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À l’indépendance, la production nationale de la Côte d’Ivoire en café était de 185.000 tonnes. Dans les années 1980, la production est passée à 320.000 tonnes. Ce qui faisait de notre pays, le 1er producteur de café en Afrique. Au début des années 2000, la production a commencé à baisser pour atteindre 120.000 tonnes. Depuis 2020, la barre de production est en dessous de 80.000 tonnes. Faisant perdre à la Côte d’Ivoire, la 1ere place Africaine pour se retrouver au 4e rang. Derrière l’Ethiopie, l’Ouganda, et la Tanzanie. Dans le classement mondial, la Côte d’Ivoire occupe la 17e place. Pourquoi cette baisse de production ?
L’importance du café dans l’économie de la Côte d’Ivoire n’est plus à démontrer. Toutefois, cette culture rencontre de nombreuses difficultés telles que le vieillissement du verger, l’action néfaste des insectes ravageurs, les effets du changement climatique. Mais surtout la trachéomycose, une maladie qu’on qualifie de « Sida du café ».
État des lieux
Selon le Centre national de recherche agronomique (Cnra), trachéomycose a fait son apparition en Côte d’Ivoire dans les années 1930-1950, détruisant de nombreuses plantations agricoles. A cette époque-là, le colonisateur a trouvé comme solution d’introduire de nouvelles variétés de café plus résistantes. C’est ainsi que le café robusta a fait son apparition dans l’univers agricole ivoirien. Plus d’un demi-siècle après, revoilà la trachéomycose. On la retrouve dans toutes les zones productrices du café du territoire national.
Une enquête menée l’an dernier par le Cnra révèle qu’à Gagnoa, 14,2% du verger est atteint par la trachéomycose, sur 169 parcelles visitées. Dans la sous-préfecture de Guépaho, dans le département d’Oumé, vers les années 2000, on avait 16000 hectares de café, contre 5000 hectares aujourd’hui. Dans la région du haut Sassandra par exemple, le taux de contamination du verger est estimé à 50%.
« La maladie a fait beaucoup de ravage, si bien que le café est en voie de disparition », fait remarquer un agent de l’Anader. Parmi les planteurs qui ont tourné le dos à la caféiculture, se trouve N’goran Clément. Il y a une vingtaine d’année qu’il a hérité de la plantation de café de son défunt père, à Danielkro. Un campement Baoulé dans la sous-préfecture de Seriho, dans le département de Gagnoa. « Quand la maladie s’est déclarée dans mon champ de café, la production a chuté, mes gains ont commencé à baisser. Je n’avais plus qu’à laisser tomber le café pour le cacao », a-t-il expliqué, le paysan, les raisons de sa reconversion dans la culture du cacao.
« Je dis aux planteurs de café de ne pas désespérer. Les scientifiques travaillent sur cette maladie. Nous allons leur apporter les techniques afin qu’ils puissent arriver à bout de la maladie. Ils peuvent garder espoir parce que le café vivra encore en Côte d’Ivoire », a exhorté Koffi Sara.
Tout est en train d’être mis en œuvre pour que la culture du café retrouve ses lettres de noblesse.
Ph: DR
Solutions
« Compte tenu des perturbations climatiques, liées à la longueur des sécheresses, il faut développer des techniques qui permettent d’économiser l’eau du sol pour la mettre à la disposition de la plante afin qu’elle survive », renseigne un agronome. Il a passé en revue les différentes techniques de conservation de l’eau, telle que l’irrigation, l’hydro-détenteur et le paillage.
« L’irrigation est très chère pour le petit producteur », a fait savoir le formateur. « Il y a aussi d’autres techniques comme l’utilisation des hydro-détenteurs qui sont des granulés qui captent l’eau pendant la pluie et, en saison sèche, rétrocède cette eau à la plante. Cette technique est facile pour le producteur », fait-il savoir. Toutefois, l’agronome conseille la pratique du paillage. Elle consiste à mettre des débris végétaux autours du pied du caféier. Ce qui permettra à la plante de conserver l’eau du sol. Comment faire le paillage ? Pourquoi le faire ? A quel moment le faire ? Voilà autant d’exercices pratiques qu’il faut maitriser pour garder sa plante en bonne santé.
Some food grown in the US, especially high-cost luxuries like almonds, are pollinated using bees. Since bees are most often rented and transported for such purposes, keeping them alive is important to owners and growers. As their value for higher-cost foods has grown, so have bee numbers; they are up 85 percent in the last 60 years. You would just never know it if your source is Greenpeace, so when you use verbiage identical to Greenpeace press releases in an academic paper press release your work is going to be suspect. And that is a paper on bee deaths we’ll discuss today.
No matter how much effort is put into prevention, bees die. A lot. Some years more than others, and when that happens environmentalists promote campaigns against weedkillers and other agricultural tools, but the number one killer of bees is not climate change or land use, it is parasites. Bees live in a small enclosed space and diseases can devastate them in a short amount of time. The only way to prevent losses of 50 percent or more is with modern medicine against pests like varroa mites and others. Parasites are all three of the top three reasons bees die of external causes.
There are other factors, severe weather will cause more deaths, and for the few bee species that can be estimated (7 out of approximately 25,000 – that’s right, we don’t even know how many bee species exist) land use changes can be implicated. If someone tries hard enough, they can even find a way to “correlate’ farming to dead bees.
