scholarly journals Evaluation of various plant extracts against the early blight disease of tomato plants under greenhouse and field conditions

2012 ◽  
Vol 48 (No. 2) ◽  
pp. 74-79 ◽  
Author(s):  
S.M.A. Nashwa ◽  
K.A.M. Abo-Elyousr

The antimicrobial activity of six plant extracts from Ocimum basilicum (Sweat Basil), Azadirachta indica (Neem), Eucalyptus chamadulonsis (Eucalyptus), Datura stramonium (Jimsonweed), Nerium oleander (Oleander), and Allium sativum (Garlic) was tested for controlling Alternaria solani in vitro and in vivo. In in vitro study the leaf extracts of D. stramonium, A. indica, and A. sativum at 5% concentration caused the highest reduction of mycelial growth of A. solani (44.4, 43.3 and 42.2%, respectively), while O. basilicum at 1% and 5% concentration and N. oleander at 5% concentration caused the lowest inhibition of mycelial growth of the pathogen. In greenhouse experiments the highest reduction of disease severity was achieved by the extracts of A. sativum at 5% concentration and D. stramonium at 1% and 5% concentration. The greatest reduction of disease severity was achieved by A. sativum at 5% concentration and the smallest reduction was obtained when tomato plants were treated with O. basilicum at 1% and 5% concentration (46.1 and 45.2 %, respectively). D. stramonium and A. sativum at 5% concentration increased the fruit yield by 76.2% and 66.7% compared to the infected control. All treatments with plant extracts significantly reduced the early blight disease as well as increased the yield of tomato compared to the infected control under field conditions.

Horticulturae ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 36
Author(s):  
Kamal A. M. Abo-Elyousr ◽  
Najeeb M. Almasoudi ◽  
Ahmed W. M. Abdelmagid ◽  
Sergio R. Roberto ◽  
Khamis Youssef

The aim of this study is to assess the effect of extracts of Nerium oleander, Eucalyptus chamadulonsis and Citrullus colocynthis against bacterial spot disease of tomato and to investigate the induction of resistance by tomato (Solanum lycopersicum) in order to promote a sustainable management system. The antibacterial activity of aqueous and ethanol plant extracts was tested against Xanthomonas axonopodis pv. vesicatoria, isolate PHYXV3, in vitro and in vivo. The highest antibacterial activity in vitro was obtained with C. colocynthis, N. oleander and E. chamadulonsis, respectively. In vivo, ethanol extracts of N. oleander and E. chamadulonsis were more effective than aqueous extracts in reducing pathogen populations on tomato leaves. Under greenhouse conditions, application of the plant extracts at 15% (v/v) to tomato plants significantly reduced disease severity and increased the shoot weight of ‘Super Marmande’ tomato. In most cases, plant extracts significantly increased total phenol and salicylic acid content of tomato plants compared to either healthy or infected ones. In addition, C. colocynthis and E. chamadulonsis extracts significantly increased peroxidase activity while only E. chamadulonsis increased polyphenol oxidase after infection with the causal agent. The results indicated that the plant extracts showed promising antibacterial activity and could be considered an effective tool in integrated management programs for a sustainable system of tomato bacterial spot control.


2021 ◽  
Vol 58 (04) ◽  
pp. 1263-1275
Author(s):  
Rashid Iqbal Khan

Plant extracts (PE’s) has emerged as a safer alternative to manage the fungal pathogens affecting tomato productivity. The current study aimed to evaluate the antimicrobial potential of methanolic fenugreek extract against Alternaria solani, a causal agent of early blight disease in tomato. Fenugreek extract was used at different concentrations of 5%, 10%, 15%, 20% and 25% under in vitro conditions. Results concluded that 25% fenugreek extract significantly reduced the radial growth (2.5 cm) of A. solani under in vitro conditions. Based on in vitro results, three concentrations (5%, 15% and 25%) of fenugreek extract was examined under greenhouse and field conditions. The outcomes expressed that 5% fenugreek extract reduced the disease severity up to 30.19% under greenhouse conditions and up to 40.53% under field trials. Although, application of fenugreek extract had exhibited non-significant impact on vegetative and reproductive growth parameters. However, its application had proved better results as compared to those plants which are infected with A. solani but received zero application of fenugreek extract. Furthermore, the effectiveness of plant extracts was evaluated by variant photosynthetic, antioxidative, polyphenolic and hypersensitive response of A. solani affected tomato plants. The 25% fenugreek extract application had augmented the chlorophyll pigments along with the significant increment of superoxide dismutase (174.16 U mg-1 protein), peroxidase (7.61 µmol min-1 g-1 protein) and catalase activity (4.73 nmol min-1 g-1 protein). Similar outcomes were observed regarding phenolic compounds, where 5% fenugreek extract application had enhanced flavonoid levels (26.62 mg QuE g-1), tannins (1.28 mg TE g-1 extract) and total phenolic contents (2.39 mg GAE g-1) in tomato leaves demonstrating its protective effect against early blight. In dose response, 25% fenugreek extract was most effective in reducing lipid peroxidation and enhancing H2O2 levels. The outcomes of study exhibited the fenugreek extract as an effective strategy to be used against A. solani to control early blight infection in tomato plants. Thus, it can serve as suitable fungicide alternative for resource-poor agriculture areas mainly in developing countries.


