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.

scholarly journals Application of Organic and Inorganic Salts to Field-Grown Potato Tubers Can Suppress Silver Scurf During Potato Storage

Plant Disease ◽  
1999 ◽  
Vol 83 (9) ◽  
pp. 814-818 ◽  
Author(s):  
Claudia Olivier ◽  
Carol R. MacNeil ◽  
Rosemary Loria
Keyword(s):  
Sodium Carbonate ◽  
Organic Salt ◽  
Postharvest Disease ◽  
Inorganic Salts ◽  
Potassium Sorbate ◽  
Silver Scurf ◽  
Potato Storage ◽  
Potato Tubers ◽  
Lesion Formation ◽  
Calcium Propionate

Silver scurf, caused by Helminthosporium solani, is an economically important postharvest disease of potato tubers. Organic and inorganic salts were evaluated for their ability to suppress silver scurf lesion development and sporulation of H. solani on potato tubers. Tubers were treated immediately after harvest with 0.2-M solutions of potassium sorbate, calcium propionate, sodium bicarbonate, sodium carbonate, ammonium bicarbonate, or water. Tween 20 was added as a surfactant to most treatments. Potassium sorbate (0.1 M), acidified potassium sorbate and calcium propionate treatments (0.2 M), and calcium chloride treatments (0.136 M) were included in additional experiments. Tubers were stored under commercial storage conditions for 4 to 6 months prior to disease evaluation. The extent of disease suppression varied among experiments; however, some treatments consistently reduced disease. Lesion formation on the tuber surface was reduced by 26 to 60% using potassium sorbate (in three of four experiments) compared to water-treated or untreated tubers. Sporulation was suppressed by 0.2 M potassium sorbate (78 to 99% reduction) in all four experiments. Sodium carbonate reduced lesion formation in two experiments and sporulation in three of four experiments. Other treatments inconsistently suppressed lesion formation or sporulation, or did not reduce disease. Addition of Tween or acidification of organic salt solutions did not improve silver scurf suppression in most cases. Potassium sorbate has very low mammalian toxicity and great potential as an innocuous and inexpensive postharvest fungicide for suppression of silver scurf during potato storage.

Ammonium Bicarbonate Inhibition of Mycotoxigenic Fungi and Spoilage Yeasts

1990 ◽  
Vol 53 (4) ◽  
pp. 324-328 ◽  
Author(s):  
DAVID A. DEPASQUALE ◽  
ANWAAR EL-NABARAWY ◽  
JOSEPH D. ROSEN ◽  
THOMAS J. MONTVILLE
Keyword(s):  
Sodium Chloride ◽  
Sodium Bicarbonate ◽  
Ammonium Sulfate ◽  
Debaryomyces Hansenii ◽  
Aflatoxin Production ◽  
Ammonium Bicarbonate ◽  
Potassium Bicarbonate ◽  
Aspergillus Ochraceus ◽  
Spoilage Yeasts ◽  
Mycotoxigenic Fungi

Sodium bicarbonate inhibits growth and aflatoxin production by Aspergillus parasiticus. This survey determined that other mycotoxigenic fungi were also sensitive to bicarbonates. Sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, ammonium sulfate, and sodium chloride were added to buffered or unbuffered potato-dextrose agar to determine the bicarbonate effect on growth and morphology of six mycotoxigenic fungi. Three nonmycotoxigenic fungi and four yeast species were also examined. Ammonium bicarbonate at 0.11M completely inhibited the growth of Fusarium tricinctum NRRL 13442, F. tricinctum NRRL 13426, F. graminearum NRRL 5883, F. sporotrichioides NRRL 3249, Penicillium griseofulvum NRRL 989, Aspergillus ochraceus NRRL 3174, A. flavus NRRL 1957, A. niger, and P. notatum. Sodium chloride and pH elevated through the use of ampso-NaOH, capso-NaOH, or glycine-NaOH buffer did not display an inhibitory effect on the filamentous fungi examined. Buffered ammonium sulfate treatments (pH approximately 9.0) completely inhibited all of the mycotoxigenic fungi, but at pH 5.6, ammonium sulfate treatments were not inhibitory. Sodium bicarbonate (0.11M) was effective only against P. griseofulvum, A. flavus NRRL 1957, A. niger, and P. notatum, causing viability reductions of 5.6, 3.7, 4.9, and 2.9 log cycles, respectively. Potassium bicarbonate was generally as inhibitory as the sodium salt. In contrast, elevated pH, alone, appeared to account for the &gt;6 log reduction observed for the yeasts Lipomyces starkeyi, Geotrichum candidum, Kluyveromyces marxianus, and Debaryomyces hansenii.

scholarly journals Effect of Organic and Inorganic Salts on the Development of Helminthosporium solani, the Causal Agent of Potato Silver Scurf

Plant Disease ◽  
2002 ◽  
Vol 86 (9) ◽  
pp. 1014-1018 ◽  
Author(s):  
V. Hervieux ◽  
E. S. Yaganza ◽  
J. Arul ◽  
R. J. Tweddell
Keyword(s):  
Calcium Chloride ◽  
Control Strategies ◽  
Sodium Formate ◽  
Postharvest Disease ◽  
Potassium Sorbate ◽  
Sodium Metabisulfite ◽  
Silver Scurf ◽  
Helminthosporium Solani ◽  
Economic Significance

