Black mold of stored onion bulbs caused by Aspergillus welwitschiae

2021 ◽  
pp. 67-72
Author(s):  
I. Vico ◽  
M. Lazarevic ◽  
N. Duduk
Keyword(s):  
Onion Bulbs ◽  
Black Mold

First Report on Post-harvest management of black mold of onion by eugenol

2022 ◽  
Vol 11 (6) ◽  
pp. 759-767
Author(s):  
Shalini Devi Suvala ◽  
P. Rajini
Keyword(s):  
Antifungal Activity ◽  
Management Practices ◽  
Negative Impact ◽  
Vapour Phase ◽  
New Method ◽  
Postharvest Disease ◽  
Post Harvest ◽  
Onion Bulbs ◽  
Black Mold ◽  
Conical Flask

Black mold of onion caused by Aspergillus niger is a serious and prevalent postharvest disease of onion. This problem drastically reduces the quality and marketability of onion bulbs. Conventional fungicides employed to con-trol A. niger contamination posed negative impact on human health and en-vironment and highlighted the need to discover ecofriendly management practices. In the present study we attempted to explore the use of eugenol for the management of black mold of onion. Eugenol may exhibit differ-ences in antifungal activity in liquid state and in volatile phase. Hence, we developed and validated a new method, conical flask- paper cone method to study the antifungal activity of vapour phase disinfectants. This method was found to be precise, reproducible, sensitive and accurate with inter-assay R.S.D < 10%, intra-assay R.S.D <5% and R2>0.99. Conical flask- paper cone method was further utilized to determine the minimum inhibitory concen-tration of eugenol against A. niger. We observed that 0.03355 μl / cm3 eu-genol caused invitro and invivo inhibition of A. niger. Onion bulbs that were stored by eugenol fumigation, prior inoculated by A. niger, did not develop black mold symptoms and maintained high sensory acceptability. Microscop-ic observations revealed that eugenol fumigation resulted in inhibition of spore germination, coagulation of cytoplasm, formation of large vesicles and shrinkage of A. niger mycelium. In conclusion, our study showed for the first time that eugenol fumigation significantly controlled black mold incidence during storage and maintained post harvest quality and sensory acceptance. This study also introduced a new method for evaluating antifungal activity of volatile compounds.

scholarly journals The Effect of Gaseous Ozone Generated by Surface Dielectric Barrier Discharge on the Decay and Quality of Stored Onion Bulbs

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1058
Author(s):  
Junghyun Lim ◽  
Jong-Seok Song ◽  
Sangheum Eom ◽  
Jung Woo Yoon ◽  
Sang-Hye Ji ◽  
...  
Keyword(s):  
Untreated Control ◽  
Color Change ◽  
Microbial Reduction ◽  
Ozone Exposure ◽  
Onion Bulbs ◽  
Gaseous Ozone ◽  
Surface Dielectric Barrier Discharge ◽  
Postharvest Loss ◽  
High Voltage Discharge

An effective and eco-friendly technology is needed to prevent postharvest loss of onion bulbs during cold storage. This study investigated the effect of gaseous ozone on the decay and quality of onion bulbs during storage at 2 °C and 70% relative humidity for two months. Gaseous ozone was adjusted to a concentration of 1.27 ± 0.024 ppm in the storage room by generating a high voltage discharge in air. After two months of storage, gaseous ozone significantly reduced the counts of aerobic bacteria (e.g., Rahnella aquatilis) and fungi (e.g., yeast and mold) in the onion bulbs by 4 log (CFU g−1) and 0.92 log (CFU g−1) compared with those of an untreated control, respectively. The microbial reduction by gaseous ozone resulted in a lower rotten rate of the onion bulbs, which was less than 20.0% compared with that of the untreated control. Moreover, the ozone exposure extended the storage life of the onion bulbs by delaying its color change and softening during storage. Our results suggest that gaseous ozone can control the decay of onion bulbs safely during storage.

Use of a Durometer to Assess Onion Bulb Hardness

1978 ◽  
Vol 14 (3) ◽  
pp. 269-272 ◽  
Author(s):  
J. F. M. Fennell
Keyword(s):  
Tensile Testing ◽  
Test Procedure ◽  
Testing Machine ◽  
Onion Bulb ◽  
Tensile Testing Machine ◽  
Varietal Differences ◽  
Onion Bulbs ◽  
Non Destructive

SUMMARYThe use of a durometer to assess hardness of onion bulbs is described, and compared with the use of a tensile testing machine. Results from the two tests were closely correlated, and significant varietal differences were detected in bulb hardness by both machines. The durometer is of particular value because of the simplicity and non-destructive nature of the test procedure.