That is not the goal of a recent paper, but they use flawed ‘false equivalence’ to enable that, by acknowledging mites but then putting farming and weather events right next to them. I like bees, I want them to stick around, but no one is helped if pesticides are given false equivalence with the pests they kill in bee deaths.
Farming is a non-existent peril for bees outside the statistical noise range but even weather events are not worth mentioning beyond creating an average. Yes, hurricanes sometimes happen but listing those alongside the top killer is a way to boost their credibility the same way as if a journalist talks to an expert on climate change and then drops in a denier for ‘balance.’
Credit: Overturf et. al.
if they invoke global warming, hurricanes, and pesticides in their false equivalence with mites, how do I argue they may be going after farming? The authors use pleas for action by Greenpeace that have no evidence basis – a manufactured claim that one third of the world’s food, 100 crops, etc. need bees or we are doomed. It was entirely made up. USDA knows it, scientists know it, everyone who reads Google outside the first 20 results knows it. But the authors ignore USDA data showing pollinators are only involved in about $15 billion of food and instead blindly repeat the Greenpeace claim that it is 1,000% greater.
Here is the science truth. The 12 crops that provide 90 percent of our food are not pollinated by bees. Some are wind pollinated, some are self-pollinated or propagate asexually or parthenocarpically – they don’t need fertilization. Not by bees or the tens of thousands of flying insects that would take their place if that one species of bees disappeared tomorrow.
Bees are not vital pollinators for 100 vital crops or even 10 percent of food. They are not even declining. We have to look at their methodology a lot more critically when they make breezy statements that a USA Today fact checker would have asked them to cite.
Greenpeace did not invent that business about 100 crops from nothing, it was an unsubstantiated claim in a 1976 Pollinator Handbook, but everyone knows better by now, but that is no excuse. The general rule on old literature is that if you don’t accept claims that a low-fat diet will make you lose weight, also believed in 1976, don’t accept claims on other things because it matches your bias.
Back to the paper. The authors used survey claims of losses by beekeepers – unfortunately that is the best we can do – and combined those with publicly available data on land use, weather, and farming, and rightly agree that mites are a problem but strangely declare that pesticides and climate change are also big culprits.
Yet the data don’t show it.
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How they seem to show it is statistical manipulation but don’t let that part alarm you. Statistical ‘manipulation’ and even ‘trick’ does not carry the colloquial negative connotation those terms have in culture. If you have data created using different methods you have to make them relevant to each other. There is no meta-analysis without manipulation so it’s important. Shedding light on arcane parts of data is a positive force in statistics, but if someone is averaging and upscaling to show a result they perhaps wanted to show it is more like data dredging or HARK-ing; Hypothesis After Results Known. A real no-no.
Credit: Sketchplanations.com
I am not sure how to feel about their data period. Mostly, why? USDA has been surveying beekeepers since 1986 but this analysis only goes back to 2015. Using recent results may be causing sampling bias. They included a hurricane event – since bees only live a few weeks why a hurricane should he included to implicate weather in a long-term decline is unknown – and they touch on culture and accept they have no way to know how competent beekeepers are, but still wave it away in their press kit.
That cultural confounder, which finer resolution upscaling can’t help with, is that beekeeping became a fad.
Since the surge of Greenpeace claims that bees are keeling over en masse, there has been a surge in amateur beekeeping. Which has meant a surge in bee deaths by amateur beekeepers who buy into ‘power of nature’ mythology that they can just put up a hive and Gaia’s supernatural abilities will kick in. Which is completely false. With a surge in amateur beekeeping there has also been a surge in deaths due to overuse of needed chemicals to cure diseases – and deaths due to not using chemicals at all. Are new beekeepers going to blame their own incompetence? I have no idea, but if an aggressive statistician looks at a map and sees a farm near where a bunch of bees died, it is easy to correlate the farm to the deaths rather than nature or even misuse of chemicals by a beekeeper. It is also the completely wrong conclusion but it can be gained with statistical significance. Upscaling and statistical tricks magnify incomplete national data in that instance, while a neutral examination would catch that bees dying from truck accidents on the way to an almond farm did not die due to pesticides used by the farmers at the almond farm even though a statistician can claim they are ‘linked’ because of geography, especially if the resolution is only by state.
Statistics can link anything to anything, that is why their claims are only exploratory. In the real world, science and evidence is what matters. Evidence shows that bees are not in decline, our food supply is not at risk, and the top killer by far is mites, with other pests way behind, and chemicals that are not misused are down in the statistical noise area.
Credit: Giuliade via CC-BY-SA-4.0
As an observational paper, this is fine, even their press release concedes that ‘other’ is a large killer compared to things like pesticides. They know they are working with limited data, much of it is subjective and changes from year to year, and they need to make a lot of assumptions to try and get it all similar enough to make sense. But for 13 years prior to COVID-19 we warned about the problems of statisticians and epidemiologists and even some biologists creating ‘red meat’ papers for anti-science activists, because it could cause real harm (and did) when it came to vaccines and trust in our food supply.
Expect to see this paper trotted out in the same way. It is not going to be compelling to the science community but for Pesticide Action Network and others, it is pure honey.
Hank Campbell founded Science 2.0 in 2006, and writes for USA Today, Wall Street Journal, CNN, and more. His first book, Science Left Behind, was the #1 bestseller on Amazon for environmental policy books. Follow Hank on Twitter @HankCampbell
A version of this article was posted at Science 2.0 and is used here with permission. Any reposts of this article should credit the original author and provide links to both the GLP and the original article.Check out Science 2.0 on Twitter @science2_0
A new set of quantitative models that incorporates pH into the metabolic theory of ecology (MTE) has been developed by an international team that includes Penn State assistant professor of plant science Francisco Dini-Andreote.
