Produced by the International Association for the Plant Protection Sciences (IAPPS). To join IAPPS and receive the Crop Protection journal online go to: www.plantprotection.org
EPPO Reporting Service no. 11 – 2022Num. article: 2022/244
First record of sweet potato chlorotic stunt virus in the Netherlands
The NPPO of the Netherlands recently informed the EPPO Secretariat of the first finding ofsweet potato chlorotic stunt virus (Crinivirus, SPCSV – EU Annexes) in sweet potato (Ipomoea batatas) plants on its territory. SPCSV was found in September 2022 in two open fields in Noord-Brabant province (11.83 and 4.72 ha) and one in Limburg province (0.5 ha). The official survey was part of the Euphresco project ‘Phytosanitary risks of newly introduced crops’ (PRONC). Tracing back investigations to the origin of the finding showed that the sweet potato slips used for planting originated from a company in another EU Member State. Sweet potato is a new crop in the Netherlands. During the survey, plants with and without virus symptoms were sampled and tested. SPCSV was identified in several plants with virus-like symptoms (e.g. vein banding, discoloration, rings, dots). Additionally, in several of these symptomatic plants a second, non-EU listed, virus was identified: sweet potato virus G (Potyvirus, SPVG00). The mixed infection may have increased the severity of the observed symptoms.
Official phytosanitary measures have been taken. The companies have to report to the NPPO when all tubers of the Ipomoea batatas plants have been harvested and the total quantity thereof. All infected lots should be stored in a traceable manner, separately from other harvested lots. Only sales for consumption/industry are allowed, otherwise the lots have to be destroyed. The companies should report when the infected lots are sold or destroyed. The lots must be sold/destroyed before 31 March 2023.
The pest status of sweet potato chlorotic stuntvirus in the Netherlands is officially declared as: Transient, actionable, under eradication.
This month’s pest alerts include the isolation and identification of the top blight pathogen of Passiflora edulis (photograph by Earth100).
We’ve selected a few of the latest new geographic, host and species records for plant pests and diseases from CAB Abstracts. Records this month include information about a new virus disease of sunflower from Nebraska and the isolation and identification of the top blight pathogen of Passiflora edulis.
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In Southern California, state agriculture officials are expanding a citrus plant quarantine in Los Angeles county after the citrus disease Huanglongbing (HLB) was detected in Pomona.
The plant disease is not harmful to people or animals but can greatly affect citrus plants. HLB is spread from plant to plant by the Asian citrus psyllid. Once a tree is infected it cannot be cured.
According to the Citrus Pest & Disease program’s press release, a citrus plant quarantine is in place throughout portions of Los Angeles, Orange, Riverside, San Bernardino and San Diego counties. To further limit the spread of the pest that can carry HLB, there are additional quarantines in place that make it illegal to bring citrus fruit or plant material into California from other states or countries.
We’ve selected a few of the latest new geographic, host and species records for plant pests and diseases from CAB Abstracts. Records this month include two new species of Plasmopara affecting wild grapes in the USA and the first report of rust disease on Potentilla indica caused by Phragmidium duchesneae in Japan.
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We’ve selected a few of the latest new geographic, host and species records for plant pests and diseases from CAB Abstracts. Records this month include the first report of Pestalotiopsis biciliata causing dieback on Quercus coccifera and Pistacia lentiscus in Tunisia and the first report of Sida leaf curl virus and associated betasatellite from tobacco.
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Source: Reliefweb, FAO report [summ. Mod.DHA, edited] https://reliefweb.int/report/ecuador/giews-country-brief-ecuador-15-june-2022 In Ecuador, harvesting of the 2022 main season maize crops is ongoing under favourable weather conditions. Yields are expected to be below average due to low precipitation in key producing provinces. In addition, a fungal disease called tar spot (mancha de asfalto) reportedly affected maize crops, with negative effects on yields. — Communicated by: ProMED [Tar spot of maize has been known to lead to serious yield losses of up to 75% in Central and South America. It is considered to be a disease complex involving the synergistic association of at least 3 fungal species: _Phyllachora maydis_, _Microdochium maydis_ (previously _Monographella maydis_) and _Coniothyrium phyllachorae_.
