Barley diseases may create problems for farmers during late spring, summerWritten by Emilee Gibb
“Most of our barley cultivars are aimed more toward whatever they’re going to be used for, say brewing, so they are focused on more agronomic kinds of issues instead of disease resistance issues,” says University of Wyoming Extension Plant Pathologist William Stump.
There are multiple diseases that could impact barley producers during late spring and early summer months, such as Fusarium head blight, stripe rust and ergot, but producers can take certain measures to limit the field’s susceptibility.
“One of the big issues lately has been Fusarium head blight (FHB), which has been an issue of concern across the country,” says Stump.
FHB is a fungal disease that affects the head and kernels of both wheat and barley. The most notable clinical sign of infection is bleaching of florets prior to maturity. Shriveled kernels, low test weights and a pink to orange mold at the base of florets may also be observed.
In barley used for brewing purposes, FHB can have a major financial impact.
“It also affects malt barley where they get some actual toxins produced, and there’s really strict guidelines on that and brewing barley, so if producers get that, they basically can’t use their barley for brewing,” emphasizes Stump.
While there are fungicides available, many are not very effective. Rather, Stump suggests using management strategies to prevent and control FHB.
“There are certain things we can do, such as avoiding irrigation during the flowering period, because that creates a more conducive environment for infection to take place,” he explains.
Producers using no-till strategies can increase residue management through chopping to speed up infected residue decomposition. Using crop rotations with non-host species such as sugar beets or alfalfa can also help control disease.
“Producers may ask, ‘Is this a situation where should we should plow?’ We’re probably getting more benefits from the minimal till than the detriments of the diseases at this point,” Stump notes.
Stripe rust background
“Another disease that’s a problem right now is stripe rust, and that can be a concern at this time of the year, too,” continues Stump.
Stripe rust is caused by the fungus Puccinia striiformis f. sp. hordei. Another distinct form affects wheat.
The clinical signs of stripe rust in barley are parallel rows of yellow to orange colored pustules on leaves and sometimes the glumes.
The disease favors cool, wet weather. It can persist on susceptible grasses and volunteer wheat.
Stump advises that producers with historical stripe rust problems use resistant barley varieties if available and apply foliar fungicides during the boot stage of development. Producers will need to determine what fungicide to use depending on if they are using the treatment prior to or during an existing infection.
Stripe rust control
As with treating any barley disease, it is important for producers to evaluate the economics of using different control strategies.
“Growers have to weigh the costs and benefit of controlling disease in the fields,” notes Stump.
Any producers interested in knowing if stripe rust is in their area can check the USDA cereal rust website for the current cereal rust situation in the United States.
For the past few years, the University of Wyoming has been assisting with the Cooperative Agricultural Pest Surveys (CAPS).
“They typically will sample some of the barley fields in the Big Horn Basin, and we scrutinize them for the different rusts,” he explains.
Ergot is another disease that can have a significant impact on producers.
“It is also caused by a fungus and infects the actual grains,” says Stump. “The fungus replaces the grain with an overwintering body, a hard sclerotia, and the problem is that those hard bodies that can be harvested when you harvest the barley.”
The sclerotia contain alkaloid toxins, which are toxic for both livestock and humans. The disease infects the grain flowers of barley and a wide range of cool-season grass hosts.
The United States Food and Drug Administration (FDA) has strict regulations on tolerable concentrations of the toxin in barley loads, making it a significant disease for producers to consider.
“The FDA tolerances are at 0.1 percent in a 30-gram sample, so it’s not a lot,” emphasizes Stump.
If toxin concentration is found to be higher than the FDA tolerance, the load will be rejected.
Ergot-infected grains can result in the disease ergotism in humans. Ergotism can result in clinical signs such as hallucinations, gangrene, tremors and death. Strict regulations are in place because heat does not deactivate the toxin.
“It survives the baking process and we still get the toxic effect of the chemicals,” he continues.
Stump explains that ergot is usually environmentally driven, particularly by early, cool, wet weather followed by wet weather during grain flowering. This favors the pathogen and delays the pollination period.
Producers can control ergot infection in fields by utilizing crop rotations because of the short-lived sclerotia. Other management strategies that can be helpful are burial of sclerotia by tillage and mowing wild grasses along field borders before they flower, as grasses are a source of the inoculum.
