Data processing: measuring – calibrating – or testing – Measurement system – Temperature measuring system
Reexamination Certificate
1999-03-29
2002-05-28
Bui, Bryan (Department: 2857)
Data processing: measuring, calibrating, or testing
Measurement system
Temperature measuring system
C702S188000, C073S029010
Reexamination Certificate
active
06397162
ABSTRACT:
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to a system, device and method for obtaining data pertaining to the stress state of a plant and its environment and for displaying such data in a readily interpretable manner. More particularly, the present invention relates to a system and method which incorporate a detector device for determining the boundary diffusion layer resistance in an environment in which a plant is cultivated, such that accurate estimation of evapo-transpiration of the plant can be effected.
Cultivation of commercial crops depends on the monitoring of the hydration of a plant or field. Maintaining the correct hydration, which is dependent on several factors including irrigation scheduling and the like is crucial for the proper development of plants and as such, precise monitoring of the hydration, at any given stage of development is advantageous.
In the past growers have mainly relied on their intuition and expertise in assessing crop hydration conditions. This expertise relied mainly on crop and soil inspection and observing the environmental conditions in which the crop was cultivated. One working assumption often relied upon, was that evaporation equals precipitation. Although this method was generally successful in predicting the condition of the crop field, it was time consuming and inaccurate mainly since the growth conditions in a field vary from one area to another. Furthermore, experience gained by a grower cultivating a certain crop under certain conditions could not be recorded or analyzed and as such was not applicable to other crops or other cultivation conditions.
The need for a more precise method with which a grower can monitor the hydration and stress of a plant has led to several solutions.
One such solution involves the use of a pan for monitoring the evaporation (Ep) of water therefrom in a specific environment. Such a pan is placed in a field or greenhouse in which the plants cultivated are to be monitored. The evaporation data collected can be converted to evapo-transpiration (Et) data of the plants by the use of correction factors which vary from 0.5 to 0.85 (Et/Ep) depending on the climatic and crop conditions.
Although this method presents a significant improvement to the above practice, it still lacks accuracy. In addition, the pan employed requires regular maintenance such as keeping the water clean, etc. Furthermore, this method is difficult to automate, and is not detective enough to small changes in the plant or environment.
In recent years, in an effort to overcome the limitations inherent to the system and methods described above, growers have increasingly utilized systems and devices which include arrays of precise detectors for measuring the temperature and humidity and other related parameters of the environment and/or soil proximal to the cultivated plants.
The advent of such precise monitoring technologies and methodologies enabled growers to track and record changes in a field or greenhouse enabling close monitoring, in some cases, of a single plant.
The information recorded is analyzed and the resultant data incorporated into a plant hydration profile, such a profile can then be used to assess crop condition and development through daily and seasonal changes. For further details see, for example, Wolf, B. Diagnostic Technique for Improving Crop Production. Haworth Press. P.185-187.
Numerous models exist and are presently in use for analyzing the collected data from monitored plants, examples include, but are not limited to, the Hargraves equation and the Harmon equation (for reference see, Shuttleworth, W. J. 1993, Evaporation Ch. 4 In D. R. Maidment (ed.) Handbook of Hydrology, Mcgraw-Hill, which is incorporated herein by reference). The major difference between these various models is derived from the type of data collected. One of the accurate and most commonly used model is the Penman equation (Greenhouse climate control: an integrated approach. J. C. Bakker, G. P. A. Bot, H. Challa, N. J. Van de Braak, Eds. Wageningen Press, Wageningen, 1995, p. 143). The Penman equation can be expressed as follows:
LE
=
s
s
+
γ
R
n
+
ρ
a
C
a
r
b
D
s
+
γ
(
Equation
1
)
where E is the evaporative water flux density (kg m
−2
s
−1
); L is the heat of evaporation (J kg
−1
); s is the slope of the saturated vapor pressure curve (Pa K
−1
); &ggr; is the thermodynamic psychrometric constant (Pa K
−1
); R
n
is the net radiation (W m
−2
); &rgr;
a
is the air density (kg m
−3
); C
a
is the specific air heat (J kg
−1
s
−1
); D is the vapor pressure saturation deficit (Pa); and r
b
is the boundary diffusion layer resistance (s m
−1
).
According to the Penman equation and other similar models, the rate of evapo-transpiration from a plant is resolved by incorporating data from several detectors/sensors such as of humidity and temperature into an equation. However, in plant leaves and for that matter any other evaporative surfaces, there exists a layer of humidified air which drastically decreases the evapo-transpiration from such a surface. This layer is known as the boundary diffusion layer, and the effect thereof on evapo-transpiration is termed the boundary diffusion layer resistance (r
h
). Since this effect drastically decreases the evapo-transpiration from a plant, precluding this parameter when calculating an evapo-transpiration rate from a plant often results in an erroneous hydration data.
Presently, there exists no system or method which employ an accurate detector for determining the boundary diffusion layer resistance of a given environment. As such, data collected from a plant cultivated in a field or a greenhouse is often processed with a disregard to this parameter. Such omission of data pertaining to this important parameter, often leads to an erroneous cultivar hydration profile and as such to great losses in crops.
In addition, the data provided to a grower utilizing present day systems and methods is presented as numerical data. Such presentation can often be difficult to perceive and analyze and as such requires an experienced operator to decipher.
There is thus a widely recognized need for, and it would be highly advantageous to have, a method and system for measuring and displaying the stress state of a plant which is devoid of the above limitations of the prior art.
SUMMARY OF THE INVENTION
According to one aspect of the present invention there is provided a system for co-displaying a state of a plant and its environment, the system comprising (a) at least one environment detector for monitoring at least one parameter of the plant's environment; (b) at least one canopy detector for monitoring at least one parameter of the plant itself; (c) a processor for processing the at least one parameter of the plant's environment and the at least one parameter of the plant itself for obtaining at least one processed parameter of the plant's environment and at least one processed parameter of the plant itself; and (d) a display for co-displaying the at least one processed parameter of the plant's environment and the at least one processed parameter of the plant itself, such that each of the at least one processed parameter of the plant's environment is realized by a first displayed area of a first color selected among at least two first colors, wherein each of the at least two first colors represents a range of the at least one parameter of the plant's environment, and further such that each of the at least one processed parameter of the plant itself is realized by a second displayed area of a second color selected among at least two second colors, wherein each of the at least two second colors represents a range of the at least one parameter of the plant itself.
According to another aspect of the present invention there is provided a method for displaying a state of a plant and it's environment, the method comprising the steps of (a) monitoring at least one para
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