URBANA, Ill. - Watching for the first blooms of spring has always been one of the most highly anticipated activities for nature and plant lovers. But keeping records of events in nature such as bloom time is actually an important scientific endeavor, says University of Illinois Extension horticulture educator Alicia Kallal.
This record keeping aids the study of the timing of biological events, known as phenology, such as flowering or migration, in relation to seasonal or climate changes.
“While phenology is one of the oldest environmental sciences that humans have studied, recent interest in understanding how plants and animals are responding to changes in our climate and weather patterns has reinvigorated this branch of science,” says Kallal.
One of the most prominent American figures to study phenology was Aldo Leopold (1887-1948). His collection of essays on phenology, conservation, and land ethics, “A Sand County Almanac,” was published after his death in 1949.
His writings beautifully illustrate the importance of keeping records of the events in nature to expand our understanding of the plants, animals, and ecosystems that surround us.
Another even earlier figure in the history of plant phenology was Robert Marsham (1708-1797).
Marsham was a wealthy land owner in England, who in 1736, began meticulously recording seasonal weather changes, tree foliation, bird migration, first sightings of butterflies and swallows, and flowering dates of several plant species.
Each year, until his death in 1797, he tracked the same phenological events.
He reported this work to The Royal Society of London in 1789 as his 27 “Indications of Spring.”
“Marsham can be considered one of the first citizen scientists in history,” Kallal says. “Citizen science projects allow average people to make observations in nature, as Marsham did, and report their observations to a larger network that will make their data available to researchers and the general public.”
One example of a flourishing, modern-day citizen science network is Project BudBurst.
Project BudBurst began its mission in 2007 at the Chicago Botanic Garden. The goal of the project was to get people involved in nature and environmental science by having them observe the seasonal life events of plants.
Now participants across the country are making careful observations of the timing of important plant life stages throughout the year and reporting their data to Project BudBurst.
These life stages, called phenophases, include leafing out, flowering, and fruit set.
Participants can choose to make single observations to report the stage of a plant on a particular date, or observe a specific plant for multiple seasons to report when it goes through each phenophase.
Choosing plants to observe is easy; the site has a list of over 250 plants that can be sorted by the state you live in or by plant category, such as a grass, wildflower, or deciduous tree.
The list includes common species such as maple trees, dandelions, and forsythias, as well as native plants like little bluestem and red columbine.
“Project BudBurst is a very accessible way to get involved in citizen science,” Kallal says. “It is great for individuals or classes of school children. The site has wonderful resources for educators that want to get youth outside and give them the experience of making scientific observations.”
To learn more about Project BudBurst, visit their website: budburst.org.
“If you are concerned about invasive plants, and plant phenology has piqued your interest, you may also consider contributing observations to the Illinois Invasive Plant Phenology Report,” Kallal adds.
The University of Illinois Extension Forestry Program relies on observations from volunteers to produce the monthly invasive plant phenology report. Anyone interested in becoming a volunteer observer should contact Chris Evans, Extension forester at 618-695-3383 or firstname.lastname@example.org. Volunteers are asked to make monthly observations on three to four invasive species in their area.
To explore other citizen science projects in Illinois and across the nation, visit the University of Illinois Library’s citizen science guide http://guides.library.illinois.edu/citizen-science/find-a-project.
Study shows increase in SNAP benefits could move families from food insecure to food secure
URBANA, Ill. – Since its inception in 1964, the Supplemental Nutrition Assistance Program (SNAP), formerly known as food stamps, has been the most important tool to reduce food insecurity in the United States. For many SNAP households, however, benefits are too low to ensure food security, according to a University of Illinois economist.
A recent study published in the Russell Sage Foundation Journal of Social Sciences looks at how much additional income in SNAP benefits would be needed in order for households to become food secure. Craig Gundersen, a professor in the U of I Department of Agricultural and Consumer Economics and lead author of the paper, says this specific aspect of SNAP has not been addressed. The study identifies potential scenarios to increase SNAP benefits that could decrease food insecurity, and what it would cost to implement additional benefits.
