scholarly journals The effect of fungicides on spore germination, mycelial growth and lesion development of Phlyctema vagabunda (syn: Neofabraea alba) (bull’s eye rot of apples)

2017 ◽  
Vol 70 ◽  
pp. 112-119 ◽  
Author(s):  
P.N. Wood ◽  
B.M. Fisher
Keyword(s):  
Spore Germination ◽  
Mycelial Growth ◽  
Pathogenic Fungus ◽  
Apple Fruit ◽  
Fruit Rot ◽  
Copper Hydroxide ◽  
Lesion Development ◽  
Lime Sulphur ◽  
Bull's Eye

Phlyctema vagabunda (syn: Neofabraea alba) is a plant pathogenic fungus that causes bull’s eye rot on apples and pears. Phlyctema vagabunda fruit infections occur in orchards predominantly pre-harvest, and eventually express as a fruit rot after 4—5 months of cool storage. Twelve fungicides (captan, carbendazim, copper hydroxide, cyprodinil, difenoconazole, dithianon, dodine, isopyrazam, metiram, lime sulphur, sulphur and trifloxystrobin) were tested in vitro for their effects on spore germination and mycelial growth of P. vagabunda. Spore germination was inhibited by metiram, captan, dodine, dithianon, lime sulphur, carbendazim and isopyrazam, in order of effectiveness. Carbendazim, isopyrazam, difenoconazole and cyprodinil, in order of effectiveness, inhibited mycelial growth when used at label rates. Wettable sulphur was ineffective in both assays. On detached apple fruit, carbendazim, cyprodinil, trifloxystrobin and isopyrazam (in order of effectiveness) inhibited lesion development.

scholarly journals Control of Sphaeropsis Rot in Stored Apple Fruit Caused by Sphaeropsis pyriputrescens with Postharvest Fungicides

Plant Disease ◽  
2011 ◽  
Vol 95 (9) ◽  
pp. 1075-1079 ◽  
Author(s):  
C. L. Xiao ◽  
Y. K. Kim ◽  
R. J. Boal
Keyword(s):  
Mycelial Growth ◽  
Disease Incidence ◽  
Apple Fruit ◽  
Conidial Germination ◽  
Fruit Rot ◽  
Mitigation Measures ◽  
The Mean ◽  
Rot Disease ◽  
Sphaeropsis Rot

Sphaeropsis rot caused by Sphaeropsis pyriputrescens is a recently reported postharvest fruit rot disease of apple grown in Washington State. The objective of this study was to develop chemical-based mitigation measures for Sphaeropsis rot in stored apple fruit. To determine in vitro sensitivity of S. pyriputrescens to the three registered postharvest fungicides thiabendazole, fludioxonil, and pyrimethanil, 30 isolates of S. pyriputrescens obtained from various sources were tested for mycelial growth and conidial germination on fungicide-amended media. Golden Delicious apple fruit were inoculated with the pathogen in the orchard at 2 or 5 weeks before harvest. After harvest, fruit were either nontreated or dipped in thiabendazole, fludioxonil, or pyrimethanil solutions, stored at 0°C, and monitored for decay development for up to 9 months after harvest. The mean effective concentration of a fungicide that inhibits mycelial growth or spore germination by 50% relative to the nonamended control (EC50) values of thiabendazole, fludioxonil, and pyrimethanil on mycelial growth were 0.791, 0.0005, and 2.829 μg/ml, respectively. Fludioxonil and pyrimethanil also were effective in inhibiting conidial germination of the fungus with EC50 values of 0.02 μg/ml for fludioxonil and 5.626 μg/ml for pyrimethanil. All three postharvest fungicides applied at label rates immediately after harvest were equally effective in controlling Sphaeropsis rot in stored apple fruit, reducing disease incidence by 92 to 100% compared with the nontreated control. The results indicated that Sphaeropsis rot may be effectively controlled by the currently registered postharvest fungicides thiabendazole, fludioxonil, and pyrimethanil.

