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Archive for the ‘Fungi’ Category

Red rot disease: Punjab minister asks for survey to assess damage to sugarcane crop


PTI | Chandigarh | Updated: 08-09-2021 21:10 IST | Created: 08-09-2021 21:08 IST

Red rot disease: Punjab minister asks for survey to assess damage to sugarcane crop
Representative Image Image Credit: ANI

Punjab Cooperation Minister Sukhjinder Singh Randhawa on Wednesday asked district administrations of Gurdaspur and Jalandhar to conduct a survey to assess the damage caused to the sugarcane crop by red rot fungus disease.

Randhawa also asked the cooperation department to prepare a compressive report for the perusal of Chief Minister Amarinder Singh, who also holds the portfolio of agriculture, to work out an effective action plan in this matter.

Chairing a meeting to review the current situation that emerged after the outbreak of this disease, the minister directed the deputy commissioners to work in tandem with the Punjab Agricultural University, cane commissioner and others, to find ways and means to combat the disease to save the crop, according to an official statement.

Randhawa stressed the need to intensify research for exploring the factors that led to a sudden attack by fungus on sugarcane.

He appealed to the cane growers not to panic in the wake of disease rather he asked the authorities to identify the hotspot areas to effectively tackle the fungus.

Joining the deliberations through video conferencing, S K Pandey, principal scientist and head of sugarcane, Breading Institute, Regional Centre, Karnal, said this disease had already affected the sugarcane crop in Uttar Pradesh and Haryana in the past due to the problem of waterlogging.

He, however, said that intensive research in this regard revealed that ‘Co 0238’ variety of sugarcane was mainly prone to this fungus and the farmers in these states who had suffered substantial losses were told not to grow this variety in future.

(This story has not been edited by Devdiscourse staff and is auto-generated from a syndicated feed.)

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Sri Lanka’s fast spreading leaf disease could wipe out rubber in fertilizer ban, industry warns

Wednesday September 1, 2021 1:05 pm

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ECONOMY NEXT – Sri Lanka’s large rubber industry has warned of a 15 to 20 percent production drop this year as leaf disease spread rapidly without enough fungicide to combat it or fertilizer to help trees recover amid an agro-chemical import ban.

Growers may be forced to shift to alternative crops as yields fall and immature plants are also hit, industry officials said.

About 20,000 hectares out of 107,000 cultivated by large farms and small holders have been hit by Pestalotiopsis, fungal leaf disease, Colombo Rubber Traders Association, an industry grouping said.

Sri Lanka’s President Gotabaya Rajapaksa has banned agro-chemicals to save foreign currency and to stop non-communicable diseases.

Sri Lanka’s Government Medical Officers Association has said according to Pliny the elder, ancient Sri Lankans lived for 140 years, when there were no agro-chemicals.

“This leaf disease is possibly best described as the equivalent of COVID-19 in the case of the rubber industry, considering both its devastation and the rapid speed at which it is spreading,” Manoj Udugampola Vice Chairman of the Colombo Rubber Traders’ Association (CRTA) said in a statement.

Farms needed fungicides, Carbendazim and Hexaconazole and also fertilizer to help the trees recover leaves.

But after the fertilizer ban, neither additional quantities or nor usual volumes were available.

Earlier in the year, some inputs had been available at the double the price before the ban, but there was no fertilizer in the market.

By July/August mature and immature plants needed fertilizer to use in recommended amounts.

“By around April – May this year we were already seeing a 10 to 20 percent reduction in output from rubber plantations due to Pestalotiopsis,” Udara Premathilake, Director Plantations (Rubber), Kelani Valley Plantations PLC said.

“Since we continue to incur huge fixed costs including labour costs in running our operations, the reduction in output is reducing our revenue substantially and therefore our profits, so the industry is fast becoming unviable.

“At this rate by year-end we are looking at a 15% to 20% reduction of the annual output. We are not sure where the industry would stand by next year.

“When this disease spreads to immature plants, their long-term growth will be badly affected.

“Since rubber trees have a life span of around 30 years this translates to a long-term decline in production. As concerted action should be taken at least now, or the industry will be unviable both in the short and the long-run.”

Companies were already looking at other crops like cardamom, pepper and cinnamon, he said.

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Tolerance to virulence phenotypes of Phytophthora capsici in pasilla pepper cultivars

Phytophthora capsici is the most important limiting factor in the production of chile pepper in Mexico. This pathogen presents virulence phenotypes capable of infecting diverse cultivars of this crop. The search and development of resistance in chile pepper is an excellent alternative for the management of P. capsici. The objective of this work was to evaluate the response of four pasilla pepper cultivars to infection with five virulence phenotypes of P. capsici. Pasilla pepper landraces PAS-1, PAS-2, PAS-3, and PAS-4 were inoculated with P. capsici isolates MX-1, MX-2, MX-7, MX-8, and MX-10. Two experiments were conducted under greenhouse conditions from April through June 2017 and April through June 2018. ‘California Wonder’ was included as a susceptible control, and uninoculated plants were included as a negative control. In each experiment, groups of six 56-day-old plants from each pepper cultivar were inoculated with each virulence phenotype. Disease severity was evaluated 20 days after inoculation using an individual plant severity scale. All pepper cultivars were classified as resistant = R, moderately resistant (MR), tolerant (T), moderately tolerant (MT), or susceptible (S), according to the frequency of resistant plants (severity 0–1). ‘California Wonder’ and ‘PAS-4’ were susceptible to all five virulence phenotypes. The rest had different responses to the virulence phenotypes, but ‘PAS-2’ and ‘PAS-3’ were susceptible to only one of the five virulence phenotypes. Pasilla peppers with low severity exhibited a slow rate of infection, which is a mechanism we have called “slow wilting.” The pasilla pepper cultivars PAS-1, PAS-2, and PAS-3 could be used in plant breeding programs as sources of genetic tolerance and moderate resistance against P. capsici.

