California Fruit and Vegetable

Category: Legumes

  • 2023 UCCE Blackeye Bean Variety Evaluation

    UC Cooperative extension experts led by Michelle Leinfelder-Miles evaluated blackeye bean varieties in a commercial field in Stanislaus County in 2023. The season began with cool and wet spring conditions, which lasted through the month of June and delayed planting. Seven varieties from the University of California blackeye breeding program were planted on July 7th. The varieties were grown on a Hanford sandy loam, and the soil temperature was approximately 75°F at the time of planting. Each variety was planted across six rows on 30-inch spacing, on a row length of approximately 275 feet. The seeding rate was 40 pounds per acre. This was a non-replicated evaluation due to a limitation in seed; therefore, no statistical analysis is presented.

    The trial was planted in a field of CB46, and fertility and pests were managed by the grower in the same manner as the field. Data are presented in Table 1. Stand counts were made approximately two weeks after planting on July 20th. The stand was assessed as the number of plants per two-foot length. Twelve replicate counts were averaged. We evaluated aphid and lygus damage on September 8th, which were low due to the grower’s management. For lygus, we took 10 sweeps from four locations in each plot and counted the lygus. Data were averaged and are presented as a 10-sweep count. For aphids, we used a rating scale from 0 to 10 that accounted for visible crown damage and aphid incidence. In addition to the in-field assessment of lygus, we also evaluated harvest samples for stings and found that, on average, about 1.2 percent of the beans had lygus damage. No diseases were observed.

    We harvested on November 6th. All six rows of each variety were cut and raked into one windrow. At the time of cutting, the grower observed that CB77 plants were laying flat, but they were laying in such a way that the knives still picked up the plants. The grower also observed that CB74 had an upright growth habit that could potentially make it a variety viable for swather cutting. We evaluated 100-seed weight as a measure of seed size, evaluating five 100-seed samples per variety.

    We would like to thank the cooperating grower, the CA Crop Improvement Association for funding regional trials, and the CA Dry Bean Advisory Board for assistance with statewide research prioritization and assistance with outreach. — Images & Article By Michelle Leinfelder-Miles, UCCE

    Table 1. 2023 Blackeye Bean Variety Evaluation Results

  • Aphid ‘honeydew’ May Promote Bacteria that Kill Them

    The word ‘honeydew’ sounds benign, but the sugary waste product of aphids can promote growth of bacteria that are highly virulent to the pests, according to a new study.

    The research takes a step towards understanding how some strains of the bacteria Pseudomonas syringae that live on leaves and are pathogenic to aphids might one day be used to control the pests. Aphids transmit plant viruses when they feed on sap, costing billions of dollars in annual crop damage around the world.

    The paper, “Context Dependent Benefits of Aphids for Bacteria in the Phyllosphere,” published Jan. 12 in The American Naturalist, assessed the virulence of different strains of P. syringae to aphids. The researchers also investigated how well the bacteria survive on leaf surfaces without aphids, and whether bacteria benefited from the presence of aphids.

    “For one of the experiments, we actually took the aphids out of the picture entirely,” said Melanie Smee, the paper’s first author and a postdoctoral researcher in the lab of co-author Tory Hendry, assistant professor of microbiology in the College of Agriculture and Life Sciences.

    “We literally just sprayed fake honeydew on to leaves, and we still saw the same increase for the bacteria [as when aphids were present], so it’s really just the honeydew that’s helping the bacteria,” Smee said.

    In the study, Smee and Hendry identified 21 strains of varying virulence to aphids. They then chose eight of those strains. For each strain, they sprayed bacteria onto plants with aphids and other plants without aphids, to see if the bacteria benefited from the aphids presence. They measured bacterial growth on leaves and found that half of the strains benefited significantly.

    The next step was to try to understand the source of that benefit. They knew the bacteria are consumed and then grow within aphids and then are excreted out, so they wanted to see if passage through the aphids helped bacterial populations thrive. They set up a new experiment, with the aphids suspended above leaves that had been sprayed with bacteria. They fed one set of aphids an artificial diet with bacteria, and another set without bacteria, and the aphids then excreted honeydew onto the leaves below.

    They found it didn’t matter whether aphids were fed bacteria; all the bacteria on the leaves did better in the presence of aphids. It turned out that the honeydew was the only factor that boosted bacterial populations.

    They also found that benefits from honeydew to bacteria were not correlated to strain traits, but they were affected by the initial population densities, such that smaller populations increased more with honeydew, compared with large populations, which increased less.

