Hatchery releases are contributing to
sockeye salmon recovery

by Marlene Fritz

Painstaking efforts to ensure that hatchery-reared sockeye salmon contribute to—rather than detract from—the fish’s reproductive success appear to be paying off for endangered Redfish Lake sockeye salmon.

UI student’s research: “essential to the program”
In Willard’s study, the only significant difference in survival rates among the young was in the percentage that endured from the fry to the smolt stage: that percentage was greater among anadromous fish that spawned in the lake than among hatchery-produced fish that were released as “eyed-eggs” in egg boxes. Willard believes the eyed-eggs may be more susceptible to predation.
Another reassuring finding: In Redfish, Alturas, and Pettit lakes, where the study was conducted, genetic diversity among young salmon was greater than expected, indicating that strategies to prevent inbreeding in hatcheries have been effective, and that resident kokanee salmon and non-migrating sockeye salmon are also contributing their genes to the pool.

Madison Powell, UI animal scientist and Willard’s major professor, says her research was “one piece of the puzzle” that the Stanley Basin Sockeye Technical Oversight Committee needed to demonstrate. The committee, funded by the Bonneville Power Administration, is comprised of biologists from the IDFG, Shoshone-Bannock Tribes, National Oceanic and Atmospheric Administration Fisheries, and the UI, including Powell.

“Catherine’s research was essential to the program because her data showed that fish produced in the hatchery are successfully spawning with wild fish and, thus, that the hatchery program and the strategy of releasing pre-spawning adults and eyed-eggs are contributing to recovery,” he says.
Contact Madison Powell at mpowell@uidaho.edu.

Rerouting Roots
by Bill Loftus

UI junior horticulture major Brandon Davis hopes to straighten out a few tree roots during the course of a research project. It promises to help homeowners and landscapers avoid the problem of installing trees whose roots strangle themselves to death a few years later.

The Washington State Department of Agriculture is providing up to $5,000 for a research project that Davis developed with help from John Lloyd, UI assistant professor of arboriculture.

Davis is studying whether simple boards can reroute roots that would otherwise grow around a tree trunk, girdling it by cutting sap flow and killing it.
“We were learning about the problem in class one day. I asked if anyone had tried redirecting the roots and no one had an answer,” Davis said. The problem can be a costly one for landscapers and their customers.

“Usually these trees don’t indicate they have the problem developing until they die several years after planting,” Lloyd said. By that time, the trees often are fairly large and replacing them is expensive.

Grazing offers bluegrass growers burning alternative

by Bill Loftus

Cattle can offer growers of Kentucky bluegrass another tool to stimulate their plants to maintain seed production the next year, University of Idaho researchers say.

But cattle grazing, like burning or other ways to manage residue, is another tool rather than the ultimate answer for growers, said John Holman, a UI Extension grass seed cropping systems research scientist. The research team recently reported one key is to make sure at least 80 percent of the residue is removed each fall.

Studies compare burning with several alternatives to residue management including grazing and baling at the Hatter Creek Ranch near Potlatch. Other studies, now four years old, near Worley focus on herbicides and other aspects of bluegrass production.

Donn Thill, the project leader and UI weed science professor, describes the 26-acre research site as the largest and most comprehensive among the several study locations. This fall marks its second year of testing.

“The big thing is these are long-term experiments,” Thill said. While the work has yielded some promising information, the results must be repeated several more years to ensure their accuracy.

Two bulletins published by the college this year, Kentucky Bluegrass Production and Kentucky Bluegrass: Growth, Development, and Seed Production by Holman and Thill, review research results gained so far. Both can be downloaded free from the Internet at http://info.ag.uidaho.edu/. Follow the links catalog/category crops/seed crops.

Contact John Holman at jholman@uidaho.edu and Donn Thill at dthill@uidaho.edu.

Resistance could be trump card in wireworm management in potatoes
by Marlene Fritz

Wireworms—the larval form of click beetles—spend their winters snugly in the depths of Idaho potato fields. After soils begin to warm in spring, they ascend several feet and start feeding on freshly planted potato seedpieces. These seedpieces have usually been treated with one preplant or at-planting application of either a carbamate or organophosphate insecticide. Time may be running out on EPA registrations for these classes of chemicals—just as it runs out on the chemicals’ effectiveness against wireworms as every season progresses.

Juan Alvarez, University of Idaho entomologist at Aberdeen, has found that most of the havoc that wireworms wreak on Idaho potatoes occurs late in the season, when early-season insecticides have “run out of powder.” Because it is illegal to reapply wireworm insecticides closer to harvest, wireworms can run amok and run up crop losses of 5 to 25 percent. Alvarez is encouraged by another strategy entirely: building wireworm resistance directly into potatoes.

A cure in South American potato genetics?
In serendipitous research on aphid resistance in the early 2000s, Alvarez and USDA Agricultural Research Service Potato Breeder Rich Novy found that some untreated potatoes with South American genetics incur 50 to 90 percent less damage to wireworms than insecticide-treated Russet Burbanks. While it may be 6 to 10 years before these crosses with Chilean and Bolivian potatoes are table-ready, Novy—also of Aberdeen—is optimistic: “The fact that we have plant material with genetic resistance is exciting,” he says.

Some of the resistant plant material contains unacceptably high levels of glycoalkaloids, naturally occurring plant chemicals already known to protect potatoes against Colorado potato beetles and other leaf-feeding insects. Total tuber glycoalkaloid levels over 20 milligrams per 100 grams of fresh potato are considered toxic to humans. But other wireworm-resistant plant material has glycoalkaloid levels well below this cutoff. “Those are the ones we’re interested in,” says Novy.