The work is included in a new paper published by the Proceedings of the National Academy of Sciences, titled, “Integrating pH into the metabolic theory of ecology to predict bacterial diversity in soil.”
“Soils are the most complex and biodiverse ecosystems on Earth,” said Dini-Andreote, a member of Penn State’s Microbiome Center. “In soils, microbial diversity plays indispensable roles in the anabolic and catabolic cycles of carbon, nitrogen and sulfur, without which the diversity of life forms—including plants, animals and other microbes—that evolved on our planet would not have been possible. In addition, advancing our ability to predict patterns of soil biodiversity is critical to better understanding how climate change will affect soil functioning and how soil microbes will respond to shifts in temperature and precipitation regimes.”
In general terms, the metabolic theory of ecology links rates of organism diversification (i.e., the metabolic rate of an organism) with the organisms’ body size and body temperature, explained Dini-Andreote. Building upon the factors that are parametrized in the MTE, the researchers introduced variation in local pH as an additional variable that acts as a stringent selective filter of biodiversity in soils, impacting the species of microbes acting and surviving in the soil.
By considering all these factors—the metabolic rate, mass, and temperature as well as pH—the researchers were able to capture and account for previously unexplained variation in the relationship between soil edaphic properties (the physical, chemical, and biological properties of the soil), temperature, and biogeographical patterns of bacterial diversity. The team then continued to test and validate their models across multiple scales—such as single bacterial strain diversification rates, local and continental scale soil communities—yielding robust results.
“By layering these models, researchers can start to better understand patterns of microbial distribution in soils and start to answer long-standing questions in this field, such as: ‘What determines variation in soil biodiversity?’ and “How dynamic changes in soil biodiversity can be modeled and predicted?” said Dini-Andreote.
“With that, we will be able to better harness the genomic and functional potential of these soil microorganisms to effectively manipulate them for desirable outcomes. These outcomes vary from essential ecosystem functions, such as carbon storage in soil, to the manipulation of beneficial plant-associated microorganisms to enhance crop productivity in agriculture.”
This study also represents a nexus point for the integration of other variables into these quantitative models, such as variation in soil moisture and salinity, among others. The authors foresee new avenues of research ahead that will greatly improve scientists’ ability to understand the distribution of soil microbial species, and the diverse ways they operate as engineers of essential ecosystem processes and services in soils.
“Dr. Dini-Andreote’s scholarship shines a bright light on the abundance of the soil microbiome and the processes and mechanisms that shape soil health. From the soil on up, microbial communities connect different ecosystems as microorganisms flow from soil to hosts and back. With soil as the largest reservoir of microbial diversity on Earth, this important work raises the call to action as soils vary and degrade due to climate change, erosion, and chemical contamination,” said Seth Bordenstein, director of the Penn State Microbiome Center, Dorothy Foehr Huck and J. Lloyd Huck Chair in Microbiome Sciences, professor of biology and entomology.
More information: Lu Luan et al, Integrating pH into the metabolic theory of ecology to predict bacterial diversity in soil, Proceedings of the National Academy of Sciences (2023). DOI: 10.1073/pnas.2207832120
Hisar: A team of scientists from the department of plant pathology, Haryana Agricultural University (HAU), engaged in finding out causes of dwarfism in paddy crops (basmati, non-basmati, hybrid etc.), has found that the disease is not only caused by Southern Rice Black Streaked Dwarf Virus (SRBSDV), but also the Rice Gall Dwarf Virus (RGDV). Information has also been obtained about whom these two viruses, belonging to the spinareoviridae virus group, have made their host. HAU vice-chancellor professor BR Kamboj said SRBSDV infection has been found more in this disease and this virus has made Pova Anova, a weed of the Rabi season wheat crop, its host which is a matter of concern. There has not been any instance of this virus infecting the wheat crop. Therefore, if the farmer destroys this weed from the wheat crop, the possibility of this disease in the paddy crop next year will almost end. For this, apart from mechanical methods, farmers can also spray weed killer Clodinafop 200 grams and Matribugene 240 grams per acre, VC said. VC informed that the varsity’s plant pathologist, Vinod Kumar Malik, and biotechnologist Shikha Yashveer had decoded the virus in nucleic acid and coat protein regions. This has been confirmed by the use of virus-specific primers and molecular studies of the S4, S9 and S10 segments of the virus. University scientists O P Lathwal, Promil, Mahavir Singh, Rakesh Kharb, Ankit Judd, Sumit Saini, Manjunath, Vishal and Amit Kumar are working on the problem of dwarfism in paddy, VC said.
HAU director of research Jeet Ram Sharma said they were regularly studying the path of the virus. Emphasizing on clean farming, Hawa Singh Saharan, head of the department of plant disease, asked for regular cleaning of drains, so that further transfer of virus could be prevented.
Ninth International Conference on Management of the Diamondback Moth and Other Crucifer Insect Pests
Photo by Dr. Srinivasan Ramasamy
The Ninth International Conference on Management of the Diamondback Moth and other Crucifer Insect Pests will be organized by the World Vegetable Center in association with Royal University of Agriculture (RUA) in Cambodia and Taiwan Agricultural Chemicals and Toxic Substances Research Institute (TACTRI). The conference will be held during May 2-5, 2023 at Phnom Penh, Cambodia. About 100 – 150 researchers worldwide are expected to participate and present research papers. The conference is designed to provide a common forum for the researchers to share their findings in bio-ecology of insect pests, host plant resistance, biological control, pesticides and insect resistance management on crucifer crops and integrated pest management. As with previous workshops / conference, a comprehensive publication of the proceedings will be published.
