跳至主要内容

Comparing Canopy Hyperspectral Reflectance Properties of Palmer amaranth to Okra and Super-Okra Leaf Cotton

Cotton (Gossypium spp.) is an important crop grown throughout the world. It is an important source of fiber and is one of the few crops with unique leaf shapes: 1) normal, 2) sub-okra, 3) okra, and 4) super-okra. Leaf shape plays a major role in cotton survival.

Palmer amaranth (Amaranthus palmeri S. Wats.) is a major weed affecting cotton production systems in the southern U.S. In ideal environmental conditions, it grows faster and outcompetes cotton plants for available resources, and it has been linked to a reduction in cotton yield.

Hyperspectral remote sensing has shown promise as a tool for crop weed discrimination, and there is a growing interest in using this technology for identifying weeds in cotton production systems. Currently, there is no research available comparing the canopy hyperspectral profiles of okra and super-okra leaf cotton to the canopy hyperspectral profile of Palmer amaranth. Also, no information is available on which regions of the spectrum are optimal for okra and super-okra leaf canopies separation from Palmer amaranth.

In this paper, two greenhouse studies were conducted to compare canopy hyperspectral reflectance profiles of Palmer amaranth to canopy hyperspectral reflectance profiles of okra and super-okra leaf cotton and to identify optimal regions of the electromagnetic spectrum for their discrimination. Ground-based hyperspectral measurements of the plant canopies were obtained with a spectroradiometer (400 - 2350 nm range). Analysis of variance (ANOVA, p ≤ 0.05), Dunnett’s test (p≤ 0.05), and difference and sensitivity measurements were tabulated to determine the optimal wavebands for Palmer amaranth and cotton discrimination. 

Results were inconsistent for Palmer amaranth and okra leaf cotton separation. Optimal wavebands for distinguishing Palmer amaranth from super-okra leaf cotton were observed in the shortwave infrared region (2000 nm and 2180 nm) of the optical spectrum. Ground-based and airborne sensors can be tuned into the shortwave infrared bands identified in this study, facilitating application of remote sensing technology for Palmer amaranth discrimination from super-okra leaf cotton and implementation of the technology as a decision support tool in cotton weed management programs. The future research initiatives will focus on testing vegetation indices and derivative spectra as tools for discriminating Palmer amaranth and okra leaf cotton.

Article by Reginald S. Fletcher and Rickie B. Turley, from Agricultural Research Service, United States Department of Agriculture, Stoneville, USA.

Full access: http://t.cn/EbhNuVB
Image by Inthemind Ofnature, from Flickr-cc.

评论

发表评论

此博客中的热门博文

Incorporation of High-Altitude Balloon Experiment in High School Science Classrooms

High-altitude balloon is a balloon, filled usually with helium or hydrogen that ascends into an area called “near space” or stratosphere. The most common type of high-altitude balloons are weather balloons. Other purposes include use as a platform for experiments in the upper atmosphere. Modern balloons generally contain electronic equipment such as radio transmitters, cameras, or satellite navigation systems, such as GPS receivers. The mission of the High-Altitude Balloon Experiment (HABE) is to acquire supporting data, validate enabling technologies, and resolve critical acquisition, tracking, and pointing (ATP) and fire control issues in support of future space-based precision pointing experiments. The use of high-altitude balloons offers a relatively low-cost, low-vibration test platform, a recoverable and reusable payload, worldwide launch capability, and a 'near- space' emulation of the future space systems operational scenarios. More recently, several university...
1 条评论
阅读全文

Effects of Karate Training on Basic Motor Abilities of Primary School Children

“You never attack first in karate” might be the best conclusion of karate, which is a martial art practiced typically without weapons. It’s reported that karate has a long history for several hundred years, but the modern karate was spread to the whole Japan from Okinawa in the early part of 20th century. Now it has become one of the most widely practiced martial art forms in the world. Usually, it’s divided into Kihon, Kata and Kumite. As for the beginners, Kihon is more suitable for them because it involves basic techniques. Due to karate consists of dynamic offensive and defensive techniques using all parts of the body to their maximum advantage, the best understanding of true karate practice is the perfection of oneself through the perfection of the art. It not only develops coordination, quickens reflexes, and builds stamina, but also develops composure, a clearer thought process, deeper insight into one’s mental capabilities, and more self-confidence. So many researchers stu...
发表评论
阅读全文

Electron Spin and Proton Spin in the Hydrogen and Hydrogen-Like Atomic Systems

Read full paper at: http://www.scirp.org/journal/PaperInformation.aspx?PaperID=52202#.VIj7tMnQrzE Author(s) Stanisław Olszewski * Affiliation(s) Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland . ABSTRACT The mechanical angular momentum and magnetic moment of the electron and proton spin have been calculated semiclassically with the aid of the uncertainty principle for energy and time. The spin effects of both kinds of the elementary particles can be expressed in terms of similar formulae. The quantization of the spin motion has been done on the basis of the old quantum theory. It gives a quantum number n = 1/2 as the index of the spin state acceptable for both the electron and proton ...
发表评论
阅读全文