Use of low tunnels to improve the productivity of day-neutral strawberry plants under the Québec climatic conditions

Low Tunnel and Cultivar Effects on Day-neutral Strawberry Yield and Characteristics in New Hampshire

“…Aside from 'Sweet Ann' in 2018, low tunnels did not impact season-long marketable or total yield in either year of our experiment, a finding that agrees with studies conducted in Minnesota (Petran et al, 2016) and in 1 of 2 years in Quebec, Canada (Van Sterthem et al, 2017). This differs from what has been reported in the mid-Atlantic region of the United States, where greater yields under low tunnels have been attributed to warmer temperatures and a growing season that was extended as late as December (Lewers et al, 2017).…”

“…However, following the adoption of the plasticulture production system (Poling, 1993), early field trials in North Carolina showed that cultivars could produce as much as 1.02 kg/plant annually on the east coast of the United States (Ballington et al, 2008), suggesting great potential for DN production across the country. Recently, cultivar evaluations conducted from the mid-Atlantic region of the United States to as far north as Quebec, Canada, indicate that DN productivity is influenced by cultivar, site, and growing season, and annual marketable yields have ranged from between 189 and 950 g/plant (Condori et al, 2017;Lewers et al, 2017;Petran et al, 2016;Pritts, 2017a;Pritts and McDermott, 2017;Van Sterthem et al, 2017;Weber et al, 2018). Using a standard plasticulture plant spacing of 17,424 plants/acre (Lantz et al, 2010) such yields equate to between 8137 and 40,902 kgÁha -1 , well exceeding the 5900 lb/acre (6613 kgÁha -1 ) harvested by New England growers (U.S. Department of Agriculture National Agricultural Statistics Service, 2018 the fruiting period, but also offer high annual yields compared with shortday plants.…”

“…Several studies have found that low tunnel protective structures increase the marketable yield (grams per plant) and/or the percent marketable yield, especially late in the season and following weather events (Lewers et al, 2017;Petran et al, 2016;Pritts, 2017a;Resende et al, 2010;Van Sterthem et al, 2017). This suggests that low tunnels may be a useful tool for protecting fruit marketability in regions with frequent precipitation events, such as throughout the northeastern United States, but little is known about low tunnel effects on plant growth and development.…”

“…Furthermore, recent experiments comparing the microclimate under low tunnels with the traditional open bed environment have reported that season-long air and soil temperatures are greater under low tunnels (Condori et al, 2017;Van Sterthem et al, 2017). Warmer temperatures have been associated with greater yields and an extended fruiting season, especially in the mid-Atlantic region where temperatures are milder than the northeastern United States (Condori et al, 2017;Lewers et al, 2017;Van Sterthem et al, 2017). Given these findings, it is important to understand the effect of low tunnels on microclimate and season duration in the northeastern United States, where summers are hot but nighttime temperatures can drop precipitously in the fall.…”

“…Of particular interest is whether low tunnels increase temperatures during the summer months even when low tunnels are vented, and whether they provide any thermal insulation at night during the fall months, when they may be used to assist in season-extension. Experiments conducted in warmer regions suggest low tunnels do not provide a substantial buffer in nighttime temperatures (Condori et al, 2017;Van Sterthem et al, 2017), but since most studies present season-long averages, not daily fluctuations in temperature, this remains unclear.…”