    More work is needed to determine which P. syringae strains are pathogenic to plants, an important consideration if bacteria are used for pest control. The researchers are also interested in investigating the role of the interaction of bacterial communities.

    The study was funded by the U.S. Department of Agriculture’s National Institute of Food and Agriculture and by Cornell. — By Krishna Ramanujan, Cornell College of Agriculture & Life Sciences

  • Black Beans Help Fix Insulin Resistance and Gut Bacteria Balance

    USDA ARS — Adding cooked black beans to a high-fat diet improved sensitivity to insulin and other measures often related to diabetes and restored gut bacteria balance in obese mice, according to a USDA Agricultural Research Service study.

    As little as the mouse-size equivalent of a single serving a day of black beans—about a half cup for a human—lowered insulin resistance 87 percent in obese mice compared to obese mice eating the same high-fat diet without the black beans. Insulin resistance is when a body’s response to the hormone insulin is impaired so glucose in the blood cannot be used for energy, resulting in high blood sugar, a factor often leading to diabetes.

    Mice on the high-fat plus black beans diet also decreased low density lipoprotein (LDL) cholesterol, the so-called bad cholesterol, 28 percent and triglyceride levels 37 percent compared to mice eating the high-fat diet without black beans. These are both risk factors for cardiovascular disease.

    Other diabetes-related biomarkers such as the levels of leptin, glucagon, and a group of inflammatory biochemicals were all significantly better in the mice on the high-fat plus black beans diet.

    The researchers also found that adding black beans to the high fat diet restored the balance of healthier bacteria in the gut, particularly decreasing the ratio of Firmicutes bacteria to Bacteroidetes bacteria in the gut by 64 percent compared to mice on the high fat diet without black beans  and mice on a low fat diet. High ratios of Firmicutes to Bacteroidetes are associated with obesity. Intestinal bacteria associated with inflammation such as Blautia and Clostridium all were significantly reduced in mice fed the high fat plus black beans diet compared to mice on the high fat diet without beans.

    “This research suggests that eating even a small amount of black beans can have multiple health benefits,” said ARS research chemist Wallace Yokoyama with the Healthy Processed Foods Research Unit of the Western Regional Research Center in Albany, California. Yokoyama led the study, which was published in the scientific journal Foods.

    “We also tested if supplementing the high fat diet with individual components from black beans would have the same beneficial impacts on the obese mice and didn’t find the same effects at all. It was only adding whole black beans, and cooked whole beans at that, which had the benefits,” Yokoyama said.

    Perhaps the most interesting scientific information coming from this study, according to Yokoyama, is data to begin determining just how black beans improve insulin resistance. It appears that black beans may inhibit the JNK/c-Jun pathway, a key metabolic pathway that has many but not necessarily well-defined functions including regulating inflammatory responses. Chronic inflammation is believed to be the basis for insulin resistance and other metabolic diseases.

    Black beans, or more precisely black turtle beans (Phaseolus vulgaris), are generally low in fat and high in fiber and protein. They are popular in Latin American, Mexican and Caribbean cuisines as well as in Cajun and Creole cooking. Like all common beans, black beans are native to the Americas. Today, they have been introduced around the world to become known as frijoles negros or poroto negro in Spanish, feijão preto in Portuguese, and karuppu kaaramani and kala ghevada in various regional cuisines of India.

    The Agricultural Research Service is the U.S. Department of Agriculture’s chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in agricultural research results in $17 of economic impact.

  • New Dry Beans from UC Davis Combine Qualities for Both Farmers & Consumers

    Beans in the UC Davis breeding program, whose varieties have been selected to combine excellent culinary with improved yields and resistance to bean common mosaic virus. Credit: Travis Parker

    Plant breeders are constantly working to develop new bean varieties to meet the needs and desires of the food industry. But not everyone wants the same thing.

    Many consumers desire heirloom-type beans, which have great culinary quality and are visually appealing. On the other hand, farmers desire beans with better disease resistance and higher yield potential.

    The bean varieties that farmers want to grow are sometimes different than the varieties consumers want to purchase. Until now.

    Travis Parker, a plant scientist at University of California, Davis, has worked with a team of researchers to release five new varieties of dry beans that combine the most desirable traits.

    The new varieties, UC Sunrise, UC Southwest Red, UC Tiger’s Eye, UC Rio Zape, and UC Southwest Gold, were recently highlighted in the Journal of Plant Registrations, a publication of the Crop Science Society of America.