2021 ◽  
Vol 15 (3) ◽  
pp. 1591-1601
Author(s):  
Sumit Kumar ◽  
Ram Chandra ◽  
Lopamudra Behera

Botanicals obtained from the plants are well known for the suppression of inimical plant pathogens. The present study explores the efficacy of five locally available plant extracts for their antifungal activity against the early blight of potato incited by Alternaria solani. The extracts include Datura stramonium, Allium sativum, Azadirachta indica, Eucalyptus globulus, and Lantana camara. All extracts reduced mycelial growth and conidial germination of A. solani. In vitro studies showed that extracts obtained from A. sativum and A. indica have significant inhibition of mycelial growth of A. solani (88.80 and 86.62 percent) at 20 percent concentration. Higher concentrations of A. sativum extract caused a higher reduction of A. solani radial growth on potato dextrose agar medium. Extracts obtained from A. sativum and A. indica at 20 percent concentration, were found most effective for inhibition of conidial germination (85.50 and 80.04 percent) respectively of A. solani. Observations by scanning electron microscope (SEM) showed dramatic alteration in A. solani hyphae collapsed and spores shrinked when treated with extract of A. sativum at a 20 per cent concentration. The qualitative and quantitative analysis of various phytochemicals like flavonoids, alkaloids, saponins, tannins, steroids, terpenoids, glycosides, and phenols was showed A. sativum extract better than all the other plant extracts. Observation also revealed that 20 percent concentration of garlic extract has potential to inhibit to A. solani.


2021 ◽  
Vol 8 (2) ◽  
pp. 255-262
Author(s):  
Salman Ahmad ◽  
Muhammad Aslam Khan ◽  
Irfan Ahmad ◽  
Zafar Iqbal ◽  
Ejaz Ashraf ◽  
...  

Two fungicides, Aliette and ThiovitJet @ 0.15%, containing Aluminum tris (O-ethyl phosphonate) and sulphur compounds, respectively; two plant extracts, Melia azedarach and Azadirachta indica @ 8% and one biocontrol agent, Trichoderma harzianum @ 107 conidia ml-1 were investigated against ascochyta blight of chickpea under field conditions. Treatments were evaluated on three varieties susceptible to chickpea blight. Field trial revealed that Aliette and ThiovitJet significantly decreased disease severity to 17 and 23% respectively, followed by M. azedarach and A. indica which decreased severity to 50 and 56% respectively, compared to control with 75% disease severity. T. harzianum, with a severity of 63%, was significantly less effective than fungicides and both plant extracts in controlling blight disease. The current research revealed that systemic and sulphur containing fungicides, both plant extracts and the biocontrol agent have the potential to control ascochyta blight of chickpea.


2011 ◽  
Vol 10 (42) ◽  
pp. 8291-8295 ◽  
Author(s):  
Yanar Yusuf ◽  
Gouml kccedil e Ayhan ◽  
Kadioglu Izzet ◽  
Ccedil am Halit ◽  
Whalon Mark

2021 ◽  
Vol 10 (1) ◽  
pp. 094-104
Author(s):  
Ahmed S. Abdel–Aty ◽  
Elsayed A.M. Abdallah ◽  
Ezzat A. kaduos ◽  
Mohamed R. A. Gad