scholarly journals In vitro fungicide testing for control of avocado fruit rots

2007 ◽  
Vol 60 ◽  
pp. 99-103 ◽  
Author(s):  
K.R. Everett ◽  
O.E. Timudo-Torrevilla
Keyword(s):  
Spore Germination ◽  
Mycelial Growth ◽  
Effective Concentration ◽  
Colletotrichum Acutatum ◽  
Copper Hydroxide ◽  
Copper Fungicides ◽  
Avocado Fruit

Avocado fruit rots are most commonly caused by five fungi Colletotrichum acutatum C gloeosporioides Botryosphaeria parva B dothidea and Phomopsis sp These rots are controlled by applying copper fungicides in the field on eight occasions during the season Alternatives to standard copper fungicides were screened in the laboratory against these five pathogens for inhibition of spore germination and mycelial growth In total seven fungicides were tested (boscalid boscalid/pyraclostrobin three formulations of copper hydroxide copper hydroxosulphate and dithianon) The effective concentration at which 50 of spore germination or mycelial growth was inhibited (EC50) was calculated for each fungicide The EC50 values for spore germination were lowest for boscalid/pyraclostrobin and dithianon and were le;185 g/ml against all five test fungi For boscalid/pyraclostrobin all EC50 values were le;7 g/ml Copper formulations effectively inhibited spore germination by 50 at concentrations ranging from 01 g/ml to 141 g/ml but were less effective against mycelial growth

scholarly journals Antifungal activity of medicinal plants, Adathoda vasica and Andrographis paniculata against Colletotrichum capsici, the chilli fruit rot pathogen

2021 ◽  
Vol 42 (6) ◽  
pp. 1461-1469
Author(s):  
K. Priya ◽  
◽  
G. Thiribhuvanamala ◽  
C. Sangeetha ◽  
A. Kamalakannan ◽  
...  
Keyword(s):  
Medicinal Plants ◽  
Spore Germination ◽  
Mycelial Growth ◽  
Andrographis Paniculata ◽  
Fruit Rot ◽  
Antimicrobial Compounds ◽  
Ftir Analysis ◽  
Antimicrobial Metabolites ◽  
Ethyl Acetate Extracts

Aim: The objective was formulated to screen the extracts of medicinal plants for tapping the antimicrobial activity against Collectotrichum capsici. Further, the work was planned to characterize and identify the nature of antimicrobial compounds and their functional groups. Methodology: Extracts of eleven medicinal plants were tested against the mycelial growth and spore germination of C. capsici under in-vitro conditions. Based on these results, the potential plant extracts of A. vasica and A. paniculata found effective against C. capsici were assayed for the presence of antimicrobial metabolites through TLC, GC-MS and FTIR analysis. Results: Among the medicinal plants screened, the crude extracts from Adathoda vasica and Andrographis paniculata inhibited mycelial growth and spore germination of C. capsici by 53.33% and 38.14%, respectively, under in-vitro conditions. GC-MS analysis of ethyl acetate extracts of A. vasica indicated antimicrobial compound, 1H-Pyrrolo[2,1-b]quinazolin-9-one,3-hydroxy-2,3-dihydro- and A. paniculata showed the presence of two compounds, docosahexaenoic acid and oleic acid. Similarly, FTIR analysis revealed esters, alcohols, and halide groups, which are known antimicrobials. Interpretation: The medicinal plants, A. paniculata and A. vasica possessed antimicrobial metabolites, which was responsible for inhibiting the mycelial growth and spore germination of C. capsici.

scholarly journals First report of Penicillium glaucum Link causing Penicillium rot of pear fruits Pyrus communis L. in Jammu and Kashmir, India