Immunodetection of Botrytis allii, the causal agent of neck rot of onion bulbs

EPPO Bulletin ◽  
1995 ◽  
Vol 25 (1-2) ◽  
pp. 39-46
Author(s):  
C. A. LINFIELD ◽  
N. F. LYONS ◽  
S. R. KENNY
Keyword(s):  
Causal Agent ◽  
Onion Bulbs ◽  
Botrytis Allii

The Role of Schwann Cells in the Formation of “Onion Bulbs” Found in Chronic Neuropathies***†

1967 ◽  
Vol 26 (2) ◽  
pp. 276-299 ◽  
Author(s):  
Henry deF. Webster ◽  
J. Michael Schröder ◽  
Arthur K. Asbury ◽  
Raymond D. Adams
Keyword(s):  
Schwann Cells ◽  
Onion Bulbs

Blue mould decay of stored onion bulbs caused byPenicillium polonicum,P. glabrumandP. expansum

2017 ◽  
Vol 165 (10) ◽  
pp. 662-669 ◽  
Author(s):  
Nataša Duduk ◽  
Marina Lazarević ◽  
Aleksandra Žebeljan ◽  
Miljan Vasić ◽  
Ivana Vico
Keyword(s):  
Blue Mould ◽  
Onion Bulbs

The role of exogenous plant regulators in the dormancy of onion bulbs

1974 ◽  
Vol 82 (1) ◽  
pp. 113-116 ◽  
Author(s):  
M. Abdel-Rahman ◽  
F. M. R. Isenberg
Keyword(s):  
Abscisic Acid ◽  
Growth Regulators ◽  
Maleic Hydrazide ◽  
Rest Period ◽  
Storage Period ◽  
Inhibitory Effect ◽  
Onion Bulbs ◽  
Subsequent Application

SUMMARYExperiments were conducted to study the effect of plant injection with growth regulators on the dormancy of onion bulbs cv. Elba Globe. Application of abscisic acid induced early senescence of the leaves and prolonged the rest period of the bulbs. This effect was partially overcome by subsequent applications of gibberellin, auxin or cytokinin and totally overcome with the application of a mixture of the three hormones. Maleic hydrazide application prolonged the rest period by inhibiting both sprouting and rooting of the bulbs throughout the storage period. This inhibitory effect was not overcome by the subsequent application of auxin, gibberellin, kinetin, or their combinations. Ethephon application increased rooting of bulbs and partially overcame the effect of abscisic acid on dormancy.

scholarly journals Fructo-oligosaccharide content and fructosyltransferase activity during growth of onion bulbs

1997 ◽  
Vol 136 (1) ◽  
pp. 105-113 ◽  
Author(s):  
NORIO SHIOMI ◽  
SHUICHI ONODERA ◽  
HIDEKI SAKAI
Keyword(s):  
Onion Bulbs

scholarly journals Effect of maleic hydrazide on respiratory parameters of stored onion bulbs (Allium cepa L.)

2004 ◽  
Vol 16 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Noureddine Benkeblia
Keyword(s):  
Activation Energy ◽  
Respiration Rate ◽  
Allium Cepa ◽  
Maleic Hydrazide ◽  
Co2 Production ◽  
Onion Bulbs ◽  
Respiratory Parameters ◽  
Allium Cepa L ◽  
Significant Difference ◽  
And Control

The respiration rate (RR) (CO2 production), activation energy (Ea) and Q10 of maleic hydrazide-treated onion bulbs (Allium cepa, cv. Rouge Amposta) at 20.10-6 mol.L-1 (MH1) and 45.10-6 mol.L-1 (MH2) were measured at 4, 10 and 20ºC. Immediately after treatment, the Q10 of MH-treated and control bulbs were not significantly different. After 8 weeks of storage, Q10 of control and both MH-treated bulbs increased and ranged from 2.34 and 2.89. Respiration rate of onions increased during storage, and after 24 weeks, RR values of control, MH1 and MH2 were 0.43, 0.32 and 0.26 mmol CO2.kg-1.h-1 at 20ºC respectively; and 0.26, 0.20 and 0.17 mmol CO2.kg-1.h-1 at 10ºC respectively. At 4ºC, no significant difference was observed between control and MH-treated bulbs. After 24 weeks, sprouting of the control and MH1 and MH2-treated bulbs was 75%, 38% and 33% at 20ºC respectively, and 50%, 22% and 17% at 10ºC respectively. At 4ºC, the sprouting level of control bulbs did not exceed 7% and was 5% for MH-treated bulbs. No difference was observed in rotting of control and MH-treated bulbs, and the low rotting observed at 4ºC could be attributed to low temperature rather than maleic hydrazide treatment.

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