among any other planting dates.