2017 ◽  
Vol 4 (8) ◽  
pp. 265-272
Author(s):  
Shazia Parveen ◽  
Abdul Hamid Wani ◽  
Mohd Yaqub Bhat ◽  
Tariq Ahmad Wani ◽  
Abdul Rashid Malik
Keyword(s):  
Spore Germination ◽  
Mycelial Growth ◽  
Pyrus Communis ◽  
Fruit Rot ◽  
Morphological Data ◽  
Morphological Observation ◽  
Pathogenicity Test ◽  
First Report ◽  
Pyrus Communis L

Pears Pyrus communis L. collected from different sites of Kashmir Valley were found infected with Penicillium glaucum causing Penicillium rot. The diseased fruits appears light tan to dark brown. The decayed tissue becomes soft, watery and the lesion has a very sharp margin between diseased and healthy tissues. Decayed fruit has an earthy, musty odor. The pathogen was isolated and cultured on PDA medium for further fungal morphological observation and confirming its pathogenicity according to Koch’s postulates. Results of morphological data and pathogenicity test showed that the pears were infected by Penicillium glaucum Link resulting in Penicillium rot of pears. To our knowledge, it is the first report of pear fruit rot caused by P. glaucum in India. Study was also undertaken for the management of Penicillium rot of pear with some fungicides. It was revealed from the study that different concentration of fungicides brought about significant reduction in the mycelial growth and spore germination of Penicillium glaucum under in vitro conditions. Amongst the tested fungicides, carbendazim proved highly effective in inhibiting the mycelial growth and spore germination of Penicillium glaucum followed by hexaconozole, bitertanol and myclobutanil respectively. Higher concentration proved effective than lower concentrations.

Preharvest Applications of Fungicides for Control of Sphaeropsis Rot in Stored Apples

2013 ◽  
Vol 14 (1) ◽  
pp. 9
Author(s):  
Y. K. Kim ◽  
C. L. Xiao
Keyword(s):  
Mycelial Growth ◽  
Apple Fruit ◽  
Fruit Rot ◽  
Economic Losses ◽  
In Vitro Tests ◽  
Conidial Suspension ◽  
Growth Assay ◽  
Rot Disease ◽  
Sphaeropsis Rot

Sphaeropsis rot caused by Sphaeropsis pyriputrescens is a recently reported postharvest fruit rot disease of apple in Washington State and causes significant economic losses. Infection of apple fruit by the fungus occurs in the orchard, but decay symptoms develop during storage or in the market. The objective of this study was to evaluate preharvest fungicide applications to control Sphaeropsis rot. Thirty isolates of the fungus collected from various sources were tested for sensitivity to the registered fungicides Pristine, Topsin M, and Ziram using an in vitro mycelial growth assay. In the orchard, ‘Golden Delicious' apple fruit were inoculated with the conidial suspension of the fungus at 2 or 5 weeks before harvest, sprayed with fungicides within 2 weeks before harvest, and harvested and stored at 0°C for disease evaluation. All three fungicides effectively inhibited mycelial growth of the fungus in the in vitro tests. On apple fruit in four seasons, Pristine applied 1 week and Ziram applied 2 weeks before harvest significantly reduced incidence of Sphaeropsis rot compared to the nontreated control by 43 to 80% and 42 to 83%, respectively. In 4 years of testing, the performance of Topsin M was less consistent than that of Pristine and Ziram. Accepted for publication 18 July 2013. Published 19 September 2013.

scholarly journals Effects of Temperature and Moisture on the Infection and Development of Apple Fruit Rot Caused by Phytophthora cactorum

Plant Disease ◽  
2018 ◽  
Vol 102 (9) ◽  
pp. 1811-1819 ◽  
Author(s):  
Fang Liu ◽  
Bao-hua Li ◽  
Sen Lian ◽  
Xiang-li Dong ◽  
Cai-xia Wang ◽  
...  
Keyword(s):  
Free Water ◽  
Weibull Model ◽  
Apple Fruit ◽  
Infection Process ◽  
Fruit Rot ◽  
Phytophthora Cactorum ◽  
Optimal Temperature ◽  
Zoospore Release ◽  
Effects Of Temperature