Read the entire paper at journals.ashs.org

Publication date: Mon 30 Aug 2021

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Aspergillus niger fungus growing on a white onion

Modified yeast inhibits fungal growth in plants

External application could reduce agricultural reliance on fungicides

AUTHOR: HOLLY OBER July 14, 2021 SHARE THIS: FacebookTwitterLinkedInEmailPrintFriendly

About 70-80% of crop losses due to microbial diseases are caused by fungi. Fungicides are key weapons in agriculture’s arsenal, but they pose environmental risks. Over time, fungi also develop a resistance to fungicides, leading growers on an endless quest for new and improved ways to combat fungal diseases. 

The latest development takes advantage of a natural plant defense against fungus. In a paper published in Biotechnology and Bioengineering, engineers and plant pathologists at UC Riverside describe a way to engineer a protein that blocks fungi from breaking down cell walls, as well as a way to produce this protein in quantity for external application as a natural fungicide. The work could lead to a new way of controlling plant disease that reduces reliance on conventional fungicides.

To gain entrance into plant tissues, fungi produce enzymes that use catalytic reactions to break down tough cell walls. Among these are polygalacturonases, or PGs, but plants are not helpless against this attack. Plants produce proteins called PG-inhibiting proteins, or PGIPs, that slow catalysis.

Yanran Li
Yanran Li

A group of UC Riverside researchers located the segment of DNA that tells the plant how to make PGIPs in common green beans. They inserted complete and partial segments into the genomes of baker’s yeast to make the yeast produce PGIPs. The team used yeast instead of plants because yeast has no PGIPs of its own to muddy the experiment and grows quicker than plants.

After confirming the yeast was replicating with the new DNA, the researchers introduced it to cultures of Botrytis cinerea, a fungus that causes gray mold rot in peaches and other crops; and Aspergillus niger, which causes black mold on grapes and other fruits and vegetables. 

Yeast that had both the complete and partial DNA segments that coded for PGIP production successfully retarded fungal growth. The result indicates the yeast was producing enough PGIPs to make the method a potential candidate for large-scale production.

Alexander Putman
Alexander Putman

“These results reaffirm the potential of using PGIPs as exogenous applied agents to inhibit fungal infection,” said Yanran Li, a Marlan and Rosemary Bourns College of Engineering assistant professor of chemical and environmental engineering, who worked on the project with plant pathologist Alexander Putman in the Department of Microbiology and Plant Pathology. “PGIPs only inhibit the infection process but are likely not fatal to any fungi. Therefore, the application of this natural plant protein-derived peptide to crops will likely have minimal impact on plant-microbe ecology.”

Li also said that PGIPs probably biodegrade into naturally occurring amino acids, meaning fewer potential effects for consumers and the environment when compared with synthetic small molecule fungicides.

“The generation of transgenic plants is time-consuming and the application of such transgenic crops in agricultural industry requires a long approval period. On the other hand, the engineered PGIPs that are derived from natural proteins are applicable as a fast-track product for FDA approval, if they can be utilized exogenously in a manner similar to a fungicide,” Li said.

By tweaking the yeast a slightly different way, the researchers were able to make it exude PGIPs for external application. Previous studies have shown freeze drying naturally occurring microbes on apples, then reconstituting them in a solution and spraying them on crops, greatly reduces fungal disease and loss during shipping. The authors suggest that PGIP-expressing yeast could be used the same way. They caution, however, that because plants also form beneficial relationships with some fungi, future research needs to ensure plants only repel harmful fungi.

Li will continue to engineer PGIPs for enhanced efficiency and broader spectrum against various pathogenic fungi. Meanwhile, Li and Putman will keep evaluating the potential of using engineered PGIPs to suppress fungi-induced pre-harvest and post-harvest disease.  

Li and Putman were joined in the research by doctoral student Tiffany Chiu and plant pathologist Anita Behari, both of whom are at UC Riverside, and Justin Chartron, who was a professor at UC Riverside when the research was conducted. The paper, “Exploring the potential of engineering polygalacturonase‐inhibiting protein as an ecological, friendly, and nontoxic pest control agent,” is available here. The work was supported by LG Chem Ltd. and the Frank G. and Janice B. Delfino Agricultural Technology Research Initiative and partially supported by the National Institutes of Health.

Header photo: Aspergillus niger fungus growing on a white onion. (S. K. Mohan, Bugwood.org)

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New study shows decreasing effectiveness of fungicides to control the devastating Black Sigatoka disease of banana

Published onMay 19, 2021

The fungus Pseudocercospora fijiensis causes black leaf streak disease or Black Sigatoka of banana, which is the most damaging leaf disease of bananas worldwide. An analysis of 592 P. fijensis isolates from seven banana-producing countries on three continents shows how P. fijensis is evolving to insensitivity to azole fungicides due to the heavy use of pesticides.