    “Our new beans combine the best of both worlds for farmers and consumers,” says Parker. “They combine the better qualities of heirloom-type beans with the better qualities of commercial types.”

    Heirloom-type beans often represent older bean types that are known for culinary qualities and seed patterns. These are highly desired by consumers. Heirloom types often fetch a higher market value than other beans.

    Commercial dry beans often have higher yields, shorter maturity times, and improved disease resistance. While they possess qualities desirable to producers, they don’t command as high of a market price compared to their heirloom counterparts.

    A comparison of the heirloom variety “Tiger’s Eye” (left, with virus symptoms) and the newly released “UC Tiger’s Eye” (right, healthy leaves). These varieties have similar culinary qualities, but UC Tiger’s Eye is resistant to the common mosaic virus and has higher yields. Credit: Travis Parker

    “Our goal was to improve field characteristics of the heirloom beans without losing culinary characteristics,” said Parker. “We have an interest in higher-value varieties and want them to grow well.”

    Farmers growing the heirloom dry beans often sell the beans to health-conscious consumers or high-end restaurants. This sale often leads to a higher price point. However, these beans are prone to disease and don’t perform well in the field.

    “We know that existing heirloom beans don’t usually do well in terms of yield,” said Parker. “Breeding beans for high yields is a major improvement for farmers. The new varieties are high-yielding, heat-tolerant, and are also resistant to bean common mosaic virus.”

    Incorporating disease resistance was essential when developing the new bean varieties. Bean common mosaic virus is a well-known problem that is hard to control in the field.

    “The only really effective means to handle the virus is through genetic resistance,” explains Parker.

    The new varieties, such as UC Sunrise, satisfy the need for farmers to have a bean that is disease resistant while also yielding 50% more than heirloom types. In addition, the beans do not take as long to grow between planting and harvest.

    UC Sunrise seeds Photo Caption: A detailed view of UC Sunrise, one of the new varieties of the heirloom-like dry bean. The colorful pattern is desirable to consumers. Credit: Travis Parker

    Commercial and heirloom beans come from the same species, but they are in different market classes. The heirloom varieties are bred with intimate knowledge of what tastes good and what works well in the kitchen.

    “In recent decades, there has been less attention paid to consumer desires during the bean breeding process,” says Parker. “There are more layers between the breeder and the consumer. We are trying to make sure to keep consumers in mind while incorporating qualities that are beneficial to the farmer.”

    With consumer desires in mind, the research team used cross-pollination to breed plants with key characteristics they selected. As Parker and the team continued the breeding process, they performed taste tests to ensure the beans met the level of culinary quality expected of an heirloom-type bean, in terms of flavor and visual appeal.

    This research was supported by the Clif Bar Family Foundation, Lundberg Family Farms, the United States Department of Agriculture Organic Agriculture Research & Extension Initiative, and the United States Department of Agriculture Western Sustainable Agriculture Research and Education program.

    To learn more about the research behind these new dry bean varieties, watch this video from Travis Parker.

  • New Bean Defeats Both Leafhoppers & Drought

    Agricultural Research Service (ARS) scientists in Puerto Rico have developed a new pinto bean germplasm that may increase a farmer’s yield, reduce production expenses, and help the environment.

    The new bean, called TARS-LH1, is resistant to two types of leafhopper – Empoasca fabea, the potato leafhopper, which can reduce common bean yield by 20 percent in temperate areas, and the tropical leafhopper, E. kraemeri, which can reduce yield by almost 80 percent in tropical areas.

    Further, TARS-LH1 is resistant to the bean common mosaic virus and drought stress. It also yields well and has good seed size, said Tim Porch, research geneticist at the ARS Tropical Agriculture Research Station in Mayagüez, Puerto Rico.

    Beans are among the most important crops grown worldwide, Porch said. “They are a nutrient-dense food and an excellent source of protein and fiber,” he said. “Eating more beans can potentially reduce the chances of heart disease, diabetes, and certain types of cancer.”

    In addition, the properties of the TARS-LH1 pinto bean offer economic benefits to farmers around the world by reducing pesticide input and increasing organic dry bean production. “Beans are primarily a crop of poor farmers worldwide, so reducing the amount of pesticide could increase farmer income and food security, and decrease the environmental impact of production.”

    Pinto beans are also a favorite of U.S. bean growers, accounting for about one-third of America’s bean crop.