Scientific Sessions
Diamondback moth and other crucifer pests: The global challenge in a changing climate
Biology, ecology and behavior of diamondback moth and other crucifer pests: What’s new?
Insect plant interactions, host plant resistance and chemical ecology of crucifer pests and their natural enemies
Insecticide resistance and management in crucifer pests: the on-going challenge
Biological and non-chemical methods of management of crucifer pests (including organic agriculture)
Genetic approaches to manage crucifer pests: transgenic plants, CRISPR, RNAi, and genetic pest management
Constraints and opportunities to the sustained adoption of integrated pest management (IPM) for the management of DBM and other crucifer pests
Cruciferous crops such as cabbage, cauliflower, broccoli, mustard, radish, and several leafy greens are economically important vegetables vital for human health. These nutritious vegetables provide much-needed vitamins and minerals to the human diet—especially vitamins A and C, iron, calcium, folic acid, and dietary fiber. Crucifers also are capable of preventing different types of cancer.
The diamondback moth (DBM), Plutella xylostella, is the most serious crucifer pest worldwide. In addition, head caterpillar (Crocidolomia pavonana), web worm (Hellula undalis), butterflies (Pieris spp.), flea beetle (Phyllotreta spp.) and aphids (Brevicoryne brassicae, Lipaphis erysimi, Myzus persicae) also cause significant yield losses in crucifers. Farmers prefer to use chemical pesticides for controlling this pest because they have an immediate knock-down effect and are easily available when needed in local markets. Pesticides constitute a major share in the total production cost of crucifer crops, accounting for about one-third to half of the cost of production of major crucifer crops in Asia, for instance. As a result, pest resistance to insecticides is on the rise, leading farmers to spray even more pesticides. Insecticide resistance, environmental degradation, human health impacts, resource loss and economic concerns have triggered a growing interest in integrated pest management (IPM).
Previous International Workshop / Conference(s) on Management of the Diamondback Moth and other Crucifer Insect Pests
Photo by Dr. Srinivasan Ramasamy
The International Working Group on DBM and other Crucifer Insects is an informal group of researchers worldwide who are actively engaged in research and development in crucifer pest management.
This research group participates in an international workshop on the management of DBM and other crucifer insect pests that occurs every five to six years.
The first and second workshops were organized by Asian Vegetable Research and Development Center (AVRDC) in Taiwan in 1985 and 1990.
The third workshop was organized by the Malaysian Agricultural Research and Development Institute in Kuala Lumpur in 1996.
The fourth workshop was organized in Australia in 2001 and the fifth workshop was organized by the Chinese Academy of Agricultural Sciences in Beijing in 2006.
The sixth workshop was organized by AVRDC – the World Vegetable Center in Thailand in 2011 and the seventh workshop was organized by the University Agricultural Sciences Bangalore in 2015.
The eighth International Conference on Management of the Diamondback Moth and other Crucifer Insect Pests was organized by the World Vegetable Center in Taiwan in 2019.
Four pathogenic bacterial species of the genus ‘Candidatus Liberibacter’, transmitted by psyllid vectors, have been associated with serious diseases affecting economically important crops of Rutaceae, Apiaceae and Solanaceae families. The most severe disease of citrus plants, huanglongbing (HLB), is associated with ‘Ca. Liberibacter asiaticus’ (CaLas), ‘Ca. Liberibacter americanus’ (CaLam) and ‘Ca. Liberibacter africanus’ (CaLaf), while ‘Ca. Liberibacter solanacearum’ (CaLsol) is associated with zebra chip disease in potatoes and vegetative disorders in apiaceous plants. Since these bacteria remain non-culturable and their symptoms are non-specific, their detection and identification are done by molecular methods, mainly based on PCR protocols. In this study, a new quantitative real-time PCR protocol based on TaqMan probe, which can also be performed in a conventional PCR version, has been developed to detect the four known phytopathogenic species of the genus Liberibacter. The new protocol has been validated according to European Plant Protection Organization (EPPO) guidelines and is able to detect CaLas, CaLam, CaLaf and CaLsol in both plants and vectors, not only using purified DNA but also using crude extracts of potato and citrus or psyllids. A comparative analysis with other previously described qPCR protocols revealed that this new one developed in this study is more specific and equally or more sensitive. Thus, other genus-specific qPCR protocols have important drawbacks regarding the lack of specificity, while with the new protocol there was no cross-reactions in 250 samples from 24 different plant and insect species from eight different geographical origins. Therefore, it can be used as a rapid and time-saving screening test, as it allows simultaneous detection of all plant pathogenic species of ‘Ca. Liberibacter’ in a one-step assay.
Plant multitrophic interactions are extremely complex, and the underlying mechanisms are not easy to unravel. Using tomato plants as a model system, we demonstrated that a soil fungus, Trichoderma afroharzianum, widely used as a biocontrol agent of plant pathogens, negatively affects the development and survival of the lepidopteran pest Spodoptera littoralis by altering the gut microbiota and its symbiotic contribution to larval nutrition. Our results indicate that insect-plant interactions can be correctly interpreted only at the metaorganism level, focusing on the broad network of interacting holobionts which spans across the soil and the above-ground biosphere. Here, we provide a new functional framework for studying these intricate trophic networks and their ecological relevance.