The results of the study have been published in Pest Management Science and underscore the need to stop this vicious circle by developing alternative disease control methods and new banana varieties.

Black leaf streak disease is the most important banana disease worldwide. Cavendish bananas represent more than 50% of the global production – and dominate the export (95%) – but are very susceptible to this disease. In most countries, banana production relies on continual intensive disease control, usually at weekly intervals, throughout the year. It demonstrates the fragility of global banana production and its overall unsustainability. Azole fungicides are the cornerstone for fungal disease control in plants, animals and humans.

Nieuwe studie bevestigt dat verwoestende bananenziekte Black Sigatoka wereldwijd resistent raakt tegen pesticiden 2.jpg

First comprehensive analysis of reduced sensitivity

This study is the first comprehensive analysis of reduced sensitivity to these fungicides in banana production. In their study, researchers of Wageningen University & Research (WUR) and their collaborators, analyzed 592 P. fijensis isolates from seven countries in Latin America, the Caribbean, Africa and Southeast Asia for the sensitivity to three azole fungicides.

In addition, they sequenced the target gene – Pfcyp51 – in 266 isolates, to determine every mutation and analyzed the overall genomes of 155 isolates to study geographical clustering. All identified mutations could be associated with reduced sensitivity to the fungicides. This trend results in a vicious circle of even more fungicide applications in banana cultivation. Taken together, these alarming data call for a new view on sustainable banana production. For the benefit of the manifold producers and domestic and international consumers.

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Ghent scientists develop vaccine against potato blight

Monday, 16 August 2021

By Alan Hope

Potatoes in the field. © Pixabay

Scientists at the university of Ghent have developed a vaccine to combat potato blight, one of the most common diseases in potatoes, and the one that led to the Great Famine in Ireland in the 1840s.

Potato blight or late blight is caused by the organism Phytophthora infestans, a type of fungus that can also attack tomatoes. There is also another unrelated disease known as potato blight or early blight, caused by a different organism.

Late blight was responsible for the failure of potato crops, leading to famine in Europe in Europe in the 1840s, in Ireland in the years 1845-1852, and in the Scottish Highlands in 1846.

The usual treatment currently is with fungicides, but that can lead to problems related to over-use, producing eco-toxic results.

But now a team from the faculty of bio-engineering sciences at Ghent University has developed a vaccine that can prevent late blight without the negative environmental side-effects.

The vaccine works like any other: by using a mutation of P. infestans to provoke an immune response, the vaccine allows the plant to develop its own immune system to protect against the disease.

“On unprotected potato fields, the pathogen can cause the entire harvest to fail within a period of seven to ten days,” explained Professor Geert Haesaert, who leads the project.

That option is very much reduced by the EU’s Green New Deal, which foresees a 50% reduction in fungicide use.

“Our research group therefore started to search for alternatives, including a possible effect of Green Leaf Volatiles or GLVs on the resistance of the potato plant to the pest,” he said.

GLVs, in fact, use a natural phenomenon to increase plant resistance to disease organisms. The volatile substances are released naturally when plants undergo fibre damage, for example when grass is being cut. Some GLVs have been found to improve plant resistance even in other species.

That unique property is now being studied by the CropFit group in the university’s Plant and Crops group, with special attention to the Bintje potato – particularly susceptible to late blight, and coincidentally Belgium’s favourite, especially for making frites.

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New Technology Delivers Resistance Against Cercospora — The ‘No. 1 Production Problem’ In Sugarbeets

By Becca Roberts Last updated Aug 16, 2021

New technology delivers resistance against cercospora — the 'No. 1 production problem' in sugarbeets

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New sugarbeet seed varieties resistant to cercospora leaf spot disease were commercially available for growers to plant in southern North Dakota and Minnesota in 2021. The improved varieties will save tens of millions of dollars in spray and processing costs and could save hundreds of millions in crop losses.

Mohamed Khan, a professor and Extension sugarbeet specialist for the University of Minnesota and North Dakota State Unviersity, said he expects to see most farmers to adopt the technology in the next three years. He thinks its use in the next two or three years will extend to Michigan, Montana, Nebraska, Colorado and Wyoming.

Sugarbeets are the most prominent specialty crops from southern Minnesota to the Canadian border through the Red River Valley, accounting for some $5 billion in economic activity. But that activity can be hurt by cercospora, which turns green leaves brown, shutting down yield potential.

The new CR+ (cercospora resistance plus performance), from KWS Saat, parent company for Betaseed, commercialized seed for some growers in southern Red River Valley of North Dakota and into southern Minnesota.

