2026/05/27 by Smriti Chaudhary, Ajay Nair · 1 voice
Agricultural and Biological Sciences · #Insect-Plant Interactions and Control #Berry genetics and cultivation research #Plant Physiology and Cultivation Studies
paper · doi:10.21273/hortsci19422-26
openalex publication_date 2026/05/27 · openalex created_date 2026/05/28 · openalex updated_date 2026/06/26
Insect management in organic eggplant production is challenging, as growers are limited to organically approved insecticides, which often have short residual activity and require repeated applications. Mesotunnel systems, described as medium-height (1 m) tunnel structures covered with insect exclusion netting, may provide an alternative strategy by physically excluding pests. Field experiments were conducted in 2024 and 2025 at the Horticulture Research Station, Iowa State University (Ames, IA, USA) to evaluate the effects of insect exclusion netting on insect pressure, microclimate, plant growth, and yield of organically grown eggplant ( Solanum melongena L. ‘Turkish Delight’). Treatments included a mesotunnel, an organic insecticide program, and an untreated control arranged in a randomized complete block design with four replications. Mesotunnels reduced incident light by 42% to 54% relative to open-field conditions without significantly altering seasonal mean air and soil temperature or relative humidity. Flea beetle abundance before harvest was significantly lower under mesotunnels than in the untreated control in both years and was comparable to the organic insecticide treatment. Aphid incidence increased under mesotunnels, indicating the need to integrate biological control strategies within these systems. The mesotunnel system increased vegetative growth and aboveground plant biomass. Marketable fruit number did not differ among treatments in 2024, whereas in 2025, mesotunnels produced more marketable fruit than the control. Across both years, nonmarketable yield, including insect-damaged and sunscald-affected fruit, was consistently lower under mesotunnels. Overall, mesotunnel systems effectively reduced key insect pests and fruit losses while maintaining eggplant yield. These results demonstrate the potential of mesotunnels as a season-long pest management strategy for organic eggplant production in the Midwest when integrated with appropriate crop management practices.