scholarly journals Effect of different plant extracts and nanoparticles on Thrips tabaci (Lind.) (Thysanoptera: Thripidae) under field conditions and their allelopathic potential on the onion, Allium cepa L. using bioassays and RAPD analysis

2020 ◽  
Vol 30 (1) ◽  
Author(s):  
Sameer H. Qari ◽  
Abdelhalem H. Khalil ◽  
Nilly A. H. Abdelfattah ◽  
Ayman A. Shehawy
Keyword(s):  
Allium Cepa ◽  
Plant Extracts ◽  
Rapd Analysis ◽  
Thrips Tabaci ◽  
Field Conditions ◽  
Allelopathic Potential ◽  
Allium Cepa L

Bulb Development in Onion (Allium cepa L.) I. Effects of Plant Density and Sowing Date in Field Conditions

1986 ◽  
Vol 58 (2) ◽  
pp. 187-195 ◽  
Author(s):  
M. F. MONDAL ◽  
J. L. BREWSTER ◽  
G. E. L. MORRIS ◽  
HEATHER A. BUTLER
Keyword(s):  
Allium Cepa ◽  
Plant Density ◽  
Sowing Date ◽  
Field Conditions ◽  
Allium Cepa L

scholarly journals Allium cepa L. responses when Gaeolaelaps aculeifer Canestrini and Parasitus bituberosus Karg are used to control Thrips tabaci Lindeman

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Mayerly Alejandra Castro-López ◽  
John Wilson Martínez-Osorio
Keyword(s):  
Population Density ◽  
Allium Cepa ◽  
Plant Development ◽  
Insect Pest ◽  
Predatory Mites ◽  
Thrips Tabaci ◽  
Physiological Variables ◽  
Allium Cepa L ◽  
Mite Density ◽  
Chlorophyll Index

Thrips tabaci Lindemann is the main insect pest of Allium cepa L., causing both direct and indirect damage to crops. T. tabaci is controlled by applying chemically synthesized products; however, this insect has already developed resistance to organophosphates, carbamates, and pyrethroids. This study evaluated the effect of soil predatory mites (Gaeolaelaps aculeifer Canestrini and Parasitus bituberosus Karg) on the population density of T. tabaci in potted bulb onion (Allium cepa L.) plants and on the response of physiological variables related to photosynthesis and plant development. Seven treatments were evaluated that released 50, 75 or 100 G. aculeifer or P. bituberosus adults, along with a control without predatory mites. Significant differences (P≤0.05) in the population density of T. tabaci were observed for 13 weeks, with a 78% reduction of individuals in the presence of G. aculeifer and a 72% reduction with P. bituberosus, regardless of mite density, as compared to the control. In addition, the relative chlorophyll index, foliar area, dry leaf weight and fresh bulb weight increased, as compared to the control. The application of 100 individuals of the two species recorded the highest values in the evaluated variables. These results indicate that G. aculeifer and P. bituberosus controls should be explored as an option for integrated T. tabaci management.

Bacteria occurring in onion (Allium cepa L.) foliage in Puerto Rico.

1969 ◽  
pp. 199-219
Author(s):  
Juan Calle-Bellido ◽  
Lydia I. Rivera-Vargas ◽  
Myrna Alameda ◽  
Irma Cabrera
Keyword(s):  
Puerto Rico ◽  
Pseudomonas Syringae ◽  
Allium Cepa ◽  
Leaf Tissue ◽  
Field Conditions ◽  
Bacterial Strains ◽  
Burkholderia Glumae ◽  
Pathogenic Potential ◽  
Allium Cepa L ◽  
Leaf Tissues

Bacteria associated with foliar symptoms of onion (Allium cepa L.) were examined in the southern region of Puerto Rico from January through April 2004. Different symptoms were observed in onion foliage of cultivars 'Mercedes' and 'Excalibur' at Juana Díaz and Santa Isabel, Puerto Rico. Ellipsoidal sunken lesions with soft rot and disruption of tissue were the most common symptoms observed in onion foliage in field conditions. From a total of 39 bacterial strains isolated from diverse symptoms in onion foliage, 38% were isolated from soft rotting lesions. Ninety-two percent of the bacteria isolated from onion foliage was Gram negative. Pantoea spp. with 25%, was the most frequently isolated genus, followed by Pasteurella spp. and Serratia rubidae with 10% each. Fifty- six percent of the strains held plant pathogenic potential; these strains belong to the genera Acidovorax sp., Burkholderia sp., Clavibacter sp., Curtobacterium sp., Enterobacter sp., Pantoea spp., Pseudomonas spp., and Xanthomonas spp. Pathogenicity tests showed that seven out of eight tested bacterial strains evaluated under field conditions caused symptoms in onion foliage for both cultivars. Acidovorax avenae subsp. citrulli, Burkholderia glumae, Pantoea agglomerans, P. dispersa, Pseudomonas sp., Xanthomonas sp., and Xanthomonas-Wke sp. were pathogenic to leaf tissues. Clavibacter michiganensis was not pathogenic to leaf tissues. Other bacteria identified as associated with onion leaf tissue were Curtobacterium flaccumfaciens, Cytophaga sp., Enterobacter cloacae, Flavimonas oryzihabitans, Mannheimia haemolytica, Pantoea stewartii, Pasteurella anatis, P. bettyae, P. langaaensis, Photobacterium damselae, Pseudomonas syringae pv. aptata, Rhizobium radiobacter, Serratia rubidae, Sphingobacterium spiritivorum, Sphingomonas sanguinis, and an unknown strain. This paper is the first survey of bacteria associated with onion foliage in Puerto Rico. The role of non- phytopathogenic bacteria associated with the life cycle of onion under field conditions remains unknown.

