Fungitoxic Activity Research Articles

Fungicide Effect of a Novelty Antimicrobial Biosurfactant Extract Alone or Combined with Copper Oxychloride on Botrytis cinerea Cells

Microbial contaminations represent an important issue for crop production, resulting in tons of losses worldwide every year. One of the highest-risk pathogens involved in these infections is Botrytis cinerea, which is responsible for the grey mold disease. In this study, a biosurfactant extracted from corn steep liquor (CSL), an agro-industrial residue from the corn-milling industry, was used in combination with copper oxychloride (Cu-Oxy), a copper-based pesticide, to evaluate their fungitoxic activity on B. cinerea cells. The results showed that the mixture of 2 g/L of Cu-Oxy with 16 g/L of the biosurfactant extract from CSL, named biosurfactant pesticide formulation (BS-P), helped in the reduction of colony growth, in the decrease of biomass production, and in the improvement of copper bioaccumulation on fungal mycelium in comparison with aqueous solutions of commercial and pure-copper-based fungicides. A factorial design was conducted to obtain the best operational conditions for enhancing the bioaccumulation of copper by B. cinerea cells in the presence of BS-P, resulting in a maximum copper uptake of 2122 µg Cu/g dry weight when using 1 g/L of Cu-Oxy combined with 8 g/L of CSL biosurfactant extract at an incubation temperature of 15 °C. It was also proved that, due to the absence of the biosurfactant extract, the amount of copper bio-adsorbed by fungal mycelium was considerably decreased and, therefore, so was its fungitoxic activity. These results suggest that the biosurfactant extract studied could be involved in eco-friendlier pesticide formulations, reducing the environmental impact of copper-based active principles.

Inventory and Management of Fungi Associated with Banana Plant through the Use of <i>Allium ampeloprasum</i> and <i>Cymbopogon citratus</i> Extracts

Despite the nutritional, economic and medicinal values of banana plant, independent of the region and production system is confronted with some diseases such as the fungi disease. These fungal diseases are responsible for the low yields. The objective of this study was to improve the sanitary state of banana plant. To achieve this objective, fungi associated with banana leaves were isolated on Potato Dextrose Agar (PDA) culture medium and their identification was done on the basis of morphological and microscopic characteristics using reference documents. Antifungal activity of Allium ampeloprasum and Cymbopogon citratus extracts were evaluated in vitro on agar medium on the development of Pseudocercospora fijiensis, P. musicola and Pestalopsis sp. The results showed that banana plant harbours a diversity of fungal species, the most frequent being P. fijiensis (51.58%), Pestalopsis sp. (15.47%) and P. musicola (12.03%). Aqueous extracts of C. citratus at the concentration of 15 mg/ml, inhibited 100% of the radial growth of P. fijiensis and Pestalopsis sp with a fungitoxic activity. Similarly, ethanolic extract A. ampeloprasum inhibited at 100% the radial growth of Pestalopsis sp. This antifungal activity was fungistatic. These results suggest that the aqueous and ethanol extracts of the tested plants could be used as alternatives to chemical products in the fight against banana diseases especially Sigatoka. Hence further studies need to be undertaken to isolate the active compounds from these extracts with fungicidal potential.

The efficacy of various fungicides against the tomato early blight (Alternaria solani)

The tomato is one of the most popular vegetables farmed worldwide. One of the most harmful tomato diseases is early blight, which is a disease that the fungus Alternaria solani causes.This will reduce the quality and quantity of tomatoes. Nearly 80% losses were reported due to this disease. To evaluate the fungi-toxic activity of the fungicides Kavach, Cbrio Top, Merivon, Avtar, Amistar, and Tilt at the plant pathology department of the faculty of agriculture at LPU, Punjab, over the years 2021–2022, the poisoned food approach was adopted. Six different fungicides were checked at different concentration like 50, 100, 150 ppm at lab condition. Propiconazole (Tilt) was found to be most effective, i.e. percent inhibition was 100%. Same fungicides were checked at field.Among this fungicides Cbrio Top, Merivon, Amistar were found to be most effective followed by kavach, Tilt and Avtar.

The Synthesis, Fungicidal Activity, and in Silico Study of Alkoxy Analogues of Natural Precocenes I, II, and III.