Of these, _P. maydis_ is usually the 1st to cause leaf lesions. While _M. maydis_ is a common benign saprophyte on leaf surfaces, it becomes highly virulent only in association with _P. maydis_ and forms necrotic rings around the _P. maydis_ lesions. _C. phyllachorae_ may be a hyperparasite of the other 2, but its role is not fully understood yet. Leaf lesions may coalesce, causing blight and complete burning of the foliage. In addition, characteristic black shiny spots (“tar spots”) are produced both within lesions and on other leaf areas. Affected ears have fewer kernels which may germinate prematurely on the cob. Weakening of stems may lead to increased lodging. The disease reduces photosynthetic potential and therefore plant vigour.
_P. maydis_ is an obligate parasite; its spores are spread by wind and with infected plant material. It produces a potent toxin killing plant tissue. The disease is favoured by cool, humid conditions. Tar spot management may include fungicide treatments and use of maize varieties with tolerance or low sensitivity to the disease. However, resistance breeding is difficult because of the involvement of multiple pathogens. So far, little is known about the genetics of tar spot resistance.
Texas forage producers are facing high fertilizer prices, but Texas A&M AgriLife Extension Service experts do not expect they will face an early outbreak of fall armyworms.
David Kerns, AgriLife Extension state integrated pest management specialist and professor in the Department of Entomology, said recent weather has not created conditions for the early migration of the devastating pest experienced in 2021.
Populations typically build following large rain events and cooler weather. But Kerns said there is no indication that armyworm populations are building in southern areas of the state following recent weather systems that dropped temperatures and delivered moisture.
Fall armyworms’ name is indicative of their active season, but cool, wet weather can trigger outbreaks, Kern said. Populations of armyworms, which are extremely damaging to forage production, typically begin increasing sometime between July and September.
“Fall armyworms typically build up in southeastern Texas, and the moths move northward throughout the eastern half of the state,” he said. “Last year, with all the spring and summer rains, that buildup occurred earlier than usual, but conditions are much drier this year despite the recent storm fronts.”
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No reports of armyworms so far
Fall armyworms are green with brown or black colorations and can be identified by the white inverted Y on their head. They can grow up to 1 inch in length when mature.
The pest got its name because they appear to march army-like across hay fields, consuming the grass in their path.
Armyworm moths can lay up to 2,000 eggs that hatch in two to three days, according to a 2019 report by Allen Knutson, AgriLife Extension entomologist, retired.
Vanessa Corriher-Olson, AgriLife Extension forage specialist, Overton, said there are four to five generations that move throughout the state per growing season. They typically move north from Mexico and South Texas as temperatures warm in the spring. Generations will push further north into midwestern states, but moths and larvae remain present throughout the state.
Drier, hotter conditions slow their life cycles, Corriher-Olson said. Moths lay fewer eggs and caterpillar growth is slowed. But rainfall and cooler temperatures can trigger major infestations when local populations, new hatches and migrating moths descend on areas with quality food sources.
Corriher-Olson said continued drier conditions overall in southern parts of the state are likely to curb any early issues forage producers may have experienced in 2021.
“I have not received any reports or phone calls, and that tells me populations in areas where the armyworm migration begins have not reached any level of concern,” she said.
No problem until there is a problem
Corriher-Olson said producers typically react to fall armyworm outbreaks when they occur, which has led to product availability issues during the pandemic. She noted, however, that she had not received any reports about insecticide shortages to date.
“Many producers take a reactionary approach to armyworms because of the expense,” she said. “Some producers may have products on hand that are left over from last year, but most are going to be monitoring the situation to their south and plan accordingly.”
Kerns said conditions may not be shaping up for armyworms at this point in the forage production season, but producers with Sudan grass, hay grazer and other forages related to sorghum should be on the lookout for sorghum aphids, also known as sugarcane aphids.