Phytophthora fruit rot, caused by Phytophthora cactorum, is an important disease of apple in China, often causing more than 50% fruit rot in rainy years. We examined the effects of temperature and moisture on the development of the disease and effects of the variables on zoospore release and germination, infection, and lesion development. In vitro, a temperature range of 5 to 20°C had no significant effects on zoospore release dynamics but did significantly affect the quantities of released zoospores. The largest quantity of zoospores was released at 9.9°C according to a fitted model. Zoosporangia released zoospores within 15 min at the test temperatures (0 to 20°C), which peaked at the fourth hour. Zoospores germinated in vitro, requiring free water, at temperatures from 5 to 35°C. The optimum germination temperature was 25.1°C according to a fitted model. The minimum wetness duration required for zoospores to complete the infection process and induce visible lesions on Fuji fruit was 0.40 h at the optimal temperature of 23.0°C according to the fitted model, whereas observed values were 4.5, 1.5, 0.5, 1.5 and 8.5 h at 10, 15, 20, 25, and 30°C, respectively. The number of zoospore infections on fruit at various temperatures and wetness durations were well fitted by the modified Weibull model; based on the model, the optimal temperature for zoospore infections was 23.0°C. Young apple fruit infected by zoospores developed visible lesions from 10 to 30°C, with a predicted optimum of 23.5°C; no lesions developed at 5 or 35°C. The shortest incubation period of the disease was 4 days. These results can be used to develop disease forecasting models for improved fungicide control.

Screening of Existing and New Boxwood Cultivars for Disease Resistance and In Vitro Fungicide Screening to Manage Boxwood Dieback Caused by Colletotrichum theobromicola

2021 ◽  
Author(s):  
Harleen Kaur ◽  
Monique DeSouza ◽  
Raghuwinder "Raj" Singh
Keyword(s):  
Active Ingredient ◽  
Spore Germination ◽  
Mycelial Growth ◽  
Management Practices ◽  
Management Strategies ◽  
Host Susceptibility ◽  
Germination Inhibition ◽  
Industry Professionals ◽  
The U.S

Boxwood is one of the most common and widely planted perennial ornamentals in both home gardens and commercial landscapes. Recently reported boxwood dieback, a fungal disease caused by Colletotrichum theobromicola, has been spreading at an alarming rate within the U.S. Boxwood breeders, nursery growers, and landscape professionals have shown great concerns regarding the lack of effective management practices. Therefore, the primary objectives of this study were to devise effective disease management strategies including screening cultivars to determine their susceptibility to boxwood dieback and screening various fungicides to determine their effectiveness in managing the disease. Host range studies were conducted by screening a wide variety of boxwood cultivars under greenhouse conditions. Although, boxwood cultivar ‘Little Missy’ showed much delayed symptom expression as compared to rest of the cultivars but none of the 11 cultivars were found to be resistance to boxwood dieback. In vitro screening of nine fungicides was conducted to determine mycelial growth as well as spore germination inhibition of eight isolates of C. theobromicola collected from eight states in the U.S. Of the nine fungicides, difenoconazole+pydiflumetofen showed maximum mycelial growth and spore germination inhibition at 1 ppm active ingredient followed by fluxapyroxad+pyraclostrobin, and pyraclostrobin+boscalid at 5 ppm active ingredient. Azoxystrobin+benzovindiflupyr significantly inhibited mycelial growth at 1 ppm but reduced spore germination at 10 ppm active ingredient. This study provides the boxwood industry professionals with critical and applied information pertaining to host susceptibility and fungicide efficacy to effectively mitigate boxwood dieback and to reduce its further spread.

scholarly journals Evaluation of three plant species to control black scurf disease of Irish potato (Solanum tuberosum Linn.)

