High Tunnel Coverings Alter Crop Productivity and Microclimate of Tomato and Lettuce

Abstract

The implementation of high tunnels has shown to increase marketability and/or yield of tomato (Solanum lycopersicum) and lettuce (Lactuca sativa) crops compared with open-field systems. These structures provide the opportunity to alter light intensity and spectral quality by using specific polyethylene (poly) films and/or shadecloth, which may affect microclimate and subsequent crop productivity. However, little is known about how specific high tunnel coverings affect these parameters. The overall goal of this study was to evaluate the impact of various high tunnel coverings on the microclimate and crop productivity of tomato and lettuce. The coverings included standard, ultraviolet (UV)-stabilized poly film (standard); diffuse poly (diffuse); full-spectrum clear poly (clear); UV-A/B blocking poly (block); standard + 55% shadecloth (shade); and removal of standard poly 2 weeks before initial harvest to simulate a movable tunnel (movable). Microclimate parameters that were observed included canopy and soil temperatures, canopy growing degree-days (GDD), and photosynthetic active radiation (PAR), and crop productivity included yield and net photosynthetic rate. Hybrid red ‘BHN 589’ tomatoes were grown during the summer, and red ‘New Red Fire’ and green ‘Two Star’ leaf lettuce were grown in both spring and fall in 2017 and 2018. Increased temperature, GDD, and PAR were observed during the spring and summer compared with the fall. The soil temperatures during the summer increased more under the clear covering compared with the others. For tomato, the shade produced lower total fruit yield and net photosynthetic rate (Pn) compared with the other treatments, which were similar (P < 0.001 and <0.001, respectively). The greatest yield was 7.39 kg/plant, which was produced under the clear covering. For red leaf lettuce grown in the spring, the plants under the clear, standard, and diffuse coverings had significantly greater yield than the movable and shade coverings (P < 0.001). The coverings had less effect on the yield during the fall lettuce trials, which may have been attributed to the decrease in PAR and environmental temperatures. The findings of this study suggest that high tunnel coverings affect both microclimate and yield of lettuce and tomato.

Plant Growth, Fruit Yield, and Tomato Leaf Curl Disease of High Tunnel Organic Tomato Affected by Shade Net and Plastic Mulch Color

“…Plastic film coverings retain heat from solar radiation, increasing air and soil temperatures inside HTs (Gude et al 2022;Knewtson et al 2010;Kong et al 2017). In both seasons, air temperatures were higher inside the HTs than outside.…”

“…The use of shade nets in tomato production has shown variable results. In Kansas, a shade mounted on an HT film cover reduced tomato fruit yield compared with no shade covering (Gude et al 2022). Covering a greenhouse with 50% shade for more than 6 weeks reduced tomato fruit yield by 30% (Gent 2008).…”

“…In the United States, there is an increasing interest in producing organic tomatoes (Solanum lycopersicum) in HTs (Frey et al 2020). HTs allow tomato growers to produce crops out of season and obtain high-quality fruit (Briar et al 2011;Gude et al 2022;Warren et al 2015). HTs modify the environment compared with the open field, which may increase crop yield, quality, and irrigation water use efficiency and reduce damage by pests and diseases (Carey et al 2009;Reiss et al 2004).…”

Photosynthetic and antioxidant‐related properties in blueberry under low‐ and high‐density covering material

“…(ROS) produced in chloroplasts, mitochondria, and peroxisomes under high light conditions (Santos et al, 2017). Thus, some reports have shown that plastic covering reduces phenolic compounds and antioxidant activity levels in leaves of S. lycopersicum and Lactuca sativa L. due to low light levels; meanwhile, other authors have demonstrated that polyethylene covering can induce the accumulation of phenolic compounds due to high temperature inside (Dannehl et al, 2012;Gude et al, 2020;Oh et al, 2011;Wilkens et al, 1996). Highbush blueberry (V. corymbosum) is an important fruit crop cultivated in Southern Chile, Peru, and the United States (González-Villagra et al, 2020;Retamales et al, 2014).…”

“…Otherwise, phenolic compounds have been reported as important antioxidant molecules, which scavenge reactive oxygen species (ROS) produced in chloroplasts, mitochondria, and peroxisomes under high light conditions (Santos et al., 2017). Thus, some reports have shown that plastic covering reduces phenolic compounds and antioxidant activity levels in leaves of S. lycopersicum and Lactuca sativa L. due to low light levels; meanwhile, other authors have demonstrated that polyethylene covering can induce the accumulation of phenolic compounds due to high temperature inside (Dannehl et al., 2012; Gude et al., 2020; Oh et al., 2011; Wilkens et al., 1996).…”