“There’s so much talk lately about cutting back on SNAP or changing it in some way, but SNAP, I believe, is the most successful government program we have,” Gundersen says. “Instead of cutting back or making changes to the program, let’s talk about how we could really make it better.”
In the study, Gundersen and colleagues focused on eligible SNAP recipients. The group was broken down into all households or households without children. They then measured the resource gap—the difference between the resources a household has and what they would need to be food secure—using data from the 2014 Current Population Survey (CPS).
As part of the CPS, households self-reported on how much additional money they would need to have enough food. According to the study, the average resource gap for all households among SNAP recipients was calculated at $41.62 per week.
The study also considered households that were ineligible for SNAP—those falling between 130 and 185 percent of the poverty line. Researchers reported that the average resource gap for SNAP-ineligible households was $30.91 per week.
Under their most plausible scenario—to increase SNAP benefits, for all households by the same amount—there would be an over 60 percent reduction in food insecurity. This would cost the federal government around $20 billion.
Gundersen believes that expanding benefits can make a big difference for recipients in the SNAP program.
“SNAP sets out to alleviate food insecurity and it does so. Part of the reason it works so well is it gives low-income families the dignity and autonomy to make their own decisions,” Gundersen adds. “There’s really no better way to reduce food insecurity in the United States than through SNAP.
“It’s so direct—we’re giving people money that they can spend on food, which would really have a huge impact,” he adds. “And, increasing their benefit levels would lead to an even larger impact of SNAP.”
The study, “Reconstructing the supplemental nutrition assistance program to more effectively alleviate food insecurity in the United States,” is published in The Russell Sage Foundation of the Social Sciences. Co-authors include Craig Gundersen, Brent Kreider, and John V. Pepper.
Gundersen is a professor in the Department of Agricultural and Consumer Economics in the College of Agricultural, Consumer and Environmental Sciences at the University of Illinois. He is the Soybean Industry Endowed Professor in Agricultural Strategy.
Study says Mekong River dams could disrupt lives, environment
URBANA, Ill. – The Mekong River, one of the world’s largest, traverses six Southeast Asian countries and supports the livelihoods of millions of people. New efforts to provide hydroelectric power to a growing and modernizing population include more than eight proposed main-stem dams and 60 or more existing tributary dams in the lower Mekong basin. A new article from University of Illinois and Iowa State University scientists lays out what dam construction could mean for residents and the environment in the region.
“Development projects, such as dam construction on the Mekong River and tributaries to support a booming hydropower industry, are bringing great change to ecological, agricultural, and cultural systems in this region,” says Kenneth Olson, professor emeritus in the Department of Natural Resources and Environmental Sciences at U of I and co-author of the article.
In the article, Olson and co-author Lois Wright Morton provide the context of this unique coupled natural-human river system – its hydrology, geology, ecology, seasonal flood cycle, and human dimensions. They also delve into the politics and the potential effects of the dams, focusing specifically on the Xayaburi Dam in Laos.
Olson and Morton report that construction on the Xayaburi Dam, the first dam south of the China border to be constructed across the main stem of the Mekong River, has been quietly underway for years and is scheduled for completion in 2018. The dam has incited worldwide opposition, as well as local protests and violence.
“Many are concerned that the Xayaburi Hydropower Dam in Laos, could cause irreversible and long-term ecological damage to a river that feeds millions of people, force the resettlement of 2,100, directly affect 202,000 people who use the Mekong bottomlands to produce food, and may push endangered fish, such as Mekong giant catfish, to extinction,” Olson says.
Morton, professor emeritus in the Department of Sociology at Iowa State, adds, “The Mekong River and adjacent lands are where the poorest people in Southeast Asia live. Average annual income is less than $200. They make their living from floodplain and riverbank agriculture and fishing. Laos is a mountainous country and the fertile soils are in the floodplains, many of which will be permanently flooded with the construction of these large dams.
