To compare the pest control and pollination efficacy of four different row cover management strategies (on-off, on-off-on, open ends, and full season) for organic acorn squash

• Field studies were conducted at the University of Kentucky Horticulture Research Farm (Lexington, KY) during two consecutive summers (2020 and 2021).
• Treatment fields were amended at a rate of ~4 tons/ha with organic compost, spaded, and cultivated. Organic ‘Table Ace’ acorn squash seeds were started in a USDA certified-organic greenhouse and grown for four weeks prior to transplanting. Immediately after transplanting, mesotunnels (1m tall) were installed over each treatment, and fine mesh netting was installed over the hoops.
• The four row cover treatments included:
  1. 1. On-Off: Mesotunnels established at planting until flowering. At flowering, nets were removed for the remainder of the growing season.
     2. On-Off-On: Mesotunnels established at planting until flowering. At flowering, nets were removed and reinstalled once pollination was completed (~3 weeks) for the remainder of the growing season.
     3. Open Ends: Mesotunnels established at planting until flowering. At flowering, the 6.4m short ends of plots were opened. Following the completion of pollination, the net ends were reclosed for the remainder of the growing season.
     4. Full Season: Mesotunnels established at planting until flowering. At flowering, one Natupol-Excel bumblebee colony was placed in the center bed at the center of the plot to provide pollination services. Mesotunnels remained covered until harvest.

• One week after transplanting, one sticky card was placed 1.5m inward from each plot end in the center bed of each plot and removed after 7 days. A second set of sticky cards were deployed after the completion of pollination and removed after 7 days. All cucurbit insect pests trapped on the sticky cards were identified and quantified.
  • • Additionally, visual plant surveys were conducted weekly beginning one week after transplanting (2021) and at flowering (2020) by assessing six plants per subplot at varying distances from the ends of the row covers. A trained surveyor observed key pests, monitoring for striped and spotted cucumber beetles, squash bug adults, nymphs, and egg clusters.
• Pollinator activity was monitored via visual surveys of the same six plants (see above), once weekly during the crop’s flowering period. A trained surveyor monitored the number of flower visitations by squash bees, honey bees, small native bees, and bumblebees. Pollinator activity was defined as the number of bees flying over or present within the survey area during the 45-second survey period.
  • • Sample acorn squash fruits were evaluated for number of seeds per fruit (a proxy for pollination success).
• Based on weekly pest survey results, organic insecticides were applied once weekly if pest numbers exceeded action thresholds determined from existing literature/standard management practices.
• At harvest, data was collected from squash harvested at each of the six sampling locations (varying distances from ends of row covers) on fruit number, total fruit weight, and quality.