scholarly journals Occurrence and Anastomosis Grouping of Rhizoctonia spp. Inducing Black Scurf and Greyish-White Felt-Like Mycelium on Carrot in Sweden

2021 ◽  
Vol 7 (5) ◽  
pp. 396
Author(s):  
Shirley Marcou ◽  
Mariann Wikström ◽  
Sara Ragnarsson ◽  
Lars Persson ◽  
Monica Höfte

Carrots with different Rhizoctonia-like symptoms were found in the main Swedish carrot production areas from 2001–2020. The most commonly observed symptoms were a greyish-white felt-like mycelium and black scurf, the latter often associated with Rhizoctonia solani anastomosis group (AG) 3-PT on potato. An overall increase in disease incidence in all studied fields over time was observed for both symptoms. The majority of Rhizoctonia isolates sampled from carrot in the period 2015–2020 were identified as AG 3 (45%) and AG 5 (24%), followed by AG 1-IB (13%), AG 11 (5%), AG-E (5%), AG BI (3%), AG-K (3%) and AG 4-HGII (2%). To our knowledge, this is the first report describing AG 5 in Sweden as well as AG 3, AG 11 and AG-E inducing Rhizoctonia-like symptoms on carrot. Secondly, we report for the first time that R. solani AG 3, and the less observed AGs: AG 1-IB and AG 5 can induce black scurf symptoms on the taproot of carrots. Due to a widely used carrot-potato crop rotation in Swedish areas, a possible cross-over from potato to carrot is suggested. This information is of high importance to reduce Rhizoctonia inoculum in soils, since avoiding carrot-potato crop rotations needs to be considered.

Plant Disease ◽  
2013 ◽  
Vol 97 (9) ◽  
pp. 1245-1245 ◽  
Author(s):  
J. W. Woodhall ◽  
B. Lutomirska ◽  
J. C. Peters ◽  
P. S. Wharton

Rhizoctonia solani is a species complex of 13 related but genetically distinct anastomosis groups (AGs). In potato, R. solani can infect the stems, stolons, and roots, resulting in quantitative losses. It can also cause qualitative losses through blemishes occurring on progeny tubers, such as black scurf and elephant hide (corky cracking). Knowledge of the AG in local populations is important because they differ in host range, fungicide sensitivity, and disease severity (2). To determine the AGs present in Poland, 54 tuber samples displaying typical R. solani symptoms were taken from six different fields in 2011. The fields were representative of five different administrative regions of Poland and from at least 10 different varieties. Rhizoctonia was isolated from tubers by placing symptomatic material on to tap water agar amended with streptomycin and penicillin and after 2 to 3 days Rhizoctonia colonies were identified and hyphal tips of these transferred to potato dextrose agar. Rhizoctonia was successfully isolated from 48 tubers displaying black scurf and two tubers displaying elephant hide symptoms. DNA was extracted from Rhizoctonia cultures using a Wizard Food kit (Promega) and the AG was determined using specific real-time PCR assays (1). All Rhizoctonia isolates were determined to be AG3 and this was confirmed for 10 selected isolates by observing hyphal fusion with a known AG3 tester isolate (Rs08) as described previously (3). Pairings were also conducted amongst the 10 Polish isolates, C2 reactions were typically observed indicating numerous vegetative compatible groups are present. This study shows that AG3 is likely to be the predominant AG in potato tubers in Poland. This is similar to other studies in Europe, which have all determined that AG3 accounts for at least 92% of isolates from potato (2,3). AG2-1, 4, and 5 have also been found in tubers worldwide and climate and certain crop rotations can influence the presence of these other AGs in potato tubers (2). However, climate and crop rotations in Poland are similar to other parts of Europe so the predominance of AG3 is expected. AG3 was also isolated from elephant hide symptoms; however, it was more frequently isolated from sclerotia. The ability of AG3 to prolifically produce sclerotia and thereby survive on seed tubers may explain its predominance in potato crops (4). Therefore, studies focusing on the management of Rhizoctonia potato disease in Poland should consider AG3 in the first instance. References: (1) G. E. Budge et al. Plant Pathol. 58:1071, 2009. (2) L. Tsror. J. Phytopathol. 158:649, 2010. (3) J. W. Woodhall et al. Plant Pathol. 56:286, 2007. (4) J. W. Woodhall et al. Plant Pathol. 57:5, 2008.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Kabita Kumari Shah ◽  
Bindu Modi ◽  
Hari Prasad Pandey ◽  
Arjun Subedi ◽  
Geeta Aryal ◽  
...  

