Sweet Corn Yield Varies According to Seed Company
A new analysis from the University of Illinois Urbana-Champaign and the USDA Agricultural Research Service (ARS), published in the journal Precision Agriculture, has identified the top factors accounting for yield variability in processing sweet corn (used for canned and frozen products). One factor in particular is within the control of farmers.
“We used a very robust approach to account for sweet corn yield with field-level data across some 16,000 fields and 27 years. Year and production region were the two most important variables, which makes logical sense. But the third was seed source: the company that developed the hybrids. That’s interesting because it’s actually something the industry has a choice over,” said senior study author Marty Williams.
The analysis drew from confidential industry data on 67 variables relating to crop genetics, management, weather and soil factors from fields in the Upper Midwest and Pacific Northwest, where most of the nation’s processing sweet corn is grown. The researchers used machine learning techniques to narrow down which of the dozens of factors correlated most strongly to yield across nearly 30 years.
Williams said the top two — year and production area — reflect big-picture environmental conditions affecting the crop over time and space. The third, seed company, came as a surprise because the researchers had only grouped hybrids into nine companies out of necessity. Without grouping the hundred-odd hybrids in some way, the already unwieldy dataset would have been even more challenging to analyze and impossible to interpret.
However, the million-dollar question doesn’t have a satisfying answer, as the analysis doesn’t differentiate or rank the seed companies. Williams said there is a reason for that outside the confidentiality agreement.
“We don’t know that every company’s hybrids were grown under conditions identical to their competitors,” Williams said. “One company may have higher yields, but it may also be that their hybrids were grown only in more favorable conditions. We know that processors prefer hybrids that perform well under all conditions, particularly less-than-ideal conditions. Still, it’s interesting that seed source linked highly to yield. We can’t say exactly why, but seed source is the one thing processors can choose.”
Another striking variable, ranking just below seed company, was high nighttime temperature. Warmer-than-usual nights increase respiration, which offsets gains made during daytime photosynthesis. According to the analysis, sweet corn yield starts taking a hit above 16 degrees Celsius (61 Fahrenheit). Field corn yield, by contrast, doesn’t start declining until nighttime temperatures exceed 21 C.
“Sweet corn is a shallower rooted crop. It’s a smaller plant, and it’s more delicate overall than field corn. So that makes some sense,” Williams said. “It could be concerning, because, at least in the Midwest, we are projected to have warmer nighttime temperatures. It’s a correlation, but it’s a concerning one.”
The same dataset already signaled sweet corn may be in trouble under a warming climate, but the current analysis gives Williams some hope, with at least one variable under processors’ control.
New Coating Can Protect Microbes for Seed Treatment
Bacteria that can convert nitrogen gas to ammonia provide nutrients that plants need, help regenerate soil, and protect plants from pests. Relying more on these bacteria to provide plants’ nutritional needs could also help reduce annual application of synthetically produced fertilizer, which has a large carbon footprint. However, these bacteria are sensitive to heat and humidity, so it’s difficult to scale up their manufacturing and ship them to farms.
To overcome that obstacle, MIT chemical engineers have devised a metal-organic coating that protects bacterial cells from damage without impeding their growth or function. In a new study, published in the Journal of the American Chemical Society Au, they found that these coated bacteria improved the germination rate of a variety of seeds, including vegetables such as corn and bok choy.
This coating could make it much easier for farmers to deploy microbes as fertilizers said Ariel Furst of MIT, the senior author of the study.
“We can protect them from the drying process, which would allow us to distribute them much more easily and with less cost because they’re a dried powder instead of in liquid,” Furst said. “They can also withstand heat up to 132 degrees Fahrenheit, which means that you wouldn’t have to use cold storage for these microbes.”
Chemical fertilizers are manufactured using an energy-intensive process known as Haber-Bosch, which uses extremely high pressures to combine nitrogen from the air with hydrogen to make ammonia.
In addition to the significant carbon footprint of this process, another drawback to chemical fertilizers is that long-term use eventually depletes the nutrients in the soil. Nitrogen-fixing bacteria, which convert nitrogen gas to ammonia, can aid in efforts to replenish the ground.
Some farmers have already begun deploying these “microbial fertilizers,” growing them in large onsite fermenters before applying them to the soil. However, this is cost-prohibitive for many farmers. And shipping these bacteria to rural areas is not currently a viable option because they are susceptible to heat damage. The microbes are also too delicate to survive the freeze-drying process that would make them easier to transport.
To protect the microbes from both heat and freeze-drying, Furst decided to apply a coating called a metal-phenol network (MPN), which she previously developed to encapsulate microbes for other uses, such as protecting therapeutic bacteria delivered to the digestive tract.
The coatings contain two components — a metal and an organic compound called a polyphenol — that can self-assemble into a protective shell. The metals used for the coatings, including iron, manganese, aluminum and zinc, are considered safe as food additives. Polyphenols, which are often found in plants, include molecules such as tannins and other antioxidants. The FDA classifies many of these polyphenols as GRAS (generally regarded as safe).
“We are using these natural food-grade compounds that are known to have benefits on their own, and then they form these little suits of armor that protect the microbes,” Furst says.
For this study, the researchers created 12 different MPNs and used them to encapsulate Pseudomonas chlororaphis, a nitrogen-fixing bacterium that also protects plants against harmful fungi and other pests. They found that all of the coatings protected the bacteria from temperatures up to 50 degrees Celsius (122 degrees Fahrenheit), and also from relative humidity up to 48 percent. The coatings also kept the microbes alive during the freeze-drying process.