“Resettling rural people in uplands means the soils are different, often less fertile and not well suited to rice and vegetable crops they are familiar with. They will need to learn new agricultural practices, different fishing strategies [river vs. lake] and make or purchase different fishing equipment. This kind of change takes time and personal resources that people often don’t have,” she says.
Olson points out that the dams also affect the seasonal pulse of the river, change fish diversity and abundance, and impact downstream water flows and availability. “Further, dams trap sediment needed as a nutrient source for fish, block fish migration, and reduce the amount of sediment deposited in the Mekong Delta,” he says. “Lower Mekong River levels have accelerated saltwater intrusion into the delta region, adversely affecting rice production, and have contributed to ground water pollution.”
The Mekong River Commission was established in 1995 by Laos, Cambodia, Thailand, and Vietnam to coordinate competing interests and assure the river is protected for current and future uses. However the commission is often set back by government roadblocks and receives limited support from two adjacent upstream countries, China and Myanmar, who also use the Mekong.
“The MRC is only powerful if the countries that fund it give respect and authority to its rules and regulations, even if they don’t always agree with them. This is a difficult governance challenge which they are working through,” Morton says.
Ultimately, the Mekong River presents a huge opportunity for hydropower to modernize Laos, but Olson and Morton argue human and environmental concerns are at risk. They advocate for governments in Southeast Asia to empower the MRC to carry out its mission to mitigate the negative impacts of dam building while realizing the benefits.
The article, “Water rights and fights: Lao dams on the Mekong River,” is published in the Journal of Soil and Water Conservation. Financial support for the project was provided by the U of I College of Agricultural, Consumer and Environmental Sciences and the College of Agriculture and Life Sciences at Iowa State.
ACES Twitter chat March 13: Personal Finance for You
Why should I write financial goals? And, how do I get started?
What are the benefits of saving money?
Is it better to pay down debt or invest my money?
What are the advantages of investing while a young adult instead of waiting until I’m in my 50s?
A financial plan guides and empowers people to reach their goals. Financial planning includes setting goals, managing your money wisely, establishing a solid financial foundation, and investing for the future. Create a financial plan and allow time to be on your side! Join us March 13, from noon to 1 p.m. CT on Twitter for a chat with Department of Agricultural and Consumer Economics expert Dr. Craig Lemoine and University of Illinois Extension expert Kathy Sweedler to ask your questions about financial planning and money management using #askACES.
How can you take part in this exciting conversation?
- Go to Twitter. Type in #askACES. Click the “Latest” tab. Watch the questions and answers from noon-1 p.m. CT.
- Ask your own questions and contribute to this conversation by including #askACES with your question.
If you aren’t on Twitter, watch the live feed at http://research.aces.illinois.edu/askACES.
If you have a question, but can’t participate in the live chat, send it to email@example.com.
- Watch ACES social media (Twitter and Facebook) for a follow-up podcast with Craig Lemoine and Kathy Sweedler.
Don’t miss the discussion on March 13. Your questions are important to us as we tackle this impactful topic.
The College of ACES is excited to host this series of chats - #askACES - on Twitter addressing some of the hot topics in social media today. Recently, we’ve discussed a variety of topics from water quality with Dr. Laura Christianson, Dr. Paul Davidson and Jonathan Coppess to nutrition labeling with Dr. Brenna Ellison, Dr. Anna Arthur, and Dr. Jennifer McCaffrey. Our goal is to distribute sound science on social media and provide the public an opportunity to engage in a conversation and ask their questions about these topics. We would love to have you join us on Twitter for these chats and contribute to the conversation. Or, listen to the follow-up podcasts at http://research.aces.illinois.edu/askACES.
News Source:ACES Staff
Starting seeds at home
URBANA, Ill. – As we get closer to spring, many people will begin starting seeds for their gardens. “If you’ve never started your own seeds before, there are several advantages to doing so,” says University of Illinois Extension horticulture educator Ken Johnson.
“You tend to get better germination rates when starting seeds indoors because you are providing them with ideal conditions,” said Johnson. “They also won’t have competition from other plants, and there should be fewer insect and disease problems.”
