Fresh from the Field, Oct. 4, 2018

Aphids Use Sight to Avoid Deadly Bacteria, Could Lead to Pest Control

Pea aphids, a serious agricultural pest, have the ability to see and avoid common, aphid-killing bacteria on plant leaves, according to a new Cornell University study.

Pea aphids lack immune-response genes, making them highly susceptible to infection. In the lab, pea aphids that became infected with virulent strains of the bacteria all died. They make up for their immune deficiency by reproducing in large numbers but can still die from bacterial infection at a high rate.

It turns out, the bacteria (Pseudomonas syringae) fluoresce in ultraviolet (UV) light – wavelengths that exist in sunlight. Furthermore, pea aphids can distinguish the unique blue-green light that virulent strains of P. syringae emit.

The findings have implications for pest control. For example, organic farmers could spread virulent P. syringae on leaves to deter pea aphids, though more study is needed to test the effectiveness of these strategies.

NIFA supports this research through the Agriculture and Food Research Initiative.

Read the full story at the Cornell Chronicle. Contact: Tory A. Hendry, Cornell University. Photo: Brendan Wray, AphID, USDA APHIS PPQ, Bugwood.org

Tomato Food Safety Innovation

Researchers at the University of Nevada set out to determine whether engineered nanoparticles accumulate in fresh produce and, if so, to find a way to degrade them to reduce any potential food safety risk. Engineered nanomaterials are found in wastewater, biosolids, and biosolids-amended soils. 

The researchers developed a novel detection and quantification method for carbon nanotubes, and subsequently found nanotubes in the root, stem, and leaf tissues of lettuce plants after exposure, indicating uptake and translocation occurred in this edible plant. The researchers then developed a mechanism for degrading carbon nanoparticles, using a naturally occurring microorganism, Mycobacterium vanbaalenii PYR-1. This organism could be used to remove carbon nanotubes from the environment, preventing their uptake by edible plants and reducing the likelihood of any food safety risk associated with carbon nanotubes in produce.

NIFA supports this research through Agriculture and Food Research Initiative. Contact: Yu Yang, University of Nevada, Reno. USDA photo.

This is Not Your Grandfather’s Weed Eater

Every home gardener knows the woe of weeds, but not everyone has problems like Ohio. When weeds affect the Buckeye State’s $100 billion agriculture industry, the war against weeds takes on a new meaning altogether. 

A multi-disciplinary team of plant scientists, engineers, computer scientists, and undergraduate students at Central State University (CSU) are using NIFA Capacity Building Grant funds to develop new weed control technology that vanquishes the pesky plants with directed light energy. 

CSU’s unique weed control machine spot-illuminates weeds with predetermined light frequencies, intensities and duration – all controlled by integrated sensors and robotics. In both greenhouse and field conditions, the prototype demonstrated the ability to manage, prevent, and abate weeds like dandelions, crabgrass and ragweed.

CSU and its research partner, Global Neighbor, Inc., have developed protocols so that urban gardeners and farmers can adopt it. The researchers are also adapting the technology to kill weeds in natural settings, roadsides, and service roads. USDA photo.