By Emily Unglesbee
DTN Staff Reporter
ST. LOUIS (DTN) -- This bi-monthly column condenses the latest news in the field of crop technology, research and products.
PREDATORS FEAST SAFELY ON BT-RESISTANT PESTS
As most farmers know, not all the bugs lurking in corn and cotton fields are bad. One example is the assassin bug, which stabs corn and cotton pests with its dagger-like mouthpiece, injects a saliva that liquefies their insides, and then slurps them up. Thanks to a new study from Cornell, we now know that this helpful predator can safely execute this violent feast on Bt-resistant insects that have fed on Bt-corn crops. Along with colleagues from USDA and China, a Cornell entomologist let assassin bugs feed on Bt-resistant armyworms and cabbage loopers. They then measured several "fitness parameters" of the assassin bugs, such as their survival, weight, lifespan and fertility. They found no significant difference in the health of assassin bugs that fed on the Bt-resistant pests versus the control group, which fed on pests that had not eaten any Bt-proteins. They also discovered that although the Bt-proteins were present in the corn and cotton crops at the highest levels, the armyworms and cabbage loopers had lower amounts in their system, and the assassin bugs had even less of the proteins after eating the insects. "While [the assassin bug] was exposed to Cry1F and Cry1Ac and Cry2Ab when it fed on hosts that consumed Bt-transgenic plants, the proteins did not affect important fitness parameters in this common and important predator," the researchers concluded. You can see their study here: http://goo.gl/….
Growers who struggle with the persistent and invasive weed species downy brome might find some relief in 2015. Verdesian Life Sciences is bringing a biological herbicide, known as strain D7 of the bacterium Pseudomonas fluorescens, to market next year to control the weed. Downy brome has an extensive root system and past research has shown it can actually alter the biology of the soil around it in order to thrive. The weed is an enormous problem for rangeland owners and farmers of cereals, alfalfa, and grass seed. In addition to suppressing perennial grasses and out-competing crops, downy brome has proven to be a good fire starter and its seeds irritate grazing livestock. According to a Verdesian press release, D7 secretes chemicals that target and hinder downy brome's growth and development. The company says the new herbicide offers a new mode of action for wheat growers who predominantly use ALS-inhibitors to control the weed. "We've seen some resistance development in the last few years, and D7 will give growers a tool to help mitigate that risk by offering a novel mode of action," Ryan Bond, Verdesian's vice president of marketing, said in the press release. You can see the company press release here: http://www.vlsci.com/….
SORGHUM VARIETIES TOLERATE SUGARCANE APHID
Sorghum growers are now able to select sorghum varieties with a natural tolerance for a growing pest, the sugarcane aphid. After the USDA's Agricultural Research Service (ARS) evaluated the performance of different grain sorghum hybrids against the aphids, two seed companies have announced that some of their varieties displayed good tolerance to the pest. Monsanto released a press release stating that their DeKalb grain sorghum varieties DKS37-07 and PULSAR brand "exhibit a high level of genetic tolerance to the sugarcane aphid." Likewise, Chromatin announced that several varieties in its Sorghum Partners brand, namely P6929, KS310, NK5418, and K73-J6 hybrids, "exhibit strong tolerance to the sugarcane aphid pest." The sugarcane aphid showed up in Texas sorghum fields in 2013 and has spread as far north as southern Kansas and as far east as Florida. The aphids produce a sticky honeydew that clogs combines and encourages fungal growth. Early infestations can attack and destroy seedlings and later infestations can inhibit grain formation. In 2013, some growers lost up to 50% of their sorghum yield to the pest. You can see the company press releases about their aphid-tolerant varieties here: http://goo.gl/… and here: http://goo.gl/…. You can read more about the sugarcane aphid at this Texas Agri-Life Extension website: http://goo.gl/….
Emily Unglesbee can be reached at firstname.lastname@example.org
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