While armyworms prefer wetter, cooler weather, sorghum aphids prefer hot, dry conditions, he said. There have been reports of the aphids in grain sorghum fields in South Texas.
Aphids feed on leaves and leave a sap that further damages the plant, and major infestations can greatly impact forage yields.
Corriher-Olson said forage pests like fall armyworms and aphids are always a threat to producers’ bottom lines, but yield losses could magnify their impact on budgets due to higher input costs, especially fertilizer applications.
Many forage producers are forgoing or reducing fertilizer applications, which could impact where infestations build, she said. Fall armyworms will settle on any green pasture, but they prefer lush, fertilized forages.
“Fertilized fields are more at risk to be damaged,” she said. “So, when it comes to armyworms, we don’t want to see a producer spend money to produce quality forage and have armyworms destroy it.”
AgriLife Extension district reporters compiled the following summaries:
The 12 Texas A&M AgriLife Extension Districts
ROLLING PLAINS
Rainfall amounts were from 1.5-3 inches. The rains helped the soil moisture profile, but more rain was needed to fill stock tanks. There was very little green grass in pastures. Wheat harvest continued in the little bit of wheat worth combining. Yield reports ranged from 3-25 bushels per acre. Supplemental hay feeding of cattle continued.
COASTAL BEND
Southern parts of the area reported showers that produced trace amounts to 2 inches of rain. Crops with irrigation looked good, but dryland producers were concerned about crop losses. Cotton benefitted the most from rain, but more moisture will be needed to see good yields. Corn and grain sorghum were drying down and any moisture would probably only help with the kernel weight. Rangeland and pastures showed a slight color change with rain, but not much growth occurred, and conditions remained poor to fair. Livestock were still in a decline and receiving supplemental feed. Hay supplies were dwindling. More cattle producers were weaning early and culling out poor producing cows. Cattle market prices remained high.
EAST
Recent rains helped, but soils dried quickly. Pasture and rangeland conditions were fair. Subsoil and topsoil conditions were short to adequate. Hay production continued. Yields were much lower than normal as producers reduced fertilizer applications due to higher input costs. Harrison County reported problematic fly populations. Livestock were in fair to good condition.
SOUTH PLAINS
Producers received another significant rainfall shower this week across the county. Rainfall totals ranged from 0.5 inches to 2 inches. Some large hail was also mixed with the heavier rain. Cooler temperatures helped conditions. Rain was in the forecast. Cotton planting was in full swing with about 80% of acres planted so far. More rain will be needed for decent cotton, corn and sorghum yields. Pumpkin farmers started planting. Cattle were being supplementally fed. The recent rainfall helped pastures a little.
PANHANDLE
Soil moisture conditions were very short to short. Recent rains helped irrigated crops like wheat, corn and cotton some. Earlier planted corn was up and growing, but some silage corn plantings were still on hold. Cotton was already planted or going in, but producers were not optimistic about yields. Rangeland and pasture conditions improved, but much more rain will be needed to sustain a green-up. Overall, rangeland and pasture conditions remained poor, and crop conditions were poor to fair.
NORTH
Soil moisture ranged from adequate to short. Warmer temperatures and higher wind speeds dried up soil moisture. Corn, cotton and soybeans were doing well. Early planted corn was tasseling. The wheat harvest began, and fields looked good. No widespread insect or disease pressure was reported. Pasture and rangeland conditions were fair to good and had improved slightly following recent rainfall. The first hay harvests of Bermuda grass, ryegrass, Bahia grass or oats were cut and rolled without issue this year. This was the first early forage harvest in the past few years not delayed by rainfall or wet conditions. Cattle were in good to excellent condition. Horn and stable flies were increasing significantly, and horseflies and deerflies were worsening. Spring calves appeared to be gaining well. Supplemental feeding continued for livestock and wildlife, and forage quality looked poor. Rainfall will be necessary for continued forage production. Some hay producers were considering transitioning pastures to native forage production due to lack of rain and increased fertilizer costs.