This study aimed to synthesize, characterize, and explore the eco-friendly and antifungal potential of precocenes and their derivatives. The organic synthesis of the mono-O-alkyl-2,2-dimethyl 2H-1-chromene series, including the natural product precocene I, and the di-O-alkyl 2,2-dimethyl-2H-1-chromene series, including the natural 2H-1-chromenes precocenes II and III, was achieved. The synthetic compounds were subjected to spectroscopic analysis, 1HNMR,13CNMR, and mass characterization. The antifungal activity of synthesized precocenes I, II, and III, as well as their synthetic intermediates, was evaluated by the poison food technique. Precocene II (EC50 106.8 µg × mL-1 and 4.94 µg mL-1), and its regioisomers 7a (EC50 97.18 µg × mL-1 and 35.30 µg × mL-1) and 7d (EC50 170.58 × µg mL-1), exhibited strong fungitoxic activity against Aspergillus niger and Rhizoctonia solani. Some of the novel chromenes, 11a and 11b, which had never been evaluated before, yielded stronger fungitoxic effects. Finally, docking simulations for compounds with promising fungitoxic activity were subjected to structure-activity relationship analyses against the polygalactouronases and voltage-dependent anion channels. Conclusively, precocenes and their regioisomers demonstrated promising fungitoxic activity; such compounds can be subjected to minor structural modifications to yield promising and novel fungicides.

Fungitoxic activities of Citrus limon L. peel extracts in controlling anthracnose of mango

Fungitoxic activities of Citrus limon L. peel extracts in controlling anthracnose of mango

The efficacy of various fungicides against tomato Fusarium wilt (Fusarium oxysporum f. sp. lycopersici)

The tomato is one of the most popular vegetables farmed worldwide. One of the most harmful tomato disease is Fusarium wilt, which is a disease that the fungus Fusarium oxysporum f.sp. lycopersici causes. Disease causes about 30% to 40% losses in yield. The poisoned food technique was used to assess the fungitoxic activity of the fungicides Blitox 50, Aliette, Roko, Amistar, Avtar, and Cabrio Top at the plant pathology department of the college of agriculture at LPU, Punjab, throughout the years 2021-2022. Six different fungicides were tested in the lab at various concentrations such as 50, 100, and 150 ppm. Thiophanate Methyl (Roko) show the best result in laboratory. Same fungicides were checked at field. Among this fungicides Copper Oxychloride (Blitox 50) shows the best result in field condition.

Management of Stemphylium Blight of Garlic (Allium sativum) by Botanicals

Stemphylium blight is an economically important disease of garlic causing significant reduction in crop yield. Usually, the management tactics relies on the use of synthetic chemicals. So, in this context, an eco-friendly approach was followed by using botanicals for controlling the disease. The antifungal effects of aqueous extracts were tested under in vitro and in vivo conditions. The fungitoxic activity of these botanicals was compared with the standard check (mancozeb 75 WP). The maximum colony growth inhibition was shown by mancozeb (62.4%), neem oil (43.3%) followed by neem extract (28.8%), aak (23.8%) and lantana (22.9%). The maximum spore germination inhibition was shown by mancozeb (56.6%), neem oil (40.2%) followed by neem extract (24.7%) and lantana (19.9%). The lowest disease severity was recorded in plants sprayed with mancozeb 75WP (14.8%) followed by the neem oil (34.8%) under in vivo conditions. The study revealed that neem oil can be a good candidate for managing this disease for avoiding the harmful effects of synthetic chemicals.

Evaluation of Fungicides against Fusarium oxysporum f.sp. lycopersici the Cause of Fusarium Wilt of Tomato

Tomato is very significant and full of nutrition vegetable crop. It is enriched with vitamin a and C, lycopene, and protects from prostate cancer, cardiovascular diseases. Tomato wilt disease (TWD) caused by F. oxysporum f.sp. lycopersici (Fol) is a serious threat to tomato crop in Pakistan and spreading to those areas in which it was not previously present. The current research was planned to evaluate the fungi-toxic activity of fungicides against F. oxysporum in vitro and under greenhouse conditions. Four fungicides which include Carbendazim, Benomyl, Curzate and Nativo, at 500ppm, 750ppm and 1000ppm concentrations, were evaluated using food poison technique. The overall results showed that all fungicides significantly (P < 0.05) inhibited mycelial growth of F. oxysporum, however, Nativo proved to be best followed by Carbendazim, Benomyl at all concentrations. The reduction in colony growth of pathogen gradually increased by increasing the fungicide concentration. Two fungicides, Nativo and Carbendazim and their concentrations 750 and 1000 ppm, which proved to be effective in laboratory conditions, also evaluated under greenhouse conditions. Both fungicides effectively controlled TWD under greenhouse conditions. The present research revealed that Nativo and Carbendazim at 750 and 1000 ppm concentrations are effective against Fol, thus may be included in management strategy of TWD.

