In Belgium, ornamental plants account for almost 0.46 billion euro in sales, or about 34% of total horticultural production output. For growers, finding ways to control pests in production facilities is more difficult as the availability of authorized plant protection products becomes more regulated. Ninety percent of Belgian growers still use high-pressure spray equipment to apply plant protection products, but a recent survey of ornamental plant growers showed that present-day spray application techniques are unsatisfactory. As more growers implement automated spray boom systems, many questions remain concerning the optimal settings for the equipment. New research now offers some clear recommendations for production greenhouse operators.
Besides the traditional fixed or rolling benches on the floor, Belgian potted plant growers frequently use hanging shelves positioned 2 to 4 meters high in the greenhouse arches. This technique allows growers to make the most of limited greenhouse space. Because these shelves are located above the traditional benches and close to the greenhouse roof, the only currently available and useful equipment for applying plant protection products are spray guns. In most cases, the spray gun is operated from the ground floor and the spray "cloud" has to be targeted from a distance and sprayed from below to the canopy. When spray guns, or "lances", are use to apply pesticides to potted plants grown on hanging shelves, much of the pesticide ends up on the ground; the amount of pesticide retained on the crop depends on the formulation of the pesticide, the volume of spray applied, the type of spray equipment, weather, and other factors.
David Nuyttens of the Institute for Agricultural and Fisheries Research (ILVO) and a team of research scientists investigated the effect of spray application technique on the spray deposition in ivy pot plants grown on hanging shelves in greenhouses. The experiment was conducted in a commercial greenhouse during January and February 2008 using the ivy cultivar Hedera algeriensis cv. Montgomery (Hibb.). Two different spray application systems were tested: a spray gun equipped with a disc-core nozzle, and vertical spray booms mounted on a trolley. The effect of application rate, nozzle type, size and spray pressure, and the difference between the traditional spray gun and a vertical spray boom system were recorded. The full study was published in HortScience.
The scientists found that the spray system and application rate clearly influenced the system's effectiveness. "Evaluating the deposition results for the two crop zones reveals that the spray gun performed quite well on the runners", Nuyttens explained. "With this technique, the spray liquid was targeted from below to the easily accessible runners, which might explain the higher spray deposition on this part of the crop." For the sprays performed with the spray boom system, a significant difference was found between the lower and higher application rate. Because the concentration of tracer was the same for both application rates, doubling the application rate justifies the increase in spray depositions.
On the main crop canopy, the spray gun performed a lot worse", Nuyttens added. "Although the spray gun operated from the ground floor still performed best on the easily accessible crop zone with the runners, its performance in the more dense main crop canopy zone was inferior."
Summarizing the significance of the research, the researchers said that the experiment underlines that, besides the application rate, the spray application equipment is an important factor defining the spray deposition achieved when spraying ivy pot plants stored on hanging shelves in greenhouses.
Founded in 1903, the American Society for Horticultural Science (ASHS) is the largest organization dedicated to advancing all facets of horticultural research, education, and application. More information at ashs.org
Michael W. Neff | EurekAlert!
Light green plants save nitrogen without sacrificing photosynthetic efficiency
21.11.2017 | Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign
Filling intercropping info gap
16.11.2017 | American Society of Agronomy
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
22.11.2017 | Business and Finance
22.11.2017 | Physics and Astronomy
22.11.2017 | Physics and Astronomy