FAR WEST
Weather was variable. A cold front dropped temperatures into the 40s and brought rainfall, hail and dust storms that took visibility to zero, but temperatures quickly returned to the 90s. A very narrow band of storms left trace amounts of rain up to 1.5 inches. Hail damage to farm equipment, barns, trees and residences was severe. Emerged cotton was hailed out. Cotton, especially Pima fields, looked good in other areas. Corn continued to make progress, but heat was starting to take its toll. Melons looked good and were making good progress. Pecan trees were coming along nicely and set a good crop. Some pecan nut casebearer pressure was reported. Alfalfa looked decent. Pastures remained completely bare. Cattle conditions continued to worsen, and some ranchers completed weaning.
WEST CENTRAL
Thunderstorms delivered from 1.5-3 inches of rainfall to most areas. Forages perked up with the moisture, but temperatures in the 90s and windy days could impact moisture retention. Some farmers harvested wheat last week, but yields were poor. Cotton outlooks were looking slim as well. Herd liquidation was slowly happening. Some producers with hay chose to feed through drought, but many were selling off their herds. An ongoing wildfire near Abilene was under control, but not before it burned 10,900 acres.
SOUTHEAST
Heavy rains helped soil moisture levels. Some hay was cut, and rice was fertilized. Forages were growing and producers in several areas cut their first hay crop with no pests reported. Rains slowed crop planting in some areas. Rice planting was not complete. Some areas remained dry and reported declining pasture, rangeland and crop conditions. Rangeland and pastures ranged from very poor to excellent condition. Soil moisture levels were short to surplus.
SOUTHWEST
Some areas received 0.75-3 inches of rain. The rainfall helped alleviate the drought stress for crops that survived to this point. Hot temperatures persisted and pastures looked overgrazed. Wheat and oat harvests were complete with below-average yields reported. Irrigated corn looked good, and cotton was doing well. Producers eased up on supplemental feeding due to the recent rains, but pasture conditions continued to decline in drier areas. Mesquite spraying was underway. Diet supplementation continued for livestock and wildlife, and forage production looked poor. Irrigated hay fields were in good condition.
SOUTH
Moisture levels in northern areas were very short, while eastern and western areas reported short to adequate soil moisture. Southern areas reported adequate to surplus moisture. Most areas reported rainfall with amounts ranging from 0.3-8 inches. Pastures and rangelands responded well to the moisture. Livestock conditions were improving and producers were decreasing supplemental feed. Cattle prices remained strong. Cattle producers in drier areas continued to provide supplemental feed to maintain body condition scores. Producers who planted hay grazer before the rains were expecting good growth. Significant rain missed croplands in northern parts of the district. Row crops and forages in areas that received rain were expected to improve significantly. Irrigated crops like watermelons, cantaloupes and Bermuda grass looked good. Cotton was expected to respond well to the moisture. Flooding and hail damaged some crops. Hail damaged around 5,000 acres of grain, sesame, sunflowers, watermelons and corn. Sorghum aphid pressure increased, and weeds were becoming an issue as fields were too wet to spray.
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Mecyclothorax, a diverse genus of ground beetles inhabiting Pacific island volcanoes, has reached 241 species with two new species discovered at the National Ecological Observatory Network’s Pu’u Maka’ala Natural Area Reserve. At left is a male Mecyclothorax neonomas, and at right is a male Mecyclothorax brunneonubiger. (Photos by Kip Will, Ph.D.)
By Zoe Gentes
Editor’s Note: This post was originally published on the National Ecological Observatory Network’s Observatory Blog. Republished with permission.
It’s always exciting when a new species is identified at a National Ecological Observatory Network field site. At Pu’u Maka’ala Natural Area Reserve (PUUM) in Hawai`i, researchers have verified the discovery of two previously undescribed species of carabids (ground beetles). Kip Will, Ph.D., of the University of California, Berkeley, and James Liebherr, Ph.D., of Cornell University recently published their findings in The Pan-Pacific Entomologist: “Two new species of Mecyclothorax Sharp, 1903 (Coleoptera: Carabidae: Moriomorphini) from the Island of Hawai’i.”