While ergot was historically a significant problem in the middle ages and is a problem is developing countries, Stump reminds producers that it is an uncommon disease for Wyoming producers to see.
“It’s normally not really a problem. It’s one of those really rare diseases,” he concludes.
Management practices may reduce infections of wheat streak mosaic virusWritten by Natasha Wheeler
Caused by wheat streak mosaic virus (WSMV), wheat streak mosaic disease heavily impacts wheat in the Great Plains, where native grasses provide favorable habitat for the wheat curl mite (WCM).
Wheat curl mites
“WSMV is transmitted through the vector of the WCM. WCMs are microscopic, less than 0.3 millimeters long and can only be seen under magnification,” explains South Dakota State University Extension Plant Pathologist Emanuel Byamukama.
Mites grow from eggs to adults within eight to 10 days, and population densities can grow dramatically over a short period of time.
“WCMs are not capable of moving from plant to plant or from field to field on their own. They are blown by wind to nearby plants. They are however, capable of crawling over short distances between stems or leaves that are in contact with each other,” he continues.
Because wind carries the mites between plants, heavy WSMV infections are often seen along the edges of fields.
“Winter wheat is more impacted by this virus than spring wheat because of the longer infection period for infections that take place in the fall. This disease can also take place in other crops like barley, corn, rye, oats and several other perennial and annual wild grasses,” Byamukama describes.
Symptoms of the disease often appear as pale green and yellow stripes, creating a mosaic pattern of colors. Depending on the variety of wheat that has been infected, the virus can also stunt growth in the plants.
“Symptoms worsen with stress caused by dry and hot weather conditions,” he adds.
A number of cultural practices can be implemented to help control WSMV, including the use of crop rotation.
“We should rotate away from crops that could also host this virus, such as corn, oats or sorghum. We need to use broad leaf crops such as field peas, lentils or sunflowers to help keep pressure low,” remarks Byamukama.
Using resistant wheat varieties or cultivars tolerant to the virus is another management option, as is using delayed planting.
“Planting early in the fall, especially if temperatures are mild, increases the risk of mites landing and transmitting viruses in emerging winter wheat,” he says.
To manage for WSMV, producers can also destroy volunteer wheat or grassy weeds at least two weeks before planting to reduce chances of infection. Volunteer wheat and grassy weeds serve as a “green bridge” when left in the field, allowing for the mites to survive and transfer to the new crop.
“Volunteer wheat and grassy weeds are the most important risk factor for the WCMs and WSMV. Volunteer wheat or weeds can be destroyed through the use of tillage or herbicides,” Byamukama suggests.
Losses from WSMV can vary from negligible to total loss. In some cases, the wheat becomes so stunted that it cannot be picked by the combine.
“This disease can be devastating to wheat. To manage this disease, we need to destroy the green bridge at least two weeks before planting, practice crop rotation and plant resistant or tolerant cultivars,” states Byamukama.
Land Institute researches perennial grainsWritten by Saige
Wes Jackson founded the Land Institute in 1976 with a focus on building agricultural systems with ecological stability.
Their research efforts toward such goals have included the breeding of perennial crops, as well as domestication of wild plants for human use. Their work has been successful and is ongoing.
Stan Cox, the Coordinator of Science for the Land Institute recently reported in the Fiscal Year 2011 update that 30,000 plants were transplanted to fields at the Land Institute. An updated greenhouse and additional research building facilitated an increase from last year.
“Although the bulk of growing occurs in the fields, the first generation of many of our new hybrids starts in the greenhouse, with a capacity of about 4,500 plants,” said Cox in the annual report. “Cross pollination of wheat is more successful under the protection of the greenhouse.”
The research teams at the Land Institute study perennial wheat and sorghum, as well as domestication of intermediate wheatgrass, perennial oilseeds and Illinois bundleflower. There have also been hybrid crosses involving corn and sunflowers made at the institute.
“We have done some work with sorghum bicolor and Johnson grass,” said Jackson on Oct. 4 in a presentation for the Northwest College Writers Series in Powell. “We are working to tame the Johnson grass. In China and Indonesia, we have support to breed perennial varieties of upland rice. In sunflowers, we are working to get the heads more centralized.”
“The seed weight is going up in our collection,” said Jackson. “In only three selection cycles we have been able to increase the size of the seed to more than double.”
