Rot Fusarium Research Articles

Effect of coating maize seed with entomopathogenic fungi on plant growth and resistance against Fusarium graminearum and Costelytra giveni

ABSTRACTSome entomopathogenic fungi such as Metarhizium and Beauveria not only have the ability to infect and kill insects but also the capability to associate with plant roots. The potential benefits from this plant-fungus association include nutrient acquisition, plant growth promotion and protection against stressors. The objective of this study was to evaluate the delivery of entomopathogenic fungi in seed coating to determine whether the fungal presence affected maize performance. Additionally, fungal biocontrol ability was assessed in terms of plant resistance to the larvae of Costelytra giveni (Coleoptera: Scarabaeidae) and to the fungus Fusarium graminearum (Nectriaceae). Maize seeds were coated with conidia from Metarhizium spp. or Beauveria bassiana and plant performance was evaluated as seed germination and plant dry weight. Larval mortality and the presence of Fusarium root rot symptoms were also determined. The entomopathogenic fungal persistence on the maize rhizosphere was demonstrated with a M. anisopliae isolate expressing the green fluorescent protein. Presence of both challengers was detrimental to maize performance with 33% reduction in root dry weight in control plants while no variation was observed when the entomopathogenic fungi were used to coat seeds. Some seed coatings resulted in up to 67% mycosis of C. giveni larvae and a reduction in Fusarium rot root symptoms between 24 – 44%. This study showed that seed coating with conidia of Metarhizium or Beauveria can be used as a delivery system for pests and plant pathogen control, while at the same time hyphae formed a close association with plant roots after conidial germination.

Acetylsalicylic acid treatment reduce Fusarium rot development and neosolaniol accumulation in muskmelon fruit

Fusarium rot of muskmelon is a common and frequently-occurring postharvest disease, which leads to quality deterioration and neosolaniol (NEO) contamination. New strategies to control postharvest decay and reduce NEO contamination are of paramount importance. The effects of acetylsalicylic acid (ASA) treatment on the growth of Fusarium sulphureum in vitro, and Fusarium rot development and NEO accumulation in fruits inoculated with F. sulphureum in vivo were investigated. The results showed that ASA inhibited the growth of F. sulphureum, evident morphological and major cellular changes were observed under the microscope. In vivo testing showed that 3.2 mg/mL ASA significantly suppressed Fusarium rot development and NEO accumulation after 6 and 8 d of pathogen inoculation. Meanwhile, Tri gene expressions involved in NEO biosynthesis were down-regulated after treatment. Taken together, ASA treatment not only reduced Fusarium rot development by inhibiting the growth of F. sulphureum, but decreased NEO accumulation by suppressing NEO biosynthesis pathway.

The potato protection from major pests and diseases

Goal. To study the effectiveness of pesticides in protecting potato plantations from major pests and diseases.
 Methods. Comparative, analytical and field.
 Results. The data of technical and economic efficiency of pesticides against the main pests and diseases of potatoes are given. It was noted that the most effective against the complex of pests were drugs from the group of neocotinoids, and against diseases — fungicides of systemic and systemic contact action of various classes of chemical compounds.
 Conclusions. The most common potato diseases during the growing season of the crop were Alternaria and blight, the development of which in 2016—2017. amounted to 12.6—36.4% and 10.6—48.6%, respectively. Two spraying of potatoes with fungicides ensured technical effectiveness against Alternaria — 26.4—64.8%, against late blight — 24.3—53.9%. The main disease of potato tubers in 2017—2018 there was a common scab, the proportion of which in the control was 15.6%, and in the variants with the use of disinfectants — 5.4—8.6% of the total mass of the infected tubers. Dry Fusarium rot in the variants of the experiment was 2.5—2.8%, in the control — 9.3%. The number of bastards damaged by wireworms in the control was 7.2%, in the variants with the use of insecticidal and insecticidal and fungicidal disinfectants — 1.0—2.2%. It was established that the treatment of tubers with insecticidal and insecticide antifungal preparations against the Colorado potato beetle was effective for 40—50 days after planting potatoes, and further it is necessary to additionally spray it with insecticide.