Starting seeds to make your own transplants can also be cheaper than going out and buying them later in the year. You also have a lot more variety to choose from when you start your own seeds compared to buying transplants from the store—hundreds as opposed to a handful when it comes to popular plants like tomatoes.
According to Johnson, starting seeds isn’t very difficult to do. “There are just a few things you need in order to get started: your desired seed, a container to start them in, some growing media, water, and light.”
When selecting a growing medium, use a seed-starting mix, not garden soil.
“Garden soil is going to have weed seeds and possibly diseases in it, as well as being very dense and heavy,” Johnson says. “That means it won’t drain as well as seed-starting or potting soil.”
Seed-staring mix is sterile and usually is made from milled peat moss, perlite, coconut coir, and vermiculite. This combination provides a light, fine-textured medium that is ideal for starting seeds.
When it comes to your container, there are a variety of different options, including plastic sheets of small containers (cell flats), plastic pots, peat pots, egg shells, toilet paper tubes, and egg cartons. Whatever you choose, make sure the container can hold your potting medium and has drainage holes to allow excess moisture to drain away.
Several options are also available when it comes to lighting. “Fluorescent grow-lights are often used, but you can use regular fluorescent bulbs, a desk lamp, or even a windowsill,” Johnson says. “If you decide to start your seeds on a windowsill, make sure it has good southern exposure and isn’t drafty.”
Once you’ve selected the seeds you want to grow, take a look at the back of the package. It should tell you when the seeds should be sown, or planted, generally a certain number of weeks before the last frost. It may also tell you how deep the seeds need to be planted.
Once you’ve gathered all of you supplies, it’s time to plant some seeds.
- Fill your desired container with your seed-starting mix. “It’s often easier to wet media before filling the containers,” Johnson says. Make sure the media is settled, and there aren’t large air pockets in the container.
- Make an indentation in the seed-starting mix to the recommended depth. Place two to three seeds inside this indentation and cover. Press the seed-starting mix down to make sure there is good contact with the seeds.
- Gently mist the seed-starting mix with water.
- The container can then be covered with plastic to help retain moisture and warmth. Remove the plastic to spray the container if the media dries out. If uncovered, you will need to water more frequently. Once the seeds begin to germinate, remove the plastic cover.
- Johnson says, “If you are starting seeds in a cool area, it may be a good idea to get a heat mat that is specifically made for starting seeds, so that the seeds will properly germinate. It will also help to prevent disease problems.”
As your seedlings grow, keep your lights three inches above the tallest plant – higher if using incandescent bulbs – and provide them with 12 to 16 hours of light a day. “It may be a good idea to get the Christmas light timer back out so you don’t have to worry about remembering to turn lights on and off,” says Johnson.
Water media as needed, making sure it remains moist. Once the seedlings produce their first true leaves, you can water with a weak fertilizer. “Once it’s time to take your plants outdoors,” Johnson says, “make sure to harden them off before you put them in their permanent home.”
Early-killed rye shows promise in edamame
URBANA, Ill. – With the rise of herbicide-resistant weeds in most grain and vegetable crops, farmers are looking for alternatives to herbicides to control weeds. Cover crops offer one potential weed management tool. Their use in specialty crops is limited, and no testing has been done so far in edamame. However, a new University of Illinois study reports that early-killed cereal rye shows promise for edamame growers.
“Early-killed rye reduced weed density by 20 percent and suppressed early-season weed growth 85 percent,” says Marty Williams, an ecologist with the Department of Crop Sciences at U of I and the USDA Agricultural Research Service.
Edamame is notoriously hard to get started. The soybean variety’s large seeds make them good for eating – edamame seeds are consumed at an immature stage, when they’re firm and green – but the crop can suffer from low seedling emergence in the field. Williams wasn’t sure that asking them to struggle through a layer of cover crop residue would work.
“The question was: Can we find a cover crop management system that provides some amount of weed suppression without causing a problem for the crop? Edamame is far more sensitive to soil conditions during emergence than grain-type soybean,” he says.