Synthesis, Fungitoxic Activity against Botrytis cinerea and Phytotoxicity of Alkoxyclovanols and Alkoxyisocaryolanols

Clovane and isocaryolane derivatives have been proven to show several levels of activity against the phytopathogenic fungus Botrytis cinerea. Both classes of sesquiterpenes are reminiscent of biosynthetic intermediates of botrydial, a virulence factor of B. cinerea. Further development of both classes of antifungal agent requires exploration of the structure–activity relationships for the antifungal effects on B. cinerea and phytotoxic effects on a model crop. In this paper, we report on the preparation of a series of alkoxy-clovane and -isocaryolane derivatives, some of them described here for the first time (2b, 2d, 2f–2h, and 4c–4e); the evaluation of their antifungal properties against B. cinerea, and their phytotoxic activites on the germination of seeds and the growth of radicles and shoots of Lactuca sativa (lettuce). Both classes of compound show a correlation of antifungal activity with the nature of side chains, with the best activity against B. cinerea for 2d, 2h, 4c and 4d. In general terms, while 2-alkoxyclovan-9-ols (2a–2e) exert a general phytotoxic effect, this is not the case for 2-arylalkoxyclovan-9-ols (2f–2i) and 8-alkoxyisocaryolan-9-ols (4a–4d), where stimulating effects would make them suitable candidates for application to plants.

Characterization of the Fungitoxic Activity on Botrytis cinerea of N-phenyl-driman-9-carboxamides.

A total of 12 compounds were synthesized from the natural sesquiterpene (-) drimenol (compounds 4 to 15). The synthesized compounds corresponded to N-phenyl-driman-9-carboxamide derivatives, similar to some fungicides that inhibit the electron-transport chain. Their structures were characterized and confirmed by 1H NMR, 13C NMR spectroscopy, and mass spectrometry. Compounds 5 to 15 corresponded to novel compounds. The effect of the compounds on the mycelial growth of Botrytis cinerea was evaluated. Methoxylated and chlorinated compounds in the aromatic ring (compounds 6, 7, 12, and 13) exhibited the highest antifungal activity with IC50 values between 0.20 and 0.26 mM. On the other hand, the effect on conidial germination of B. cinerea of one methoxylated compound (6) and one chlorinated compound (7) was analyzed, and no inhibition was observed. Additionally, compound 7 decreased 36% the rate of oxygen consumption by germinating conidia.

Purification and characterization of embryo-specific soy urease (Glycine max) and its antifungal potential against Paracoccidioides brasiliensis

Ureases are amidohydrolases that catalyze the hydrolysis of urea to ammonia and carbamate. In addition to the enzymatic function, ureases have fungitoxic and insecticidal function, which are independent of their catalytic activity. Soy (Glycine max) has two main urease isoforms: ubiquitous and embryo-specific, the latter is present in beans. In view of the potential applications of ureases, this work aimed to extract, purify, characterize the structure, activity and fungitoxic activity of soy urease against Paracoccidioides brasiliensis. The biochemical characterization was performed, in terms of optimal pH and temperature, as well as the determination of the Michaelis�Menten constant (KM) and maximum velocity (Vmax). The protein sequence was identified by mass spectrometry and used in computational modeling of the biological structure. The optimum pH and temperature of the enzyme were 6.5 and 65 �C, respectively, KM 526 mmol L-1 and Vmax 7.4 mmol L-1NH3׵gurease-1�s-1 and biological unity as a trimer. The antifungal activity assays (in vitro) were promising, showing a fungicidal profile of the urease, with a minimum inhibitory concentration of 10 �g�mL-1. This work demonstrated, for the first time, the fungitoxic activity of embryo-specific soy urease against the Pb18 strain of P. brasiliensis.