ДОЛИ ВЛИЯНИЯ ПРИЕМОВ АГРОТЕХНИКИ НА РАСПРОСТРАНЕННОСТЬ ГНИЛЕЙ В СВЕКЛОВИЧНОМ АГРОЦЕНОЗЕ

In the paper shares of influence of the main processing methods (factor A) and fertilization backgrounds (factor B) on the prevalence of sugar beet root diseases are investigated and established. As a result of the research, a complex of typical and random pathogens of sugar beet root rot was established: dominant - F. oxysporum, F. solani, R. stolonifer; frequent - bacteria, F. oxysporum v. ortoceras; rare - Mucor sp., A. alternata, Aspergillus sp., F. gibbosum; random - Penicillium sp., Gliocladium sp., T. viride. Analysis of the species composition of root rot pathogens showed that every year the structure of the population expanded. As independent pathogens of rot were: R. stolonifer v. stolonifer-Rhizopus rot (2010- 2011), Penicillium sp. - penny rot (October 2010), A. alternata - Alternaria rot (October 2012-2013), bacterial rot (2012-2013). The main pathology was Fusarium rot (Fusarium sp.). It was found that phytopathogenic mycobiota of soil and rhizosphere developing on plant residues accumulated in the upper soil horizons during tillage promotes the spread of the disease and increases the probability of pathogens. The greatest prevalence of root rot is established in the variant with flat-cutting treatment and high background (N 6g P 6g K 6g + 11 tons of manure/1 ha of crop rotation) fertilizer (up to 26.1%). The prevalence of rot in the variants during the main treatment with the formation turnover was the lowest (P = 0 - 16.3 %). Mathematical processing of the data showed that the share of influence of the main tillage on the prevalence of root rot was 68%, the share of influence of fertilizers - 24%.

First report of fusarium rot caused by Fusarium circinatum on sweet potato (Ipomoea batatas)

First report of fusarium rot caused by Fusarium circinatum on sweet potato (Ipomoea batatas)

Detection of NEO in muskmelon fruits inoculated with Fusarium sulphureum and its control by postharvest ozone treatment

Fusarium rot of muskmelon, caused by Fusarium spp., is one of the most important postharvest decays, that not only causes economic losses but leads to trichothecenes contamination. A rapid and sensitive method was developed for neosolaniol (NEO) analysis in muskmelon inoculated with F. sulphureum, utilizing acetonitrile/water (84:16, v/v) extraction and PriboFast M270 columns purification and UPLC-MS/MS detection. Method validation was evaluated by linearity (R ≥ 0.9990), recovery (88.1–136.9%), precision (RSD ≤ 3.97%) and sensitivity (LOD, 0.5 μg/kg; LOQ, 1.5 μg/kg). The effect of ozone treatment on Fusarium rot development and NEO accumulation in inoculated muskmelon was also evaluated. The results showed that UPLC-MS/MS method was suitable for analyzing NEO in inoculated muskmelon, and 1.10 mg/l ozone treatment for 120 min significantly controlled Fusarium rot development and NEO accumulation in fruits after 5, 8 and 11 days. In vivo tests showed that ozone at 1.10 mg/l effectively degraded NEO in acetonitrile.

Investigation of Potential Biological Control of Fusarium Oxysporum f.sp.Lycopersici by Plant Extracts, Antagonistic sp. and Chemical Elicitors In Vitro