At Potato Growers of Idaho, executive director Keith Esplin is interested, too. Esplin is fostering integrated pest management among Idaho potato growers. “Wireworms are one of the most difficult pests to control, with the fewest options,” he says. “If we had a potato that was resistant to wireworm damage, it would lessen the need for pesticide and fumigant use quite a bit.”
Contact Juan Alvarez at jalvarez@uidaho.edu.

Wind power's potential in Idaho energy, jobs
by Bill Loftus

Idaho residents want to know more about harnessing the wind to deflate ballooning energy costs, a University of Idaho agricultural economist says.
Garth Taylor, UI associate professor of agricultural economics at Moscow, said Bonneville, Bingham, and Cassia counties appear to have the best prospects for commercial wind generation.

Power County also may one day live up to its name with a wind farm producing electricity. “As a whole, Idaho is not a particularly windy state, but it does have high quality wind in very specific areas,” Taylor said.

His work is part of a review he conducted with Terry Hoebelheinrich of the Idaho Department of Water Resources Energy Division at Boise.
One 1.5-megawatt wind turbine can power 450 homes
A number of factors determine the economic feasibility of locating wind generators on a site, Taylor said.

A site’s average annual wind speed, the price received for electricity, and the size and number of turbines in the project are among those factors. A 1.5-megawatt wind turbine can power 450 homes, Hoebelheinrich said.
The spin-off effects of the giant wind turbines on local economies are relatively modest compared to agricultural enterprises, however. Taylor said every $1 million in sales from wind power generates 6.24 jobs at the site and in neighboring communities.

Put another way, every $1 from wind power sales generates 23 cents in wages and sales, one of the smallest economic multipliers on record. That’s because wind farms, once built, require small staffs and relatively few goods available locally.

“Once you set a wind farm up, the fuel is free,” Taylor said, adding that despite the low multiplier, clean wind farms with their high-paying jobs are a great development alternative for rural Idaho communities.
Contact Taylor at gtaylor@uidaho.edu.

Lighting up spud sales
by Marlene Fritz

Store potatoes in the dark and they’ll keep for as long as they’re biologically capable of doing so, but they won’t catch the eyes of today’s consumers. Indeed, produce managers are no longer content to simply display their living wares under their stores’ ambient lights: they’re determined to lure customers to their produce with supplemental accent lighting hung directly over the displays.

“Accent lighting is effective,” says UI Extension Potato Specialist Nora Olsen. “It makes the food glow. It pulls you over and says, ‘Come look at me.’”

The same lighting that lights up produce sales, however, also greens up potatoes. Because they are the living reproductive tissue of potato plants, these well-lit tubers will accumulate chlorophyll—and undesirable greening—on their surfaces. To help industry representatives and produce managers determine how best to illuminate their spuds, Olsen conducted two repeated experiments that included altogether six kinds of lighting: fiber optic, ceramic metal halide, halogen, two types of fluorescent, and a fluorescent with filters. She held the light intensity constant so that she could focus on the light sources’ quality, since potatoes tend to accumulate more chlorophyll when they’re exposed to blue and red wavelengths.

At the Kimberly Potato Storage Research Facility, Olsen stored the potatoes in especially constructed plywood “light rooms” that were 4 feet wide, 4 feet deep, and 7.5 feet high. Within the boxes, the various kinds of lighting glowed for 22 hours a day, and the potatoes were continually monitored for ambient temperature. At 2, 4, 7, and 9 days, Olsen removed sample tubers, evaluating them for greening and chlorophyll levels.

Fiber optic lights worked best
The fiber optic lights generally outperformed the other lighting, Olsen says: they kept the spuds about a degree cooler and extended shelf-life by almost a day.
Although Olsen says some greening still occurred under the fiber optic lights, it developed to a lesser extent—with lower accompanying chlorophyll levels—under these lights than under the other types she studied.

True, the control group of potatoes that were protected entirely from lights didn’t green up at all during the 9-day trial, but Olsen says, “You can’t keep potatoes in the dark because nobody’s going to buy them. We’re trying to get people to buy potatoes, so the last thing we want to do is hide them. We want to put our potatoes right out in the forefront and light them up so that people can see them.”

Contact Nora Olsen at norao@uidaho.edu.

Rising fuel price/organics connection
by Bill Loftus

As fuel prices rise, the public’s attraction to home-grown alternative fuels grows, and that could be a very good thing for organic farmers. Biodiesel made from mustard and its related crops canola and rapeseed offer benefits for farmers ranging from important additions to crop rotations, value-added products, and amendments for organic farming.

Car engines may not care whether biodiesel is organic or not, but organic farmers pay close attention when mustards’ potential uses as fertilizer and pesticide is discussed.

A UI team is focusing scientific scrutiny on the meal left over after oil is pressed from seeds. Jodi Johnson-Maynard said the cornflake-like meal contains more nitrogen than most animal manures, one of the most common organic fertilizers.

That’s where the other research on the Parker Research Farm near Moscow reaches the realm of high science. Experiments there focus on intriguing questions such as why mustard meal appears to release more nitrogen for plant use from the soil than the meal alone contains. The work is funded by a $613,000 USDA National Research Initiative grant.

The NRI team is tracking the path of nitrogen through the soil. One promising result so far, Johnson-Maynard said, is that the most common form of nitrogen found after the meal is applied is ammonium, which is less mobile than nitrates and so less likely to contaminate groundwater.

Contact Jodi Johnson-Maynard at jmaynard@uidaho.edu


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