Abstract
Plants generate energy flows through natural food webs, driven by competition for resources among organisms, which are part of a complex network of multitrophic interactions. Here, we demonstrate that the interaction between tomato plants and a phytophagous insect is driven by a hidden interplay between their respective microbiotas. Tomato plants colonized by the soil fungus Trichoderma afroharzianum, a beneficial microorganism widely used in agriculture as a biocontrol agent, negatively affects the development and survival of the lepidopteran pest Spodoptera littoralis by altering the larval gut microbiota and its nutritional support to the host. Indeed, experiments aimed to restore the functional microbial community in the gut allow a complete rescue. Our results shed light on a novel role played by a soil microorganism in the modulation of plant–insect interaction, setting the stage for a more comprehensive analysis of the impact that biocontrol agents may have on ecological sustainability of agricultural systems.
Bioluminescence May Shine Light on Roundworm Secrets
USDA
For media inquiries contact: Jan Suszkiw Even though roundworms are nearly too small to be seen, they can pose major problems in corn, soybean, peanut and other crops. Collectively, these roundworms are known as plant-parasitic nematodes, and they cause $173 billion in crop losses worldwide each year.
These losses to crop yield and quality can occur even though chemical controls, resistant cultivars and other methods are available to farmers. So, a team of Agricultural Research Service (ARS) and university scientists decided to take a deeper dive into the basic biology of these nematodes and, more specifically, their genes for reproducing.
But the furtive nature of these millimeter-long pests and peculiarities of their lifecycle evaded the latest high-tech tools that the scientists had hoped to study them with.
Fortunately, they found a “work-around” in the form of electroporation. In short, the technique involves immersing nematodes in a plexiglass chamber with a buffer solution and pulsing it with small jolts of electricity. This stuns the creatures and temporarily opens pores in their bodies through which the solution’s chief “active ingredient” can enter—namely, bits of genetic material called NanoLuc luciferase mRNA.
Luciferase is an enzyme that oxidizes a compound called luciferin, producing a type of light called bioluminescence, such as that emitted by fireflies. In this instance, scientists “retooled” a luciferase coding sequence taken from a bioluminescent, deep-sea shrimp and electroporated it into the nematodes.
“Nematodes have primitive nervous systems,” explained Leslie Domier, a plant pathologist (retired) with the ARS Soybean/Maize Germplasm, Pathology, and Genetics Research unit in Urbana, Illinois. “When they were electroporated, they were immobilized for up to an hour, but then recovered and behaved normally.” Scientists then harvested the nematodes so that the contents of their cells, including luciferase, could be blended into a mixture called a “homogenate.” Next, they mixed the homogenate with a luciferin-like chemical called furamazine and presto—bioluminescence achieved!
Rather than observe this with the naked eye, the scientists used biochemical assays and sensitive light-detecting equipment to gauge the strength of the homogenate’s bioluminescence and determine how well their experiments had worked. So far, the researchers have successfully electroporated luciferase mRNA into the likes of soybean cyst nematodes (SCN) and root-knot nematodes—both costly crop pests—and Caenorhabditis elegans, a free-living species that doesn’t require a host in which to reproduce.
According to Glen Hartman, another plant pathologist (ARS retired) on the research team, the approach opens the door to introducing other synthetic mRNAs into nematodes to reveal how they change and where, as well as when the nematode’s own genes are activated in cells.
There may be pest-control applications, as well. For example, electroporation could offer a way to rear laboratory colonies of soybean cyst nematodes that carry pieces of genetic code whose sole purpose is to skew the ratio of male- to-female offspring. In theory, releasing these lab-reared nematodes to mate with those in the wild would eventually cause a generational population crash.
“We hypothesized that if we could interfere with the sex determination in nematodes, we could reduce nematode populations below crop-damaging thresholds,” said Domier. That, in turn, could diminish the need for chemical controls or help prolong the effectiveness of elite, resistant cultivars favored by growers, among other potential benefits.
More details about the technique and its implications for nematode control were reported in the journal Molecular & Biochemical Parasitology by Domier, Hartman and co-authors Thanuja Thekke-Veetil and Kris Lambert—both with the University of Illinois—Nancy McCoppin (ARS), Reza Hajimorad (University of Tennessee) and Hyoun-Sub Lim (Chungnam National University).
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 U.S. agricultural research results in $20 of economic impact.
Iron treatment boosts rice immune system, shows study
by Center for Research in Agricultural Genomics (CRAG)
Rice plant leaves which have been treated or not with iron (5 days) and infected with the fungus M. oryzae. Credit: CRAG
Rice (Oryza sativa L) is the world’s most widely used cereal for human consumption and the second most produced in the world after maize. However, rice production is seriously threatened by rice blast, a fungal disease that has been reported in more than 80 countries on all continents, including the growing areas of almost all rice-producing regions in Spain (Andalusia, Extremadura, Catalonia, Valencia, etc.).
A study recently published in the journal Rice and led by Blanca San Segundo, CSIC researcher at CRAG, has revealed that exposing rice plants to moderately high levels of iron increases resistance to infection by the pathogenic fungus Magnaporthe oryzae, the agent causing rice blast, the most common disease in this crop and responsible for large production losses worldwide.
Iron is an essential nutrient for plant growth and development. Although it is an abundant element in most agricultural soils, its availability to crops might be low. Depending on the soil characteristics, iron is found in its insoluble or soluble form, and therefore the plant can absorb it more or less effectively. In addition, both a deficiency and an excess of iron can become toxic to the plant. Thus, the precise control of the amount of iron as well as its bioavailability turn out to be crucial for the correct growth and productivity of the crops.