Williams and his research team conducted a three-year field experiment testing 11 edamame cultivars and multiple fall-seeded cover crops: oilseed radish, winter canola, and cereal rye. Radish was killed by winter temperatures, and the researchers applied early (April) or late (May) burndown herbicide treatments to kill canola and rye at different growth stages. For all of the cover crop types, the researchers were looking for edamame emergence and weed suppression.
Only early-killed rye offered the right combination of conditions to suppress weeds and allow edamame to emerge easily. Others allowed emergence but didn’t control weeds, or suppressed both weeds and edamame.
“Early-killed rye resulted in a relatively thin layer of cover crop residue. With thicker layers of residue, you start to have problems with crop emergence. But with no cover crop residue, there’s no weed control benefit. Early-killed rye provided the sweet spot,” Williams says.
Williams acknowledges that early-killed rye alone won’t be a silver bullet for weed control in edamame. “Clearly, this work doesn’t mean we can grow edamame without other weed management tools. Cover crops are just one of many little hammers. By reducing weed density and weed growth, we know we’re headed the right direction.”
The article, “An early-killed rye (Secale cereale) cover crop has potential for weed management in edamame (Glycine max),” is published in Weed Science. Williams’ co-authors include Laura Crawford and Sam Wortman, both affiliated with U of I at the time of the study. The work was supported by the USDA Agricultural Research Service.
Backyard grapes for Illinois
URBANA, Ill. – Grape vines are a beautiful feature for your landscape that provide both aesthetic and edible benefits, says a University of Illinois Extension horticulture educator.
“Fresh-picked-from-the-vine grapes are delicious,” says Bruce J. Black. “The work you put into growing your grapes definitely pays off during harvest.”
Grapes can be grown in Illinois if you choose a variety that is hardy enough to survive the cold winter temperatures. According to the U.S. Department of Agriculture’s Hardiness Zone Map, Illinois has spans zones 5a through 6b. In addition to selecting for cold hardiness, select varieties for flavor, sugar content, use, maturity, and disease resistance. “This could be difficult if you are set on a certain cultivar taste, such as a French variety,” Black says.
Two categories of grapes are cold hardy for Illinois: American and French-American varieties. American varieties (Concord, Catawba, Niagara, etc.) have the most cold hardiness and better disease resistance than French-American or French varieties. French-American varieties (Edelweiss, Frontenac, St. Croix, etc.) are French varieties of grapes on American rootstocks. American rootstocks allow for increased disease resistance and increased cold hardiness.
Begin your preparations for the soil the year before by removing sod and cultivating the soil in a full-sun location. Test the soil to make sure that the pH is 5.5 to 6.5 with 2 to 3 percent organic matter. After soil preparation is complete, begin building your trellis. Many variations of trellises are available, and the type you choose can depend on your cultivar. Grapes need to be spaced 8 feet apart in the row and rows should be at least 10 feet apart. At planting, secure plants to the trellis wire and wrap them with chicken wire to prevent deer from eating the leaves.
Pruning is key to well-developed grape clusters. Prune grape vines after the first year of growth, generally between February and early March, while it’s still cold but before buds swell. Sunlight exposure to the core of the grapevine helps to produce sugars and allows airflow to prevent disease. On average, pruning should remove 80 to 90 percent of the previous year’s growth.
“This helps to eliminate dead or dying parts of the plant that could be a source of disease,” Black says. “Removal of this much of the plant can be alarming for some gardeners, but we are removing a lot of foliage annually to help provide a strong and lasting trunk for longer productivity through the years.
“The first five years of establishment are critical for a long, productive life for your grapevines,” Black says.
For more information on grape varieties and production, check out the University of Illinois Extension’s “Small Fruit Crops for The Backyard” at extension.illinois.edu/fruit/grapes.cfm?section=small or University of Minnesota Extension’s “How to Train Young Grape Vines” at https://www.extension.umn.edu/garden/fruit-vegetable/grape-training-young-vines/index.html.