The two new species are both members of Mecyclothorax, a genus of ground beetles most diverse on volcanoes in the Hawaiian Islands and the Society Islands of French Polynesia. The newly named Mecyclothorax neonomas and Mecyclothorax brunneonubiger bring the number of known Mecyclothorax species in Hawai`i to 241 (many of them previously described and cataloged by Liebherr). Their discovery could provide new insights into the evolutionary history of the genus.
The Road to Discovery
At the the National Ecological Observatory Network’s Pu’u Maka’ala Natural Area Reserve in Hawai`i, researchers have verified the discovery of two previously undescribed species of ground beetles. Kip Will, Ph.D., of the University of California, Berkeley, and James Liebherr, Ph.D., of Cornell University recently published their findings in March in The Pan-Pacific Entomologist. (Photo courtesy of National Ecological Observatory Network)
Will is one of two researchers contracted by the NEON program for definitive identification of carabids. He studies carabids worldwide and provides identification for the NEON program for carabids found in the western United States, including Hawai`i. Liebherr is one of the premier U.S. experts on carabids, especially those of the Hawaiian Islands. Over the last 20 years, he and his students have created the most extensive and authoritative guide to Hawaiian carabids to date. Will completed his Ph.D. thesis at Cornell under Liebherr’s tutelage.
Will first discovered the suspect specimens in a group of carabids sent to him for identification from PUUM. “When the NEON samples arrived for identification, it was my first time seriously working with Hawaiian carabids,” he says. He quickly realized that two of the specimens did not match species already described in Liebherr’s publications: “I said, hey, Jim, your key doesn’t work—these must be something new!” He sent the specimens to Cornell, where Liebherr confirmed the identification of two new species. Discovering new carabid species is par for the course for these researchers, but these are the first new Hawaiian carabid species identified with NEON samples.
Hawai’i is where Will first found his love of the insect world. He served eight years in the U.S. Army prior to starting his scientific career; while stationed at Schofield Barracks in Hawai’i in the 1980s, he started volunteering with the Bishop Museum in Honolulu, which had a very active field entomology program at that time. He was smitten with the diversity of the insect world. “They had a fantastic collection there, and the researchers were very enthusiastic,” says Will. “They brought me on as a volunteer and took the time to explain everything.”
After leaving the Army, Will earned a degree in entomology from Ohio State University and eventually a Ph.D. from Cornell. He spent much time in the southern hemisphere, chasing carabids through South Africa, South America, and Australia. “Carabids give me an excuse to go everywhere. Wherever they are found, I’ll be there,” he says. Finding these two new species in the Hawaiian samples brings him full circle to his entomology roots on the islands.
Mecyclothorax neonomas (male at left, female at right) is one of two new species of carabid beetle discovered recently at the National Ecological Observatory Network’s Pu’u Maka’ala Natural Area Reserve in Hawai`i. (Photo by Kip Will, Ph.D.)
Illuminating Evolutionary Relationships Among Ground Beetles in Hawai`i
Will’s primary interest in entomology is phylogenetics, or the evolutionary relationships among species. Carabids in general, and Mecyclothorax in particular, provide excellent opportunities for phylogenetic studies. According to Liebherr, the 241 known species of Mecyclothorax in Hawai`i evolved over a period of 1.2 million to 1.9 million years. “They aren’t messing around when it comes to diversification,” he says.
Studying the differences between the species and the habitats they are found in can provide insights into how they evolved and diversified. Many species are found in tiny evolutionary niches. Over the course of Liebherr’s field studies in Hawai’i, he and his students identified 116 species of Mecyclothorax on a single volcano, including 74 species new to science. Volcanic islands, like those found in Hawai’i, have numerous “microhabitats” that promote rapid speciation for insects like Mecyclothorax. For example, individuals of a species might prefer streamside or aquatic habitats, leaf litter habitats on the forest floor, or arboreal microhabitats in epiphytic mosses or plants. Also, species on oceanic islands (especially wingless species such as those in the Mecyclothorax genus) often exhibit diminished dispersal abilities, and so each volcanic ridge may support species different from those on an adjoining ridge. The two new species discovered at PUUM, for example, are among those more likely to be found in terrestrial habitats within the forest, which makes them more susceptible to capture in the pitfall traps used by the NEON program.
