Modulating Vapor Pressure Deficit in the Plant Micro-Environment May Enhance the Bioactive Value of Lettuce

Growing demand for horticultural products of accentuated sensory, nutritional, and functional quality traits has been driven by the turn observed in affluent societies toward a healthy and sustainable lifestyle relying principally on plant-based food. Growing plants under protected cultivation facilitates more precise and efficient modulation of the plant microenvironment, which is essential for improving vegetable quality. Among the environmental parameters that have been researched for optimization over the past, air relative humidity has always been in the background and it is still unclear if and how it can be modulated to improve plants’ quality. In this respect, two differentially pigmented (green and red) Salanova® cultivars (Lactuca sativa L. var. capitata) were grown under two different Vapor Pressure Deficits (VPDs; 0.69 and 1.76 kPa) in a controlled environment chamber in order to appraise possible changes in mineral and phytochemical composition and in antioxidant capacity. Growth and morpho-physiological parameters were also analyzed to better understand lettuce development and acclimation mechanisms under these two VPD regimes. Results showed that even though Salanova plants grown at low VPD (0.69 kPa) increased their biomass, area, number of leaves and enhanced Fv/Fm ratio, plants at high VPD increased the levels of phytochemicals, especially in the red cultivar. Based on these results, we have discussed the role of high VPD facilitated by controlled environment agriculture as a mild stress aimed to enhance the quality of leafy greens.

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Response of Plant Rhizosphere Microenvironment to Water Management in Soil- and Substrate-Based Controlled Environment Agriculture (CEA) Systems: A Review

Frontiers in Plant Science ◽

10.3389/fpls.2021.691651 ◽

2021 ◽

Vol 12 ◽

Author(s):

Bo Tan ◽

Yihan Li ◽

Tiegang Liu ◽

Xiao Tan ◽

Yuxin He ◽

...

Keyword(s):

Water Management ◽

Environmental Parameters ◽

High Tech ◽

Controlled Environment ◽

Relevant Research ◽

Efficient Tool ◽

Physiological Processes ◽

Controlled Environment Agriculture ◽

Productivity Decline ◽

Potential Food

As natural agroecology deteriorates, controlled environment agriculture (CEA) systems become the backup support for coping with future resource consumption and potential food crises. Compared with natural agroecology, most of the environmental parameters of the CEA system rely on manual management. Such a system is dependent and fragile and prone to degradation, which includes harmful bacteria proliferation and productivity decline. Proper water management is significant for constructing a stabilized rhizosphere microenvironment. It has been proved that water is an efficient tool for changing the availability of nutrients, plant physiological processes, and microbial communities within. However, for CEA issues, relevant research is lacking at present. The article reviews the interactive mechanism between water management and rhizosphere microenvironments from the perspectives of physicochemical properties, physiological processes, and microbiology in CEA systems. We presented a synthesis of relevant research on water–root–microbes interplay, which aimed to provide detailed references to the conceptualization, research, diagnosis, and troubleshooting for CEA systems, and attempted to give suggestions for the construction of a high-tech artificial agricultural ecology.

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Quantifying temperature effects in controlled environment agriculture leafy greens and culinary herbs

10.31274/etd-20210114-67 ◽

2020 ◽

Author(s):

Christopher Stephen Imler

Keyword(s):

Temperature Effects ◽

Controlled Environment ◽

Leafy Greens ◽

Controlled Environment Agriculture ◽

Culinary Herbs

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TOLERANCE OF EARLY-MATURING SOYBEAN CULTIVARS TO METRIBUZIN

Canadian Journal of Plant Science ◽

10.4141/cjps86-016 ◽

1986 ◽

Vol 66 (1) ◽

pp. 125-130 ◽

Cited By ~ 6

Author(s):

G. H. FRIESEN ◽

D. A. WALL

Keyword(s):

Sandy Loam ◽

Controlled Environment ◽

Clay Loam ◽

Clay Loam Soil ◽

Soybean Cultivars ◽

Early Maturing ◽

Glycine Max L ◽

Loam Soil ◽

Environment Chamber ◽

Chamber Studies

McCall, Maple Presto, Maple Amber and OT80-3 soybean (Glycine max (L.) Merr.) cultivars were evaluated under field conditions for their response to metribuzin. Maple Amber was found to be less tolerant than the other cultivars. In controlled environment chamber studies, injury to this cultivar was more severe on a sandy loam soil than on a clay loam soil. Fall applications of metribuzin, alone or tank-mixed with trifluralin, were tolerant to Maple Amber soybeans and such applications may offer a practical alternative to spring treatments for broad spectrum weed control in the less tolerant soybean cultivars grown in Manitoba.Key words: Metribuzin, trifluralin, preplant incorporation, fall treatments, soybean cultivars

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Humidity Effects on Porous Silica Thin Films

MRS Proceedings ◽

10.1557/proc-411-419 ◽

1995 ◽

Vol 411 ◽

Cited By ~ 2

Author(s):

J. R. Kokan ◽

R. A. Gerhardt

Keyword(s):

Thin Films ◽

Ac Conductivity ◽

Sol Gel ◽

Porous Silica ◽

Controlled Environment ◽

Alkali Ions ◽

Humidity Effects ◽

Silica Thin Films ◽

Environment Chamber ◽

Humidity Sensitivity

ABSTRACTImpedance Spectroscopy is being used to study the humidity sensitivity of porous silica thin films. The films are processed via a colloidal sol-gel method which leaves some remnant potassium and sodium. Previous work on bulk porous silica samples processed by the same method showed that the dielectric properties and ac conductivity were very sensitive to changes in humidity. The aim of this work was to determine if the same dependencies could be found in the thin films. The capacitance, dielectric loss, and ac conductivity of the films were measured in a controlled environment chamber from 20–80% RH for frequencies ranging from 10Hz–10MHz. In addition to characterizing films with varying amounts of residual alkali ions obtained through leaching, we have also measured films that were surface doped with controlled amounts of KCl, LiCl, or NaCl. Relative humidity dependencies in the films are not as dramatic as in the bulk samples. The reasons for this behavior are not yet clear, but may be associated with the porosity, thickness, and surface area of the films.

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