LA SEMENCE INFECTEE, SOURCE D’INOCULUM DE LA TACHE ARGENTEE DANS LES SOLS AFFECTES A LA CULTURE DES POMMES DE TERRE

1969 ◽  
Vol 49 (1) ◽  
pp. 83-86
Author(s):  
Jacquelin Santerre
Keyword(s):  
Organic Soil ◽  
Loamy Sand ◽  
Silver Scurf ◽  
Potato Tubers ◽  
Infected Seed ◽  
Seed Potatoes ◽  
Source Of Infection ◽  
Healthy Seed ◽  
Disease Free

This study was carried out during three years on St. Pacôme loamy sand and on organic soil defined as a well-decomposed muck with shoots of healthy seed-potatoes and shoots of tubers infected with silver scurf. The disease-free shoots yielded very few infected potato tubers compared with infected shoots which yielded a high percentage of infected tubers. Results obtained on the loamy sand indicate that growing potatoes in the same field during several years does not induce the development of Helminthosporium atrovirens in the soil to the extent of becoming an important source of infection. Infected potato debris left over in the field from the preceding crops are a negligible source of inoculum compared with infected seed-potatoes which are considered the main source of infection.

Helminthosporium solani. [Descriptions of Fungi and Bacteria].

1968 ◽  
Author(s):  
M. B. Ellis
Keyword(s):  
Solanum Tuberosum ◽  
Geographical Distribution ◽  
Storage Conditions ◽  
Silver Scurf ◽  
Helminthosporium Solani ◽  
Potato Tubers ◽  
Entire Surface ◽  
Infected Seed ◽  
Seed Tubers ◽  
Large Numbers

Abstract A description is provided for Helminthosporium solani. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Solanum tuberosum. DISEASE: Silver scurf of potato tubers. It causes a blemish of the skin which becomes discoloured brown or silvery in patches, more conspicuous in spring especially on greened tubers. The silvery appearance is most apparent when tubers are washed. Sometimes the affected areas become dry and flake-off. Where infection is severe under storage conditions the entire surface of the tuber may become sooty owing to the presence of large numbers of conidiophores and conidia. GEOGRAPHICAL DISTRIBUTION: CMI Map 233 shows distribution up to 1951. Countries from which the disease has been reported since then include: Greece, India, Jersey, Mozambique, Peru, Switzerland, U.S.S.R., Venezuela. TRANSMISSION: Through infected seed tubers.

EVALUATION DE L’IMPORTANCE RELATIVE DU SOL ET DE LA SEMENCE COMME SOURCE D’INOCULUM DE LA TACHE ARGENTEE DES POMMES DE TERRE AU MOYEN D’ESSAIS DE REPRESSION

1967 ◽  
Vol 47 (6) ◽  
pp. 695-702 ◽  
Author(s):  
Jacquelin Santerre
Keyword(s):  
Cultural Practices ◽  
Inorganic Mercury ◽  
Health Condition ◽  
Potato Seed ◽  
Silver Scurf ◽  
Seed Potatoes ◽  
Mercury Compounds ◽  
Seed Tubers ◽  
Good Surface ◽  
Disease Free

The disinfection of potato seed tubers with formalin, organic and inorganic mercury compounds is useless against silver scurf of potatoes caused by Helminthosporium atrovirens. Although generally good surface disinfectants, these fungicides cannot reach the mycelium of the fungus growing underneath the skin. When conditions are again favorable, the pathogen will grow conidiophores that will bear conidia, the germination of which is not impaired by the previous treatments.Cultural practices such as fallow, crop rotation as well as soil treatments with Lanstan (soil fungicide) or Vapam (soil fumigant) did not reduce the percentage of infected tubers at harvest when used in conjunction with apparently disease-free potato seed tubers.Besides showing the ineffectiveness of disinfecting potato seed tubers, these results indicate that evaluating the true health condition of seed-potatoes according to whether or not the fungus is present on the skin is not to be relied upon, that sorting out visibly infected tubers does not suffice to free a "seed" from the disease, and that cultural practices and chemical soil treatments are useless if the seed-potatoes are already infected, thereby laying emphasis on the infected potato seed tubers as the main source of inoculum for silver scurf.