Different species of Mecyclothorax are recognized by distinct morphology, striations evident in their exoskeletons, the species-specific form of the genitalia, and other physical characteristics, which also provide clues about the relationships between species. Will says, “The average person would just say, ‘There’s another shiny little brown beetle,’ but each species is unique based on their characteristics.” Species with more similar markings or morphology may be more closely related. Will explains, “We can look at the current distribution of species for clues as to how the taxa of particular fauna assembled over time. Looking at where we have representatives of related species on different volcanoes, and knowing the ages of each volcano, can tell us how they diversified and how they came to be where they are.”
Why Care About Carabids?
Mecyclothorax brunneonubiger (male shown here) is one of two new species of carabid beetle discovered recently at the National Ecological Observatory Network’s Pu’u Maka’ala Natural Area Reserve in Hawai`i. (Photo by Kip Will, Ph.D.)
Carabids are found in practically every ecosystem across the globe, with an estimated 35,000 to 45,000 species worldwide and nearly 2,500 known species in the U.S. alone. They are also good environmental indicators. Many species are highly specialized for their habitats and very sensitive to changes in the environment. These characteristics make them ideal subjects for NEON data collection. The NEON program collects ground beetles in pitfall traps at terrestrial field sites. Studying carabid populations across geographic regions and over time can provide insights into climate and ecosystem change and ecosystem dynamics.
Will explains, “The NEON program made a smart choice in sampling carabids. They are a group of insects that can be uniformly sampled to get at both shorter- and longer-term dynamics. They show just enough sensitivity to ecosystem and climate change—they’re tough enough to survive some change, but sensitive enough to show a response we can learn from.”
Carabids are found in large numbers in many habitats and play important roles in the ecosystem. Most are predators or scavengers. Some are the apex predators of the insect world in their domains, making some species very useful for bio-pest control. Many are highly specialized, with unique adaptations that allow them to go after specific prey such as hard-shelled snails or poison-spewing millipedes. These differences were what made carabids so fascinating to Will. “They are really important players in the ecosystem. If you want to have a robust ecosystem, they are part of that,” he says.
In the years to come, the NEON program’s carabid data will allow researchers to keep a close eye on shifting populations in Hawai’i and across the country. One issue Will plans to keep an eye on in Hawai’i is the impact of invasive carabid species on native Hawaiian species—for example, the invasive Trechus obtusus, which has shown up in large numbers in pitfall traps at PUUM. “That’s the beauty of consistent sampling year after year,” he says. “It allows us to see how populations ebb and flow and where additional native or non-native species are moving in or native species are getting pushed out. NEON lets us see these shifts over time.”
Zoe Gentes is a senior communications specialist at Battelle with the National Ecological Observatory Network Program. Email: gentes@battelleecology.org.
Citation: Yu L, Yang C, Ji Z, et al. First Report of New Bacterial Leaf Blight of Rice Caused by _Pantoea ananatis_ in Southeast China. Plant Disease. 2022; 106 (1); doi: 10.1094/PDIS-05-21-0988-PDN. —————————————————————————————————————————- In autumn 2020, leaf blight was observed on a number of varieties of rice (_Oryza sativa_) in Zhejiang and Jiangxi provinces. The disease incidence was 45-60%. The symptoms were assumed to be caused by _Xanthomonas oryzae_ pv. _oryzae_ (Xoo), the pathogen of rice bacterial blight.
Sixty-three isolates were obtained from collected diseased leaves. 16S rRNA sequence analysis from 6 isolates revealed that the amplified fragments shared 98% similarity with the _Pantoea ananatis_ type strain in GenBank. Analysis of further sequences and phylogenetic analyses was carried out. Based on the obtained morphological, physiological, biochemical, and molecular data, the isolates were confirmed as _P. ananatis_. Pathogenicity tests resulted in symptoms similar to those in the field.