This year’s sugar beet crop near Foxhome, Minn., shows potential for a healthy, 30-ton-per-acre yields, but Cercospora leaf spot can quickly cut yields, reduce sugar content from 18% sugar down to 15%, and increase the processing costs of removing impurities. Photo taken July 16, 2021, at Foxhome, Minn. Mikkel Pates / Agweek

This year’s sugar beet crop near Foxhome, Minn., shows potential for a healthy, 30-ton-per-acre yields, but Cercospora leaf spot can quickly cut yields, reduce sugar content from 18% sugar down to 15%, and increase the processing costs of removing impurities. Photo taken July 16, 2021, at Foxhome, Minn. Mikkel Pates / Agweek

German-based genetics company KWS Saat in its website on the topic says about two-thirds of global sugarbeet acreage has a moderate to high cercospora pressure. Cercospora is the most destructive leaf disease of sugarbeets, sometimes cutting crop yield by 50% in some places, the company says on its website.

Khan said the new technology will prolong the usefulness of other fungicide treatment.

“It’s a real game-changer,” he said, describing the technology in a private tour of his cercospora research plots near Foxhome, Minn., about an hour east of Fargo, N.D. The site has a plot tour on Aug. 24, 2021.

Khan manages research/demonstration plots annually of about 25 acres on land farmed by Kevin Etzler of Foxhome. The research is open to the public, usually replicated four times, on a scale similar to typical farm fields. Here, the Minn-Dak Farmers Cooperative of Wahpeton, N.D., and American Crystal Sugar Co., of Moorhead, Minn., evaluate (blind-)“coded” varieties they test for various seed companies to ensure they meet minimum standards for cercospora vulnerability. Much is at stake.

Extension Service sugarbeet specialist Mohammed Khan supervises inoculation and other studies at sugar beet research plots at Foxhome, Minn., helping to evaluate new disease-resistant varieties and fungicide spray regimens. Photo taken July 16, 2021, at Foxhome, Minn. Mikkel Pates / Agweek

Extension Service sugarbeet specialist Mohammed Khan supervises inoculation and other studies at sugar beet research plots at Foxhome, Minn., helping to evaluate new disease-resistant varieties and fungicide spray regimens. Photo taken July 16, 2021, at Foxhome, Minn. Mikkel Pates / Agweek

Infested fields hit can easily lose 40% of their yield and about 2 to 3 percentage points of sugar — a loss of millions of pounds of sugar and millions of dollars throughout the growing regions.

“You can easily lose $300, $400, $500 per acre,” Khan said.

A primer on the history of cercospora

South to north

University researchers at Foxhome, Minn., test plots inoculate varieties to help study disease resistance and effectiveness of fungicide combinations. Photo taken July 16, 2021, at Foxhome, Minn. Mikkel Pates / Agweek

University researchers at Foxhome, Minn., test plots inoculate varieties to help study disease resistance and effectiveness of fungicide combinations. Photo taken July 16, 2021, at Foxhome, Minn. Mikkel Pates / Agweek

Since 2016 in the Minnesota/North Dakota region, cercospora has been most prevalent in the two southern co-ops: Minn-Dak Farmers Cooperative and Southern Minnesota Beet Sugar Cooperative. The areas where those co-ops operate generally get more rainfall and heat, which increases yields but also creates more problems with cercospora. Over the past two decades, sugarbeet yields have increased nearly 50%.

Beets are a high investment crop in the three closed cooperatives. Farmers in North Dakota and Minnesota together produce 650,000 acres of beets. Diseased plants can produce 1 trillion spores per acre.

“That’s trillions and trillions of spores are circulating. The larger the number of spores, the more mutations that can lead to fungicide resistance,” Khan said. “We are trying to kill the fungus and the fungus wants to live.”

From 2000 to 2015, farmers got excellent control by applying two to four fungicide applications per year, depending on the farms’ locations.

One fungicide type is the “quinone outside inhibitors” (“QoI”), a fungicide that specifically stops the production of energy. The main QoI for sugarbeets has been “Headline,” a pyraclostrobin (from the strobilurin class of chemistry). Because of its high specific activity, it has been effective against target fungi.

But Headline suddenly became ineffective.

“If you sprayed the field in 2016, and went back to that fields three to four weeks later, it started to turn brown,” Khan said.

The reason? Mutations.

One mutation resulted in complete resistance to the QOI fungicides.

“All the fungus had to do was change an amino acid at one position (in its genes) for another — an alanine changed to guanine,” Khan explained.

And that was that.

At the same time, it developed “reduced sensitivity” to another previously effective fungicide group — triazoles (also called “demetallization inhibitors”). This puts holes in the fungi’s cell membranes.

Khan started recommending using one new fungicide with another mode of action — “especially an older chemistry.” (The older fungicides are “multi-site” types, used since the 1970s.)

Mohammed Khan, a professor and sugar beet specialist for the University of Minnesota and North Dakota State University,  uses a battery-powered spore trap to monitor levels of Cercospora leaf spot disease at research plots near Foxhome, Minn. Photo taken July 16, 2021, at Foxhome, Minn. Mikkel Pates / Agweek

Mohammed Khan, a professor and sugar beet specialist for the University of Minnesota and North Dakota State University, uses a battery-powered spore trap to monitor levels of Cercospora leaf spot disease at research plots near Foxhome, Minn. Photo taken July 16, 2021, at Foxhome, Minn. Mikkel Pates / Agweek

The most popular older fungicides were ethylenbisdithiocarbamates. The EBDCs included trade names Mancozeb and Penncozeb. Other old chemistry are known as “tins” — triphenyltin hydroxide (TPTH). The common “coppers” were copper hydroxide and copper oxychloride..

