USDA research finds conservation tillage works better after first year

In Southeast Farm Press

An onslaught of the weed Palmer amaranth in the southeastern United States has left many farmers wondering if they should continue using environmentally friendly cover crops and conservation tillage or switch to conventional tillage.

Palmer amaranth is aggressive, drought tolerant, a prolific seed producer, and capable of developing resistance to glyphosate, known as Roundup. Because of that, thousands of acres in Alabama and elsewhere are at risk of being converted to conventional tillage, which may better control the weed, but increases soil erosion and threatens long-term soil productivity.  Continue reading

“Good-Guy” Fungus to Take on Killer of Oaks and Ornamental Crops

by Jan Suszkiw, USDA Agricultural Research Service

A beneficial soil fungus could offer a biobased approach to battling Phytophthora ramorum, a pathogen that kills oaks, other tree species and woody ornamentals.

BioWorks, Inc. of Victor, New York, is collaborating with Agricultural Research Service (ARS) plant pathologist Tim Widmer to commercially formulate the fungus, Trichoderma asperellum. The species is a mycoparasite, meaning it attacks and kills other fungi, including P. ramorum, a fungus-like pathogen, notes Widmer, with ARS in Fort Detrick, Maryland. Continue reading

USDA Scientists and Partners Investigate Hawaiian Tree Deaths

A team of U.S. Department of Agriculture (USDA) scientists and their collaborators are pursuing a fungal killer that’s attacking Hawaii’s native ‘Ōhi’a trees. Fortunately, their efforts are already turning up important new leads and tools to counter the fungus, known scientifically as Ceratocystis fimbriata.

Identified in 2014, C. fimbriata causes a vascular wilt disease called “Rapid ‘Ōhi’a Death” (ROD) that’s killed hundreds of thousands of ‘Ōhi’a trees in forest and residential areas. Affected areas include the Big Island of Hawaii’s South Hilo, Puna and Ka’ū districts, according to Lisa Keith, a plant pathologist with USDA’s Agricultural Research Service (ARS) in Hilo, Hawaii. Continue reading

Scientists discover the Mediterranean fruit fly’s genetic code

By Jan Suszkiw, Agricultural Research Service

An international team of scientists from the U.S. Department of Agriculture (USDA) and other research organizations have sequenced the complete genome of the Mediterranean fruit fly, Ceratitis capitata. This pest attacks more than 260 fruit, vegetable and nut crops worldwide, causing billions of dollars annually in direct damage, export sanctions, lost markets, and other costs.

Reported in the September issue of Genome Biology, this advance is like finding the medfly’s playbook of life. It gives researchers an edge in spotting weaknesses to exploit, particularly genes tied to the pest’s ability to reproduce, withstand pathogens, find host plants, and break down environmental toxins. The advance should also foster greater understanding of how the insect’s genetics make it such a successful invasive pest. Continue reading

Discovery of fungus genome could help save cacao trees

In USDA Agricultural Research Service news

By Jan Suszkiw

U.S. Department of Agriculture (USDA) scientists have sequenced the frosty pod rot fungus genome. That advance could speed the development of cacao tree varieties that better withstand this costly blight.

The fungus that causes frosty pod rot disease, Moniliophthora roreri, occurs in most cacao-growing countries of Central and South America. Unchecked, the disease can destroy as much as 90 percent of the beans from which cocoa, cocoa butter, and ultimately chocolate are made. Continue reading

Extract from nematodes stops pecan scab

In Southeast Farm Press

by Sharon Durham, USDA

Researchers know that substances produced by bacteria from the guts of entomopathogenic nematodes (ones that infect insects) can suppress certain plant diseases, including pecan scab, the major disease currently limiting productivity and quality of pecan trees in the southeastern United States. But the specific compounds responsible for the suppression have not been previously identified.

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Survey finds fewer bee losses last year

From USDA ARS News:

Total losses of managed honey bee colonies from all causes were 23.2 percent nationwide for the 2013-2014 winter, according to the annual survey conducted by the Bee Informed Partnership and the U.S. Department of Agriculture (USDA).

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