scholarly journals Damping-off of sugar beet in Finland: I. Causal agents and some factors affecting the disease

1982 ◽  
Vol 54 (4) ◽  
pp. 225-244
Author(s):  
Mauritz Vestberg ◽  
Risto Tahvonen ◽  
Kyösti Raininko
Keyword(s):  
Sugar Beet ◽  
Fusarium Species ◽  
Damping Off ◽  
Fusarium Spp ◽  
Factors Affecting ◽  
Pathogenicity Tests ◽  
Phoma Betae

The fungus Pythium debaryanum auct. non Hesse is the main cause of damping-off on sugar beet in Finland. The fungus is found especially in diseased seedlings during the first two weeks after emergence. Later on, when the plants have one or two pairs of true leaves, Fusarium spp. can be isolated to a rather great extent. However, pathogenicity tests with three different Fusarium species have shown that this fungus is unble cause damping-off on sugar beet when inoculated into peat substrate. Among the fungi tried in this respect, only Pythium debaryanum and Phoma betae Frank showed clear pathogenicity. Sugar beet seedlings that outlive the disease grow slower, and their quality at harvest in the autumn is poorer than that of healthy beets.

scholarly journals Seedlings damping-off of Chenopodium quinoa Willd.

2010 ◽  
Vol 40 (No. 1) ◽  
pp. 5-10 ◽  
Author(s):  
M. Dřímalková ◽  
K. Veverka
Keyword(s):  
Sugar Beet ◽  
Chenopodium Quinoa ◽  
Damping Off ◽  
Greenhouse Experiments ◽  
Ascochyta Caulina ◽  
Pathogenicity Tests ◽  
Lower Ability

The causal agents of damping-off of quinoa seedlings were determined in greenhouse experiments. <I>Ascochyta caulina</I>,<I> Fusarium</I> <I>avenaceum</I>,<I> Fusarium</I> spp., <I>Alternaria </I>spp. and <I>Pythium</I> spp. were isolated from infected parts of quinoa seedlings. The most frequent <I>Pythium</I> sp. was <I>P. aphanidermatum</I>. Pathogenicity tests confirmed that <I>P. aphanidermatum</I> and <I>F. avenaceum</I> were the causal agents of damping-off of quinoa seedlings under greenhouse conditions. A comparison of the reaction of quinoa with that of other susceptible plants (spinach, cabbage, sugar beet) showed that quinoa is most susceptible to the pathogen before emergence, during germination till the end of the stage of the first pair of true leaves. Germinable quinoa seeds seemed to have a lower ability to emerge from the soil. This serious problem is caused not only by pre-emergence damping-off from pathogens but more so by a complex of several adverse factors during germination when quinoa is most sensitive.

scholarly journals Stalk Rot of Sugar Beet Caused by Fusarium solani on the Pacific Coast

Plant Disease ◽  
2007 ◽  
Vol 91 (9) ◽  
pp. 1204-1204 ◽  
Author(s):  
L. E. Hanson ◽  
R. T. Lewellen
Keyword(s):  
Sugar Beet ◽  
Seed Production ◽  
Fusarium Species ◽  
Lesion Size ◽  
Negative Control ◽  
Vascular Bundles ◽  
Water Control ◽  
The Pacific ◽  
Salinas Valley ◽  
Pathogenicity Tests