Biochar-derived smoke-water exerts biological effects on nematodes, insects, and higher plants but not fungi

The pyrolysis of organic feedstock yields the solid fraction biochar, bio-oils, and a volatile fraction that can be reused for energetic purposes or technological applications in agro-ecosystems in the form of smoke-water (SW). In this study, 10 SW types were created from five organic feedstocks (i.e. cellulose, wood sawdust, olive mill residues, maize, and alfalfa litter) at two pyrolysis temperatures (i.e. 300 and 500 °C). We characterized SW using liquid chromatography (LC)–electrospray ionization–time-of-flight (TOF) mass spectrometry (MS) combined with a multi-species bioassay including five crop plants, four fungi, one root-knot nematode (Meloidogyne incognita), and the olive fly pest (Bactrocera oleae). All SW types were acidic, exhibiting a pH range of 1.9–4.6. LC-MS analysis revealed differences in the chemical profiles of SW types in relation to the organic feedstock type and pyrolysis temperature. All SW types exerted concentration-dependent effects on crops, with evident phytotoxic activity at high concentrations. Conversely, they exerted stimulatory effects when diluted with water at ratios ranging from 1:100 to 1:1000. Moreover, all SW types displayed slight or null fungitoxic activity. On the contrary, SW strongly inhibited egg hatching by M. incognita after 72 and 144 h of incubation. The strongest inhibition was found for olive mill SW, and the weakest effect was noted for alfalfa SW. Finally, the application of SW over fresh olives reversed the attraction of B. oleae adults, demonstrating a strong repellent effect toward this pest. Nevertheless, only olive mill SW consistently attracted B. oleae. In conclusion, biochar SW exhibited notable biological activities and potential applications for plant growth promotion, if opportunely diluted, and for the control of root-knot nematodes and olive fruit flies.

Conhecimentos sobre hortelã grande (Plectranthus amboinicus Lour) como proposta curricular na educação básica, Amazônia/Brasil

Este artigo tem como objetivo apresentar os saberes tradicionais de uma comunidade amazônica sobre o uso da planta “Hortelã Grande”, como alternativa complementar de saúde e inserir esses saberes em uma proposta curricular para a Educação Básica. Para tanto, foi necessário realizar uma pesquisa qualitativa do tipo descritiva, para levantamento do conhecimento local sobre o uso da planta, tendo sido acessado 25 informantes-chave, moradores da Bacia do Caeté, no Estado do Pará, por meio de entrevistas, observações e aplicação de um formulário padronizado, além da coleta de amostra vegetal para identificação botânica. Em Camutá-PA, a Plectranthus amboinicus Lour, popularmente conhecida como “Hortelã Grande” é usada no tratamento de complicações respiratórias, utilizando-se as folhas. A espécie possui compostos químicos como carvacrol e timol que possuem atividades microbianas, fungitóxicas e antitumoral. Esses saberes tradicionais e científicos possibilitaram a construção de uma proposta curricular que envolve as disciplinas de Língua Portuguesa, Geografia e História, Ensino Religioso, Ciências e Matemática através da teia do conhecimento em Paulo Freire.

Biological Activity of <i>Syzygium aromaticum</i> and <i>Ravensara aromatica</i> Essential Oils from Madagascar and Their Possible Use against Postharvest Mango Anthracnose

The fungitoxicity of five Malagasy essential oils (Eos) against Colletotrichum asianum was assessed in terms of conidial germination and mycelial growth. Their effect on defense-related compounds content, physicochemical properties and anthracnose lesions in mango fruits was also determined. Four of the tested Eos were from Ravensara aromatica leaves, and the last Eo was extracted from clove leaves. Their chemical compositions were then determined through GC-MS analysis and the active compound of the most fungitoxic Eo was determined by testing the toxicity of its major component to C. asianums spore germination, mycelial growth and its ability to inhibit anthracnose development on mango fruits. The R. aromatica Eos tested were fungistatic to C. asianum, whereas clove Eo was fungitoxic and the 4 chemotypes of R. aromatica Eo exhibited variable inhibiting capabilities: 1) all tested doses of all Eos (112.5 and 225 μL/L of air) were effective against C. asianum mycelial growth (10% - 100% inhibition) but doses of 225 μL/L were more inhibitory than those of 112.5 μL/L, 2) Conidial germination was more resistant to Eos toxicity since only 225 μL/L of methyl eugenol chemotype of R. aromatica Eo, all tested doses of the sabinene chemotype of R. aromatica Eo and clove Eo were found inhibitory toward conidial germination of C. asianum. 30 μL/L of sprayed clove Eoweretested on inoculated mangoes and were found to be effective against anthracnose development without affecting the resorcinol content in mango peel and the physicochemical properties of mango pulp. Tests on the major components of clove Eo showed fungitoxic activities against mycelial growth and conidial germination of C. asianum similar to those of clove Eo.

