scholarly journals Effect of Temperature and Water Potential on Survival and Mycelial Growth of Phaeomoniella chlamydospora and Phaeoacremonium spp.

Plant Disease ◽  
2001 ◽  
Vol 85 (2) ◽  
pp. 195-201 ◽  
Author(s):  
E. C. Whiting ◽  
A. Khan ◽  
W. D. Gubler

Phaeomoniella chlamydospora, a species of Phaeomoniella, and two species of Phaeoacremonium, P. inflatipes and P. aleophilum, have been associated with young grapevine decline in major production regions of California. Phaeomoniella chlamydospora has been isolated from healthy vines and inoculated but non-symptomatic vines and rooted cuttings. Effects of temperature and water potential on fungal response in culture were investigated to find effective control strategies for nurseries. Mycelial growth rates at temperatures 5 to 37°C showed a quadratic response with optimum growth rates for Phaeomoniella chlamydospora and P. aleophilum at 25°C and at 30°C for P. inflatipes. Response to water potential varied by isolates within a species, but isolates of Phaeomoniella chlamydospora were not sensitive to decreasing water potential. A conidial suspension and plugs of agar with mycelia were placed in glass vials and incubated in hot water for 15 to 120 min. Conidia were sensitive to hot-water treatment after 15 and 30 min. Nevertheless, mycelia of P. inflatipes from agar plugs grew on potato dextrose agar at 22°C after 120 min incubation at 51°C. Because the fungi were not killed by incubation in glass vials at 51°C, methods other than hot-water treatment may be more effective in eliminating Phaeomoniella chlamydospora and Phaeoacremonium spp. from dormant vine cuttings.

1934 ◽  
Vol 10 (6) ◽  
pp. 793-797 ◽  
Author(s):  
R. J. Hastings ◽  
W. Newton

In a moist environment, a minimum exposure of 120 min. at 110–113°F. is required to destroy pre-adult larvae of the bulb nematode Anguillulina dipsaci (Kühn, 1858) Gerv. and v. Ben., 1859, but progressively shorter exposures are required as the temperature is raised. At 116.5–118.5°F. the lethal exposure is 60 min. and at 118.5–120°F. an exposure of 30 min. is required.In a dry environment exposures of 150 min. to temperatures as high as 140°F. are not lethal to pre-adults and the heat treatment does not affect their ability to induce the characteristic symptoms of infestation in barley seedlings.The pre-adults are more resistant to heat than any other stage in the life history of the nematode.The data suggest that the ineffectiveness of the standard hot water treatment when applied late in the season is due to the fact that the major development of pre-adults takes place after the bulbs are lifted, and also because the masses of dormant pre-adults are often well isolated from the moisture of the bath by the bulb scales and corky basal plates, and are more resistant to heat in a dry, compared with a moist, state. It is recommended that the hot water treatment be employed not later than four weeks after lifting when the lifting is done as soon as the foliage dies down.A pre-soak is suggested as a possible means of increasing the effectiveness of the standard hot water treatment.


2018 ◽  
Vol 85 (0) ◽  
Author(s):  
Ana Beatriz Monteiro Ferreira ◽  
Luís Garrigós Leite ◽  
José Luiz Hernandes ◽  
Ricardo Harakava ◽  
Carlos Roberto Padovani ◽  
...  

ABSTRACT: Petri disease is complex, attacks young vine plants and it is difficult to be controlled. The fungus Phaeomoniella chlamydospora (Phc) has been identified as the main causative agent of this disease. This study aimed to evaluate the prevalent colonization of the Petri disease fungi in different portions of vine plants; to assess the susceptibility of grapevine rootstocks to the fungus P. chlamydospora; to assess the effect of solarization and biofumigation, followed by hot-water treatment (HWT), on the disinfection of cuttings of the rootstock IAC 766 infected with P. chlamydospora, and assess the effect of solarization and biofumigation, followed by HWT, on the rooting of cuttings of the rootstock IAC 766. For the prevalent colonization test, the fungus species detected and identified in ‘Niagara Rosada’ grafted on two rootstocks different were Phc and Phialemoniopsis ocularis. This is the first report of P. ocularis in a young vineyard in Brazil. Both fungi, in particular Phc, colonized only the plant’s basal part, drawing attention to the rootstock as target for control measures. Measurement of the dark streaks in the vascular system revealed that Golia was the least susceptible rootstock, and IAC 572 was the most susceptible to Phc. Moreover, biofumigation or temperature of 37°C applied for 7 and 14 days, both followed by HWT, suppressed Phc in cuttings of the rootstock IAC 766 without hampering their rooting. Meanwhile, new studies are needed to validate the efficiency of these disinfection techniques.


2021 ◽  
Vol 27 ◽  
pp. 102284
Author(s):  
Jakub Pečenka ◽  
Zuzana Bytešníková ◽  
Tomáš Kiss ◽  
Eliška Peňázová ◽  
Miroslav Baránek ◽  
...  

MRS Advances ◽  
2021 ◽  
Author(s):  
Quinshell Smith ◽  
Kenneth Burnett ◽  
Nawzat Saadi ◽  
Khulud Alotaibi ◽  
Atikur Rahman ◽  
...  

Author(s):  
Mohammad Khairul Basher ◽  
S. M. Shah Riyadh ◽  
Md. Khalid Hossain ◽  
Mahmudul Hassan ◽  
Md. Abdur Rafiq Akand ◽  
...  

Zinc-oxide (ZnO) nanostructures including nanorods are currently considered as a pioneer research of interest world-wide due to their excellent application potentials in various applied fields especially for the improvement of energy harvesting photovoltaic solar cells (PSC). We report on the growth and morphological properties of zinc-oxide (ZnO) nanorods grown on the surface of plain zinc (non-etched and chemically etched) plates by using a simple, economical, and environment-friendly technique. We apply hot water treatment (HWT) technique to grow the ZnO nanorods and varies the process parameters, such as temperature and the process time duration. The morphological, and elemental analysis confirm the agglomeration of multiple ZnO nanorods with its proper stoichiometry. The obtained nanostructures for different temperatures with different time duration showed the variation in uniformity, density, thickness and nanonorods size. The ZnO nanorods produced on the etched zinc surface were found thicker and uniform as compared to those grown on the non-etched zinc surface. This chemically etched Zinc plates preparation can be an easy solution to grow ZnO nanorods with high density and uniformity suitable for PSC applications such as to enhance the energy conversion efficiency of the photovoltaic (PV) solar cells towards the future sustainable green earth.


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