In 2006, symptoms of stalk blight (2) were observed on sugar beet (Beta vulgaris L.) plants from roots produced in Oregon that were being grown for seed production in a greenhouse in Salinas, CA using Salinas Valley soil. Symptoms included vascular and cortical browning, necrosis, and death of seed stalks. Isolations were made from the edge of stalk lesions and the crown. In addition to Fusarium oxysporum, the known cause of stalk blight (2), two isolates of F. solani were identified by morphology. For pathogenicity tests, sugar beet plants (FC606 [4]), grown in pasteurized potting mix and induced to flower by exposure at 4 to 7°C for 90 days (1) were used. Bolting plants were maintained in a greenhouse at 24 to 27°C. A 100-μl drop of a spore suspension (104 spores per ml) of each Fusarium isolate was placed on the surface of the seed stalk. The plant was stabbed through the drop with a sterile 18-gauge needle so that the drop was taken into the plant by hygroscopic pressure. Positive and negative control treatments were a stalk blight isolate of F. oxysporum from an Oregon seed production field and sterile water, respectively. Three plants were inoculated per isolate. Each inoculation site was wrapped loosely in Parafilm for 1 week to maintain a high humidity level around the site of inoculation, and seed stalks were covered in cloth bags (1). After 1 week, the Parafilm was removed and plants were examined weekly for symptoms. At 4 weeks, lesion size was measured. After 5 weeks, sections were taken from the seed stalk around the site of inoculation, surface disinfested with 0.5% NaOCl, and plated on potato dextrose agar to confirm the presence of the pathogen. The experiment was done twice. One of the two isolates of F. solani caused dark brown lesions on all inoculated seed stalks. On one plant, at 4 weeks after inoculation when the bag was being removed for observation, the seed stalk broke at the site of inoculation because of a spreading, brown lesion at the site. No lesions were observed on the water control plants. Brown lesions were observed on seed stalks inoculated with the known stalk blight isolate. Lesions were significantly (P = 0.001) larger with F. oxysporum than with F. solani when measured at 4 weeks (mean of 6.3 cm versus 2.2 cm, respectively). Lesions caused by F. solani showed a dark discoloration through the cortical tissue, as opposed to those caused by F. oxysporum, for which most of the initial discoloration was in the vascular bundles and epidermis. Fusarium isolates recovered from inoculated plants were morphologically similar to the isolates used for inoculation. Fusarium spp. were not isolated from the water control plants. While some F. solani isolates cause seedling or mature root disease in sugar beet (3), to our knowledge, this is the first report of a Fusarium species other than F. oxysporum causing a rot of sugar beet stalks. References: (1) E. Biancardi et al. Genetics and Breeding of Sugar Beet Science Publishers, Inc., Enfield, NH, 2005. (2) A. N. Mukhopadhay. Handbook of Diseases of Sugar Beet, Vol. 1. CRC Press, Boca Raton, FL 1987. (3) E. G. Ruppel. Plant Dis. 75:486, 1991. (4) G. A. Smith and E. G. Ruppel. Crop Sci. 19:300, 1980.

scholarly journals Comparative Pathogenicity and Virulence of Fusarium Species on Sugar Beet

Plant Disease ◽  
2012 ◽  
Vol 96 (9) ◽  
pp. 1291-1296 ◽  
Author(s):  
Pragyan Burlakoti ◽  
V. Rivera ◽  
G. A. Secor ◽  
A. Qi ◽  
L. E. Del Rio-Mendoza ◽  
...  
Keyword(s):  
Sugar Beet ◽  
Fusarium Oxysporum ◽  
Fusarium Species ◽  
Field Studies ◽  
Fusarium Spp ◽  
Foliar Symptoms ◽  
Vascular Discoloration ◽  
Fusarium Sp ◽  
Bare Root ◽  
Highly Virulent

In all, 98 isolates of three Fusarium spp. (18 Fusarium oxysporum, 30 F. graminearum, and 50 Fusarium sp. nov.) obtained from sugar beet in Minnesota were characterized for pathogenicity and virulence on sugar beet in the greenhouse by a bare-root inoculation method. Among the 98 isolates tested, 80% of isolates were pathogenic: 83% of the F. oxysporum isolates, 57% of the F. graminearum isolates, and 92% of the Fusarium sp. nov. isolates. Symptoms varied from slight to moderate wilting of the foliage, interveinal chlorosis and necrosis, and vascular discoloration of the taproot without any external root symptoms. Among the pathogenic isolates, 14% were highly virulent and 12% were moderately virulent. Most of the highly virulent isolates (91%) and moderately virulent isolates (89%) were Fusarium sp. nov. All pathogenic isolates of F. graminearum and most pathogenic isolates (87%) of F. oxysporum were less virulent. In general, more-virulent isolates induced first foliar symptoms earlier compared with less-virulent isolates. This study indicates that both F. oxysporum and Fusarium sp. nov. should be used in greenhouse and be present in field studies used for screening and developing sugar beet cultivars resistant to Fusarium yellows complex for Minnesota and North Dakota.