scholarly journals Comparative HPTLC Analysis of Leaves of Allium cepa L., Ficus carica L. and Ziziphus mauritiana L. with Standard Quercetin

2017 ◽  
Vol 9 (5) ◽  
Author(s):  
Une H. D. ◽  
Khan D. ◽  
Mohammed M.
Keyword(s):  
Quantitative Analysis ◽  
Allium Cepa ◽  
Plant Extracts ◽  
Calibration Curve ◽  
Methanolic Extract ◽  
Solvent System ◽  
Ficus Carica ◽  
Ziziphus Mauritiana ◽  
Pharmacological Activities ◽  
Allium Cepa L

Flavonols aglycones are well established in plant extracts with omnipresence of common flavonols like kaempferol, quercetin and myricetin. Quercetin has been reported for various pharmacological activities with major ones in the field of inflammation, cancer, arthritis, diabetes and its complications. Leaves of plants selected for this study viz. Allium cepa L., Ficus carica L. and Ziziphus mauritiana L. reported to have antioxidant, anticancer, hypoglycemic activities. It is hypothetised thisactivities are due to flavonoids present in these plants. Hence the ethylacetate fraction of methanolic extract of these leaves was obtained as it provides flavanoid rich fraction and the samples were prepared and HPTLC analysis was performed against standard quercetin and their quantitative analysis was performed, the solvent system toluene: ethyl acetate: formic acid (9: 1: 0.5) was selected. It was observed that these plants shows presence of quercetin where A. cepa has highest concentration with F. carica and Z. mauritiana having quercetin in declining order. The calibration curve was linear in the range of 0.1 to 0.7 μg for quercetin. Further a correlation coefficient of 0.999 indicates good linearity between concentration and area. Thus, it was proved that the plants used in the study has presence of quercetin which is possibly the reason having the pharmacological uses.

Insecticides and populations of Thrips tabaci (Lindermann) and Liriomyza trifolii (Surges) in onions

1969 ◽  
Vol 92 (1-2) ◽  
pp. 87-101
Author(s):  
Irma Cabrera-Asencio ◽  
Alberto L. Vélez
Keyword(s):  
Allium Cepa ◽  
Thrips Tabaci ◽  
Liriomyza Trifolii ◽  
Allium Cepa L

The use of insecticides to decrease Thrips tabaci and Liriomyza trifolii population in onion (Allium cepa L.) was evaluated for two consecutive years.The insecticides most frequently used by farmers were evaluated: cypermethrin, avermectin, oxamyl, azadirachtin and dimetyl. A treatment with water only, plus the control, was also evaluated. It was observed that the use of cypermethrin resulted in the least number of nymphs and adults of Thrips tabaci and the best onion yield. As for Liriomyza trifolii, it was observed that the use of avermectin and cypermecthrin resulted in the least numbers of larvae.

scholarly journals Impacto da adubação orgânica sobre a incidência de tripes em cebola

2003 ◽  
Vol 21 (3) ◽  
pp. 459-463 ◽  
Author(s):  
Paulo Antônio de S. Gonçalves ◽  
Carlos Roberto Sousa e Silva
Keyword(s):  
Allium Cepa ◽  
Thrips Tabaci ◽  
Allium Cepa L

Analisou-se a relação entre adubação orgânica e a incidência de Thrips tabaci Lind. em cebola (Allium cepa L), na EE de Ituporanga, entre agosto e dezembro de 1998. Os tratamentos foram determinados de acordo com a necessidade de N para a cultura pela análise de solo. Empregou-se como fonte orgânica diversos adubos fornecendo 75 Kg/ha de N (esterco suíno; adubo Barriga Verde® proveniente de esterco de aves; composto orgânico; esterco de peru; húmus); 37,5 Kg/ha de N (metade da dose normal com esterco de suíno); as testemunhas foram adubação mineral fornecendo 30-120-60 kg/ha de N-P2O5-K2O e o dobro da dose (60-240-120 kg/ha de N-P2O5-K2O); e testemunha sem adubação. Nenhum tratamento apresentou incidência de T. tabaci superior à testemunha sem adubo. A adubação mineral em relação à orgânica não favoreceu significativamente a incidência de T. tabaci . O processo de conversão do manejo do solo da área experimental de convencional para orgânico pode ter favorecido a infestação similar do inseto entre tratamentos. No período de maior incidência de T. tabaci, a relação com nutrientes foi descrita por um modelo envolvendo K/Zn, B e N de maneira positiva. A correlação entre nutrientes e T. tabaci não foi linear na maioria das avaliações. A adubação orgânica pode substituir a adubação mineral na cultura da cebola, pois foi possível atingir níveis de produtividade similares para ambos tratamentos.

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