Tomato (Lycopersicon esculentum L.) is the most popular vegetable in the world. These fruits carry heavy spore loads when they leave the field. As a result of poor packaging and improper management, the fruits arrive at their destination bruised and squeezed and different types of rots set in under favourable conditions. Fusarium rot is one of the most devastating diseases of ripe tomatoes. The pathogen was isolated from the infected material and it was identified as Fusarium oxysporum f.sp. lycopersici. Diseases caused by fungal pathogens have been a major challenge to agriculture, health as well as national economy. The resistance of this pathogen to the wide variety of chemicals has stimulated the search of new alternatives for control measures. Use of plants extract is one of the most promising, effective, safer and eco-friendly method to eradicate the pathogen from ripe tomato. The present paper aims at the study on the potential for the control of Fusarium oxysporum f.sp. lycopersici by nine plant extracts (Calotropi sprocera, Curcuma domestica, Moringa oleifera, Tricosanthes dioica, Nigella sativa, Wedelia calendulacea, Andrographis paniculata, Trigonell afoenum-graceum and Momordi cacharantia), three fungicides (Sulcox, Indofil M 45 and Ridomil MZ 68) and three antagonistic fungi. It was found that almost all plant extracts at 25% concentration were effective in reducing the mycelium growth of Fusarium oxysporum f. sp. lycopersici. The highest inhibition (87%) of mycelium growth of this pathogen was observed when treated after the plant extract of Calotropis proceraon 12 DAI at 25% concentration and lowest inhibition (27%) of this pathogen was observed when treated after the plant extract of Momordi cacharantia on 12 DAI at 5% concentration. Antagonistic effect of Trichoderma sp., Sclerotium sp. and Aspergillus sp. shows that the highest percent inhibition radial growth (82%) was of Trichoderma sp. and the lowest (68.95%) was of Aspergillus sp. against Fusarium oxysporum f.sp. lycopersici. Chemical treatment with Sulcox was proved that the most effective fungicides against this pathogen.

Evaluation on reaction of early maturing maize lines and hybrids to fusarium ear rot

In order to investigate the amount of resistance in and early maturity lines and hybrids to ear rot fusarium disease, an experiment was caried out with 56 lines and 34 hybrids which were extracted from material corn and forage crop department were planted in Gharakhil agricultural research station in 2010-2011. Inter row space was 75 centimeters, row legth was 2/5 m and pland distance in row was 25 centimrters. By using artifical inoculation, all of gonotyps were inoculated by using scale rating, the rate of resistance was indentfied (Diseas severity) and the result in2010 showed that three lines were very suseptible, 11 lins were susceptible and others were tolorant. Two hybrids were susceptibl and others tolorant. Results in 2011 showed that five lines were susceptibleand12 lines were very tolorant. Hybrid, KE77007/14 × KE1264/5-1 was resistant, 31 hybrids were tolorant and one hybrid was susceptibl.

Fungi Causing Storage Rot of Apple Fruit in Integrated Pest Management System and their Sensitivity to Fungicides

Abstract Apple fruit rot can be caused by several fungi. In Northern Europe, the most common storage rot, Bull’s eye rot, is caused by Neofabraea spp., bitter rot by Colletotrichum spp., brown rot by Monilinia fructigena, grey mould is caused by Botrytis cinerea and Fusarium rot by several Fusarium species. Blue mold decay caused by Penicillium expansum is an important disease in several European countries. Incidence of different causal agents may vary depending on cultivar, climate during growing season and agricultural practices. The main objective of the study was to obtain baseline information about apple rot-causing fungi, their incidence during fruit storage and to evaluate the fungicide sensitivity of most of isolated fungal species. The study was performed during the storage period of apples after the growth season of 2013. Rotten apples were sorted in the storage and part of them was brought to the laboratory in order to obtain fungal isolates. Fungi were identified according to the morphological characteristics and sequencing of the ITS1-5.8S-ITS2 region. During storage in February and March the total percentage of rotten apples in various cultivars varied from 3.6 to 58.9%. All post-harvest diseases described in Northern Europe were detected. In part of the storehouses apple rot caused by Cadophora luteo-olivacea was observed. Alternaria spp. and Cladosporium spp. were detected on few apples as secondary infection agents. Using the most often isolated fungal species, sensitivity tests were performed against five commonly used fungicides. In general, the sensitivity of tested fungi to the fungicides was high with exception of several Neofabraea and Alternaria isolates.

Combining UV-C treatment with biocontrol yeast to control postharvest decay of melon.