Synergy between Cu-NPs and fungicides against Botrytis cinerea

Combating drug-resistance is a daunting task, especially due to the shortage of available drug alternatives with multisite modes of action. In this study, the potential of copper nanoparticles (Cu-NPs) to suppress 15 Botrytis cinerea isolates, which are sensitive or resistant to fungicides, alone or in combination with conventional fungicides, was tested in vitro and in vivo. Sensitivity screening in vitro revealed two fungicide resistance phenotypes, resulting from target site mutations. DNA sequencing revealed three B. cinerea isolates highly resistant to benzimidazoles (BEN-R), thiophanare methyl (TM), and carbendazim, bearing the E198A resistance mutation in the β-tubulin gene, and four isolates highly resistant to the QoI pyraclostrobin (PYR-R) with a G143A mutation in the cytb gene. Cu-NPs were equally effective against sensitive and resistant isolates. An additive/synergistic effect was observed between Cu-NPs and TM in the case of BEN-S isolates both in vitro and when applied in apple fruit. A positive correlation was observed between TM and TM + Cu-NPs treatments, suggesting that an increased TM availability in the target site could be related with the observed additive/synergistic action. No correlation between Cu(OH)2 and Cu-NPs sensitivity was found, indicating that different mechanisms govern the fungitoxic activity between nano and bulk counterparts. A synergistic profile was observed between Cu-NPs and fluazinam (FM) - an oxidative phosphorylation inhibitor - in all isolates regardless of resistance phenotype, suggesting that ATP metabolism could be involved in the mode of action of Cu-NPs. Furthermore, the observed cross sensitivity and antagonistic action between Cu-NPs and NaCl also provided evidence for copper ions contribution to the fungitoxic action of Cu-NPs. The results suggested that Cu-NPs in combination with conventional fungicides can provide the means for an environmentally safe, sustainable resistance management strategy by reducing fungicide use and combating resistance against B. cinerea.

Effects of Combination of Diniconazole Fungicide with Antioxidants on Vital Ingredients of Certain Fungi

The main objective of this study is to evaluate addition of some antioxidants to diniconazole fungicide on the three isolated fungi, i.e., Alternaria alternata, Fusarium graminearum and Pyrenophora tritici-repentis. Three antioxidants, i.e., selenium at 5ppm, butylated hydroxyanisole at 50ppm and ascorbic acid at 100ppm were combined with different concentrations of diniconazole, 0.1, 0.5, 1, 3 and 5ppm, in Potato Dextrose Broth (PDB) medium. The vital ingredients, i.e., fresh weight, total carbohydrates, lipids and proteins of the fungi were determined. The results clearly indicated that fungicide-antioxidant mixtures decreased the vital ingredients of the tested fungimore effectively than the fungicide or antioxidants applied alone. Regardless the isolated fungi, the percent reduction of any of the vital ingredients followed the order; Se < BHA < AsA. These effects increased with increasing the concentration of the fungicide in culture medium. This means that antioxidants, especially selenium, enhanced the fungitoxic activity of diniconazole against the isolated fungi.

CONTROL OF THE ROOT ROT DISEASES OF WHEAT USING FUNGICIDES ALONE AND IN COMBINATIONS WITH SELENIUM

Five fungicides (tebuconazole, fludioxonil, iprodione, azoxystrobin and flutolanil) were evaluated separately or in mixtures with the antioxidant (selenium) against Fusarium graminearum and Rhizoctonia solani which causing root rot diseases of wheat. Depend upon EC50 values of the tested fungicides, the in vitro studies showed that the descending order of fungicidal activity against F.graminearum growth was as follows;fludioxonil> tebuconazole > iprodione > azoxystrobin > flutolanil, while it was flutolanil >fludioxonil> tebuconazole > iprodione > azoxystrobin against R. solani growth.The two fungi tolerated high concentration of selenium. Interestingly, the fungitoxic activities of the tested fungicides were greatly increased by adding selenium to the fungicide- amended medium. In greenhouse trials, the fungicides were applied at rates of 1.5 and 3.0 g /kg seeds, while selenium was applied at 10 and 20 μg / ml (as seed treatments) alone or in combinations with fungicides for controlling root rot diseases. The results showed that all fungicides treatments significantly reduced diseases incidence and increased emergence and plant stands. Generally the addition of the antioxidant (Se) at 20μg / ml to the higher rate (3.0 g/kg seeds) of each fungicide caused significant reduction of the pre- and post- emergence damping off and subsequently increased plant survivals. However, the addition of Se to the low rate of each fungicide gave satisfactory fungicidal action as well as minimizing the environmental pollution.

Characterization of the fungitoxic activity on Botrytis cinerea of the aristolochic acids I and II.