From property damage to lost production and beyond: How natural disasters impact economics
URBANA, Ill. – When a natural disaster strikes, major disaster databases tend to compile information about losses such as damages to property or cost of repairs, but other economic impacts after the disaster are often overlooked—such as how a company’s lost ability to produce products may affect the entire supply-chain within the affected region and in other regions.
Without using the right model to study these losses, the data may give an incomplete picture of the full financial impact of the disaster as it doesn’t fully portray business interruptions incurred locally, or by trade partners, after the event. As a result, a locality may receive less than it should in state or federal government recovery support.
In a recent study, published in Earth System Dynamics, an interdisciplinary journal devoted to the study of Earth and global change, economists at the University of Illinois partnered with atmospheric scientists and hydrologists from U of I and UCLA, and with the Army Corps of Engineers to capture the characteristics of an atmospheric river—a transporter of water vapor in the sky—that hit the western part of Washington State in 2007. This event resulted in record flooding (a 500-year stream peak event in some parts of the river) and record damages.
The team hopes to show that carefully selecting the characteristics of the extreme weather event under study and the correct model to estimate losses—based on characteristics of the disaster and the affected region, and on the interdependence between one area and another—can help in determining vulnerability and preparing for future disasters, from an economic standpoint.
“This is quite different from what insurance companies do,” explains Sandy Dall’Erba, an associate professor in the Department of Agricultural and Consumer Economics at U of I, and a co-author of the study. “After a disaster, when an insurance company comes, they basically say that your building has been destroyed by this particular amount. And because you were out of the building for, say, a week, you couldn’t produce anything for a week. What insurance companies forget, and what our paper is trying to demonstrate is that the total amount of economic losses is much greater.”
The ripple effects from a disaster can be significant if major industrial chains are disrupted when infrastructure is comprised. For instance, while the study finds that intersectoral and interregional linkages add up to around 10 percent in standard economic damage estimates in the small rural area chosen in this study, that share could go up to 50-70 percent for a major metropolitan area like Houston, Texas, because of its enormous transportation system and interregional trade.
“Let’s say for instance that a company producing tires is flooded. Obviously, no tires are coming from that company,” Dall’Erba explains. “The car company, which could be located in a place that wasn’t flooded, suddenly is expecting a delay in the tires that are not coming on time anymore. There are all of these connections from one city to the next that are traditionally not accounted for after a disaster.”
In his U of I lab, the Regional Economic Applications Laboratory (REAL), Dall’Erba studies very specific disaster events using a technique called input-output—a technique that shows the interdependencies between the sectors within a region and across different regions. He also teaches this technique in his home department (ACE) on a regular basis.
“We look at each industry. What kind of products and services do they buy? To whom do they sell their goods and services? In the case of Chehalis, Washington, that was flooded in 2007, it was mainly companies selling to other companies, not to individual households. Those are the kinds of links that we try to include in the work we do in REAL, how to understand that level of dependence between one location and other places. We also provide measurements that are very specific to each locality,” Dall’Erba says.
Using the input-output technique helped the researchers calculate the actual losses after the event in Chehalis. “We rely on a huge amount of data to do it. We have information from each locality about how each industry is connected to every industry within that locality and outside of that locality so we can understand how dollars flow,” he adds.
In addition, they must account for the timing of the event. “While the affected area is very agricultural, the luck it had is that the flood took place in December, way ahead of the growing season of the crop the locality depends the most on, corn. If it had taken place a few months later, the local economy would have experienced much larger losses,” Dall’Erba says.
Finally, Dall’Erba’s team is particularly careful to account for the location of the companies in charge of reconstruction. “Most of the literature assumes without evidence that reconstruction will dampen the local losses and boost employment. It turns out that for small rural communities—like the one in our study—no local construction company is present or is large enough to be in charge of reconstruction. As such, reconstruction efforts are delivered by companies outside of the affected economy and it is these other localities that see an increase in output and construction jobs,” Dall’Erba adds.
The latter part of their study focuses on the future. Assuming that climate change will result in 15 percent more streamflow (water from rivers or streams) for all return periods, the authors find that the total losses would increase from $6.2 million, the figure seen during the actual event, to $8.6 million (a 39 percent increase).