Diversified crop rotation (DCR) improves the efficiency of farming systems all over the world. It has the potentiality to improve soil condition and boost system productivity. Improved soil attributes such as increased soil water uptake and storage, and a greater number of beneficial soil organisms, may improve yield tolerance to drought and other hard growing conditions in a variety of crop rotations. Crop rotations with a variety of crops benefit the farmers,reduce production risk and uncertainty, and enhance soil and ecological sustainability. Farmers may be able to diversify their sources of income by adopting diversified crop rotations. Furthermore, because of the distinct structure, function, and relationship of plant community with soil in DCR, it contributes to the long-term development of soil health by decreasing insect, weed, and disease incidence and increasing the physical and chemical structure of the soil. DCR is becoming more popular approach for maintaining sustainable crop production. This review provides the evidence of the significance of DCR, challenges to adapt it, and possible way out to overcome the challenges.


2008 ◽  
Vol 18 (3-4) ◽  
pp. 223 ◽  
Author(s):  
M.J. LEHTONEN ◽  
P.S. WILSON ◽  
P. AHVENNIEMI

Development of black scurf on potato tubers (cv. Nicola) was compared in plants inoculated with isolates of Rhizoctonia solani of three anastomosis groups (AG2-1, AG3 and AG5) which occur in potato crops in Finland. All isolates induced stem canker lesions but only isolates of AG3 formed efficiently black scurf on progeny tubers. Among the AG2-1 and AG5 isolates tested, only one AG2-1 isolate formed a few sclerotia on 13.5 % of the progeny tubers in one experiment. The data indicate that isolates of AG3 differ from those of AG2-1 and AG5 in having a higher ability to form sclerotia on tubers. Therefore, while AG2-1 and AG5 isolates have a broader host range, AG3 is more efficient in producing black scurf, which provides this anastomosis group with more efficient means of dissemination on seed potatoes. These differences probably explain the predominance of AG3 (98.9 % of isolates) in potato crops in Finland and other northern potato production areas.;


Author(s):  
Ol'ga Gladysheva ◽  
Oksana Artyuhova ◽  
Vera Svirina

The results of long-term research in experiments with crop rotations with different clover saturation are presented. It is shown that the cluster has a positive effect on the main indicators of vegetation of dark-gray forest soil. The introduction of two fields of perennial grasses into the six-field crop rotation significantly increases both the humus reserves and increases the productivity of arable land by 1.5–2 times compared to the crop rotation with a field of pure steam.


Author(s):  
Saulius GUŽYS ◽  
Stefanija MISEVIČIENĖ

The use of nitrogen fertilizer is becoming a global problem; however continuous fertilization with nitrogen ensures large and constant harvests. An 8 year research (2006–2013) was conducted to evaluate the relationships between differently fertilized cultivated plant rotations. The research was conducted in Lipliunai (Lithuania) in the agroecosystem with nitrogen metabolism in fields with deeper carbonaceous soil, i.e. Endocalcari Endohypogleyic Cambisol (CMg-n-w-can). The research area covered three drained plots where crop rotation of differently fertilized cereals and perennial grasses was applied. Samples of soil, water and plants were investigated in the Chemical Analysis Laboratory of the Aleksandras Stulginskis University certified by the Environment Ministry of the Republic of Lithuania. The greatest productivity was found in a crop rotation with higher fertilization (N32-140). In crop rotation with lower fertilization (N24-90) productivity of cereals and perennial grasses (N0-80) was 11–35 % lower. The highest amount of mineral soil nitrogen was found in cereal crop rotation with higher fertilization. It was influenced by fertilization and crop productivity. The lowest Nmin and Ntotal concentrations in drainage water were found in grasses crop rotation. Crop rotations of differently fertilized cereals increased nitrogen concentration in drainage water. Nmin concentration in water depended on crop productivity, quantity of mineral soil nitrogen, fertilization, and nitrogen balance. The lowest nitrogen leaching was found in the crop rotation of grasses. Cereal crop rotation increased nitrogen leaching by 12–42 %. The usage of all crop rotations resulted in a negative nitrogen balance, which essentially depended on fertilization with nitrogen fertilizer.


Author(s):  
V.V. Ilinich ◽  
◽  
A.A. Naumova

the presented research is dedicate to confirming the hypothesis about increase in extreme precipitation of recent decades, affecting the degree of soil erosion in crop rotations.