scholarly journals Occurrence and epidemiological aspects of potato silver scurf in California

2004 ◽  
Vol 22 (4) ◽  
pp. 690-695 ◽  
Author(s):  
Marcos G. Cunha ◽  
David M. Rizzo
Keyword(s):  
Storage Period ◽  
Storage Conditions ◽  
Silver Scurf ◽  
Inoculum Potential ◽  
Helminthosporium Solani ◽  
Potato Tubers ◽  
Commercial Potato ◽  
Tuber Disease ◽  
Fusarium Sp ◽  
Over Time

A new potato tuber disease has been observed in the Tulelake region, California, USA, since 1995, with tuber symptoms suggestive of silver scurf disease (Helminthosporium solani). In this work we isolated, identified and demonstrated the nature of the causal agent of this potato disease in California. In addition, the distribution of H. solani in potato fields and the inoculum potential at harvest time were investigated. Disease progress and H. solani spore populations were also characterised under commercial storage conditions. The main fungal genera associated with potato tubers in storage were Helminthosporium solani, Colletotrichum sp., Fusarium sp., and Rhizoctonia sp. The results of Koch's postulates indicated that H. solani is responsible for the outbreak of silver scurf in the Tulelake region. In a disease survey in three commercial potato fields naturally infested, H. solani infections occurred in all fields. However, the extension of the infections differed significantly between the fields. During potato storage, silver scurf usually increased over time. The percentage of the tuber surface covered by silver scurf varied from 3.5% up to 35.5% during the storage period. The number of H. solani lesions per tuber also progressively increased from 6% up to 35%, six months after storage. H. solani spore populations also increased over time in all studied potato stores; nevertheless, they followed no consistent pattern, exhibiting multiple and variable peaks of increase and reduction during the period of storage.

scholarly journals Evaluation of Fungicides Applied Via Drip Irrigation for Control of Silver Scurf on Potato in Western Washington

2015 ◽  
Vol 4 (1) ◽  
pp. 84
Author(s):  
McMoran D. W. ◽  
Buller S. J.
Keyword(s):  
Drip Irrigation ◽  
Washington State ◽  
Silver Scurf ◽  
State University ◽  
Potato Tubers ◽  
Washington State University ◽  
Mount Vernon ◽  
Loam Soil ◽  
Western Washington ◽  
Important Disease

Silver scurf is an economically important disease on potato tubers caused by Helminthosporium solani. Two studies were established near Mount Vernon, WA at Washington State University NWREC on 20 May 2011 and 21 May 2012 in Skagit silt loam soil.  Five treatments included: penthiopyrad applied at 45 days after planting (dap), penthiopyrad applied at 60 dap, azoxystrobin (Quadris; 9 oz/acre) applied at 45 dap, and azoxystrobin applied at 60 dap, and a non-treated non-irrigated control.  This study did not control for the effect of irrigation, as azoxystrobin- and penthiopyrad-treated plots were drip-irrigated while non-treated plots were not irrigated. The results of this study are therefore limited but do suggest a reduction in silver scurf incidence and severity with no significant impact on yield of potatoes when treated fungicide applied through drip irrigation systems.