Additional developments have enabled the plants an increased rate of survival.
“Out of almost 2,000 plants, 43 percent survived the summer of 2010,” explained Jackson. “Those are the parents for the future generations of plans, and from there, a bigger percentage will survive.”
There has also been some evidence showing good drought resistance in plants across the globe.
The variety of perennial wheat that the Land Institute has helped to create is called Kernza. The Land Institute describes Kernza as their domesticated intermediate wheatgrass. They are currently working to increase seed size and yield.
Kernza shows an intermediate between common annual wheat varieties and perennial grains from the dawn of civilization, exhibiting increased root systems and larger plants.
According to the Land Institute FY 2011 Annual Report, “In the 2010-11 field nursery, 819 (wheat) plants survived both the summer after harvest and the winter, a much larger number than in any previous case.”
Additionally, more than 50 new DNA markers were developed to identify each chromosome in the hybrid population. The population of wheat/wheatgrass plants is constantly being improved to expand genetic diversity, as well.
Other research in sorghum has developed a selection of “winter-hardy” perennials that are seen as superior plants. Continued research with sorghum in Hawaii has allowed development of plants that are growing faster in the second generations.
Along with research at the Land Institute, collaborating institutions, including the University of Minnesota, Prescott College, Dordt College and Michigan and Minnesota universities, as well as Applied Ecological Services in Wisconsin, have helped to further research.
Jackson has also begun approaching various foundations with a plan to increase research that is feasible.
“We need to have a 30-year program devoted to developing agriculture based on the way natural ecosystems work,” said Jackson. “We can do it now because we have perennials on the horizon, and we are able to take what we have learned from the broad discipline of ecology and apply it to our fields.”
Jackson’s plan involves using scientists and 11 candidate locations around the globe to continue research, as well as five virtual research sites at academic institutions across the United States.
“If we were to train 110 PhDs in various disciplines, we would have them work in clusters around the planet,” added Jackson. “The cost to educate and train those 110 fellows is only $24 million.”
Research efforts at the Land Institute utilize natural processes and molecular genetics, but not gene splicing, to reach the end goals.
Molecular genetics is a tool, according to Jackson, to help identify the markers in plants that code for the traits they desire. He emphasizes they are not genetically splicing or modifying plants, but rather using the approach to reduce the workload and time required to develop successful perennial plants.
Jackson describes that. by merging molecular biology techniques and knowledge of ecology, a new revolution in science will begin.
“Every time there has been a synthesis, there has always been a flowering of knowledge and energy develops, something great,” emphasized Jackson, who used examples of Darwin’s merge of natural history and biology and Watson and Crick’s development of genetic code as being prominent starting points in the development of scientific knowledge. “Now we have the chance for the fourth synthesis with perennials on the horizon – ecology and agriculture coming together for crop and for grain agriculture.”
Jackson hopes that perennial plants will combine agriculture and ecology to ultimately create more sustainable systems.
“There is a reservoir of knowledge that has been paid for and put on the shelf. We know how these systems work,” said Jackson.
Do You Know DON?Written by Jeremiah Vardiman
No, we are not talking about your neighbor or relative. DON is in reference to Fusarium Head Blight, also known as scab or DON, which is a fungal disease that significantly effects wheat and barley crops. This could be a potential concern to Wyoming’s farmers, who produced 4.75 million bushels of wheat and 6.74 million bushels of barley in 2014.
This fungus attacks the grain of the crop causing yield loss, low test weights, low seed germination and mycotoxin contaminated grain, which results in lost revenues for farmers and potential rejection of the harvested grain at elevators. The main identifying symptom for this disease is bleaching of some florets in the crop’s head prior to maturity, while severe infections can cause premature bleaching of the entire head. Infected kernels often have pink- or orange-colored mold on them and are often shriveled, white and chalky in appearance.
The disease is caused by several species of fungi from the group known as Fusarium, hence the name. Fusarium graminearum is the most common. This disease can be introduced into fields by spores blown in by the wind or contaminated seed. Like most fungi, Fusarium Head Blight thrives in warm moist conditions that can be caused through rain, irrigation, fog and/or long, evening dew events. Therefore, this disease is more prevalent in irrigated fields than dryland. However dryland fields can become infected if climatic events line up correctly.
