Greenhouse Cooling With Continuous Generation of Upward-Moving Fog for Reducing Wetting of Plant Foliage and Air Temperature Fluctuations: A Case Study

Toida, Hiromi; Kozai, Toyoki; Ohyama, Kenji

doi:10.17660/actahortic.2008.797.45

Cited by 10 publications

(9 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Fog adhesion index and droplet size: fog adhesion index was examined as described by Ohyama [ 11 ]. Water sensitive papers were placed at a height of 0, 1.2 and 1.7m from the ground, exposed to fogging for 1 min when the system performed.…”

Section: Methodsmentioning

confidence: 99%

“…During the operation of fog systems, droplets waft in the air and maintain the correct air humidity level to prevent the dehydration of the crops caused by heat stress [ 9 , 10 ]. However, the application of conventional fog systems is still limited in China [ 11 , 12 ]. A possible reason for its limited application is that the nozzles of traditional systems were designed as large pore size, resulting in enlargement of the droplet size.…”

Section: Introductionmentioning

confidence: 99%

“…During the last decades, nozzles were improved and designed as the micro-fog which dramatically reduced droplet size, indicating a much higher fog evaporation ratio. As a result, micro-fog systems will help reduce wetting of the plant foliage during greenhouse cooling [ 11 ]. In additional, most previous fog systems were automatic controlled on the basis of temperature or relative humidity [ 13 – 17 ], failed to take into account basic physical principles of plants transpiration due to the interaction between vapor concentration and temperature.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Regulation of Vapor Pressure Deficit by Greenhouse Micro-Fog Systems Improved Growth and Productivity of Tomato via Enhancing Photosynthesis during Summer Season

Zhang

et al. 2015

PLoS ONE

View full text Add to dashboard Cite

The role of a proposed micro-fog system in regulating greenhouse environments and enhancing tomato (Solanum lycopersicum L.) productivity during summer season was studied. Experiments were carried out in a multi-span glass greenhouse, which was divided into two identical compartments involving different environments: (1) without environment control and (2) with a micro-fog system operating when the air vapor pressure deficit (VPD) of greenhouse was higher than 0.5 KPa. The micro-fog system effectively alleviated heat stress and evaporative demand in the greenhouse during summer season. The physiologically favourable environment maintained by micro-fog treatment significantly enhanced elongation of leaf and stem, which contributed to a substantial elevation of final leaf area and shoot biomass. These improvements in physiological and morphological traits resulted in around 12.3% increase of marketable tomato yield per plant. Relative growth rate (RGR) of micro-fog treatment was also significantly higher than control plants, which was mainly determined by the substantial elevation in net assimilation rate (NAR), and to a lesser extent caused by leaf area ratio (LAR). Measurement of leaf gas exchange parameters also demonstrated that micro-fog treatment significantly enhanced leaf photosynthesis capacity. Taken together, manipulation of VPD in greenhouses by micro-fog systems effectively enhanced tomato growth and productivity via improving photosynthesis during summer season.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Regulation of Vapor Pressure Deficit by Greenhouse Micro-Fog Systems Improved Growth and Productivity of Tomato via Enhancing Photosynthesis during Summer Season

Zhang

et al. 2015

PLoS ONE

View full text Add to dashboard Cite

show abstract

“…These designs use a fine mist (or fog) produced by spraying water inside the protected cropping structure. Fogging systems with reduced water droplet size of between 2-60 µm prevent water droplets adhering to plant foliage [105]. This method combats leaf dehydration and heat stress due to excessive temperatures [106,107] and maintains favourable leaf water status when evaporation demands are higher [106].…”

Section: Fogging Systemsmentioning

confidence: 99%

Protected Cropping in Warm Climates: A Review of Humidity Control and Cooling Methods

2019

View full text Add to dashboard Cite

The projected increase of the world’s population, coupled with the shrinking area of arable land required to meet future food demands, is building pressure on Earth’s finite agricultural resources. As an alternative to conventional farming methods, crops can be grown in protected environments, such as traditional greenhouses or the more modern plant factories. These are usually more productive and use resources more efficiently than conventional farming and are now receiving much attention—especially in urban and peri-urban areas. Traditionally, protected cropping has been predominantly practised in temperate climates, but interest is rapidly rising in hot, arid areas and humid, tropical regions. However, maintaining suitable climatic conditions inside protected cropping structures in warm climates—where warm is defined as equivalent to climatic conditions that require cooling—is challenging and requires different approaches from those used in temperate conditions. In this paper, we review the benefits of protected cropping in warm climates, as well as the technologies available for maintaining a controlled growing environment in these regions. In addition to providing a summary of active cooling methods, this study summarises photovoltaic (PV)-based shading methods used for passive cooling of greenhouses. Additionally, we also summarise the current humidity-control techniques used in the protected cropping industry and identify future research opportunities in this area. The review includes a list of optimum growing conditions for a range of crop species suited to protected cropping in warm climates.

show abstract

“…Because fog droplets adhere to plants when there is a low rate of evaporation, they can act as a medium for pathogen growth (Hanan, 1998); consequently, with this system, there must be periods wherein no fog is generated so that the plant foliage can dry. With regard to the single-fluid nozzle system, control of the fogging time Yasuba et al, 2009), the means by which the fog is sprayed (Ohyama et al, 2008), and the effects of the water pressure of the fog system (Li and Willits, 2008) have been investigated in previous studies.…”

Section: Introductionmentioning

confidence: 99%

Analysis of the Aerial Environment of a Tomato Greenhouse Equipped with Different Fog Cooling Systems

Ishigami

Tetsuka

Gotō

2014

J. Agric. Meteorol.

View full text Add to dashboard Cite

Fog cooling systems with natural ventilation are a type of evaporative cooling technique that is widely used in Japan. One drawback of these systems is that it is difficult to maintain the greenhouse air temperature at its optimum range in summer using the conventional single-fluid nozzle system because it has a low cooling efficiency and produces a high risk of pathogen invasion due to excessive wetting of the plant foliage. Therefore, we introduced a twin-fluid nozzle system as an alternative fogging system. This system affords a higher evaporation ratio and a lower degree of plant foliage wetting because it generates fog droplets with diameters smaller than those generated by single-fluid nozzles. We installed these two types of fogging systems in tomato greenhouses and investigated the different aerial environments that they produced. We observed that the twin-fluid nozzle system maintained the air temperature at the same level as that maintained by the single-fluid nozzle system. We also observed that the single-fluid nozzle system significantly inhibited the evapotranspiration in the tomato plants due to wetting of the plant foliage, whereas the evapotranspiration rate when using the twin-fluid nozzle system was 70-100 % higher.

show abstract

Greenhouse Cooling With Continuous Generation of Upward-Moving Fog for Reducing Wetting of Plant Foliage and Air Temperature Fluctuations: A Case Study

Cited by 10 publications

References 0 publications

Regulation of Vapor Pressure Deficit by Greenhouse Micro-Fog Systems Improved Growth and Productivity of Tomato via Enhancing Photosynthesis during Summer Season

Regulation of Vapor Pressure Deficit by Greenhouse Micro-Fog Systems Improved Growth and Productivity of Tomato via Enhancing Photosynthesis during Summer Season

Protected Cropping in Warm Climates: A Review of Humidity Control and Cooling Methods

Analysis of the Aerial Environment of a Tomato Greenhouse Equipped with Different Fog Cooling Systems

Contact Info

Product

Resources

About