A $200M hit

The 2016 season was the warmest and wettest in the 121-year weather record history for Minnesota. This was good for growing beets but devastating if you had cercospora that had become resistant to the previously most-effective fungicides.

“Because the best modes of action were no longer effective in 2016, our growers lost close to $200 million — less income to producers in North Dakota, Minnesota and Michigan,” Khan said.

From 2016 to 2020, growers in Southern Minnesota applied six to seven fungicide applications per year, always in mixtures, with mixed success, depending on the amount of rain.

A weather station at the sugar beet Cercospora leaf spot research plot near Foxhome, Minn., provides temperature (air and soil), relative humidity and precipitation data that is correlated with a spore trap to help scientists recommend the best way to fight yield- and quality-robbing disease. Photo taken July 16, 2021, at Foxhome, Minn. Mikkel Pates / Agweek

A weather station at the sugar beet Cercospora leaf spot research plot near Foxhome, Minn., provides temperature (air and soil), relative humidity and precipitation data that is correlated with a spore trap to help scientists recommend the best way to fight yield- and quality-robbing disease. Photo taken July 16, 2021, at Foxhome, Minn. Mikkel Pates / Agweek

QOI fungicides worked well until years like 2019, when repeated rains washed them off and they had to be reapplied. “The disease will overtake the plants. You will have low yields, very little to harvest,” he said.

In 2020, the southern Minnesota growers had effective disease control — with yields of nearly 30 tons per acre, with 17% sugar. In 2019, Southern Minnesota Beet Sugar Cooperative had reported a yield of 23.4 tons per acre and a sugar content of 15.63%; however, the 2019 season was further challenged by weeds, diseases and poor harvest conditions.

NDSU started urging seed companies to speed up work they already were doing to incorporate tolerance. The new cercospora improvements came through conventional breeding, not genetic modifications. KWS breeders had been finding strong cercospora tolerance in a broad range of wild beets.

Khan and his research team inoculate plots to allow cooperatives to rate sugarbeet varieties for their cercospora leaf spot resistance. He also studies fungicides for their effectiveness, as well how they work in mixes and rotations.

Mike Metzger, vice president of agriculture for Minn-Dak Farmers Cooperative at Wahpeton, N.D., has had the new CR+ varieties in his company’s research plots for two years. He describes cercospora as the co-op’s “No. 1 production problem.”

Metzger said that 60% of seed planted by Minn-Dak Farmers Cooperative at Wahpeton this year were the improved cercospora-resistant sugarbeet varieties. Khan said about 15% of the crop for Southern Minnesota at Renville also also are the new varieties.

All of Minn-Dak’s members this year were offered an opportunity to buy the new seed, and Metzger estimates that 80% to 85% did. The new seed came at about a $40 per acre cost above the typical seed price, which ranges from $200 to $250 an acre.

“It’s going to offset three sprays,” which Metzger and Khan say is at about $25 to $30 per spray.

Mohamed Khan, a North Dakota State University and University of Minnesota sugarbeet specialist, says new ‘improved cercospora leaf resistant” beet varieties were used on 60% of Minn-Dak Farmers Cooperative growers and 15% of Southern Minnesota Beet Sugar Co-op, and should be available to most growers nationwide in two to three years. 
Photo taken July 16, 2021, at Foxhome, Minn. Mikkel Pates / Agweek

Mohamed Khan, a North Dakota State University and University of Minnesota sugarbeet specialist, says new ‘improved cercospora leaf resistant” beet varieties were used on 60% of Minn-Dak Farmers Cooperative growers and 15% of Southern Minnesota Beet Sugar Co-op, and should be available to most growers nationwide in two to three years.
Photo taken July 16, 2021, at Foxhome, Minn. Mikkel Pates / Agweek

Metzger likened the new variety impact to the to “herd immunity” when it comes to COVID-19. Going to resistant varieties could drastically reduce the amount of fungus over a two-or three-year period.

“We don’t have to worry about that massive cercospora cloud hanging over our head. It gives us a chance to take a breath, hit the reset button,” he said.

Khan said the new cercospora-tolerant varieties appear to have tonnage yield comparable to approved sensitive varieties. The sugar concentration may be a little lower.

“But overall, the recoverable sucrose is as good as the other varieties we’ve had,” he said.

In June 2021, researchers inoculated sugar beets in research trials with  Cercospora leaf spot disease spores. They were just beginning to show symptoms on July 16, 2021. 
Photo taken July 16, 2021, at Foxhome, Minn. Mikkel Pates / Agweek

In June 2021, researchers inoculated sugar beets in research trials with Cercospora leaf spot disease spores. They were just beginning to show symptoms on July 16, 2021.
Photo taken July 16, 2021, at Foxhome, Minn. Mikkel Pates / Agweek

He said other seed companies (Crystal Beet Seeds, SESVanderHave, Hilleshog and Maribo) also are working toward commercializing resistant varieties.

While the cercospora-resistant varieties so far have come through conventional breeding, Khan said the industry is looking at developing other traits through genetic modification. Some on the horizon include triple-stack resistance to glyphosate (Roundup) glufosinate (Liberty) and dicamba perhaps in 2025 or 2026. The only sugarbeet GMOs now approved for use are for Roundup (glyphosate) resistance.