The fungitoxic effect of aristolochic acids I and II on mycelial growth and conidial germination of Botrytis cinerea was analysed. Aristolochic acid I had a higher effect on mycelial growth of B. cinerea than aristolochic acid II with IC50 value of 18·7 and 57·0μgml-1 , respectively. These compounds did not affect the conidia germination. Also, the effect of both compounds on DNA and plasmatic membrane integrity of B. cinerea was studied. Only aristolochic acid II was able to cause damage to the integrity of the plasmatic membrane. When the fungus was incubated with a mixture of these compounds, degradation of DNA was observed. Finally, biotransformation products were not detected in the culture broth when B. cinerea was incubated in the presence of the aristolochic acids. Studies of structural characteristics that increase the antifungal effect of compounds against B. cinerea will permit to design new molecules to control this phytopathogenic fungus. SIGNIFICANCE AND IMPACT OF THE STUDY: The fungitoxic effect on Botrytis cinerea of aristolochic acids I and II was characterized. The only structural difference among these compounds is a methoxy group at carbon 8. However, despite their structural similarity, the fungitoxic effect of aristolochic acid I was higher than the effect of aristolochic acid II. This result suggests that the methoxy group is important for the fungitoxic activity of these compounds on B. cinerea.

Ecofriendly Synthesis of Silver Nanoparticles Using Potato Steroidal Alkaloids and Their Activity Against Phytopathogenic Fungi

ABSTRACT In order to reduce the excessive reliance on the toxic chemical fungicides, the present study aimed to isolate the total potato glycoalkaloids (TPAs), and the two steroidal alkaloids α-chaconine and α-solanine from potatoes, Solanum tuberosum L. Their structures were characterized using physical and spectroscopic methods including (UV, IR, 1H, 13C--NMR, 2D 1H-1H COSY, HMBC and NOESY). Silver nanoparticles (AgNPs) were prepared from potato alkaloids through a green synthesis approach. Potato alkaloids and their nanoparticles inhibited mycelial growth of the phytopathogenic fungi Alternaria alternate, Rhizoctonia solani, Botrytis cinerea and Fusarium oxysporum f. sp. lycopersici with low minimal inhibitory and minimal fungicidal concentrations. R. solani was the most susceptible, while F. oxysporum was the most resistant. TPAs was the most fungitoxic (EC50's were 19.8, 22.5, 26.5 and 32.3 µg/ml against R. solani, A. alternate, B. cinerea and F. oxysporum respectively). A mixture of α-solanine and α-chaconine (1:1) showed a marked antifungal activity. AgNPs (size 39.5-80.3 diameter) from alkaloids showed improved fungitoxic activity (EC50's of TPAs nanoparticles ranged between 10.9 and 16.1 µg/ml). Alkaloids exhibited no or a slight phytotoxicity against wheat and radish. Results recommend the potential of using potato alkaloids and their nanoparticles as biorational alternatives to conventional fungicides.

Pre-harvest root application of soluble silicon improves postharvest quality and induces antifungal compounds in bitter gourd (Momordica charantia L.)

Beneficial effects of Silicon (Si) on disease control have been shown in a number of plant pathosystems. The present study ascertained the effect of root application of soluble Si on postharvest quality of bitter gourd (Momordica charantia L.) with special reference to the disease development by Fusarium oxysporum. Plants were treated with Potassium silicate (Si+) by amending the soil mix (200 mgSi /kg soil). Treatments were started at the four leaf stage and continued up to 28 days at seven days intervals. Soil amendments with Si significantly reduced the postharvest weight loss and extended the shelf life by 2 days through delayed ripening and reduced fungal rot development. Si analysis in bitter gourds, harvested from Si + plants revealed that fruit tissues accumulated nearly1.5 times as much silicon (0.54% dry weight) as those grown in control (Si-) mix (0.36% dry weight). Extracts from Si + plants exhibited a stronger antifungal activity on thin layer chromatography (TLC) against Cladosporium cladosporioides. Methanolic extracts of fruit pericarp separated on TLC plates showed four antifungal zones at Rf 0.17, 0.51, 0.64 and 0.93. Compound separated at Rf 0.64 was observed in samples from Si + and/or challenged with F.oxysporum. Antifungal zone at Rf 0.51 was present only when Si + fruits were challenged with the fungus. These results suggest that by using soil application of soluble Si, postharvest quality of bitter gourd can be improved and shelf life can be enhanced by 2 days compared to the control. Enhanced fungitoxic activity may have some role in Si-induced disease resistance againstpostharvest fungal pathogens.