Fungicidal activity of nine selected conventional fungicides, identified five plant oils and their combined effect against A. solani, the causal pathogen of early blight on tomato. GC-MS analysis of the tested oils indicated that terpene hydrocarbons (97%) with cinnamaldehyde as the major compound; sulfur compounds; fatty acids and organo-sulfur-containing compounds were the main components in cinnamon, garlic, mustard and onion oils, respectively. In vitro, Speedcide® (difenoconazole) and Cabrioduo® (Dimethomorph + Pyraclostrobin) were the most effective against the A. solani fungus with EC50 values of 94.6 and 88.6 ppm respectively. Toledo® (Tebuconzole) achieved EC50 value of 631.2 ppm. Roxyl-M® was significantly more effective than Roxyl–plus® or Remik®. Speedcide® alone or mixed with mandipropamid or azoxystrobin in Revus-Top® or Cruze® were the lowest effective in vitro. Garlic and mustard oils were more effective in liquid media than solid one. Cinnamon, onion, garlic and bitter almond oils caused moderate fungi-toxicity against early blight pathogen and could be implemented in the IPM program. Lower EC50 values were obtained in case of combinations of fungicides with oils than separate treatments. Effect of the active conventional fungicides and plant oils on disease indices, relative disease control, chlorophyll content, sugar contents and poly phenol oxidase in tomato plants was also studied.


Author(s):  
Mara Quaglia ◽  
Marika Bocchini ◽  
Benedetta Orfei ◽  
Roberto D’Amato ◽  
Franco Famiani ◽  
...  

AbstractThe purpose of this study was to determine whether zinc phosphate treatments of tomato plants (Solanum lycopersicum L.) can attenuate bacterial speck disease severity through reduction of Pseudomonas syringae pv. tomato (Pst) growth in planta and induce morphological and biochemical plant defence responses. Tomato plants were treated with 10 ppm (25.90 µM) zinc phosphate and then spray inoculated with strain DAPP-PG 215, race 0 of Pst. Disease symptoms were recorded as chlorosis and/or necrosis per leaf (%) and as numbers of necrotic spots. Soil treatments with zinc phosphate protected susceptible tomato plants against Pst, with reductions in both disease severity and pathogen growth in planta. The reduction of Pst growth in planta combined with significantly higher zinc levels in zinc-phosphate-treated plants indicated direct antimicrobial toxicity of this microelement, as also confirmed by in vitro assays. Morphological (i.e. callose apposition) and biochemical (i.e., expression of salicylic-acid-dependent pathogenesis-related protein PR1b1 gene) defence responses were induced by the zinc phosphate treatment, as demonstrated by histochemical and qPCR analyses, respectively. In conclusion, soil treatments with zinc phosphate can protect tomato plants against Pst attacks through direct antimicrobial activity and induction of morphological and biochemical plant defence responses.


Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 209
Author(s):  
Nadia Lyousfi ◽  
Rachid Lahlali ◽  
Chaimaa Letrib ◽  
Zineb Belabess ◽  
Rachida Ouaabou ◽  
...  

The main objective of this study was to evaluate the ability of both antagonistic bacteria Bacillus amyloliquefaciens (SF14) and Alcaligenes faecalis (ACBC1) used in combination with salicylic acid (SA) to effectively control brown rot disease caused by Monilinia fructigena. Four concentrations of salicylic acid (0.5%, 2%, 3.5%, and 5%) were tested under in vitro and in vivo conditions. Furthermore, the impact of biological treatments on nectarine fruit parameters’ quality, in particular, weight loss, titratable acidity, and soluble solids content, was evaluated. Regardless of the bacterium, the results indicated that all combined treatments displayed a strong inhibitory effect on the mycelial growth of M. fructigena and disease severity. Interestingly, all SA concentrations significantly improved the biocontrol activity of each antagonist. The mycelial growth inhibition rate ranged from 9.79% to 88.02% with the highest reduction rate recorded for bacterial antagonists in combination with SA at both concentrations of 0.5% and 3.5%. The in vivo results confirmed the in vitro results with a disease severity varying from 0.00% to 51.91%. A significant biocontrol improvement was obtained with both antagonistic bacteria when used in combination with SA at concentrations of 0.5% and 2%. The lowest disease severity observed with ACBC1 compared with SF14 is likely due to a rapid adaptation and increase of antagonistic bacteria population in wounded sites. The impact of all biological treatments revealed moderate significant changes in the fruit quality parameters with weight loss for several treatments. These results suggest that the improved disease control of both antagonistic bacteria was more likely directly linked to both the inhibitory effects of SA on pathogen growth and induced fruit resistance.


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