Mohammed Khan, a University of Minnesota and North Dakota State University extension sugar beet specialist,  pores through charts that show the effect and timing of different mixes and timing for fungicides to fight Cercospora leaf spot disease. Photo taken July 16, 2021, at Foxhome, Minn. Mikkel Pates / Agweek

Mohammed Khan, a University of Minnesota and North Dakota State University extension sugar beet specialist, pores through charts that show the effect and timing of different mixes and timing for fungicides to fight Cercospora leaf spot disease. Photo taken July 16, 2021, at Foxhome, Minn. Mikkel Pates / Agweek

Khan and his technicians in late June intentionally inoculate the entire site with cercospora leaf spot disease, accumulated from infected leaves from growers’ fields the previous year, mixed with a talcum powder.

Also, Khan’s larger job is to determine which fungicides are effective in combatting the disease.

The researchers apply the fungicides in applications in 10- to 14-day intervals (depending on rainfall) — about five to six applications across the entire season from late June into September. Khan applies the combinations to beets with varying levels of cercospora resistance. Those include varieties more susceptible than the “conventional, susceptible” growers would normally use.

“If something is working in my research site, it will work in a grower’s field,” he said.

Sugar beet research at Foxhome, Minn., includes a “spore trap.” It uses a vacuum to pull Cercospora leaf spot spores. The spores stick to a sticky tape, moving in a one-week cycle. Researchers have found they’re most prevalent between 5:30 a.m. and 8 a.m. Data from the study should improve fungicide timing.  Photo taken July 16, 2021, at Foxhome, Minn. Mikkel Pates / Agweek.

Sugar beet research at Foxhome, Minn., includes a “spore trap.” It uses a vacuum to pull Cercospora leaf spot spores. The spores stick to a sticky tape, moving in a one-week cycle. Researchers have found they’re most prevalent between 5:30 a.m. and 8 a.m. Data from the study should improve fungicide timing. Photo taken July 16, 2021, at Foxhome, Minn. Mikkel Pates / Agweek.

Part of Khan’s research is using fungicides with the improved varieties to see if he can reduce the fungicide applications and still get high yields. In some of the improved varieties he thinks he can use as few as one — or zero — applications in some years.

In the end, the samples are analyzed at an American Crystal Sugar Co. tare laboratory at East Grand Forks, Minn.

“We do calendar sprays — for growers who don’t want to scout,” he said. “If they they want good yields, they’ll probably have to spray every 10 to 14 days.”

Cercospora first attacks the oldest leaves, which produce the most sugar. The disease doesn’t hit younger leaves until late in the season. Those who scout do so based on leaf spots and daily infection values, some relying on scouts or consultants to determine disease severity and the best time to apply fungicides.

Mohamed Khan’s conducts Cercospora leaf spot research on a 25 acre cercospora leaf plot  at Foxhome, Minn., on parts of the Kevin Etzler farm. Photo taken July 16, 2021, at Foxhome, Minn. Mikkel Pates / Agweek

Mohamed Khan’s conducts Cercospora leaf spot research on a 25 acre cercospora leaf plot at Foxhome, Minn., on parts of the Kevin Etzler farm. Photo taken July 16, 2021, at Foxhome, Minn. Mikkel Pates / Agweek

In a related study at the research plots, Khan is working with drones to aerially collect images to determine the amount of “brownness” that would indicate an infestation. That will be correlated to infestation data on the ground, and eventually cut the time and cost of scouting fields.

If the drone technology proves itself, Khan is working with an engineering colleague at NDSU to develop a sensor for agriculture that is also usable for detecting weeds in sugarbeets and other crops.ShareBecca Roberts 1268 Posts 0 Comments

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By Tracking the Weather, A New System Can Protect Brazilian Farmers from Wheat Blast

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Cynthia Carmona

Aug 09, 2021

Bangladesh Agricultural Research Institute scientist during the surveillance training program in Bangladesh
Bangladesh Agricultural Research Institute scientist during the surveillance training program in Bangladesh

This post is written by Doug Johnson.

Every year, the spores of the wheat blast fungus lie in wait on South American and Bangladeshi farms. In most years, the pathogen has only a small impact on the countries’ wheat crops. But, the disease spreads quickly, and when the conditions are right, there’s a risk of a large outbreak — which can pose a serious threat to the food security and livelihood of farmers in a specific year.

To minimize this risk, an international partnership of researchers and organizations have created the wheat blast Early Warning System (EWS), a digital platform that notifies farmers and officials when weather conditions are ideal for the fungus to spread. The team is introducing the technology to Brazil. Wheat blast was originally discovered in the country in 1985.

The International Maize and Wheat Improvement Center (CIMMYT), the Brazilian Agricultural Research Corporation (EMBRAPA), Brazil’s University of Passo Fundo (UPF) and others developed the tool with support from USAID under the Cereal Systems Initiative for South Asia project. Although first developed for Bangladesh, the team is excited that the EWS is now endorsed and being used by agriculture workers in Brazil. The team hopes that the system will give farmers time to take preventative measures against wheat blast. Outbreaks can massively reduce crop yields if no preventative actions are taken.

“It can be very severe. It can cause a lot of damage,” says Maurício Fernandes, a plant epidemiologist with EMBRAPA.

