Apparatus for determining water stress in crops
First Claim
1. A portable apparatus for determining the water stress condition of an agricultural crop growing in a field comprising:
- a first, pistol shaped housing carrying a plurality of sensor means for sensing a group of crop and field conditions, including air temperature, crop canopy temperature, relative sunlight intensity and relative humidity, and for generating a group of electrical sensor signals including a sensor signal indicative of each of said conditions, said pistol shaped housing having barrel means for aiming said crop canopy temperature sensor means carried by said housing at a crop and having pistol grip including trigger switch means for actuating said control means to receive said sensor signals, and wherein said relative sunlight sensor comprises at least two photoresponsive electronic devices, each device having a light-receiving surface, said surfaces being disposed at an obtuse angle relative to each other, whereby sensed sunlight intensity is relatively independent for different orientations of said barrel means;
a second housing carrying control means interconnected to said sensor means for controllably receiving said sensor signals and for calculating, in said field using said sensor signals, at least one water stress index or a particular crop;
operator input means, carried by at least one of said first and second housings and interconnected to said control means, for selectively controlling receipt of said sensor signals by said control means, said operator input means including said trigger switch means; and
display means, carried by said second housing and interconnected to said control means, for visually displaying in said field the at least one calculated crop water stress index.
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Accused Products
Abstract
An apparatus for determining the water stress condition of an agricultural crop growing in a field includes sensors for sensing environmental and crop conditions, such as air temperature, crop canopy temperature and relative humidity, and for generating signals indicative of the sensed conditions, a microprocessor for receiving the generated signals and for calculating a crop water stress index from the signals and a visual display for displaying, in the field, the calculated index. In one embodiment, the sensors are mounted in a pistollike, hand held housing and the microprocessor, display and a keyboard control are carried by a second housing. The microprocessor compares one or more of the sensed conditions to reasonable value limits and rejects a set of measurements containing values beyond the limits. Crop-specific data needed to calculate water stress indices for a particular crop are stored in a programmable, read only memory. When data for a different crop are needed, the memory may be removed and replaced by a memory containing the appropriate crop data, or, if erasable, the memory may be erased and reprogrammed for the different crop. The apparatus preferably includes a memory for storing a number of calculated crop water stress indices, each calculated from conditions sensed on a different day, in records including the date of the measurements. The stored indices can be retrieved and displayed with their measurement dates so that historical trends of crop water stress may be discerned.
74 Citations
33 Claims
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1. A portable apparatus for determining the water stress condition of an agricultural crop growing in a field comprising:
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a first, pistol shaped housing carrying a plurality of sensor means for sensing a group of crop and field conditions, including air temperature, crop canopy temperature, relative sunlight intensity and relative humidity, and for generating a group of electrical sensor signals including a sensor signal indicative of each of said conditions, said pistol shaped housing having barrel means for aiming said crop canopy temperature sensor means carried by said housing at a crop and having pistol grip including trigger switch means for actuating said control means to receive said sensor signals, and wherein said relative sunlight sensor comprises at least two photoresponsive electronic devices, each device having a light-receiving surface, said surfaces being disposed at an obtuse angle relative to each other, whereby sensed sunlight intensity is relatively independent for different orientations of said barrel means; a second housing carrying control means interconnected to said sensor means for controllably receiving said sensor signals and for calculating, in said field using said sensor signals, at least one water stress index or a particular crop; operator input means, carried by at least one of said first and second housings and interconnected to said control means, for selectively controlling receipt of said sensor signals by said control means, said operator input means including said trigger switch means; and display means, carried by said second housing and interconnected to said control means, for visually displaying in said field the at least one calculated crop water stress index. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An apparatus for determining the water stress condition of an agricultural crop growing in a field comprising:
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a first housing carrying a plurality of sensor means for sensing a group of crop and field conditions, including air temperature, crop canopy temperature and relative humidity, and for generating a group of electrical sensor signals including a sensor signal indicative of each of said conditions; a second housing carrying control means interconnected to said sensor means for controllably receiving said sensor signals and for calculating, in said field using said sensor signals, at least one water stress index for a particular crop; operator input means, interconnected to said control means, for selectively controlling receipt of said sensor signals by said control means; first display means, carried by said second housing and interconnected to said control means, for visually displaying the at least one calculated crop water stress index; and second display means, carried on said first housing interconnected to said control means, for visually displaying in said field the difference between the sensed crop canopy and air temperatures. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
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18. An apparatus for determining the water stress condition of an agricultural crop growing in a field comprising:
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a plurality of sensor means for sensing a group of crop and field conditions, including air temperature, a crop canopy temperature and relative humidity, and for generating a group of electrical sensor signals including a sensor signal indicative of each of said conditions; control means interconnected to said sensor means for controllably receiving said sensor signals and for calculating, using said sensor signals, at least one water stress index for a particular crop, said control means including memory means for storing, for a particular operator-identified field in which a crop is growing, at least two calculated water stress indices, each of said at least two indices having been calculated from crop and field conditions sensed on a different day and for storing with each of said indices their respective dates of said crop and field condition sensing; operator input means interconnected to said control means, for selectively controlling receipt of said sensor signals by said control means; and display means, interconnected to said control means, for visually displaying said at least two indices graphically as a function of the date of crop and field condition sensing. - View Dependent Claims (19, 20, 21, 22, 23)
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24. An apparatus for determining the water stress condition of an agricultural crop growing in a field comprising:
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a plurality of sensor means for sensing a group of crop and field conditions, including air temperature, crop canopy temperature and relative humidity, and for generating a group of electrical sensor signals including a sensor signal indicative of each of said conditions; control means interconnected to said sensor means for controllably receiving said sensor signals and for calculating, using said sensor signals, at least one water stress index for a particular crop, said control means including means for comparing a function of at least one sensed condition indicated in a said group of sensor signals with at least one limit value for said sensed condition and for rejecting said group of sensor signals when said function of at least one condition falls outside said at least one limit value; operator input means, interconnected to said control means, for selectively controlling receipt of said sensor signals by said control means; and display means, interconnected to said control means, for visually displaying the at least one calculated crop water stress index. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32, 33)
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Specification