Significant losses in harvested melon can be directly attributable to decay fungi. In the present study, the use of UV-C treatment combined with biocontrol yeast, Pichia cecembensis, was evaluated for their ability to control postharvest decay of melon fruits after they were artificially inoculated with Fusarium oxysporum and Alternaria alternata. Natural infection of fruit was also assessed. As a stand-alone treatment, UV-C or P. cecembensis significantly reduced Fusarium rot and Alternaria rot, and also the level of natural infection on melon fruit, relative to the untreated control. The combination of UV-C or P. cecembensis, however, provided a superior level of decay control on artificially inoculated and naturally infected fruit, compared to either treatment alone. None of the treatments impaired fruit quality. Integrating the use of UV-C treatment with biocontrol yeast has potential as an effective method to control postharvest decay of melon.

In vitro Inhibition of Fusarium by Lactic Acid Bacteria (LAB): Implication of Yam Disease Control for Economic Growth in Nigeria

Yam is an important crop in Nigeria, where it is produced both as food and cash crop. Fusarium rots of yam are among the most important postharvest pathogens of yam worldwide, causing a lot of postharvest losses in stored yam tubers. Lactic acid bacteria (LAB) lower the pH and create an environment that is unfavorable to pathogens and spoilage organisms. In vitro inhibition of fusarium spp by LAB was investigated; mono-culture and multi-culture were used. The inhibition tests were carried out with pure cultures of LAB and fusarium spp. The pure culture of actively growing Fusarium was used to inoculate Potato Dextrose Agar medium aseptically and then incubated at room temperature for 72h. The diameter of the growing Fusarium was measured, after which less than a loop full of actively growing (18-24 h) LAB isolates were used to inoculate

Incidence of post-harvest fungal diseases of ripe papaya in Mymensingh

A survey was conducted during November, 2012 to May, 2013 to assess the status of major post harvest diseases of papaya fruits in the local markets of Mymensingh. Average percentage of diseased fruits at the markets were 29.83 and diseased fruits ranged from 20.40% to 38.04% during the study period. Highest percentage of diseased fruits (38.04%) was recorded in the month of May, 2013 followed by March, 2013 (37.98%). The minimum percentage of diseased fruits (20.40%) was recorded in January, 2013 followed by December (22.68%). Total six post-harvest diseases was recorded, viz. Anthracnose, Fusarium rot, Stem end rot, Rhizopus rot, Aspergillus rot and Penicillium rot. Anthracnose showed highest mean incidence (14.17 %) followed by Fusarium rot (7.26%) where as Pencillium rot showed lowest mean incidence (0.70%). In the market, anthracnose showed maximum percentage of mean disease abundance (46.11%) followed by Fusarium rot (24.61%). The findings of this study revealed that total six post-harvest diseases are associated with ripe papaya in different markets of Mymensingh. Moreover, May is the predominant month of highest incidence and abundance of all diseases. DOI: http://dx.doi.org/10.3329/jbau.v12i1.21235 J. Bangladesh Agril. Univ. 12(1): 25-28, June 2014

Reduction of Fusarium rot and maintenance of fruit quality in melon using eco-friendly hot water treatment.

Significant losses in harvested fruit can be directly attributable to decay fungi and quality deterioration. Hot water treatment (HWT) has been demonstrated to be an effective and economic environment-friendly approach for managing postharvest decay and maintaining fruit quality. In this study, the effects of HWT (45 °C for 10, 15, 20, and 25 min) on in vitro growth of Fusarium oxysporum, in vivo Fusarium rot, and natural decay of melon were investigated. HWT inhibited spore germination and germ tube elongation of F. oxysporum. Protein impairment and ATP consumption triggered by HWT contributed to the inhibitory effect. Results of in vivo studies showed that HWT effectively controlled Fusarium rot and natural decay of melon. Correspondingly, HWT induced a significant increase in content of total phenolic compounds and lignin of melon. These findings indicate that the effects of HWT on Fusarium rot may be associated with the direct fungal inhibition and the elicitation of defense responses in fruit. Importantly, HWT used in this study had beneficial effects on fruit quality as well. HWT may represent an effective non-chemical approach for management of postharvest Fusarium rot.

First Report of Fusarium Rot of Garlic Bulbs Caused by Fusarium proliferatum in North Carolina.