Striking first

In order to expand into a full outbreak, wheat blast requires specific temperature and humidity conditions. So, Fernandes and his team developed a digital platform that runs weather data through an algorithm to determine the times and places in which outbreaks are likely to occur.

If the system sees a region is going to grow hot and humid enough for the fungus to thrive, it sends an automated message to the agriculture workers in the area. These messages — texts or emails — alert them to take preemptive measures against the disease.

While over 6,000 extension agents in Bangladesh are signed up for disease early warnings, most farmers in Brazil are associated with cooperatives. Fernandes and his peers are connecting with these groups, which can send them weather data to help inform the EWS. The cooperatives can also spread these alerts through their websites or in-house applications.

Wheat blast can deform a plant quickly and, given the right conditions, even kill it. As such, these advanced warnings are essential to mitigate losses. The alerts sent out will recommend that farmers apply fungicide, which only works when applied before infection. 

“If the pathogen has already affected the plant, the fungicides will have no effect,” Fernandes says.

A blast from the past

The cause of wheat blast, Magnaporthe oryzae, is also responsible for rice blast, and the pathogen likely jumped between the two crops. Because wheat had not previously been exposed to it, most wheat cultivars at the time had no natural resistance to Magnaporthe oryzae, according to Fernandes. Some newer varieties are moderately resistant to the disease, but the availability of sufficient seed for farmers remains limited.

The pathogen targets the wheat ear first, deforming it in less than a week after symptoms first appear. It can spread through leftover infected seeds and crop residue, but its spores can also travel vast distances through the air.

If the fungus spreads and infects enough plants, it can wreak havoc on nearby agriculture. In the 1990s — shortly after its discovery — wheat blast impacted around three million hectares of wheat in South America. Back in 2016, the disease appeared in Bangladesh and South Asia for the first time, and the resulting outbreak covered around 15,000 hectares of land. CGIAR estimates that the disease has the potential to reduce the region’s wheat production by 85 million tons.

In Brazil, wheat blast outbreaks can have a marked impact on the country’s agricultural output. During a major outbreak in 2009, the disease affected as many as three million hectares of crops in South America. As such, the EWS is an invaluable tool to support food security and farmer livelihoods. Fernandes also notes that affected regions can go multiple years between large outbreaks, but the threat remains.

“People forget about the disease, then you have an outbreak again,” he says.

Essential partnerships

The EWS has its roots in Brazil, but it took some time before the team launched it there. In 2017, Fernandes and his peers published a piece of research proposing the model. After that, Fernandes, Timothy Krupnik (a senior scientist and country representative with CIMMYT in Bangladesh involved with the project) and a slew of researchers and organizations launched a pilot project in Bangladesh.

There are more than 6,000 agriculture extension officers making use of the EWS the team developed for Bangladesh. Much like in Brazil, these officers receive an automated email or text message when weather conditions are ideal for wheat blast to thrive and spread. The team used this proof of concept to bring it back to Brazil, where the system was originally developed.

Krupnik notes that the Brazil platform is something of a “homecoming” for this work. He also noted that cooperation between the researchers, organizations and agriculture workers in Brazil and Bangladesh were instrumental in creating the system.

“From this, we’re able to have a partnership that I think will have a significant outcome in Brazil, from a relatively small investment in research supplied in Bangladesh. That shows you the power of partnerships and how solutions can be found to pressing agricultural problems through collaborative science, across continents,” he says.FILED UNDER:AGRICULTURAL PRODUCTIVITY

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Engineering broad-spectrum disease-resistant rice by editing multiple susceptibility genes

Journal of Integrative Plant Biology

Hui TaoXuetao ShiFeng HeDan WangNing XiaoHong FangRuyi WangFan ZhangMin WangAihong LiXionglun LiuGuo-Liang WangYuese NingFirst published: 25 June 2021 https://doi.org/10.1111/jipb.13145

Edited by:: Xuewei Chen, Sichuan Agricultural University, ChinaRead the full textPDFTOOLSSHARE

ABSTRACT

Rice blast and bacterial blight are important diseases of rice (Oryza sativa) caused by the fungus Magnaporthe oryzae and the bacterium Xanthomonas oryzae pv. oryzae (Xoo), respectively. Breeding rice varieties for broad-spectrum resistance is considered the most effective and sustainable approach to controlling both diseases. Although dominant resistance genes have been extensively used in rice breeding and production, generating disease-resistant varieties by altering susceptibility (S) genes that facilitate pathogen compatibility remains unexplored. Here, using CRISPR/Cas9 technology, we generated loss-of-function mutants of the S genes Pi21 and Bsr-d1 and showed that they had increased resistance to M. oryzae. We also generated a knockout mutant of the S gene Xa5 that showed increased resistance to Xoo. Remarkably, a triple mutant of all three S genes had significantly enhanced resistance to both M. oryzae and Xoo. Moreover, the triple mutant was comparable to the wild type in regard to key agronomic traits, including plant height, effective panicle number per plant, grain number per panicle, seed setting rate, and thousand-grain weight. These results demonstrate that the simultaneous editing of multiple S genes is a powerful strategy for generating new rice varieties with broad-spectrum resistance.