Potato silver scurf, caused by Helminthosporium solani, is an important postharvest disease of economic significance. Control of H. solani has been accomplished primarily by postharvest applications of thiabendazole. However, many strains of H. solani have become resistant to thiabendazole, resulting in failure of disease control. Consequently, alternative control strategies are needed. This study showed that several salts significantly reduced silver scurf development on potato tuber at a concentration of 0.2 M and that the timing of application also influenced salt efficacy. Among the 23 tested salts, aluminum chloride was the only one reducing silver scurf severity when applied either 2, 4, or 7 days after H. solani inoculation. Aluminum lactate, potassium sorbate, sodium carbonate, sodium metabisulfite, and trisodium phosphate also markedly reduced silver scurf severity but only when applied 2 or 4 days after inoculation. Ammonium acetate, calcium chloride, sodium benzoate, sodium citrate, and sodium formate reduced disease severity by at least 50% when applied 2 days after H. solani inoculation. With the exception of calcium chloride and sodium formate, these salts also were shown to strongly inhibit H. solani mycelial growth or spore germination in vitro. Results of this study further demonstrate the possibility of using selected salts for the control of potato 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 The Effects of Different Formulation of Baking Powder on Short Biscuits Characteristics

2011 ◽  
Vol 68 (2) ◽  
Author(s):  
Georgiana CIOROIANU ◽  
Claudia Felicia OGNEAN ◽  
Mihai OGNEAN
Keyword(s):  
Carbon Dioxide ◽  
Elevated Temperature ◽  
Tartaric Acid ◽  
Ammonium Bicarbonate ◽  
Potassium Bicarbonate ◽  
Baked Goods ◽  
Sodium Acid Pyrophosphate

Chemical leaveners are used to give cookies, cakes, and other baked goods their characteristic textures. They produce gas when a carbon dioxide source and an acid are mixed together and come into contact with water. The most common sources of gas are sodium or potassium bicarbonate alone or in combination with ammonium bicarbonate. A great variety of acids are used in baking powder formulations. The acid are classified according to their capacity to react at lower or elevated temperature as rapid or slow acting. The aim of these study is to evaluate a very rapid acting acid (tartaric acid) and a slow to very slow acting acid (sodium acid pyrophosphate - SAPP) on the characteristics of short biscuits. The acids were added to reach 0, 25%, 50%, 75% and 100% of neutralizing values (VN). The biscuits height and diameter, alkalinity and sensorial profile were determined.

scholarly journals EFFECT OF CONVENTIONAL AND ALTERNATIVE PRODUCTS ON POSTHARVEST DISEASE CONTROL IN AVOCADOS

2018 ◽  
Vol 40 (1) ◽  
Author(s):  
Ivan Herman Fischer ◽  
Matheus Froes de Moraes ◽  
Maria Cecília de Arruda Palharini ◽  
Mirian de Souza Fileti ◽  
Juliana Cristina Sodário Cruz ◽  
...  
Keyword(s):  
Essential Oil ◽  
Sodium Bicarbonate ◽  
Disease Control ◽  
Chlorine Dioxide ◽  
Physicochemical Characterization ◽  
Soluble Solids ◽  
Postharvest Disease ◽  
Postharvest Diseases ◽  
Lemon Grass ◽  
Thyme Essential Oil

ABSTRACT Postharvest diseases constitute a serious problem for avocado commercialization. Thus, the present study aimed to evaluate the effect of conventional and alternative products in controlling diseases affecting ‘Hass’ avocados in the field and in the postharvest by carrying out physicochemical characterization of fruits subjected to postharvest treatments. In the field, besides the management adopted by the farmer, seven products were sprayed three times during fruiting for evaluation. Postharvest products were diluted in water or in oxidized polyethylene wax and shellac. Water treatments with potassium phosphite, Soil-Set®, chlorine dioxide, thyme essential oil, sodium bicarbonate, lemon grass essential oil and thiabendazole reduced the incidence of diseased fruits, and anthracnose, the main disease, was controlled with sodium bicarbonate, lemon grass essential oil and thiabendazole. Greater soluble solids content was found for control (water), chlorine dioxide, acibenzolar-S-methyl and thiabendazole. For the products that reduced anthracnose, there was no correlation between the disease and the physicochemical parameters, evidencing that the disease control is not associated with delayed ripening. For wax treatments, diseases were not controlled, and the fruits presented lower titratable acidity with thyme essential oil, sodium bicarbonate, control (wax), acibenzolar-S-methyl and lemon grass essential oil. Control and thyme essential oil were highlighted for maintaining the green coloration of the fruit skin for the shortest period. Under field conditions, azoxystrobin, thiabendazole, difenoconazole+azoxystrobin and acibenzolar-S-methyl+azoxystrobin reduced the occurrence of diseased fruits, while anthracnose control was only obtained with azoxystrobin.

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.

Sign in / Sign up

Export Citation Format

Share Document