In August of 2013, garlic bulbs (Allium sativum) of the variety Chesnok Red grown and stored under dry conditions by a commercial producer in Buncombe County showed water-soaked, tan to salmon-pink lesions. Lesions on cloves became soft over time, slightly sunken, and had mycelium near the center of the bulb, which is characteristic of Fusarium rots on garlic (1,2). Approximately 10 to 20% of the bulbs inspected in the drying storage room were affected. Surface-sterilized tissue was excised from the margin of lesions on eight bulbs, plated onto acid potato dextrose agar (APDA), and incubated in the dark at room temperature (21°C). White to light pink colonies with abundant aerial mycelium and a purple pigment were obtained from all samples after 2 to 3 days of incubation. Inspection of colony morphology and reproductive structures under a microscope revealed that isolate characteristics were consistent with Fusarium proliferatum (Matsushima) Nirenberg. Microscopic morphological characteristics of the isolate included hyaline, septate hyphae; slender, slightly curved macroconidia with three to five septae produced in sporodochia; curved apical cell; and club-shaped, aseptate microconidia (measuring 3.3 to 8.3 × 1.1 to 1.3 μm) produced in chains by mono and polyphyalides. To further define the identity of the isolate, the beta-tubulin (Btub), elongation factor 1a (EF1a), and internal transcribed spacer (ITS) regions were amplified and sequenced (3). The resulting sequences were compared against the GenBank nucleotide database by using a BLAST alignment, which revealed that the isolate had 100% identity with F. proliferatum for the Btub, EF1a, and ITS regions (GenBank Accession Nos. AF291055.1, JX118976.1, and HF930594.1, respectively). Sequences for the isolate were deposited in GenBank under accessions KJ128963, KJ128964, and KJ128965. While there have been other reports of F. proliferatum causing bulb rot of garlic in the United States (1), to our knowledge, this is the first report in North Carolina. The finding is significant since F. proliferatum can produce a broad range of mycotoxins, including fumonisins, when infecting its host, which is a concern for food safety in Allium crops.

First Report of Fusarium avenaceum Causing Postharvest Decay of 'Gala' Apple Fruit in the United States.

Apples are kept in controlled atmosphere cold storage for 9 to 12 months and are highly susceptible to postharvest decay caused by various fungi. Fusarium avenaceum is a wound pathogen that has been shown to account for the majority of Fusarium rot on apple fruit in Croatia (1). F. avenaceum produces an array of mycotoxins including moniliformin, acuminatopyrone, and chrysogine, which are of primary concern for the apple processing industry (2). In February 2013, 'Gala' apple fruits with soft, circular, brown, watery lesions with characteristic abundant whitish mycelium covering the surface of the colonized fruit were obtained from bins from a commercial storage facility located in Pennsylvania. Several samples were collected and prepared for pathogen isolation. Apples were rinsed with sterile water, and the lesions were sprayed with 70% ethanol until runoff. The apple skin was aseptically removed with a scalpel, and asymptomatic tissue was placed onto full strength potato dextrose agar (PDA) petri plates without antibiotics and incubated at 25°C under natural light. Two single-spore isolates were propagated on PDA and permanent cultures were maintained as slants and stored in a cold room at 4°C in the dark. Fungal colonies initially formed abundant fluffy white mycelium and produced a golden orange pigment on PDA at 25°C. Isolates were identified as Fusarium based on cultural and conidial morphology as macroconidia were slightly falcate, thin-walled, usually 3 to 5 septate, with a tapering apical cell that was on average 23.6 μm long × 5.0 μm wide (n = 50). Microconidia were produced on PDA plates while chlamydospores were not evident. Identity of the isolates was confirmed through DNA extraction followed by amplification and sequencing of the translation elongation factor (EF-1α, 350 bp) gene region. The amplicons were sequenced using the forward and reverse primers and assembled into a consensus representing 2X coverage. MegaBLAST analysis revealed that both isolates were 100% identical with many other culture collection F. avenaceum sequences in Genbank (Accessions JQ949291.1, JQ949305.1, and JQ949283.1), which confirms their identification in conjunction with the morphological observations. Koch's postulates were conducted to determine pathogenicity using organic 'Gala' apple fruit that were surface sanitized with soap and water, sprayed with 70% ethanol, and wiped dry. The fruit were wounded with a finishing nail to 3 mm depth, inoculated with 50 μl of a conidial suspension (1 × 104 conidia/ml) using a hemocytometer, and stored at 25°C in 80-count boxes on paper trays for 21 days. Water-only controls were symptomless. Ten fruit composed a replicate for each isolate, and the experiment was repeated. Symptoms observed on artificially inoculated 'Gala' apple fruit were identical to the decay observed on 'Gala' apples that were obtained from cold storage. Decay caused by F. avenaceum may represent an emerging problem for the apple storage and processing industry. Therefore, it is important to monitor for this pathogen to prevent future losses and mycotoxin contamination of processed fruit products caused by this fungus. To the best of our knowledge, this is the first report of Fusarium rot caused by F. avenaceum on apple fruit from cold storage in the United States.

