Agricultural Research Service (ARS) scientist Dong Wang is evaluating whether infrared sensors and thermal technology can help peach growers decide precisely when to irrigate in California's San Joaquin Valley. ARS is USDA's principal intramural scientific research agency, and the research supports the USDA priority of promoting international food security.
Irrigation is the primary source of water for agriculture in the valley during the summer, and wells have been forced to reach deeper to bring up enough water to meet increasing demands. Peaches also require much of their water from June through September, when temperatures and demands for water are at their highest.
Wang and Jim Gartung, an ARS agricultural engineer, installed 12 infrared temperature sensors in peach orchards at the San Joaquin Valley Agricultural Sciences Center in Parlier and gave trees one of four irrigation treatments: applying furrow or subsurface drip irrigation, with or without postharvest water stress.
They also measured crop yields and assessed the quality of the fruit to compare the output of trees grown under deficit irrigation with trees grown under normal conditions. Deficit irrigation has been used to produce some varieties of grapes and has been studied for its potential in fruit tree and row crop production. But it has yet to be widely adopted, in part because growers need better tools to strike a balance between saving water and keeping crops viable and healthy, according to Wang.
They used the sensors to measure temperatures in the tree canopies, and calculated a "crop water stress index" based on the differences between tree canopy temperatures and the surrounding air temperatures. Higher index numbers indicated more stressed trees.
The researchers found that midday canopy-to-air temperature differences in trees that were water-stressed postharvest were in the 10- to 15-degree Fahrenheit range, consistently higher than the 3- to 4-degree Fahrenheit range in the trees that were not water-stressed.
For comparison purposes, the researchers placed leaves from stressed and non-stressed trees in a pressure chamber and measured the pressure required to squeeze water out of them. When the trees are water-stressed, it takes more pressure to squeeze moisture from them.
The results, published in Agricultural Water Management, show that the pressure chamber results were consistent with data collected by the infrared sensors, which means the sensors may be an effective tool for managing water use in peach orchards.
Read more about this research in the November/December 2012 issue of Agricultural Research magazine.
Dennis O'Brien | EurekAlert!
03.09.2015 | American Society of Agronomy
Increasingly severe disturbances weaken world's temperate forests
31.08.2015 | USDA Forest Service - Pacific Southwest Research Station
In a survey of NASA's Hubble Space Telescope images of 2,753 young, blue star clusters in the neighboring Andromeda galaxy (M31), astronomers have found that M31 and our own galaxy have a similar percentage of newborn stars based on mass.
By nailing down what percentage of stars have a particular mass within a cluster, or the Initial Mass Function (IMF), scientists can better interpret the light...
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE have developed a highly compact and efficient inverter for use in uninterruptible power...
China's Loess Plateau was formed by wind alternately depositing dust or removing dust over the last 2.6 million years, according to a new report from University of Arizona geoscientists. The study is the first to explain how the steep-fronted plateau formed.
China's Loess Plateau was formed by wind alternately depositing dust or removing dust over the last 2.6 million years, according to a new report from...
The leaves of the lotus flower, and other natural surfaces that repel water and dirt, have been the model for many types of engineered liquid-repelling surfaces. As slippery as these surfaces are, however, tiny water droplets still stick to them. Now, Penn State researchers have developed nano/micro-textured, highly slippery surfaces able to outperform these naturally inspired coatings, particularly when the water is a vapor or tiny droplets.
Enhancing the mobility of liquid droplets on rough surfaces could improve condensation heat transfer for power-plant heat exchangers, create more efficient...
Longer, more severe, and hotter droughts and a myriad of other threats, including diseases and more extensive and severe wildfires, are threatening to transform some of the world's temperate forests, a new study published in Science has found. Without informed management, some forests could convert to shrublands or grasslands within the coming decades.
"While we have been trying to manage for resilience of 20th century conditions, we realize now that we must prepare for transformations and attempt to ease...
03.09.2015 | Event News
20.08.2015 | Event News
20.08.2015 | Event News
04.09.2015 | Power and Electrical Engineering
04.09.2015 | Machine Engineering
04.09.2015 | Materials Sciences