Once established in a portion of the field, Fusarium Head Blight spreads rapidly throughout the area by wind and splashing water. The most susceptible portion of the wheat and barley plant is the head, particularly when the crop is flowering. After the growing season, the fungus overwinters on crop residue and can re-infect the following wheat or barley crop. It should also be noted that Fusarium Head Blight can also persist and colonize corn and other grass crops such as forage grasses.
Preventing and reducing disease
What can be done to prevent or reduce this disease?
First of all, if there is no history of scab in your fields, neighbor’s fields or county, then the chances of infection are extremely low, and Fusarium Head Blight is probably not a huge concern.
If there is a concern of potential infection, following an integrated pest management (IPM) or multifaceted approach is highly recommended.
Typically the first recommendation for IPM would be to use resistant varieties. Currently there are several spring wheat varieties that are tolerant, though there are no tolerant or resistant barley or winter wheat varieties.
The next management implementation is crop rotation, which breaks the cycle of the disease and declines the fungi population that causes reinfection, especially if a legume crop or broadleaf crop is rotated between grain crops. Research has proven that Fusarium Head Blight infection is two times higher when wheat is planted into wheat stubble than when wheat is planted into soybean stubble.
Research has also revealed that infections to wheat and barley are five to 10 times higher when planted after a corn crop. Wheat or barley crops are also at risk if they are planted adjacent to last year's infected fields.
The next management strategy to implement would be the removal of the grain crop residue. Unfortunately this disease is benefited by soil health practices of residue retention through no till, minimum till and strip till because the residue allows the disease to persist in the environment until the next host crop, whether that be wheat, barley, corn or grasses, can be infected.
Montana’s 2015 malt barley crop saw fairly high infections of fields that were planted after corn. The practice almost guaranteed infection of barley directly planted into corn stubble under a no-till system. Effective means for handling crop residue are burning, burying or complete removal.
Irrigation management can also be used to decrease the potential risk of scab infection.
If possible, time irrigation to prior to and after flowering of the crop. This practice provides adequate water to the crop while leaving a dry microclimate in the crop canopy that is less favorable to the fungi.
Though not necessarily an option to all farmers, it is worth noting that furrow or flood irrigation can provide a slightly drier crop canopy than pivot or areal irrigation and typically does not spread the disease through the splashing of water droplets on infected crop material.
If the prior management practices fail to prevent an infection and an infection is found early enough, then a fungicide is the last option. Fungicides only suppress the disease. They do not kill or eliminate it.
For fungicides to be effective at suppressing the disease, application timing is crucial and should occur at the first sign of anthers extruding from the wheat head or directly prior to barley head emergence. Fungicide products are locally systemic, meaning they only protect the tissue they are applied to and not the entire plant.
The most effective fungicides provide about 50 percent control compared to untreated crops, so do not base full management plan on chemical control.
In summary, if there is no history of this disease in your area, Fusarium Head Blight is probably not a large concern. However, if there is a history, then this disease is controllable with sound management practices.
Fusarium Head Blight needs warm humid conditions during flowering to favor an infection and production. Rotating crops from cereal crops to non-cereal crops will aid in breaking the disease’s life cycle. Removal of cereal crop residue will further aid in breaking the disease’s life cycle. Planting barley or wheat after corn, especially into corn stubble, greatly increases the risk of infection.
Fungicides only suppress the spread and impact of the disease on the crop. It does not kill the fungus.
For more information please contact your local Extension office or industry representative.
Sustainable soils: Land Institute president speaksWritten by Saige
Powell – On Oct. 4, Wes Jackson, President of the Land Institute in Salina, Kans., spoke to a group of nearly 100 Northwest College (NWC) students, faculty and staff and Big Horn Basin producers and community members in an update on his work at the Land Institute.
Jackson was invited to speak as a featured author in the Northwest College Writes Series this year and was noted by the group as being “a leader in the international movement for sustainable agriculture.”
Jackson founded the Land Institute in 1976, saying that he wanted the chance to get students thinking and discussing the problems that were facing agriculture and the world.
“Originally we were devoted to a search for sustainable alternatives in agriculture and energy,” said Jackson. “We focus more on the agriculture part of it by now.”
The Land Institute focuses on improving food security by improving soil quality, reducing reliance on fossil fuels and moving away from chemical contamination of the land and water.
