Archive | August, 2014

Interview: Chemical Crutch — Examining the Industrial Agriculture Cycle of Dependence from a Whole-Systems Approach

David Mortensen Interview

David Mortensen, Ph.D.

David Mortensen, Ph.D. interviewed by: Chris Walters

David Mortensen, Ph.D., is a professor of weed ecology at Penn State. Back in early 2012 he led a team of co-authors who produced a paper called “Navigating a Critical Juncture in Sustainable Weed Management.” The equivalent of an agricultural bombshell, it delivered unhappy news about the consequences of engineering crops to withstand more than one pesticide. Noting the remarkable ability of weeds to evolve resistance strategies, Mortensen and his co-authors predicted ecological disaster if crops engineered to permit the return of 2,4-D and dicamba are put into circulation. The article’s predictions of exponentially rising auxinic herbicide use were shocking until it emerged that the USDA’s estimates were even higher. Over two years later, as biotechnology’s latest assault draws closer to final regulatory approval or refusal, it seemed like a good idea to check in with Mortensen. Author of dozens of research papers, he is a veteran of decades working in fields alongside farmers in Iowa, Maryland, and many states in between.

ACRES U.S.A. What is the crux of the issue here?

DAVID MORTENSEN. This new technology that’s going to “save” herbicide- resistant crops — that is, the new stacked-trait herbicide-resistant crops — in my view is going in exactly the wrong direction. It’s going in the wrong direction for a number of reasons, not least of which is that if we adopt them we are going to double or triple herbicide use on our major commodity crops, corn and soybean, with significant increases in use on cotton. We tried to be conservative and careful in our Critical Juncture paper with that estimate of doubling and tripling herbicide use. We spent months debating that amongst the co-authors. Thus it’s intriguing for me to read in the USDA’s own assessment that we will increase use of auxinic herbicides four to seven-fold if we approve these new crops, as the USDA seems to be leaning toward doing. I find it bordering on maddening to think that’s an acceptable trajectory to put ourselves on. It goes against everything I’ve worked on for the past 30 years. Continue Reading →

Tools of the Trade — Using Refractometers & Penetrometers

tools-of-the-tradeby Gary Digiuseppe

Forage producers can measure the percentage of sucrose and other soluble content of their grasses with the use of a refractometer, although the accuracy of the reading can be dependent on the cost of the instrument.

Martin Capewell, owner of Agriculture Solutions LLC in Strong, Maine, says an analog refractometer costs around $50-$200, while a digital model can run anywhere from $190- $10,000. A “simple, hand held, decent” digital refractometer, Capewell says, costs about $350 and will last a long time provided it’s properly cleaned and maintained and protected from extreme temperatures.

All refractometers work by passing light through sap or juice extracted from a crop, and then measuring the angle of the light as refracted by a prism. The readout, a percentage of soluble content, is called Brix, named for one of the originators of the method, Adolf Brix. The Brix reading is determined by where the line produced by the light refraction crosses the scale on the device. Technically, Brix is the percentage by weight of sucrose in a solution, but the refractometer can’t differentiate between sucrose and other dissolved solids.

The scale is calibrated relative to a temperature of 20°C, and Capewell says refractometers are either temperature compensated or non-temperature compensated. “The great thing about one with automatic temperature compensation is that it gives you the correct Brix reading, and you don’t have to do that formula yourself,” he says. Continue Reading →

Bugs as Bio-Control


Image of an unidentified Ascogaster species.

University of Adelaide Ph.D. student Rebecca Kittel has discovered 18 new species of tiny parasitic chelonine wasps which have potential to be used as biological control (bio-control) agents as they specifically target individual varieties of moths.

The adult wasps inject their eggs into the eggs of host moths. The wasp larvae feed and develop inside of the moth caterpillars, emerging from the caterpillar as it dies. The larvae then form a cocoon until environmental conditions are right for the adult to emerge and the bio-control cycle begins again.

“The biology and the fact that each wasp species targets only one specific moth means that they are potentially ideal candidates for development as bio-control agents of agricultural pests,” says Kittel.

The wasps are among 150 new species discovered by Kittel. Specimens from around the country were sent to Kittel to identify, 250 of which were part of the 18 species published in her entry to the journal Insect Systematics & Evolution.

This article appears in the August 2014 issue of Acres U.S.A.

Restaurants Seek Unique Local Foods

local-foods-restaurantRestaurant chefs and food purchasing managers who have bought local foods in the past are more likely to continue adding them to menus and store shelves, according to a team of researchers. “Past experiences will have an impact on buying local foods,” said Amit Sharma, associate professor of hospitality management, Penn State. “Restaurant managers who buy local foods currently are significantly more likely to keep purchasing locally.” In a study of the cost and benefits of purchasing locally grown foods in restaurants, managers and chefs indicated that certain actions of producers stand out as reasons why they continue to buy locally grown foods. Managers said that a local farmer’s or producer’s response time was more important than delivery time as a factor when they considered buying local food products. Food purchasers also indicated that they would not stock local food just because it is local. Local foods must have a unique selling point. For instance, a special variety apple used in an apple pie may be more important to the food manager than just a locally grown apple.

This article appears in the August 2014 issue of Acres U.S.A.