Using RNA sequencing methods, which enables the analysis of expression levels of different genes, the research team has detected the activation of several genes related to plant defenses when rice has been treated with iron for a short period of time. In addition, the presence of iron increases the expression of genes related to the generation of phytoalexins, molecules with antifungal activity which are able to inhibit the growth of Magnaporthe oryzae. Thus, it has been possible to demonstrate that a moderate treatment with iron activates the innate immune system of rice.
This work reveals that, under infection conditions, in the leaves of plants treated with iron, an accumulation of both reactive oxygen species (ROS) and iron is observed in specific and very localized regions of the infected leaf, which correspond to the pathogen entry points. This triggers a process of programmed cell death in the plant cells, known as ferroptosis, which limits the progression of the fungus in the infected tissue and therefore the infection is controlled by the plant itself.
“The cell suicide response or ferroptosis has been described in rice varieties resistant to infection by M. oryzae (incompatible interactions). However, it is the first time that this response has been observed in rice plants that are susceptible to infection by this fungus as a result of iron treatment. Iron has a function that enhances the immune response in the rice plant,” says Blanca San Segundo, the leading researcher of the study.
Previous studies by the same group already pointed out that nutrients could play a key role in the resistance or susceptibility to infection by this fungus. The same research team published in 2020 that excess of phosphate, as a consequence of the excessive use of phosphate fertilizers, has the opposite effect since it makes rice more susceptible to infection by the same fungus.
Understanding the relationship between the supply of nutrients (macronutrients and micronutrients) and the defense response of the plant against pathogens can be very useful when designing new protection strategies against blast disease and hence minimize the associated economic losses. In addition, this knowledge will contribute to establish more sustainable practices for growing rice by reducing the use of agrochemicals (fertilizers and pesticides).
More information: Ferran Sánchez-Sanuy et al, Iron Induces Resistance Against the Rice Blast Fungus Magnaporthe oryzae Through Potentiation of Immune Responses, Rice (2022). DOI: 10.1186/s12284-022-00609-w
Provided by Center for Research in Agricultural Genomics (CRAG)
>On her first day of work as an assistant professor of entomology and nematology at the University of Florida, Nicole Quinn, Ph.D., explored her new research setting, the quarantine lab at the Indian River Research and Education Center in the Hayslip Biological Control Research and Containment Laboratory in Fort Pierce, Florida.
By Karen Poh, Ph.D.Editor’s Note: This is the next post in the “Standout ECPs” series contributed by the Entomological Society of America’s Early Career Professionals (ECP) Committee, highlighting outstanding ECPs that are doing great work in the profession. (An ECP is defined as anyone within the first five years of obtaining their terminal degree in their field.)Read past posts in the Standout ECPs series.
Nicole Quinn, Ph.D., is an assistant professor of entomology and nematology at the University of Florida Indian River Research and Education Center (IRREC) in Fort Pierce, Florida. She received a B.S. in biology with a minor in English from Gettysburg College, an M.S. in entomology from Michigan State University, and a Ph.D. in entomology from Virginia Tech. She completed her postdoctoral research at the U.S. Department of Agriculture-Agricultural Research Service (USDA-ARS) Beneficial Insect Introduction Research Unit in Newark, Delaware, before starting her current position at the University of Florida, where she studies classical biological control of invasive insects.Within the Entomological Society of America, Quinn has received several awards and travel scholarships including the President’s Prize for the student 10-minute paper competition and the North Central Branch Student Travel Scholarship. She currently serves as the early-career professional (ECP) representative on the Plant-Insect Ecosystems (P-IE) Section Governing Council and vice chair of the ESA ECP Committee.Poh: We love a good origin story, so can you give us a quick biography and background about yourself?Quinn:Sure! I grew up in Medway, Massachusetts, which is a small town outside of Boston. I am not from an academic family by any means. The only scientist I knew was probably Bill Nye the Science Guy. I loved bugs from a young age and spent a lot of time flipping over rocks. My dad had a big role in developing my interest in nature; we spent a lot of time fishing and hiking.Like many kids with an interest in animals, when it came time to think about careers I was really pushed into pursuing veterinary medicine. It seemed like the right choice because I was completely unaware of any potential careers in entomology. It wasn’t the right fit for me and so I returned to my first love: insects and ecology. I did several independent research (capstone) projects and an internship with an entomology lab and really fell in love with research and field work.After I graduated from Gettysburg College in 2012 with a B.S. in biology and minor in English, I felt very “done with school” and decided to join the workforce. This proved very challenging as a new graduate in yet another economic collapse! Eventually I found a job working at a science journal. Almost immediately however, I started working on my exit plan as it didn’t hold my interest at all. The two-hour commute by train probably didn’t help.While I was applying to graduate programs I ended up working as a temporary technician for about six months in east Texas as part of a project studying insectivorous bats. I spent my days driving an ATV and hiking through a swampy wildlife management area collecting blacklight insect samples and bat call recordings. It was challenging, dirty, but fun work! This adventure really solidified for me that this was what I wanted to do.From here my story is pretty straightforward. I graduated with an M.S. in entomology in December 2015. I studied habitat management for beneficial insects in squash and cucumber with Dr. Zsofia Szendrei. In December 2019, I finished my Ph.D. in entomology, which was co-advised by Dr. Chris Bergh and Dr. Tracy Leskey. My Ph.D. focused on the biological control of the brown marmorated stinkbug (Halyomorpha halys), with a focus on its adventive parasitoidTrissolcus japonicus. I started my postdoc at the USDA-ARS Beneficial Insect Introduction Research Unit in March 2020 with Dr. Jian Duan (USDA-ARS) and Dr. Joe Elkinton (University of Massachusetts). What a time to start something new right?! Despite the pandemic, my postdoc remains one of my favorite periods of my career.I started as an assistant professor of entomology and nematology the University of Florida Indian River Research and Education Center in July 2022. Specifically, I work in the Hayslip Biological Control Research and Containment Laboratory, where I study classical biological control of invasive insects.