Author(s):  
V. А. Shchedrin

In OOO “Dubovitskoe” which was organized in 2006 as investment project of the AO “Shchelkovo Agrokhim” for 2010 – 2012 three advanced crop rotations have been developed. Before their introduction the grain crops fraction in the cropping system was 62%, then it fell to 49%. At the same time the portion of raw crops increased from 15 to 20%, legumes from 6 to 8%, others (buckwheat, grain maize, etc.) - up to 23%. As of 2017, the crops of leguminous crops have increased noteworthily. There are two predominant soil types here heavy clay loam podzolized chernozem (6615 ha) and grey forest soil (856 ha). Weighted average indicators (as of 2017): humus content in the soils of arable land is 5, 34%; acidity pH is 4.92; labile phosphorus - 111.8 mg / kg soil; exchange potassium - 144 mg / kg soil. The coefficient of the soil fertility in the enterprise (weighted average) is 0.66. This means that maintaining and increasing the soil fertility for arable land of the enterprise is critical task. As a result of the research, it has been established that the technologies introduced in the crop vegetation management (CVS) in the crop rotation conditions ensure high productivity of cultivated crops and stability of humus content in soils as an energy basis and a guarantor of increasing fertility. The indicators of the labile phosphorus Р205 and exchange potassium К20 in the soils depending on the crop rotation vary from a certain decrease to expressed steady growth. Therefore it is necessary to specify seeding rates based on actual data. Sustainable soil acidification in the crop rotations under crop cultivation in OOO “Dubovitskoe” it is the result of the acid feterlizers high rates application, during studying period did not carried out required agromelioration with calcium contenting elements.


2018 ◽  
Vol 2 (95) ◽  
pp. 20-25
Author(s):  
O.J. Kachmar ◽  
O.V. Vavrynovych ◽  
O.L. Dubytsky ◽  
A.O. Dubytska ◽  
M.M. Shcherba

Scientific and methodological approaches to the formation of zonal ecologically safe crop rotations as a basic subsystem of farming in the formation of high, stable productivity of agricultural crops are substantiated, while ensuring the reproduction of soil fertility, increasing the efficiency of fertilizer systems and environmental protection. Various rotational crop rotations for introduction in the conditions of the Carpathian region in farms of different specialization and intensity of production are proposed.


2017 ◽  
Vol 1 (92) ◽  
pp. 62-68
Author(s):  
R. Holod ◽  
О. Bilinska ◽  
H. Shubala

There were analyzed and disclosed the basic components of arable farming systems and their Meaning, the current state and scientific principles in the context of the further development of field crop cultivation in the conditions of Western Forest-Steppe. The purpose of research. To study an effect of alternation of crop in crop rotation in conditions of brief rotation on the soil water regime, productivity and economic efficiency. Methods. Field, laboratory, comparative and analytical. Results. The results of researches on study of productivity of four-field crop rotations with short rotation depending on their saturation by the grain and tilled cultures, of various use of mineral fertilizers, green manure crops and collateral products which were conducted during 2014-2015 in the stationary experiment of the scientific and technological department of plant growing and arable farming, of the TDSGDS of the IKSGP of NAAN are resulted In the article. The elements of the biologization of farming are the basis of our development of crop rotations with short rotation. The study of the effect of green manure crops and collateral products in four-field crop rotations with a different set of crops on the change of soil fertility and productivity of crop rotations as a whole was carried out to this purpose. According to the results of the research, is provided the information on the effectiveness of improving the field crop rotations with short rotation with varying degrees of saturation by grain and tilled crops, that ensure the production of environmentally friendly products, reducing the cost of grain, improving the quality of marketable products. The study of the effect of alternation of crop in crop rotation in conditions of brief rotation on the soil water regime, productivity and economic efficiency showed that an increase in crop rotation productivity is observed in short-rotation crop rotations, if they are saturated by grain crops up to 100%, cereals crops reduction to 50% in crop rotations contributes to a decrease in crop productivity. Conclusion. Thus, the results of the research showed that with the correct construction of short rotational crop rotations, such problems as rational use of nutrients and soil moisture, control of weeds and pests of agricultural crops, improvement of the physical and chemical properties of the soil, increased efficiency in the use of fertilizers and equipment, Cheapening of the received agricultural product may be solved.


2020 ◽  
Vol 13 ◽  
pp. 175628482093518 ◽  
Author(s):  
Angélique Saint ◽  
Maxime Benchetrit ◽  
Sébastien Novellas ◽  
Denis Ouzan ◽  
Alexander Tuan Falk ◽  
...  

Introduction: Hepatocholangiocarcinoma (HCC-ICC) is a rare tumor presenting the histologic characteristics of both hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). As there is no consensus on it management, the therapeutic strategy rests on the specific treatments for HCC or ICC. Programmed cell death 1 (PD-1) inhibitors showed encouraging results in the second line treatment of HCC after sorafenib but it efficacy in HCC-ICC has never been reported. Methods and results: We present the case of a 72-year-old male patient treated for metastatic HCC-ICC due to a viral hepatitis C cirrhosis in progression after two lines of treatment. Tumor was characterized by a PDL-1 status of 85%. Patient received pembrolizumab at doses of 200 mg every 21 days by intravenous infusion. After one injection he was presented an immediate clinical benefit, a partial response was observed after two months of treatment and a complete response two months later. This response was maintained over time along with toxicity-free tumor control after 18 months treatment. Conclusion: To our knowledge, we reported for the first time the efficacy of a PD1 inhibitor treatment in a patient presenting metastatic HCC-ICC due to viral cirrhosis and overexpressing PDL-1 after failure of two lines of treatment.


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