Jackson began the presentation by explaining that, because we are carbon-based creatures, humans constantly seek energy-rich carbon sources, which comes from four main pools, or sources.
“When we started in agriculture, humans used carbon at a rate faster than its natural renewal in the soil,” said Jackson. “With the opening of the North American continent, soils had about six percent carbon. Now they are about three percent, and it takes a long time to build back another one percent.”
Following soil use, humans began to harvest forests and grains, then natural gas, and finally other fossil fuels, such as coal and oil.
Jackson likens human population growth and the intense use of carbon sources to bacteria utilizing a sugar source on a petri dish.
“We developed an economic system for getting to the edge of the petri dish fast,” said Jackson. “It’s called the growth economy. We are collectively moving toward the edge of the petri dish to get at the energy rich carbon.”
Jackson emphasized that it is our lack of focus on maintaining soils that is a contributing factor in exhausting resources.
“Why do we not hear much about soil?” asked Jackson, pointing out that soil provides a major carbon reservoir. Additionally, Jackson provided the native grasslands and forests across the world as an example for what agriculture should attempt to mimic.
“Looking at the prairie, there is a system that runs on sunlight, no fossil fuels, no fertilizer and no pesticide inputs – that is a system supporting livestock and running on contemporary sunlight,” said Jackson. “Meanwhile, there is a wheat field, dependent on fossil fuels, with soil erosion and chemicals. We have a system that is degrading the ecological capitol of the soil.”
Because wheat and other annual crops and grains, such as soybeans, sunflowers, sorghum, rice and corn, make up the majority of our diet, the Land Institute is looking to breed perennial varieties of these plants.
By utilizing perennial plants, rather than annuals, Jackson suggests that soils and ecosystems would be able to maintain themselves more easily.
“The plant puts down a root, and that root is an investment for years to come,” explained Jackson. “It doesn’t have to rebuild the root each year.”
In photos presented, Jackson pointed out the longer, more complex root systems of the perennial hybrid plants the Land Institute has developed, and their ability to sustain ecological disasters, such as drought, ultimately providing for the sustainability of the industry.
In an additional attempt to achieve sustainability of agriculture, Jackson has also suggested a 50-year Farm Bill to help reach goals for soil sustainability and conservation, as well as nitrogen management and water use. Under his 50-year proposed plan, Jackson still advocates for five-year Farm Bills, but only to provide intermediate goals for the longer plan.
“Export policy, commodities, subsidies, some soil conservation measures and the food programs should be in the five-year Farm Bill,” said Jackson. “The 50-year Farm Bill protects soil from erosion, cuts wasteful use of water, cuts fossil fuel dependence, eliminates toxics, looks at careful nitrogen management, and reduces the dead zones to restore the agrarian way of life.”
Jackson’s plan specifically looks at doubling fruit and nut acreage as well as vegetable acreage over the next 50 years. Additionally, he wants to reduce the percentage of land consumed by annual grains from 80 percent to only 20 percent annual grains. The remaining acreage would consist of perennial grain and dual-purpose crops, as well as an increase in hay or forage acres.
“Currently, 80 percent of our land is devoted to annuals and only 20 percent to perennials,” explains Jackson. “We want to reverse that to only 20 percent devoted to annuals. Our perennials can be grazed and you still get grain.”
“When 80 percent of the cropland is protected by perennials, you would have a few annual grains, but there are lots of benefits,” said Jackson. “There is permanent vegetation in balanced, rural and community health and chemical health in the soils.”
Jackson continued, explaining that current agricultural systems are out of phase with nature and will remain out of phase as long as there is a focus on annual production and dependence of fossil fuels.
While hunter-gatherer societies and pre-industrial agriculture are most closely related to nature, Jackson says people will not willfully go back to either of those systems.
“We cannot get completely in phase with nature, but we can do better,” explains Jackson. “We are pretty close, with perennials on the horizon.”
Ultimately, the Land Institute is searching for a way to improve the health of the soils of the world to ensure the survival of the human species, and their research toward perennial grains is the avenue they believe will accomplish that goal.
“If we miss the opportunity to save our soils by embracing ecosystems as a conceptual tool, that going to be a very bad thing,” said Jackson. “And this is the time to do it.”