Your past and present research focuses on biological control of different agricultural pests. What inspired you to pursue these different topics? What have been some of the major findings of your research thus far?Great question! The honest answer is that it didn’t start out this way. I was initially more drawn to basic ecology and tropical ecology. However, I realized that you can study these concepts in an applied setting. This allows you to get funding more easily of course, but, more importantly, I like knowing that the work I am doing has real-world applications that help people. At heart I am a pragmatist.Biological control is amazing in that, once established, it can provide long-lasting self-sustaining benefit to stakeholders with minimal inputs. For example, my postdoctoral research demonstrated that the introduced parasitoids for emerald ash borer (Agrilus planipennis) are better at dispersing and establishing than initially thought and are a significant source of emerald ash borer mortality. Of course, this does not mean that the invasive species will ever “go away!” But, reducing invasive species impact is really important economically and ecologically.With your background in the biological sciences, how did you become interested in entomology? Was there a specific moment where you knew you wanted to continue exploring the field of entomology?I became interested in entomology as a formal field of study during my undergraduate degree. I wouldn’t say there was a specific moment but several key moments. I studied abroad in Ecuador, which really reignited my interest in field ecology and entomology, especially natural enemies. Perhaps more importantly though was my internship with Dr. Greg Krawczyk at the Penn State University Fruit Research and Extension Center. He was the first entomologist I ever met and was very patient with me in answering my incessant questions! This also allowed me to get some hands-on experience in an entomology lab.After you completed your Ph.D., you moved into a postdoctoral position with the USDA-ARS Beneficial Insects Introduction Unit and the University of Massachusetts. What was it like to move to a different research system and work between academic and federal researchers?It was definitely a transition, but not in the way you would think! People always mention the excessive “red tape” associated with working with the government, but in my experience it is not any more burdensome than what you see at universities. As you alluded to, one of the main things I learned in my postdoc is how to coordinate diverse teams—both people and institutions. Modern research is collaborative by necessity. I also think collaborative work is more fun!My postdoc really helped me become a better communicator and team leader. When you are a student, you are responsible for your own project, and that’s essentially it. When you are a postdoc, you have more responsibilities, most of which are related to writing and managing other people. That transition is really hard at first. I spent a lot of time calling and emailing, ensuring everyone was on the same page. Getting a team to pull in the same direction can be challenging, but it’s hugely rewarding!An important aspect of managing multi-institutional teams is being aware of the rules and regulations associated with each institution. For example, the USDA has certain requirements about publication submission that universities do not. Being mindful of everyone’s needs from the outset can ensure a more successful project. This also includes personal needs, both yours and theirs. Clear, consistent communication and flexibility is key.You recently started as an assistant professor at the University of Florida Indian River Research and Education Center. Tell us a little bit more about your current position and what your day-to-day looks like.My work focuses on classical biological control of invasive insects in Florida. Classical, or importation, biological control involves the importation of candidate biological control agents from an invasive species’ native range, with the ultimate goal of releasing the agent to regulate the target insect’s population to a lower level, thus reducing the target’s impact.I am truly fortunate to have ended up at IRREC: I have huge amounts of laboratory space both in and out of quarantine, multiple greenhouses, environmental chambers, temperature and humidity controlled rearing rooms—you name it, it is here! The faculty and staff at IRREC and on main campus have been very supportive and welcoming as well.Last year I submitted a permit request (USDA APHIS 526) that, if approved, will allow me to bring back natural enemies of my first target insect,Nipaecoccus viridis, to rear in quarantine.This will allow me to perform a variety of studies, including host range testing. In the meantime, I have several other field and lab studies in the works. I also have a small project with snails that will be starting soon. I never thought I would end up working on snails, but there was a need, so here we are!My day-to-day involvesa lotof time at the computer, more than I would have ever thought possible. I’m constantly writing manuscripts, grants, reports, or just emails. I also have a lot of in-person and Zoom meetings. I also travel more than I ever thought possible. I do not get to spend as much time “playing with bugs” as I might like, but I am having a lot of fun building my program and relationships with other researchers.