“Adaptation strategies could include, among others, larger floodplains in upstream locations, levees close to critical buildings, and/or developing a more resilient supply-chain,” Dall’Erba says. “However it is particularly hard for small rural communities as they do not always have the budget necessary to implement large adaptation projects; yet they have already been more frequently affected by floods than urban areas over the last few decades.”
The study, “Tracking an Atmospheric River in a Warmer Climate: from Water Vapor to Economic Impacts,” is published in Earth System Dynamics (impact factor = 4.15). Co-authors include Francina Dominguez, Sandy Dall’Erba, Shuyi Huang, Andre Avelino, Ali Mehran, Huancui Hu, Arthur Schmidt, Lawrence Schick, and Dennis Lettenmaier.
Dall’Erba is an associate professor in the Department of Agricultural and Consumer Economics in the College of Agricultural, Consumer and Environmental Sciences at the University of Illinois. Since 2016, he has served as the Director of the Regional Economic Applications Laboratory at the U of I.
Funding for the study was provided by the National Aeronautics and Space Administration (NASA).
Scientists engineer crops to conserve water, resist drought
URBANA, Ill. – Agriculture already monopolizes 90 percent of global freshwater—yet production still needs to dramatically increase to feed and fuel this century’s growing population. For the first time, scientists have improved how a crop uses water by 25 percent without compromising yield by altering the expression of one gene that is found in all plants, as reported in Nature Communications.
The research is part of the international research project Realizing Increased Photosynthetic Efficiency (RIPE) that is supported by Bill & Melinda Gates Foundation, the Foundation for Food and Agriculture Research, and the U.K. Department for International Development.
“This is a major breakthrough,” said RIPE Director Stephen Long, Ikenberry Endowed Chair of Plant Biology and Crop Sciences. “Crop yields have steadily improved over the past 60 years, but the amount of water required to produce one ton of grain remains unchanged—which led most to assume that this factor could not change. Proving that our theory works in practice should open the door to much more research and development to achieve this all-important goal for the future.”
The international team increased the levels of a photosynthetic protein (PsbS) to conserve water by tricking plants into partially closing their stomata, the microscopic pores in the leaf that allow water to escape. Stomata are the gatekeepers to plants: When open, carbon dioxide enters the plant to fuel photosynthesis, but water is allowed to escape through the process of transpiration.
“These plants had more water than they needed, but that won’t always be the case,” said co-first author Katarzyna Glowacka, a postdoctoral researcher who led this research at the Carl R. Woese Institute for Genomic Biology (IGB). “When water is limited, these modified plants will grow faster and yield more—they will pay less of a penalty than their non-modified counterparts.”
The team improved the plant’s water-use-efficiency—the ratio of carbon dioxide entering the plant to water escaping—by 25 percent without significantly sacrificing photosynthesis or yield in real-world field trials. The carbon dioxide concentration in our atmosphere has increased by 25 percent in just the past 70 years, allowing the plant to amass enough carbon dioxide without fully opening its stomata.
“Evolution has not kept pace with this rapid change, so scientists have given it a helping hand,” said Long, who is also a professor of crop sciences at Lancaster University.
Four factors can trigger stomata to open and close: humidity, carbon dioxide levels in the plant, the quality of light, and the quantity of light. This study is the first report of hacking stomatal responses to the quantity of light.
PsbS is a key part of a signaling pathway in the plant that relays information about the quantity of light. By increasing PsbS, the signal says there is not enough light energy for the plant to photosynthesize, which triggers the stomata to close since carbon dioxide is not needed to fuel photosynthesis.
This research complements previous work, published in Science, which showed that increasing PsbS and two other proteins can improve photosynthesis and increase productivity by as much as 20 percent. Now the team plans to combine the gains from these two studies to improve production and water-use by balancing the expression of these three proteins.
For this study, the team tested their hypothesis using tobacco, a model crop that is easier to modify and faster to test than other crops. Now they will apply their discoveries to improve the water-use-efficiency of food crops and test their efficacy in water-limited conditions.