scholarly journals Damping-off of sugar beet with special reference to the fungus Pythium Pringsheim

1988 ◽  
Vol 60 (3) ◽  
pp. 159-178
Author(s):  
M. Vestberg
Keyword(s):  
Sugar Beet ◽  
High Temperatures ◽  
Seed Treatment ◽  
Disease Incidence ◽  
Fusarium Species ◽  
Systemic Fungicide ◽  
Second Phase ◽  
Damping Off ◽  
Short Term ◽  
Preceding Crop

In Finland damping-off of sugar beet can be divided into two distinct phases. The first phase begins with the germination of the seeds and continues until the first true leaves have developed. Under field conditions seedlings usually remain healthy up to about 1 week after emergence. Thereafter a sudden outbreak of damping-off may occur, resulting in rapid wilting and death of seedlings. During the second phase of the disease, when seedlings have one or more pairs of true leaves, disease does not always result in the death of the plant; plants may survive throughout the summer. At the pernicious phase of the disease the soil borne pathogen, Pythium debaryanum auct. non Hesse, is the most common causal agent, accounting in 1979—86 for 53.9 % (variation between years 18.3—90.1 %) of fungal isolations, and Fusarium species for 28.3 % (5.0—58.5 %). At seedling stages with one or more pairs of true leaves Fusarium spp. predominate accounting for 49.4 % (36.1—81.0 %) as compared to 23,9 % (2.9—37.8) for P. debaryanum. The importance of Fusarium species as true damping-off pathogens is, however, doubtful. The seed borne damping-off pathogen Phoma betae Frank was isolated only in 0 to 4 % and was not dependent on the stage of seedling development. Of the factors affecting damping-off, high temperatures were repeatedly shown to increase the disease. This, presumably was an effect especially on P. debaryanum, the aggressiveness of which is strongly increased at high temperatures. Pot experiments showed preceding crops of cereals to have the best disease-decreasing effect, both short-term (one growing period of preceding crop) and long-term (several growing periods of preceding crop) effect. Legumes kept the level of damping-off unchanged or even raised it, especially as a short-term effect. The influence of preceding crops varied in different soil types. Preceding crops also caused considerable fluctuations in inoculum density (0 to 3650 propagules/gram soil) and potential (0.2—16 IPU 50/gram soil) of Pythium. The correlation to damping-off of sugar beet was, however, poor. Seed treatment with the systemic fungicide hymexazol, especially when combined with thiram, prevented satisfactorily the pernicious type of damping-off. In many experiments this seed treatment repeatedly decreased disease incidence significantly, produced denser stands (7100—31200 numbers of beets more/hectare) and increased yield by 5—10 % on average.

scholarly journals First Report of Root and Basal Rot of Angelica acutiloba Caused by Fusarium solani in Taiwan

Plant Disease ◽  
2010 ◽  
Vol 94 (9) ◽  
pp. 1164-1164 ◽  
Author(s):  
L. L. Chern ◽  
C. T. Feng ◽  
C. H. Yu ◽  
W. C. Ho
Keyword(s):  
Genomic Dna ◽  
Vascular Tissue ◽  
Fusarium Species ◽  
Morphological Characteristics ◽  
Fusarium Spp ◽  
First Report ◽  
Basal Rot ◽  
Brown Discoloration ◽  
Pathogenicity Tests ◽  
Angelica Acutiloba

