Plant treatment based on a water invariant chlorophyll index

Abstract

A method and system of treating plants is provided. The method includes measuring optical properties of a plant using a plurality of spectral bands. The method further includes calculating in a computational device at least two vegetative indexes using the optical properties, each of the at least two vegetative indexes correlating to one or more plant growth parameters. The method further includes calculating in the computational device a water invariant chlorophyll index from at least two vegetative indexes using the plurality of spectral bands. The also provides for treating one or more of the plants based on the water invariant chlorophyll index.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a Divisional application of U.S. patent application Ser. No. 12 / 896,460 filed Oct. 1, 2010, which is a Continuation-in-part application of U.S. patent application Ser. No. 12 / 108,371 filed Apr. 23, 2008, which is a continuation-in-part of U.S. patent application Ser. No. 10 / 703,256 filed Nov. 7, 2003, which is now U.S. Pat. No. 7,408,145 issued on Aug. 5, 2008 and which also claims priority to U.S. Provisional Application No. 60 / 925,831 filed Apr. 23, 2007, all of which are herein incorporated by reference in their entireties.FIELD OF THE INVENTION[0002]This invention relates to a structure and a method for determining changes in the chlorophyll status of a plant via remote sensing of the plant's reflectance spectrum spanning from approximately 400 nm to 1200 nm.BACKGROUND OF THE INVENTION[0003]Techniques to remotely measure crop status have historically include the use of a spectroradiometer and other instruments (Bau...

AI Technical Summary

Benefits of technology

The present invention is a new sensor that overcomes limitations of passive technologies by incorporating its own radiant source and rejecting the influence of ambient light on the measured canopy reflectance. It can operate under completely dark or full sun conditions. This sensor is an improvement in performance and cost over competing active-sensor technologies. It allows sensors to be developed that have wavelength selectivity, improved light source performance, and detection means and signal processing. This invention would be useful in a variety of commercial applications such as agricultural and turf management. It can reduce the amount of fertilizers applied to a crop, help prevent yield loss or degradation of product quality, and improve the health of our watersheds, waterways, lakes, and ocean. It can also produce relative yield maps for forecasting crop production and monitoring turf quality. When incorporated into variable rate applicator and sprayers systems, it can significantly reduce the use of fertilizers and is operable under a wide variety of conditions including cloudy conditions, bright sunlight, artificial illumination, or even total darkness.

Problems solved by technology

For example, early research by Resource21™ determined that during the optimal fly over times between 10 a.m. and 11 a.m. for satellite imaging, cloud cover had adverse affects on visibility.

Also, spatial resolution for satellite imagery is poor (Landsat, 20 meter and panchromatic, 10 meter).

Similar problems plague aerial photographic methods as well.

Both techniques, however, suffer from the need for extensive data processing (performed by third party providers at high cost and long lead time) and geo-referencing issues.

Even with spectroradiometric methods using sunlight as the ambient light source, cloud cover and time of day (8 a.m. to 8 p.m.) demands limit the mainstream acceptance of the technology for addressing the nitrogen rate over-loading problem.

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