    The new pinto bean variety has been released publicly in the form of germplasm, intended for use by plant breeders to incorporate traits of interest – in this case, leafhopper and drought resistance – into the varieties that farmers ultimately grow.

    The Porch research team tested the bean’s resistance to leafhopper in several locations, including the Michigan State University Crop and Soil Science Research Farm, in Haiti, and in Puerto Rico.

    It’s important to improve beans, Porch said, because pests and pathogens are constantly evolving and the climate is changing. “The next step will be to incorporate this resistance into other seed classes grown in the United States and into varieties grown by farmers around the world,” he said. Other potential improvements include heat tolerance and resistance to pathogens like rust and common bacterial blight. – By Scott Elliott, USDA-ARS Office of Communications

  • Why Aren’t My Beans Drying Down?

    We cut our blackeye bean (cowpea) research plots at UC Davis almost 3 weeks ago and they’re still too green to harvest. If we tried now, the vines would get wrapped around the threshing cylinder.  Several growers in the Sacramento Valley have mentioned that their corn has sat at the same moisture level for weeks and is not drying down either, as one would normally expect for this time of year. But, nothing is normal this year!

    Why aren’t our crops drying down?

    Tragic fires throughout the West have pushed a lot of smoke and ash into the sky, creating fog-like conditions that reduce the intensity of the sun, shade crops, and lower temperatures. The blanket of smoke is like stepping into the shade under an awning on a 90oF day. This reduced sun intensity has affected the ability of crops to dry down in a timely manner. Increased humidity levels this past weeks haven’t helped either.

    While shading may be good for protecting tomatoes from sunburn with harvests running late due to COVID-related challenges, it is not good for drying down field crops.

    With the smoke finally dissipating, drying conditions are improving. We ended up turning our blackeye bean crop over to increase aeration and help it dry down.  Dry beans are sometimes turned to help dry the crop down, especially if they’re rained on, but the challenge is to be careful to prevent shattering.

    In corn, there aren’t any easy solutions.  One grower said their corn sat at 16.5% moisture for several weeks and finally they had to harvest it anyway. Dryers are available for drying corn and other crops to the proper storage moisture, but as we all know it’s expensive and with low grain prices this affects the bottom line.  — By Sarah Light & Rachael Freeman Long, UC Cooperative Extension

  • Why Aren’t my Blackeye Bean Pods Filling Out?

    Recently, I received a call about a blackeye bean field in the San Joaquin Valley with a lot of bean pods that did not fill out at the tips (photo). I contacted the UC Riverside blackeye bean breeders Drs. Phil Roberts and Bao Lam Huynh and they shared that this problem is primarily caused by heat, which affects pollen viability and thus fertilization. Here’s their response:

    It [lack of pod fill] is the typical male-sterility symptom [lack of pollen viability] associated with extreme temperatures (heat or cold). Based on the planting date you gave, we just checked the temperature in Denair, CA [farm location] and noted that it was quite warm (~100) during the flowering time (40-50 days after planting) and recently during the pod filling stage, so heat must have been a main cause. The symptom could also be more severe if water is limiting.

    Always be prepared with good irrigation management practices for all crops going into heatwaves, like the one we’re having now.  The minimum seasonal irrigation needed to produce a blackeye bean crop being managed for full yield from one pod set is 16 to 18 inches. This estimate includes a pre-irrigation of 4-inches, and irrigations of 4-inches when floral buds first appear, and 8 to 10 inches during 5 to 6 weeks of flowering and pod filling. If additional irrigations are needed during the vegetative stage, one could increase the total irrigation requirement to 20 or more inches. Irrigating for a second flush of pods could require an additional 8 to 12 inches of water. Irrigation requirements are further increased by any water required to leach salts or to compensate for an inefficient irrigation system.

    Additional water may need to be applied during extreme heat events which drive plant transpiration rates to the limit. Make sure to check the soil moisture in the top 12 to 24 inches of the soil profile and apply additional water if the soil is dry. If in doubt about how much additional water is needed, check the reference evapotranspiration (ETo) and make sure to irrigate to replace at least 120% of your daily ETo in your area.  The current (mid to late August) daily ETo in the San Joaquin Valley ranges from 0.25 to 0.30 in/day; make sure your applied irrigation replaces 120% of these values.