_P. ananatis_ has previously been reported to cause grain discolouration of rice in the country, but this is the 1st report of _P. ananatis_ as the causative agent of rice leaf blight. This raises the alarm that the emerging rice bacterial leaf blight might be caused by _P. ananatis_, instead of Xoo as traditionally assumed. Further, the differences of occurrence, spread, and control between these 2 diseases will need to be determined.
— Communicated by: ProMED
[_Pantoea ananatis_ symptoms in rice may include lesions on stems, stem necrosis, and leaf blight. The pathogen has also been reported to cause sheath and grain rot, as well as kernel discolouration. _P. stewartii_, previously known to occur on rice seeds, has also recently been associated with a leaf blight of the crop in Africa (ProMED post 20170504.5012251). Both species are considered emerging rice pathogens. The effects of different bacterial strains on hosts can vary dramatically. The bacteria are generally transmitted by insect vectors, plant material, and infected seed, making them a quarantine risk.
Species in the genus can cause diseases on a number of crops, such as Stewart’s bacterial wilt on maize and fruit bronzing of jack fruit (_P. stewartii_); leaf blights of cereals, including rice (_P. agglomerans_); pink disease of pineapple (_P. citrea_); brown stalk rot of maize (_P. ananatis_ and a novel _Pantoea_ species); and centre rot of onion (_P. ananatis_). A bacterial blight of _Eucalyptus_ and a leaf blotch disease of sudangrass have also been associated with _Pantoea_ species.
_Xanthomonas oryzae_ pv. _oryzae_ (Xoo) causes bacterial leaf blight (BLB) of rice. In Asia, millions of hectares of rice paddies are severely affected every year, with reported yield losses of up to 60% (e.g., see ProMED post 20211216.8700304). Xo pv. _oryzicola_ (Xoc) is the causal agent of bacterial leaf streak (BLS; e.g., see ProMED post 20210713.8514345), which is currently considered one of the most important emerging diseases of rice in the region. Xoc is thought to have originated in Asia but is now also spreading in Africa (e.g., recent 1st report from Senegal, see link below).
Potatoes cultivated in Regil village in Khandachakra Municipality of Kalikot have been destroyed by late blight disease. The disease has destroyed potatoes cultivated by local farmers in about five bigha land.
Mansara Shahi, a local farmer, said that the farmers of the entire village planted potatoes but the disease had completely destroyed the potato crop. “In the past, we used to earn good income from potatoes,” he said.
Mayor of the municipality Jasiprasad Pandey said that potatoes were destroyed due to late blight disease. The agriculture branch of the municipality carried out the monitoring and relief would be given to farmers whose potatoes were destroyed.
Bhakti Prasad Pandey, chief of the agriculture branch of the municipality, said that some of the farms were completely destroyed even though some were not affected by the disease. “During our monitoring, it was found that chemical pesticides were used but without technical consultation, so we found that there was a problem with late blight disease,” he said. The branch has started the procedures to control the disease.
A version of this article appears in the print on January 30, 2022, of The Himalayan Times.
This month’s pest alerts include the include the the first report of Spotted-wing drosophila associated with Actinidia kolomikta (Photograph by Martin Cooper)
We’ve selected a few of the latest new geographic, host and species records for plant pests and diseases from CAB Abstracts. Records this month include the first report of Spotted-wing drosophila associated with Actinidia kolomikta and the first report of anthracnose caused by Colletotrichum fructicola on Brassica parachinensis in China.
New host plant records. Drew, R. A. I.; Romig, M. C. (2022) The fruit fly fauna (Diptera: Tephritideae: Dacinae) of Papua New Guinea, Indonesian Papua, Associated Islands and Bougainville 81-81.
To view all search results for new geographic, host and species records for plant pests and diseases, click here or to view results by your location click here.
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