“Making crop plants more water-use efficient is arguably the greatest challenge for current and future plant scientists,” said co-first author Johannes Kromdijk, a postdoctoral researcher at the IGB. “Our results show that increased PsbS expression allows crop plants to be more conservative with water use, which we think will help to better distribute available water resources over the duration of the growing season and keep the crop more productive during dry spells.”
The paper, “Photosystem II subunit S Overexpression Increases the Efficiency of Water Use in a Field-Grown Crop,” is published in Nature Communications. Co-authors also include Katherine Kucera, Jiayang Xie, Amanda Cavanagh, Lauriebeth Leonelli, Andrew Leakey, Donald Ort, and Krishna Niyogi.
Realizing Increased Photosynthetic Efficiency (RIPE) is engineering crops to more efficiently turn the sun’s energy into food to sustainably increase worldwide food productivity. The project is supported by the Bill & Melinda Gates Foundation, theFoundation for Food and Agriculture Research, and the U.K. Department for International Development.
RIPE is led by the University of Illinois in partnership with the University of Essex, Lancaster University, Australian National University, Chinese Academy of Sciences, Commonwealth Scientific and Industrial Research Organisation, University of California, Berkeley, and Louisiana State University, and USDA/ARS.
Start your vegetable garden early with cool season crops
URBANA, Ill. – After a long winter, gardeners are always eager to get outside again. “Get a head start on your vegetable garden by planting cool-season crops,” says Gemini Bhalsod, a University of Illinois Extension horticulture educator. “Cool spring weather favors vegetables like leafy greens, root vegetables, and members of the onion and cabbage family.”
Most cool-season vegetables, also known as “cold crops,” can withstand light frosts. Cool-season vegetables can be direct-seeded or transplanted outside much earlier than late summer favorites like tomatoes.
Bhalsod explains that these plants are more frost-tolerant than others because the cool weather triggers the plant to produce more sugars, which act as a natural antifreeze for plant tissues. When this happens, we also benefit by getting sweeter tasting produce.
So what plants are cold hardy? “First, we need to go over some definitions,” Bhalsod says. “’Hardy’ plants can withstand the coldest air and soil temperatures. These plants can be planted outside about four weeks before the frost-free date in your area. In some places, that is as early as April. ‘Hardy’ plants include spinach and kale.”
Frost-tolerant, or “half-hardy,” plants can tolerate cool temperatures and can be seeded outdoors in early May, or about two weeks before the predicted frost date in the spring. Frost –tolerant plants include cabbage, carrots, chard, and broccoli.
“Be aware that the frost date is location-based, so check with your local Extension office for specific dates,” Bhalsod suggests.
In general, root crops do not do well being transplanted and should be direct-seeded. Thin seedlings to three to four inches apart, but be sure to read your seed packet to learn your plants’ specific requirements. Thin seedlings when they are a few inches tall and enjoy them as microgreens, or wait until the leaves are bigger and eat the tops.
“With root vegetables, it is important to make sure your soil is loose and well-drained,” Bhalsod says. “This prevents root stunting and gives plants ample space to grow.”
Plants with a longer growing cycle should be started indoors about five weeks before planting outside. Harden plants off by gradually and progressively exposing them to outdoor conditions. This works well for crops like head lettuce, collards, kale, broccoli, cauliflower, and Brussels sprouts. Starting these plants indoors means earlier maturation and harvest.
Most cold crops have two “seasons” in a vegetable garden, one in spring and again in the fall. Avoiding the high temperatures and long days of summer is key. Long summer daylight causes salad greens, for example, to produce flowers and set seed, also called “bolting,” which results in a bitter tasting, unpleasant salad.
No matter what plants you decide to grow, do not forget to plan your garden to get the most out of your space. Stagger your planting times to increase your harvest period and consider intercropping different varieties or plants to maximize your production.
Visit the University of Illinois Extension, “Watch your Garden Grow” website at http://go.illinois.edu/veggies, for more information.