    More information on growing blackeye beans can be found in the publication, UC ANR Blackeye bean production

    in California, http://beans.ucanr.edu/files/226601.pdf. – By Rachael Freeman Long, UCCE Farm Advisor

    Lack of pod fill in blackeye bean tips caused by heat, which affects pollen viability and fertilization; water stress can add to this problem, especially during heatwaves. San Joaquin Valley, 2020.

  • New CA Blackeye Varieties Show Resistance to Cowpea Aphid

    Field trials in the Central Valley with two new varieties of blackeye beans, CB74 and CB77, show impressive resistance to cowpea aphids compared to standard CB46, CB5, and CB50 lines. Four varieties of blackeyes including CB46, CB77, CB74, and CB5 were seeded into a blackeye CB50 field, in single lines on 30-inch beds in the Sacramento Valley in May 2020 (Photo 1). By mid-summer, CB50, CB46, and CB5 were heavily infested with aphids (photo 2), whereas CB74 and CB77 were clean (photo 3).

    Photo 1. Blackeye variety trial, Sacramento Valley, 2020; left to right, CB46, CB77, CB74 (early maturing), and CB2 compared to the standard CB50 line planted in the field on the far left.

    Cowpea aphids are serious insect pests of blackeyes. These aphids can quickly colonize plants and cause injury by direct feeding and injecting toxic saliva into plants, leading to stunted growth or death of plants. Sticky honeydew released by the aphids can stimulate black mold growth on plants, reducing photosynthesis and plant health. Cowpea aphids also vector a number of viral mosaic diseases that can cause serious losses in many crops. Biological control cannot be relied on because natural enemies often appear when cowpea aphid infestations are already high and causing serious damage. Applying pesticides early in the season prevents cowpea aphid infestations but beneficial insects can be destroyed, leading to outbreaks of other insect pests. Thus, the development of cowpea aphid resistant blackeye lines is an important breakthrough in managing this pest.

    Photo 2. Heavy cowpea aphid pressure on blackeye bean CB46 leading to significant yield and quality losses.

    Blackeye beans, also known as cowpeas, or blackeye peas in southern states, are an important food crop worldwide. In California, about 8,000 acres are grown annually for dry or canned blackeye bean markets. These new blackeye bean lines are being developed by the UC Riverside blackeye breeding program, led by Drs. Phil Roberts and Bao Lam Huynh, with support from the California Dry Bean Advisory Board and the US AID Feed the Future Innovation Lab for Legume Systems Research (formerly Innovation Lab for Collaborative Research on Grain Legumes). The aphid resistance and other traits have been introgressed into California Blackeye elite backgrounds using natural selection and new molecular markers to expedite the breeding process. Compared to standard varieties, CB74 and CB77 also have more stable yields resulting from heat tolerance, better tolerance to lygus bugs, and equivalent resistance to Fusarium wilt and root-knot nematodes.

    Photo 3. Adjacent CB77 blackeye plants show high levels of resistance to cowpea aphid infestations.

    Blackeye variety observation trials are being conducted in fields by UCCE Farm Advisors Rachael Long, Sarah Light, and Nick Clark in the Sacramento and San Joaquin Valleys, in collaboration with local farmers. More information on blackeye beans can be found in the Blackeye bean production manual for California, UC ANR 21518, http://beans.ucanr.edu/files/226601.pdf. The lead UC bean breeders hope to have these lines available to farmers within the next few years. – By Rachael Freeman Long, UCCE Farm Advisor

  • Fusarium Root Rot in Seedling Lima Beans

    In May, I looked at a lima bean field in the Sacramento Valley that showed poor seedling emergence scattered throughout the field (photo 1). I sent samples to the UC Davis Plant Pathology lab and the main pathogen consistently recovered from the roots was Fusarium root rot, a fungal disease caused by Fusarium solani f. sp. phaseoli. This pathogen is specific to beans and field peas and will not infect other field crops. A few bean seedlings also had Rhizoctonia and Pythium (also fungal pathogens).

    Finding Fusarium root rot in a lima bean seedling field was a surprise because this disease is most commonly encountered in established fields during mid- to late season, where it is one of the causes of early maturity (“cut out”). Rhizoctonia and Pythium can cause seedling damping-off in dry beans. However, plants usually outgrow these pathogens, particularly if the seed is treated with a fungicide and conditions favor rapid emergence.