CO450 corn inbred line

Reid, L. M., Zhu, X., Voloaca, C., Wu, J., Woldemariam, T., Martin, R. A. and Beres, B. L. 2014. CO450 corn inbred line. Can. J. Plant Sci. 94: 161–167. CO450 is a short-season early-maturing (average 71 d to flowering) corn (Zea mays L.) inbred line with excellent combining ability and superior resistance to eyespot (Aureobasidium zeae). This is the first inbred to be released from AAFC's eyespot resistance breeding program. CO450 also has moderate resistance to common rust, intermediate resistance to common smut and both fusarium and anthracnose stalk rot. Excellent hybrid yields and performance data were achieved when CO450 was crossed with stiff stalk inbreds such as MBS1130 and an Iodent inbred, MBS8148. CO450 also exhibited good performance at sites with 2400 CHU or less in combination with a very early inbred, CL30.

IDENTIFIKASI GEJALA DAN PENYEBAB PENYAKIT BUAH JERUK IMPOR DIPENYIMPANAN DI KOTA PEKANBARU

Citrus production in Riau have been in inadequate to meet the people's consumptionin terms ofboth quality and quantity. This presents an influx of imported fruits, including oranges in Riau. The entryof imported fruit can carry pathogens that can degrade the quality of these fruits. Research was conductedin the Laboratory of Plant Diseases of Agricultural Faculty of Riau University of from June to August2011. Purpose of this study was to identify the symptoms and causes disease in citrus fruit imports duringpost harvest in Pekanbaru. Research conducted using survey method with the determination of marketsamples are purposive sampling. Of the mind that a disease affecting citrus fruit imports in the cityPekanbaru in the supermarket is Anthracnose disease caused by Colletotrichum sp, Aspergillus rot causedby Aspergillus sp, Fusarium rot caused by Fusarium sp and Alternaria fruit rot caused by Alternaria sp.In traditional markets is a disease and rot Anthracnose disease Aspergillus.

First Report of Fusarium Rot Caused by Fusarium oxysporum on Lemon in Tucumán, Argentina.

