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When low-energy consumption measures, such as natural ventilation and external sunshade, fail to reduce the indoor temperature in greenhouses, fan-pad evaporative cooling systems can be adopted ( Chai et al., 2008 ; Chen et al., 2012 ; Franco et

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To maintain appropriate tree shapes for Asian pear trees, multi-leader system would be more suitable, which could be obtained from the proper training systems. Controlling apical dominance should be the major factor for tree shape management and this might be modified by branch bending or pruning methods. When the tree shape was managed with Alternate Fan System, too narrower branch angle depressed flower bud formation because of the vigorous shoot growth but too wider angle also decreased that formation because of the numerous water sprouts. The tree with 75 degrees of internally deviated angle performed superior result in fruiting process. Additionally, heading-back pruning could be another for water sprout emerging. For that reason, the severer heading-back pruning stimulated the more water sprout emerging. The proper pruning method could be obtained by considering the relation between main stem width and sum of remained branch width.

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fan-like shape, thus the name, Fan training system ( Wolfe, 2000 ; Zabadal et al., 2007 ). However, in 2015, the multiple 1-year-old canes, trained as new trunks, were again exposed to multiple freezing events in January and February of air

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throughout this article on seed storage as a well-studied system for low temperature and low moisture content storage. In this article, “seed storage” is for those species with orthodox storage behavior, those that can withstand desiccation ( Copeland and

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block were carried out in a single day. The shield was considered as the whole plot with the nozzle type as subplot and speed as sub-subplot factors. The two nozzle types tested were: 1) flat fan TeeJet ® Extended Range XR8002VS [XR (Spraying Systems Co

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Abstract

A soil cooling system was developed using a chest-type freezer as a central cold air reservoir. Thermostatically controlled fans circulate cold air from the freezer into smaller air chambers containing large plastic pots. The system is inexpensive, easily constructed, and provides good soil temperature control.

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Abstract

Light levels were estimated by hemispherical photography at 4 different times during the growing season, in 4 different peach [Prunus persica (L.) Batsch] hedgerow canopies: oblique fan, canted oblique fan, modified central leader, and open center. Greatest percentage of sky levels occurred in the area from above to 25 cm below the top of the canopy. There was little difference between canopy training systems except 1 m above the ground. Hedging improved the light microclimate in the canopies, but only within the top 25 cm. Spectral distribution determined in an open-center tree did not follow the general trend of total radiation. As shading increased, not all wavelengths were absorbed equally, resulting in a decrease of the visible to infrared ratio.

Open Access

Fogging systems are still not widely used for greenhouse cooling, primarily due to their low fog: evaporation ratio, resulting in a low cooling efficiency and a high risk of pathogen expansion caused by excess wetness of plant foliage. The fogging is operated intermittently because of these problems. Consequently, the air temperature and relative humidity fluctuates inside the greenhouse. If nozzles with a high fog: evaporation ratio are employed, the fogging can be operated continuously. By continuous fogging, steady air temperature and relative humidity can be achieved inside the greenhouse. In our previous study under indoor conditions, a high fog: evaporation ratio was achieved by installing two small fans close to a conventional upright nozzle in order to obtain an upward air stream. The objective of this study was to draw a comparison between the environmental conditions inside a greenhouse with the continuous fogging with small fans and that with the conventional intermittent fogging without fans. Reduced fluctuation of the air temperature and relative humidity inside the greenhouse were observed in the case of continuous fogging as compared with that observed in the case of intermittent fogging. The air temperature inside the greenhouse during cooling was lower than that before cooling in both methods. In the case of continuous fogging, the adjustment of the amount of fogged water will provide the desired environmental conditions inside the greenhouse.

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Abstract

An inexpensive, well-stirred chamber for measuring net fluxes of CO2 and H2O vapor from single leaves was constructed from readily available materials. It incorporates a fan that maximizes air turbulence and boundary-layer conductance. Leaf temperature can be maintained within ± 0.5°C of air temperature. Temperatures can be varied for experimental purposes or can be maintained constant even under varying heat loads using a temperature-controlled water circulator. When used in conjunction with such a circulator and CO2 and H2O vapor analyzers, this chamber can become an inexpensive yet useful component of a gas-exchange system.

Open Access

An inexpensive system for maintaining desired water potentials throughout seed germination was developed. During hydration, a water reservoir at the base of inclined petri dishes allowed continual saturation of filter paper on which seeds were placed. During dehydration, seeds were exposed to equilibrium vapor pressures above saturated salt solutions. Constant temperature, necessary to prevent condensation of water vapor, was achieved via a small (0.2 A) fan that furnished and circulated heat throughout an insulated chamber in which salt solutions were placed. By operating the chamber above ambient laboratory temperature, interior cooling was not required. The system allowed manipulation of the rate, degree, and frequency of dehydration episodes to which germinating seeds were exposed.

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