Treatment of potato seed and ware tubers with imazalil and thiabendazole for control of silver scurf and other storage diseases

1983 ◽  
Vol 26 (2) ◽  
pp. 163-173 ◽  
Author(s):  
G. R. Cayley ◽  
G. A. Hide ◽  
P. J. Read ◽  
Yvonne Dunne
Keyword(s):  
Potato Seed ◽  
Silver Scurf ◽  
Storage Diseases

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.

Transmission of Helminthosporium solani from potato seed tubers and effects of soil conditions, seed inoculum and seed physiology on silver scurf disease

1995 ◽  
Vol 124 (2) ◽  
pp. 219-234 ◽  
Author(s):  
D. M. Firman ◽  
E. J. Allen
Keyword(s):  
Weight Loss ◽  
Field Experiments ◽  
Soil Conditions ◽  
Potato Seed ◽  
Silver Scurf ◽  
Moisture Regime ◽  
Helminthosporium Solani ◽  
Seed Tubers ◽  
Soil Moisture Regime ◽  
One Year

SUMMARYThe transmission of silver scurf (Helminthosporium solani) disease of potatoes was examined in field experiments at Cambridge University Farm in 1988–90. Treatment factors examined were seed size, seed age, seed incubation, soil moisture regime and planting date. A laboratory experiment investigated the viability of conidia of Helminthosporium in soil stored under different conditions.Incubation of seed at high humidity before planting increased sporulation of Helminthosporium on seed tubers after planting and fewer conidia were produced from small seed than from larger seed. Delay in planting caused more rapid growth of Helminthosporium on seed tubers after planting.Early planting and late harvesting increased the severity of silver scurf on progeny tubers. Severity of silver scurf was also increased by ageing seed and by incubating seed. Weight loss of potato tubers during storage tended to be greater from treatments with most severe silver scurf in all years but a significant linear regression of weight loss on silver scurf severity was found in only one year out of three from a late harvest. The viability of conidia added to soil was found to decrease rapidly so that by 10 weeks after addition, < 1% of conidia were apparently viable.

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.

Cytoplasmic Granules in Lymphocytes from Rats Dosed with SK&F 14336-D

1971 ◽  
Vol 29 ◽  
pp. 556-557
Author(s):  
T. G. Merrill ◽  
B. J. Payne ◽  
A. J. Tousimis
Keyword(s):  
Lipid Storage ◽  
Pokeweed Mitogen ◽  
Electron Microscopic ◽  
Cytoplasmic Granules ◽  
Storage Diseases ◽  
Tay Sachs Disease ◽  
Large Numbers ◽  
Microscopic Studies ◽  
Neurovisceral Lipidosis

Rats given SK&F 14336-D (9-[3-Dimethylamino propyl]-2-chloroacridane), a tranquilizing drug, developed an increased number of vacuolated lymphocytes as observed by light microscopy. Vacuoles in peripheral blood of rats and humans apparently are rare and are not usually reported in differential counts. Transforming agents such as phytohemagglutinin and pokeweed mitogen induce similar vacuoles in in vitro cultures of lymphocytes. These vacuoles have also been reported in some of the lipid-storage diseases of humans such as amaurotic familial idiocy, familial neurovisceral lipidosis, lipomucopolysaccharidosis and sphingomyelinosis. Electron microscopic studies of Tay-Sachs' disease and of chloroquine treated swine have demonstrated large numbers of “membranous cytoplasmic granules” in the cytoplasm of neurons, in addition to lymphocytes. The present study was undertaken with the purpose of characterizing the membranous inclusions and developing an experimental animal model which may be used for the study of lipid storage diseases.

Electron Microscopy in the diagnosis of lysosomal storage diseases

1989 ◽  
Vol 47 ◽  
pp. 866-867
Author(s):  
Carole Vogler ◽  
Harvey S. Rosenberg
Keyword(s):  
Electron Microscopy ◽  
Lysosomal Enzyme ◽  
Rectal Mucosa ◽  
Lysosomal Storage Diseases ◽  
Cell Types ◽  
Lysosomal Storage ◽  
Storage Material ◽  
Ultrastructural Examination ◽  
Blood Leukocytes ◽  
Storage Diseases

Diagnostic procedures for evaluation of patients with lysosomal storage diseases (LSD) seek to identify a deficiency of a responsible lysosomal enzyme or accumulation of a substance that requires the missing enzyme for degradation. Most patients with LSD have progressive neurological degeneration and may have a variety of musculoskeletal and visceral abnormalities. In the LSD, the abnormally diminished lysosomal enzyme results in accumulation of unmetabolized catabolites in distended lysosomes. Because of the subcellular morphology and size of lysosomes, electron microscopy is an ideal tool to study tissue from patients with suspected LSD. In patients with LSD all cells lack the specific lysosomal enzyme but the distribution of storage material is dependent on the extent of catabolism of the substrate in each cell type under normal circumstances. Lysosmal storages diseases affect many cell types and tissues. Storage material though does not accumulate in all tissues and cell types and may be different biochemically and morphologically in different tissues.Conjunctiva, skin, rectal mucosa and peripheral blood leukocytes may show ultrastructural evidence of lysosomal storage even in the absence of clinical findings and thus any of these tissues can be used for ultrastructural examination in the diagnostic evaluation of patients with suspected LSD. Biopsy of skin and conjunctiva are easily obtained and provide multiple cell types including endothelium, epithelium, fibroblasts and nerves for ultrastructural study. Fibroblasts from skin and conjunctiva can also be utilized for the initiation of tissue cultures for chemical assays. Brain biopsy has been largely replaced by biopsy of more readily obtained tissue and by biochemical assays. Such assays though may give equivical or nondiagnostic results and in some lysosomal storage diseases an enzyme defect has not yet been identified and diagnoses can be made only by ultrastructural examination.

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