Do you have any advice for students who might be interested in going into academia? What are some things students should think about as they are deciding on future careers in the academic sector? What skills do you think someone needs to be successful in academia?My number-one piece of advice for people just starting out: Do things you enjoy, and don’t waste your time on things that you don’t. Academia is a hard path. If you are not working on something that you love, it will be extremely difficult to persevere when things inevitably get tough. I believe that anyone can succeed in academia if they are studying something they are passionate about and have the support of mentors or other people in their support network.Another important piece of advice: Work on your communication skills. “Use your words,” when you want or need something, or if you have a question. Encourage others to do the same. Accept feedback without judgement or deflection. It sounds simple, but small steps like this will allow your research team to function better and ultimately result in better work.You are also the new ESA Early Career Professionals (ECP) Committee vice chair. What are some ideas or initiatives you hope to pursue as the vice chair and eventually the chair of the ECP Committee?I think it will be important to poll our memberships to see what needs there might be. Outside of that: I see opportunities for us to provide some programming on project management. Another thing I’ve been thinking about is perhaps something for dual-career couples. I know of many early-career folks who are in relationships with other entomologists, myself included, which has its own set of challenges. Again though, it all depends on what our members want to see.With your involvement on the ECP Committee, what tips do you have for students and ECPs on how to get more involved within their ESA Section or Branch or the Society overall? What can they do to get the most out of ESA as an organization?My advice is to reach out to your Branch to see what opportunities might be available! Many opportunities have a surprisingly small applicant pool. You need to be your own best advocate. Keeping an eye on the newsletters can be helpful, too. If you are not selected for an opportunity, keep trying!When you’re not busy conducting biological control experiments in the lab or field, what are some ways you like to spend your time winding down from a busy workday or week?I enjoy running, hiking, and spending time with my husband and pets. We live on the coast now, and we’ve been really enjoying exploring all the natural areas near us! I also keep about 120 tarantulas and some snakes.Thank you for taking the time to talk with us about your experiences, Nicole! If you want to connect with Nicole and learn more about her work, you can find her onGoogle Scholar,ResearchGate,Twitter,Mastodon, andher personal website.Karen Poh, Ph.D., is a research entomologist at the U.S. Department of Agriculture and the Medical, Urban, and Veterinary Entomology Section Representative on the ESA Early Career Professionals Committee. Twitter: @areyoukeddingme. Email:karen.poh@usda.gov.All photos courtesy of Nicole Quinn, Ph.D.
As part of a study on the diversity of wild bee species involved in pollinating fruit crops over multi-year periods, a group of researchers mapped the timing of peak abundance for each species. One of the more than six dozen species of wild bees to visit eastern watermelon fields was Agapostemon texanus, sometimes known as the Texas sweat bee (male shown here). (Photo by Thomas Langhans via Flickr, republished with permission)
By Leslie Mertz, Ph.D.
Leslie Mertz, Ph.D.
Greater biodiversity yields greater ecosystem resilience. Despite the overwhelming acceptance of this concept, called the “insurance hypothesis,” validation for it has been sparse. A detailed study of wild bee species in fruit crops, however, has provided clear data showing that diversity in these vital pollinators is necessary for consistent flower cross-fertilization over multiple years.
“It’s a little surprising to me: This is one of the more talked-about ideas dealing with sustainability, biodiversity, and ecology,” says Rachael Winfree, Ph.D., professor of ecology, evolution and natural resources at Rutgers University. “But people haven’t really tested it empirically all that often—actually collected the data to see how it plays out—and that is exactly what this paper did.”
Winfree is a co-author of the study, published in August 2022 in Nature Ecology & Evolution. It tracked which wild bee species were doing the pollinating in two common fruit crops and found that species not only rotated during a single season but also varied from year to year.
“This is actually evidence that, yes, biodiversity really does matter. You do see fluctuations from year to year, so diversity does provide insurance for the pollination services the bees provide,” says Natalie Lemanski, Ph.D., who conducted the analytics side of the research as part of Winfree’s group and was the study’s lead author. Lemanski is now assistant professor of biology at Ramapo College of New Jersey.
For the study, the researchers identified which wild bee species were visiting blossoms over a three-year span on 16 blueberry farms in the eastern U.S. and 36 watermelon farms in the western U.S. as well as over a six-year span on 25 watermelon farms in the eastern U.S. That involved a great deal of meticulous identification work, but they took it one step further. They also wanted to know how much pollination each species was supplying, so they collected individual bees, allowed each to pollinate a virgin flower, and then counted the number of pollen grains deposited.
“So, if a single bee of this species deposits five pollen grains on average, then we can multiply that by how many visits this species is making in a given time period and use that to estimate the amount of pollen being delivered by a species in the field,” Lemanski says.
“That was quite time-consuming work to do and probably a big part of why we don’t have more of these types of longer-term datasets,” she says. “But, if you don’t look over the long term, you might be missing the fact that different bees might be important in different years or even in different parts of one year.”
The three- and six-year datasets provided a clear picture of the changeover in wild-bee pollinators. On the blueberry farms, the number of species needed to maintain a threshold level of pollination was 47 percent higher over a three-year span versus a single year. On watermelon farms, the number of needed species was 62 percent higher over three years versus one year, and 219 percent over a six-year span versus a single year. Lemanski speculates that longer-span datasets would likely reveal that even more species engage in pollination.
Although the study didn’t investigate the specific causes of species variability, many things can account for differences over a season or over years, and that includes climate change. “Climate change can make a difference in a variety of ways. One way is just through more extreme weather events that may favor certain species over others,” Winfree says. “Whenever the environment you’re living in gets more variable, it tends to be the case that you benefit from having a lot of different species, because chances are you’ll have some that are okay with the current environment, and some that aren’t.”
This study underlines why detailed, multi-year studies, as well as careful analytics, are critical to understanding ecosystem function, Lemanski says: “Going out into the field in your cargo shorts and boots is an important part of ecology, but finding patterns in data is also a huge part of ecology work, and looking at the data over years and in new ways can give you new insights. Absolutely.”
Leslie Mertz, Ph.D., writes about science and runs an educational insect-identification website, www.knowyourinsects.org. She resides in northern Michigan.
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