Supporting Information

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Bacillus Strains Could Help To Protect Banana Crops

August 2 2021 | Original story from Alliance of Bioversity InternationalCredit: Alistair Smailes/ UnsplashRead time: 2 minutes

Bananas are consumed in different ways around the world; with over 1000 varieties, one can surely find a way to use bananas besides simply eating the fruit. The Cavendish is the most commercially cultivated banana variety in the world, mainly because the characteristics of Cavendish banana plants are more climate and extreme weather resilient, and can withstand global transport. However, these characteristics don’t make it immune to pests and diseases.

The Fusarium wilt is a fungus that attacks the banana plant and causes the plant to dry up and die. One of the most dangerous strains is the Tropical Race 4 (TR4) and with no known universal control measure, it seriously threatens banana production globally, particularly the Cavendish.

In a paper published in an MPDI Journal of Fungus, scientists explored disease-biocontrol agents of five Bacillus strains that display antibiotic ability against TR4 in China, one of the largest banana growers in the world.

Bioagents as pesticides

The threat of TR4 crossed oceans and brought hectares of Cavendish plantations to a halt driving smallholder farmers into poverty.

Today, there is only one Bacillus subtilis bioagent registered in China as a pesticide against TR4. More recent research suggests however, that there are other strains that can provide control over TR4—these strains can trigger either direct or indirect antagonism on the fungus.

In terms of the need to expand biocontrol methods against TR4, Sijun Zheng, a scientist at the Alliance says, “the effectiveness of bioagents depend on its capability to colonize into host plants—this is why we need to explore other strains of Bacillus and other bioagents to combat TR4 more efficiently.”

By looking at specific gene markers, the research team found that all five Bacillus strains, namely N67, YN1282-2, WBN06, HN04, and G9R-3 have the ability to perform antagonistic biocontrol methods against TR4. The biocontrol genes studied are capable of making bacillibactin and biotin, both essential in producing antagonistic effects against TR4. In particular, strains WBN06 and YN1282-2 contained all but one biocontrol gene influencing a better control of TR4 compared to the other three strains that were studied through real-time Fluorescent Reverse Transcription Quantitative Polymerase Chain Reaction.

Unlike other pest and diseases in crops, there is no effective chemical control agent known to manage this soil-borne pathogen TR4.

By looking at what is present in the genes of the Bacillus, it presents an opportunity to explore functional gene’s biocontrol mechanisms against the deadly fungus. This study also opens up the door to see how these Bacillus strains can affect human beings and the ecosystem where it will be deployed.

Reference: Li S, He P, Fan H, et al. A real-time fluorescent reverse transcription quantitative PCR assay for rapid detection of genetic markers’ expression associated with fusarium wilt of banana biocontrol activities in Bacillus. Journal of Fungi. 2021;7(5):353. doi: 10.3390/jof7050353

This article has been republished from the following materials. Note: material may have been edited for length and content. For further information, please contact the cited source.

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The Observer

Date palm farmers must watch out for Black scorch

Zainab Al Nassriya

ZAINAB AL NASSRIYA PUBLISHED: 9:13 PM, AUG 04, 2021

Delay in eliminating black scorch may create hotspots of the pest and spread to other trees. Farmers should pay attention to irrigation, fertilisation, weed removal, and cleanliness of the palms. — Amin bin Mayouf al Hinai, MoAFWR official

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Farmers must take adequate preventive measures to protect date palms from black scorch, a fungal disease, which is spreading across many governorates in the Sultanate, advised an agriculture ministry official.

Black scorch, also called Medjnoon or Fool’s disease, has been observed on date palms in all date growing areas of the world. According to experts of the Food and Agriculture Organization, symptoms are usually expressed in four distinct forms: black scorch on the leaves, inflorescence blight, heart or trunk rot and bud rot on palms of all ages. Infections are all characterised by partial or complete damage of the tissues.

The disease gets its name from typical lesions, which are dark brown to black, hard, carbonaceous. It gives the fruit strands and fruit stalks a scorched, charcoal-like appearance.

Decay is most serious when it attacks the terminal bud and heart leading to the death of the palm. Some palms recover, but these palms show a characteristic bend in the region of infection. This is why it is called Medjnoon. They set normal growth back by several years.

Amin bin Mayouf al Hinai, Head of the Plant Protection Department, at the Ministry of Agriculture, Fisheries and Water Resources, said: “We recommend farmers to combat these pests by using fungicides, which are of several types. Each of them should be used in recommended doses. The top of the affected palm tree and its trunk must be sprayed with the same solution,” Al Hinai said.

According to al Hinai, these methods reduce the spread of the pest. The spraying of the fungicide should be repeated after two to three weeks.

Al Hinai explained that the delay in the methods of control leads to the death of the palm. “Delay in eliminating the black scorch may create hotspots of the pest and spread to other trees” he said, asking farmers to cooperate and in combating such diseases.

“Farmers should pay attention to irrigation, fertilisation, weed removal, and cleanliness of the palms. They also have to monitor the palm trees on an ongoing basis,” he said.

The affected fronds and leaves should be cut immediately and burned. After pruning, the surrounding tissues should be protected by spraying with Bordeaux mixture, lime-sulphur solution, or any copper-based fungicides. Under a severe attack, affected palms are to be removed and burnt.
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