A Comparison of Plasticulture and Strip Tillage Production Systems With and Without Row Covers for Organic and Conventional Cucurbit Production

Open Access
Author:
Lilley, Jason Michael
Graduate Program:
Horticulture
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
March 24, 2015
Committee Members:
  • Elsa Selina Sanchez, Thesis Advisor
Keywords:
  • Cucurbit
  • Plasticulture
  • Strip Tillage
  • Row Cover
  • Muskmelon
  • Summer Squash
Abstract:
The production of most cucurbit crops in the Northeastern U.S. uses polyethylene mulch on raised beds with drip irrigation, or a plasticulture system. While the use of plasticulture systems decreases weed pressure, and increases soil temperatures, typically resulting in increased yields, disadvantages include plastic disposal issues and costs, and soil degradation due to the intensive tillage required for installation. Strip tillage systems have been shown to decrease soil erosion, increase soil moisture retention and increase soil microbial communities. In conventional production, the use of spunbonded polypropylene row cover shows potential to replace the use of neonicotinoids, the common early season control method for insect pests of cucurbits. These row covers have been shown to control early season striped cucumber beetle (Acalymma vittatum ) populations, therefore decreasing the incidence of bacterial wilt caused by Erwinia tracheiphila. In organic production, the use of row covers can decrease early season pest pressure, being an alternative to expensive and largely ineffective approved insecticides. Research was conducted during the 2013-14 growing seasons at The Pennsylvania State University’s Russell E. Larson Research and Education Center in Rock Springs, PA to investigate these production practices. Plasticulture and strip tillage systems were compared with and without row covers in four separate experiments: conventionally managed summer squash (Cucurbita pepo ‘Lioness’), conventional muskmelon (Cucumis melo ‘Athena’), organic summer squash, and organic muskmelon. Soil moisture levels, air and soil temperatures, soil nitrate levels, light intensity at the plant canopy, weed densities, striped cucumber beetle (Acalymma vittatum) populations, incidence of bacterial wilt, and crop yields were measured. Plants grown in the strip tillage system generally had lower yields than in the plasticulture system in both years. Numerically higher soil moisture levels were observed in the strip tillage system during the 2013 season but no differences were observed in 2014. Row covers resulted in larger plants and generally resulted in equal or higher yields when compared to not using row covers within all systems. Late timing of row cover removal may have negatively affected summer squash yields in the plasticulture system. The use of row covers allowed for the elimination of neonicotinoid application in conventional trials and fewer insecticide applications required in organic treatments with no increase in pest pressure or incidence of bacterial wilt, although there was low incidence of bacterial wilt in both years of the experiments. Lower yields in the strip tillage system observed in the muskmelon experiment and in the majority of the summer squash experiments were beyond acceptable levels. This research found that decreased soil temperatures, high weed pressure, and dramatically lower yields in the strip tillage system limit the successful use of this system for these crops. Although economic analysis was not conducted, this research showed that row covers are a viable production alternative to the use of neonicotinoids in conventional production systems. In organic trials, row covers reduced the need for early season insecticide applications and protected plants when they are most susceptible to pest damage.