Greenhouses are an integral part of U.S. agriculture. Nearly $200 million of food is produced in domestic greenhouses each year, and the facilities play a vital role in producing seeds and transplantable vegetation. Understanding how to keep greenhouse plants healthy can translate to increased revenue for producers.
Color infrared (CIR) photography is used to detect diseases in greenhouse plants. Credit: Photo by Chris Little
Kenneth R. Summy of the University of Texas-Pan American and Christopher R. Little of Kansas State University (Manhattan) led a study examining the stresses of a variety of greenhouse plants. The study, published in the August 2008 issue of HortScience, used color infrared (CIR) photography.
CIR images are divided into wavebands. Ratios are created comparing the NIR wavebands to red wavebands. High NIR and low red values are typical of healthy vegetation because light is being reflected in the proper proportion. Ratios of colors accentuate even slight differences in light reflection, which can indicate disease.
Trifoliate orange, 'Valencia' orange, sour orange, grapefruit, 'Bo' tree, and muskmelon were infested with sooty mold, insects, and pathogens; all are common ailments in greenhouses. Leaves exhibiting a range of symptoms were chosen to compare with healthy leaves of the same species and photographed using CIR.
Certain diseases such as powdery mildew give the leaf surface a powdery finish. Another disease, sooty mold, appears on the leaf as tan, brown, or even black spots. This image analysis allows for detection of these diseases early on. Color ratio was also affected by the age of the leaf in some cases. The ratios for sour orange leaves that were 10 and 35 days old were significantly different. However, there was no difference between 20- and 35-day-old trifoliate orange leaves. This could affect the efficiency of this method when used on whole-plant foliage.
The study also showed a variation in the accumulation patterns of a particular disease on the two trees in the study. "'Valencia' orange leaves were coated very evenly with insect honeydew, whereas honeydew deposits on 'Bo' leaves were very spotty," reported the researchers. Insect honeydew can contribute to sooty mold growth. As mold infestations increased, the ratio decreased into the unhealthy proportion for all sample plants.
The study points out that this image analysis technology has potential for large-scale use in greenhouses. However, to be most beneficial, the application must be effective in distinguishing the health of plants, cost-effective enough for the purchase of CIR cameras and equipment, and user-friendly so that on-site software processing of data can be completed easily.
Michael W. Neff | EurekAlert!
Antimicrobial substances identified in Komodo dragon blood
23.02.2017 | American Chemical Society
New Mechanisms of Gene Inactivation may prevent Aging and Cancer
23.02.2017 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
23.02.2017 | Physics and Astronomy
23.02.2017 | Earth Sciences
23.02.2017 | Life Sciences