Using microbes coated with the most effective MPN — a combination of manganese and a polyphenol called epigallocatechin gallate (EGCG) — the researchers tested their ability to help seeds germinate in a lab dish. They heated the coated microbes to 50 C before placing them in the dish and compared them to fresh uncoated microbes and freeze-dried uncoated microbes.
The researchers found that the coated microbes improved the seeds’ germination rate by 150 percent, compared to seeds treated with fresh, uncoated microbes. This result was consistent across several different types of seeds, including dill, corn, radishes and bok choy.
Furst has started a company called Seia Bio to commercialize the coated bacteria for large-scale use in regenerative agriculture. She hopes that the low cost of the manufacturing process will help make microbial fertilizers accessible to small-scale farmers who don’t have the fermenters needed to grow such microbes.
“When we think about developing technology, we need to intentionally design it to be inexpensive and accessible, and that’s what this technology is.”
People Care Somewhat about the Climate, More about Animals, but Most of All for Themselves
A team of researchers from the Department of Agricultural and Food Market Research at the University of Bonn have found that consumers surveyed in their study would rather pay more for salami with an “antibiotic-free” label than for salami with an “open barn” label that indicates that the product promotes animal welfare. The results were published in the journal Q Open.
The animal husbandry sector faces a complex set of challenges as a result of various competing interests. “Sustainability goals such as animal welfare, environmental protection and human health can quickly conflict with one another,” researcher Jeanette Klink-Lehmann said. Stricter standards in animal husbandry could have an impact on competitiveness because it is not always possible to compensate for increases in costs with higher consumer prices.
The researchers investigated consumer preferences for various sustainability goals. Their study focused on three main conflicts: between animal welfare and environmental protection, between human health and animal health, and finally between human health and animal welfare. Psychographic (e.g., the level of awareness for the environment, health and animal welfare) and sociodemographic factors (such as the sex and age of the participants) were taken into account in order to explain possible differences between the preferences expressed by consumers.
In the experiment, a daily trip to the supermarket was simulated and participants who had been given different levels of information on the products were asked to choose between two different salami products in three different scenarios, whereby the salami products each represented different sustainability goals. The willingness of consumers to pay for the chosen salami was analyzed in each case.
The researchers discovered that most people chose a salami with a sustainability label and were also willing to pay more for it. However, the participants were more willing to pay for a salami with the “antibiotic-free” label than for a salami with the “open barn” label. “The results show that personal health is more important to people than animal welfare,” Klink-Lehmann said. The study also demonstrated that animal welfare considerations were more important to people than environmental protection. Furthermore, the results demonstrate that people’s willingness to choose a more sustainable alternative is highly dependent on the price.
The researchers demonstrated that the extent to which information has an effect is dependent on which sustainability aspects are being considered and how the information is presented. “We were surprised to discover that if consumers were only provided with positive information, the willingness to pay more for ´open barn´ salami in comparison to the ‘no label’ salami increased, but this was not true for ‘antibiotic-free’ salami,” Klink-Lehmann said. The team interpreted this to mean that although consumers perceive the “antibiotic-free” animal product as being beneficial for their own health, this advantage is sufficiently communicated by the label itself, and additional information has no influence on consumer preferences. In contrast, the team believes that consumers might be less aware of the positive effects of “open barn” production on animal welfare. In this case, the positive information provided to consumers improved their level of knowledge and thus their willingness to pay more for salami with the “open barn” label.
To ensure full transparency, it is important to inform consumers not only about the benefits but also the potential disadvantages of a production method. “However, our results suggest that such a strategy comes at a price,” said Milan Tatic, a doctoral candidate on the team. The team believes that two-sided information has a neutralizing effect. “This means that we were unable to detect any positive influence on the willingness of consumers to pay more for a particular product in comparison to the control group when the positive information was paired with information on potential negative effects of the production method.”
Bees Cannot Taste Even Lethal Levels of Pesticides
New research from the University of Oxford has revealed that bumblebees cannot taste pesticides present in nectar, even at lethal concentrations. This means bumblebees are not able to avoid contaminated nectar, putting them at high risk of pesticide exposure and posing a threat to crop pollination.
Bees are important pollinators of agricultural crops, but this can expose them to pesticides while they collect nectar and pollen. Since they are known to be adept at tasting and differentiating sugary solutions — certain toxic compounds, like quinine, taste “bitter” to bees — the researchers sought to find out whether this sense of taste could help them avoid drinking pesticides.
The researchers used two methods to test whether bumblebees (Bombus terrestris) could taste neonicotinoid and sulfoximine pesticides in nectar that mimicked that of oilseed rape (Brassica napus), and if they would avoid drinking pesticides over a very broad range of concentrations. They used electrophysiology to record the responses of neurons in taste sensilla (i.e., tastebuds) on bumblebees’ mouthparts. This allowed them to track how often neurons “fired” and therefore the strength of response to the taste. The researchers also tested the bumblebees’ feeding behavior by offering them either sugar solutions or pesticide-laced sugar solutions.
The results demonstrated that the responses of the neurons were the same whether the bees drank sugar solution or sugar-containing pesticides. This indicates that the bumblebees’ mouthparts do not have mechanisms to detect and avoid common pesticides in nectar.
Although bees did not drink less of the pesticide-laced solutions, the authors demonstrated “bitter” taste avoidance using the compound quinine. Quinine in sugar solution was deterrent to bees at high concentrations. At low concentrations, bees were observed to ingest less of the sugar solution, however the amount of time they spent in contact with the feeding solution was the same.