Angelica (Angelica acutiloba (Siebold. & Zucc.) Kitag.) is one of the most important traditional Chinese medicines in Taiwan. The medicinal herb has been mainly imported from China, but cultivation at a commercial scale has also been established in recent years in Hualien County, Taiwan. In September 2008, angelica plants in a field at Liou-shih-dan Mountain displayed symptoms of yellowing, stunting, rotting of roots and basal stem, and wilting. A severe brown discoloration of vascular tissue along the stems of infected plants was observed. One or more Fusarium spp. was consistently isolated from the roots and stems of diseased plants. Isolates R3, R4, and R5 were incubated for 14 days on celery tissues to produce chlamydospores, and 33 g of celery tissue with chlamydospores were mixed with 500 ml of soil per pot as inoculum. One 4-month-old angelica seedling was planted per pot. Three angelica plants were inoculated with each isolate in the first test and nine plants were inoculated with each isolate in the second test. Other seedlings were inoculated with water as checks. Pathogenicity tests were conducted twice. Incidence of diseased plants was 66, 100, and 33% in the first test, and 66, 100, and 44% in the second test for the R3, R4, and R5 isolates, respectively. Symptoms similar to those on the diseased plants in the field were produced, with leaves turning yellow starting 7 days after inoculation and wilt and discoloration of roots 14 days after inoculation. Fusarium spp. also were reisolated from the diseased plants. Genomic DNA was extracted from mycelium with a fungal genomic DNA purification kit, and the internal transcribed spacer (ITS) rDNA region was amplified and sequenced with primers ITS-4 and ITS-5. The sequence of the resulting ~550-bp amplicon was compared with those in GenBank. The ITS sequences of the R3, R4, and R5 isolates shared 98.7, 98.7, and 97.9% similarity with F. solani isolate AF129104 (3), respectively. Phylogenetic analysis also showed that the three isolates were closer to F. solani than to other Fusarium species. Both macroconidia and microconidia of the R4 isolate were produced on potato dextrose agar. Macroconidia were three to five septate and 27.2 to 37.8 × 4.4 to 6.2 μm; microconidia were zero to one septate and 9.3 to 14.7 × 2.9 to 4.8 μm. Chlamydospores produced on celery juice agar were terminal or intercalary, solitary, in pairs or in chains, and 9.3 to 12.1 μm. Morphological characteristics identified the three isolates as F. solani (Martius) Snyder & Hansen according to Fu and Chang (2) and Chung et al. (1), which agrees with the ITS comparison. To our knowledge, this is the first report of root and basal rot caused by F. solani on angelica in Taiwan. References: (1) W. C. Chung et al. Plant Prot. Bull. 40:177, 1998. (2) C. H. Fu and T. T. Chang. Taiwan J. For. Sci. 14:223, 1999. (3) H. Suga et al. Mycol. Res. 104:1175, 2000.

Damping-off of sugar beet in Finland: II. Disease control 

1983 ◽  
Vol 55 (5) ◽  
pp. 431-450
Author(s):  
Mauritz Vestberg ◽  
Risto Tahvonen ◽  
Kyösti Raininko
Keyword(s):  
Sugar Beet ◽  
Disease Control ◽  
Field Experiments ◽  
Damping Off ◽  
Good Protection ◽  
Great Damage

In pot and field experiments carried out in 1979-1981, the systemic funqicide hymexazol prevented satisfactorily soil borne damping-off of sugar beet caused mainly by the fungus Pythium debaryanum auct. non Hesse. The results with the combination hymexazol + thiram were still better. This treatment gave very good protection against the disease up to about two to three weeks after emergence, increased the yield on the average by 5-10 % and produced considerably thicker and denser stands. Thereafter a large number of beets may have become infected, but no great damage was caused as only few died. Band spraying at emergence using hymexazol with a large amount of water as well as spraying into the seed furrow prevented the outbreak of the disease almost completely. Liming had little effect on damping-off.

Kinetic and thermodynamic study of the adsorption of calcium onto sugar beet pulp

2016 ◽  
pp. 565-570
Author(s):  
Huang Qin ◽  
Zhu Si-ming ◽  
Zeng Di ◽  
Yu Shu-juan
Keyword(s):  
Sugar Beet ◽  
Adsorption Equilibrium ◽  
Ph Value ◽  
Hard Water ◽  
Sugar Beet Pulp ◽  
Order Kinetic ◽  
Factors Affecting ◽  
Isotherm Equation ◽  
Equilibrium Data ◽  
Beet Pulp