Fusarium rot is considered a minor disease of citrus fruits. Several Fusarium species have been associated with fruit decay, most commonly F. lateritium Nees, F. moniliforme J. Sheld., F. oxysporum Schltdl., and F. solani (Mart.) Sacc. (2,3). In the winters of 2007, 2009, 2010, and 2011, lemon [Citrus limon (L.) Burm. f.] fruit with white mycelium covering the peduncle were submitted to the Phytopathology Lab at the Estación Experimental Agroindustrial Obispo Colombres. All fruit samples from Tucumán, Argentina, were stored in boxes kept in packinghouse for more than 1 month. In 2007 only, light to dark brown flavedo around the peduncle was observed in less than 1% of the sample fruit received. No internal breakdown was visible. No change in rind color was observed in the samples received in remaining years. Abundant Fusarium sp. conidia were observed on the mycelium. Colonies with white to violet fluffy aerial mycelium developed on potato dextrose agar (PDA) and produced abundant ovoid or oblong microconidia (1.9 to 3.6 × 4.8 to 10.8 μm), usually unicellular, borne in false heads on short monophialides, and loculated slightly falcate macroconidia were mostly three to five septate (2.4 to 4.8 × 19.2 to 31.2 μm). Unbranched and branched-monophialidic conidiophores were observed. Simple or paired chlamydospores developed on synthetic nutrient agar (1 g KH2PO4, 1 g KNO3, 0.5 g MgSO4.7H2O, 0.5 g KCl, 0.2 g sucrose, and 20 g agar/liter distilled water). On the basis of morphological and cultural criteria, 22 isolates were identified as F. oxysporum (4) designated as D1 to D22. Morfological identification was confirmed by PCR (1) using genomic DNA extracted from the mycelium of pure culture, and an amplified product of 70 bp, specific for the species F. oxysporum, was obtained. The internal transcribed spacer (ITS) region of rDNA was amplified using the primers ITS4/ITS5 and secuenced. BLAST analysis of the 600 bp segment showed a 100% indentity with F. oxysporum, strains CCF 4362 and 1166 (GenBank Accession Nos. HE974454 and FR731133, respectively). Pathogenicity tests were conducted twice by inoculating 10 surface-disinfected wounded lemon fruit. A rind disc (5 mm in diameter and 1 mm deep) near the stem end was removed and a 5-mm-diameter agar disc of D2 isolate (grown at 25°C for 5 days on PDA) was attached to the wound replacing the rind disc. The inoculation site was covered with moistened cotton wool and the fruit were wrapped in plastic bags to prevent the inoculum from drying out. Ten control fruit were inoculated with uncultured PDA plugs (5 mm in diameter). All fruit were maintained in a growth chamber at 25°C under humid conditions. After 5 to 6 days, all inoculated fruit showed white aerial mycelium, initially on the inoculation site and then on the peduncle, similar to that observed on naturally infected fruit. After 20 days, two fruit developed stem end dry rot and showed peduncle fall but no internal breakdown was visible. Control fruit developed any symptom as described above. F. oxysporum was consistently reisolated from infected tissues, completing Koch's postulates. To our knowledge, this is the first report of Fusarium rot caused by F. oxysporum on lemon in Tucumán, Argentina.

Synthesis and antimicrobial activity of novel mancozeb derivatives containing 1,3,4-thiadiazole

Four mancozeb derivatives containing 1,3,4-thiadiazole, 5a–5d, were successfully synthesized, then characterized by IR, 1H NMR, and 13C NMR spectroscopy and elemental analysis. Their antimicrobial activity against paddy fusarium, Botrytis cinerea, cucumber fusarium, tomato gibberella, and grape white rot was tested in vitro by use of the filter paper disk-diffusion technique. Compounds 5a–5d had moderate to excellent antimicrobial activity in comparison with mancozeb, 6. Among these compounds, 5a had the best inhibitory activity.

Antifungal Activities of Essential Oils and Crude Extracts of Some Aromatic Plants Against Fusarium Rot of Trichosanthes dioica

This experiment was conducted for assessing the antifungal activities of essential oils and crude extracts of some aromatic plants against Fusarium rot of Trichosanthes dioica was at the Central Department of Botany. Pathogenicity test was taken for the confirmation of disease by transferring the inoculum from pure culture. For the control of the above fungus essential oils and extracts of five aromatic plants Zanthoxylum armatum, Mentha arvensis, Amomum subulatum, Valeriana jatamansi and Cymbopogon flexuosus were used. Each oil and extracts were diluted in different concentration in 80% acetone and in distilled water respectively. The value of minimum inhibitory concentration and percentage of mycelia growth inhibition of oil and extracts were obtained as, oil of C. flexuosus showed the higest fungitoxicity (100%) at the 5.0 and 50 ?lml-1 concentration followed by Z. armatum, M. arvensis, A. subulatum and V. jatamansi were found to be 10 and 100 ?lml-1 respectively also the higest percentage of mycelial growth inhibitors were found to be C. flexuosus followed by A. subulatum, Z. armatum, M. arvensis and V. jatamansi . Similarly extracts of C. flexuosus followed by Z. armatum, A. subulatum, V. jatamansi and M .arvensis respectively. Nepal Journal of Science and Technology Vol. 13, No. 2 (2012) 97-102 DOI: http://dx.doi.org/10.3126/njst.v13i2.7720