2020 ◽  
Vol 12 (1) ◽  
pp. 90-99
Author(s):  
Matthew O. ADEBOLA ◽  
Tunde S. BELLO ◽  
Esther A. SERIKI ◽  
Mariam B. AREMU
Keyword(s):  
Solanum Tuberosum ◽  
Mycelial Growth ◽  
Pathogenic Fungus ◽  
Inhibitory Effect ◽  
Black Scurf ◽  
Irish Potato ◽  
Diffusion Method ◽  
Leaf Extracts

Irish potato (Solanum tuberosum) is an important worldwide food crop and one of the most popular in Nigeria. Its abundance and successful yield have been immensely affected by black scurf disease caused by Rhizoctonia solani. Harnessing a cost-effective management of this pathogenic fungus, three botanical species Acalypha wilkesiana, Moringa oleifera and Carica papaya leaves, each at concentrations of 0 mg ml-1 (control), 25 mg ml-1, 50 mg ml-1 and 75 mg ml-1 were evaluated in vitro. The plant leaf extracts were prepared using methanol and were evaluated for their toxicity using agar well diffusion method. The fungus was isolated from spoilt Irish potato with black scurf symptoms. The results showed the presence of some phytochemicals in leaf extract of each of the plants tested. The three leaves extract independently inhibited mycelial growth of R. solani. The potency of all the plant extracts increased with the increase in concentration. The highest concentration (75 mg ml-1) of M. oleifera and C. papaya evaluated, gave the highest inhibitory effect of 0.81 mm and 1.63 mm respectively, which were not significantly different (p> 0.05), but was obviously different from A. wilkesiana (2.81 mm). Furthermore, M. oleifera extract gave the highest percentage of mycelial growth inhibition of the fungus in all grades of the concentrations evaluated, whereas A. wilkesiana showed the least. The leaves of the three species are therefore recommended for in vivo control of this fungus, owing to their proven efficacy and to their cheap availability.

scholarly journals Effect of Agrochemicals Used in the Cultivation of Soybean and Irrigated Rice on Beauveria bassiana (Bals.) Vuill. and Metarhizium anisopliae (Metsch.) Sorok

2019 ◽  
Vol 11 (17) ◽  
pp. 167
Author(s):  
Vanessa P. Gonçalves ◽  
Cândida R. J. de Farias ◽  
Victoria Moreira-Nunêz ◽  
Renata Moccellin ◽  
Viviana Gaviria-Hernández ◽  
...  
Keyword(s):  
Beauveria Bassiana ◽  
Entomopathogenic Fungi ◽  
Spore Germination ◽  
Metarhizium Anisopliae ◽  
Mycelial Growth ◽  
Potato Dextrose Agar ◽  
Irrigated Rice ◽  
Spray Method ◽  
Fungitoxic Effect

The objective of this work was to evaluate the fungitoxic effect of the agrochemicals used in the cultivation of soybean and irrigated rice on entomopathogenic fungi such as Beauveria bassiana and Metarhizium anisopliae by means of the mycelial growth, sporulation and spore germination. The isolates were inoculated in potato-dextrose-agar (PDA) medium containing the pesticides and exposed to spraying with the products. It was observed that chlorantraniliprole produced the best results regarding and was compatible with the two methods of contact of the product with the fungi. Flubendiamide it’s very toxic to fungi, producing 100% inhibition when incorporated into the medium, when by spraying, the fungus M. anisopliae got mycelial growth. Etofenprox and thiamethoxam changed their toxity classification according to the method of contact with product, was moderately compatible to B. bassiana and compatible to M. anisopliae and spinosad showed more compatibility with M. anisopliae than B. bassiana and was classified as compatible. Among fungicides the tricyclazole was the only compatible with the fungus by the spray method. The results showed that in vitro agrochemicals such as tricyclazole, thiamethoxam, flubendiamide and etofenprox are harmful to fungi. It was found that environmental interference could minimize the effects on organisms, especially when the chemicals are applied by spraying.

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