Sugar beet pulp (SBP) was used as low value adsorbent for the removal of calcium from hard water. Batch experiments were conducted to determine the factors affecting adsorption of the process such as pH value and Ca concentration. The adsorption equilibrium of Ca2+ by the SBP is reached after 100min and a pseudo second-order kinetic model can describe the adsorption process. The initial concentrations of Ca varied from 927 to 1127mgCa2+/L. A dose of 30g/L sugar beet pulp was sufficient for the optimum removal of calcium. The overall uptake of Ca ions by sugar beet pulp has its maximum at pH=8. The adsorption equilibrium data fitted well with the Langmuir adsorption isotherm equation.

scholarly journals Incidence and Etiology of Postharvest Fungal Diseases Associated with Bulb Rot in Garlic (Alllium sativum) in Spain

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1063
Author(s):  
Laura Gálvez ◽  
Daniel Palmero
Keyword(s):  
Negative Impact ◽  
Fusarium Species ◽  
Fungal Species ◽  
Postharvest Disease ◽  
Dry Rot ◽  
Fusarium Dry Rot ◽  
Causative Agents ◽  
Postharvest Handling ◽  
Pathogenicity Tests ◽  
Bulb Rot

In recent years, different postharvest alterations have been detected in garlic. In many cases, the symptoms are not well defined, or the etiology is unknown, which further complicates the selection of bulbs during postharvest handling. To characterize the different symptoms of bulb rot caused by fungi, garlic bulb samples were collected from six Spanish provinces in two consecutive years. Eight different fungal species were identified. The most prevalent postharvest disease was Fusarium dry rot (56.1%), which was associated with six Fusarium species. Fusarium proliferatum was detected in more than 85% of symptomatic cloves, followed by F. oxysporum and F. solani. Pathogenicity tests did not show a significant correlation between virulence and mycotoxin production (fumonisins, beauvericin, and moniliformin) or the mycelial growth rate. Penicillium allii was detected in 12.2% of the samples; it was greatly influenced by the harvest season and garlic cultivar, and three different morphotypes were identified. Stemphylium vesicarium and Embellisia allii were pathogenic to wounded cloves. Some of the isolated fungal species produce highly toxic mycotoxins, which may have a negative impact on human health. This work is the first to determine the quantitative importance, pathogenicity, and virulence of the causative agents of postharvest garlic rot in Spain.

scholarly journals Effects of Antagonists on Mycotoxins of Seedborne Fusarium spp. in Sweet Corn

Toxins ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 438
Author(s):  
Mary E. Ridout ◽  
Bruce Godfrey ◽  
George Newcombe
Keyword(s):  
Sweet Corn ◽  
Fusarium Species ◽  
Fusarium Mycotoxins ◽  
Fusarium Spp ◽  
Corn Seed ◽  
Pichia Membranifaciens ◽  
Mature Seeds ◽  
F1 Cross

Fusarium species coexist as toxigenic, systemic pathogens in sweet corn seed production in southwestern Idaho, USA. We hypothesized that fungal antagonists of seedborne Fusarium would differentially alter production of Fusarium mycotoxins directly and/or systemically. We challenged the Fusarium complex by in vitro antagonism trials and in situ silk and seed inoculations with fungal antagonists. Fungal antagonists reduced growth and sporulation of Fusarium species in vitro from 40.5% to as much as 100%. Pichia membranifaciens and Penicillium griseolum reduced fumonisin production by F. verticillioides by 73% and 49%, respectively, while P. membranifaciens and a novel Penicillium sp. (WPT) reduced fumonisins by F. proliferatum 56% and 78%, respectively. In situ, pre-planting inoculation of seeds with Penicillium WPT systemically increased fumonisins in the resulting crop. Morchella snyderi applied to silks of an F1 cross systemically reduced deoxynivalenol by 47% in mature seeds of the F2. Antagonists failed to suppress Fusarium in mature kernels following silk inoculations, although the ratio of F. verticillioides to total Fusarium double with some inoculants. Fusarium mycotoxin concentrations in sweet corn seed change systemically, as well as locally, in response to the presence of fungal antagonists, although in Fusarium presence in situ was not changed.

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