    Fusarium solani attacks underground stems and roots of plants. In established plants, early infection is characterized by elongated reddish streaks on the roots. As the disease progresses, these eventually form reddish-brown lesions that will surround the entire root, causing decay. The above ground plant symptoms of affected plants included yellowing, wilting, stunting, and dieback. On seedling plants in the affected field, I observed dieback of the growing point, stems that were a bit swollen, and roots that were brownish and not well developed (Photo 2, diseased roots on left, healthy on right).

    Fusarium root rot causes little damage to healthy plants, but under conditions of plant stress due to drought, poor nutrition, or oxygen-stressed, waterlogged soils, Fusarium root rot can cause plant dieback and yield losses, particularly in fields with a long history of bean production. In this particular lima bean field, soil moisture was lost, causing plants to be extremely water stressed. Crop rotation, use of seed treatments, and closely watching field conditions to ensure plants are not stressed will help manage Fusarium root rot. This disease tends to be a problem in fields with a long history of bean production. More information on diseases in dry beans can be found on the newly revised UC IPM guidelines for dry beans. — By Rachael Freeman Long, UC Cooperative Extension

    Photo 2. Lima bean seedlings infected with Fusarium root rot (4 left plants) compared to healthy roots (3 plants on right).

  • Keeping Pinto Beans Away from the Dark Side

    Pinto beans are good for us. They are nutritious, packed with protein and fiber. They also contain a host of micronutrients like B vitamins and folate.

    But being good isn’t enough for pinto beans. They also need to look good.

    A new variety of slow-darkening pinto beans shows benefits for the entire value chain (Photo by Juan Osorno).

    Typically, pinto beans have a striking mottled pattern of dark and light brown. However, the beans can darken after harvesting.

    Consumers perceive pinto beans with darker colors to be older, harder to cook, and less nutritious than lighter beans.

    “We eat with our eyes,” says Juan Osorno. Osorno is a researcher at North Dakota State University.

    And it’s not only consumers who are skeptical about dark pinto beans. “Farmers see darker pinto bean seeds as being of poorer quality,” says Osorno. “And when farmers try to sell darker beans, they often have to accept discounted prices.”

    That’s a big deal because pinto beans are the most common type of dry bean grown and consumed in the United States.

    In the recent study, Osorno and colleagues describe the process of developing a promising new variety of slow-darkening pinto bean. “The study found no major differences in the agronomic performance of regular versus the slow-darkening pintos,” says Osorno.

    He believes these slow-darkening pinto beans can be a good alternative for the existing pinto bean value chain. “Both farmers and consumers will benefit from it in many ways,” he says.

    For example, the slow-darkening beans cooked faster than regular beans. Needing less time to cook can be a great benefit in areas where cooking fuel is scarce.

    The key advancement has been improving agronomic performance – such as yield and bean size – of the slow-darkening beans. That’s huge progress, because past plants with the slow darkening gene have had many issues associated with agronomic performance.

    For example, one older variety of slow-darkening pinto beans has low yields. Another won’t flower under farming conditions in the United States. Yet another grows in such a way that it makes mechanical harvesting of the beans difficult.

    At the root of these difficulties lies pinto bean genetics. Physical characteristics, such as yield, bean size, or rate of darkening, are all affected by one or more genes.

    Turns out, a single gene – aptly named slow darkening or SD – controls how quickly pinto beans darken after harvesting. Researchers can breed this gene into new pinto bean varieties fairly easily without creating a genetically modified organism (GMO).

    But whenever they incorporated this gene in the past, other genes responsible for lower yields or smaller beans would come along with the slow darkening gene.

    Osorno and colleagues tested several varieties of slow-darkening and regular pinto beans over the past decade. The tests were carried out in research plots in Washington and North Dakota.

    The researchers compared traits such as seed weight, yield, and cooking time between slow-darkening and regular pinto beans.

    The initial tests – from 2010 to 2012 – did not yield encouraging results. The slow-darkening beans performed poorly compared to regular pinto beans.

    But the latest round of field trials using slow-darkening pinto beans was more promising. According to the 2018 tests, the newer slow-darkening pinto bean varieties are catching up to regular varieties in yield and bean size.

    In fact, a second generation of slow-darkening pinto beans is already showing higher yields compared to the previous generation.

    Osorno is encouraged but says there’s still work to be done. “Remember that breeding yields gains in a stepwise manner rather than through big jumps,” he says.

    Read more about this research in Crop Science. This work was funded by Northarvest Bean Growers Association, United States Department of Agriculture National Institute of Food and Agriculture, United States Department of Agriculture Agricultural Marketing Service, and the North Dakota Department of Agriculture.