Effects of silver scurf (Helminthosporium solani) on seed potatoes

1984 ◽  
Vol 27 (2) ◽  
pp. 145-154 ◽  
Author(s):  
P. J. Read ◽  
G. A. Hide
Keyword(s):  
Silver Scurf ◽  
Helminthosporium Solani ◽  
Seed Potatoes

scholarly journals Postharvest Application of Organic and Inorganic Salts for Suppression of Silver Scurf on Potato Tubers

Plant Disease ◽  
1998 ◽  
Vol 82 (2) ◽  
pp. 213-217 ◽  
Author(s):  
Claudia Olivier ◽  
Donald E. Halseth ◽  
Eduardo S. G. Mizubuti ◽  
Rosemary Loria
Keyword(s):  
Sodium Bicarbonate ◽  
Disease Severity ◽  
Ammonium Bicarbonate ◽  
Potassium Bicarbonate ◽  
Postharvest Disease ◽  
Inorganic Salts ◽  
Potassium Sorbate ◽  
Silver Scurf ◽  
Potato Tubers ◽  
Pathogen Suppression

Seven organic and inorganic salts were tested for suppression of silver scurf, a postharvest disease of potato tubers caused by Helminthosporium solani. Potassium sorbate, calcium propionate, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, and ammonium bicarbonate were added to V8 agar at concentrations of 0.06–0.2 M. Radial growth of H. solani was significantly reduced (P < 0.05) by all salts at all concentrations. All salts except sodium bicarbonate and potassium bicarbonate were fungicidal at 0.2 M. Effects of postharvest salt treatments on disease severity and sporulation of H. solani on inoculated and naturally infected potato tubers were evaluated in separate experiments. Greenhouse-grown tubers were inoculated with H. solani spore suspensions (2 × 105 spores/ml), incubated for 5 days, dipped into 0.2 M solutions of each of the salts, and incubated in a moist chamber at 22–24°C for 6 weeks. All salt treatments prevented lesion development and sporulation of H. solani and differed significantly (P < 0.05) from the control. Postharvest applications of test compounds (0.2M) also significantly (P < 0.05) reduced disease severity and H. solani sporulation on naturally infected, field-grown tubers after 15 weeks of storage at 10°C. Salt treatments did not differ in disease or pathogen suppression. These relatively nontoxic organic and inorganic salts have potential as postharvest applications for control of silver scurf.

Use of 2-aminobutane as a fumigant for control of gangrene, skin spot and silver scurf diseases of potato tubers

1973 ◽  
Vol 16 (2) ◽  
pp. 109-125 ◽  
Author(s):  
D. C. Graham ◽  
G. A. Hamilton ◽  
C. E. Quinn ◽  
A. D. Ruthven
Keyword(s):  
Silver Scurf ◽  
Potato Tubers ◽  
Skin Spot

scholarly journals Evaluation of different fungicides applied as seed tuber treatments for the control of potato silver scurf

2005 ◽  
Vol 82 (2) ◽  
pp. 41-48 ◽  
Author(s):  
V. Hervieux ◽  
R. Chabot ◽  
J. Arul ◽  
R.J. Tweddell
Keyword(s):  
Solanum Tuberosum ◽  
Seed Tuber ◽  
Field Trials ◽  
Potato Seed ◽  
Silver Scurf ◽  
Helminthosporium Solani ◽  
Potato Tubers ◽  
Experimental Conditions ◽  
Soil Inoculum ◽  
Seed Tubers

Silver scurf of potatoes (Solanum tuberosum), caused by the fungus Helminthosporium solani, is an important surface-blemishing disease of potato tubers. The objective of the study was to evaluate the efficacy of different fungicides applied to potato seed tubers for control of silver scurf. Field trials were conducted in Québec province in 1998 and 1999. Potato seed tubers infected with H. solani were treated with either talc, fludioxonil, mancozeb, iprodione, thiabendazole, imazalil or azoxystrobin, and planted at three locations in 1998 and two locations in 1999. The results showed that, under our experimental conditions, the fungicides tested, applied as seed treatments, did not significantly influence total and marketable yields as well as silver scurf severity on daughter tubers at harvest and after different storage periods. In addition, this study showed the influence of the experimental locations on silver scurf development and suggests that soil inoculum plays a role in the epidemiology of the disease.

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