First report of Fusarium pallidoroseum (Cooke) Sacc. on Bael (Aegle marmelos Correa) causing leaf spot and die back disease in nursery

Bael is a very popular indigenous fruit of India. Cultivation of bael is a lucrative venture because of its high pharmaceutical importance. The deciduous tree with trifoliate aromatic leaves offering of bael leaves is a compulsory ritual of the worship of lord shiva. In bael nursery, disease appeared during post rainy season (September) as irregular pustules, which was brown in colour, increases very fast and covers the most of the leaf area. After severe infection, affected leaves become dry and fall off. The disease progresses downward causing dieback symptoms but roots are remain healthy and they produces new shoots after destroying the vegetative parts. This type of symptoms incited by Fusarium pallidoroseum (Cooke) Sacc. was identified as a causal organism. The pathogenicity test of the fungus was established. Fusarium pallidoroseum produce smooth and creamyhite colony, grew rapidly on PDA medium at 250C to 260C and produced rose pink colored woolly to cottony, flat spreading colonies when mature. The mass of the mycelium was very compact in nature. The fungus produced both macro and micro conidia, which are hyaline, septate and ends are also hook shaped. Mycelia are thin and septate. Macro conidia were produced from phialides on unbranched or branched conidiophpres. Macro conidia born in sporodochia were curved; possess a foot cell, 3-5 septate. Micro conidia are single celled, smooth, hyaline, ovoid to cylindrical.

Fusarium pallidoroseum: A potential entomopathogenic agent for the biological management of Aphis gossypii

With rising need of switching over to sustainable agricultural practices, utilization of entomopathogenic fungi (EPF) as biocontrol agents, provides better substitute against chemical pesticides- having several side-effects. Therefore, an attempt have been made to explore the potential EPF fungi that could be incorporated into IPM practices for control of Helicoverpa armigera Hubner and Aphis gossypii Glover. Regarding this, an entomopathogenic fungus, Fusarium pallidoroseum (Cooke) Sacc, was isolated from natural population of H. armigera infesting chickpea (Cicer arietinum L.) and explored efficacy under in-vitro & field conditions. The findings of present investigation shows efficacy of F. pallidoroseum as potential biocontrol agent against okra aphid (A. gossypii), as it inflicted initial mortality of 43.33% nymphs on 2nd day and lead to complete annihilation (93.33%) of nymph population on 8th day of spore suspension application at 1x1010 spores/mL concentration. The observations against adult okra aphid clearly demonstrated that spraying of 1 x 1010 spores/mL of F. pallidoroseum resulted 66.67% mortality after 8th days of spraying. Increased mortality was recorded with increase in spore suspension concentrations. The LC50 & LC90 value for F. pallidoroseum against nymphs of A. gossypii was recorded 3.79 x 105 and 2.74 x 108, respectively. The findings were used to develop formulations (1 × 104 to 1 × 1010 spore suspension/mL conc), and tested at field-level. The results showed that formulation at 1 x 1010 spores/mL conc was most effective against A. gossypii, recorded 93.33% mortality of nymphs & 66.67% mortality of adults; could be used under IPM practices.

Botanical alternatives in management of fungal pathogens of seedling blight of cashew (Anacardium occidentale L.)

Introduction: Cashew (Anacardium occidentale L.) is an important tree crop and seedling survival is pertinent to successful establishment. Cashew seedling is infected by blight pathogens causing more than 60% seedling lost, however pesticides residues related issues and high cost of chemical necessitate efficacy trials of aqueous extracts of Mangifera indica, Azadirachta indica and Hyphtis suaveolens evaluated in-vitro on associated pathogens. Methods: Flora of blight-infected cashew seedlings was randomly collected from Cocoa Research Institute of Nigeria (CRIN) nursery between July and October, 2019. Mycoflora analysis was carried out in the plant pathology (Mycology) laboratory of CRIN. Antifungal assay of powdered Mangifera indica, Azadirachta indica and Hyphtis suaveolens were screened using aqueous extracts at 1:4 (w/v). Potato Dextrose Agar (PDA) amended with 1ml of 100%, 75%, 50%, 25%, and 0% of the extracts and Mancozeb (synthetic fungicide) as standard, 5mm mycelia mat disc of 10day old each of Lasiodiplodia theobromae, Fusarium pallidoroseum and Macrophomina sp. were placed at the centre of the amended media in triplicate and incubated 5-7days using complete randomized design (CRD). Mycelia extension inhibition and percentage growth inhibition (R) obtained. Results: Aspergillus niger, A. flavus, Fusarium oxysporium, F. pallidoroseum, Lasiodiplodia theobromae., Pythium sp., Rhizopus sp., Macrophomina sp. and Rhizotonia sp. were isolated. Fusarium pallidoroseum, L. theobromae and Macrophomina sp. screened with the varied concentrations of botanicals showed reduction in mycelia diameter; Mangifera indica (31.50%), A. indica (48.70%) and H. suaveolens (25.86%) on F. pallidoroseum favorably competed with mancozeb (39%) at 25% concentration while only M. indica was significant on L.theobromae(64.12%)and Macrophomina sp.(40.29%) and significantly different from control (0%). Conclusion: Aqueous extracts of M. indica, A. indica and H. suaveolens showed fungicidal potential on F. pallidoroseum and M. indica was significant on L. theobromae and Macrophomina sp.

Antifungal activity of essential oils of Myrcia ovata chemotypes and their major compounds on phytopathogenic fungi

This work evaluated the antifungal activity of essential oils of Myrcia ovata chemotypes (MYRO-175, MYRO-156, MYRO-154, MYRO-165, and MYRO-015) and their major compounds (linalool, geraniol, citral, and (E)-nerolidol) on the phytopathogenic fungi Fusarium pallidoroseum (which causes melon postharvest rot) and Colletotrichum musae (which causes anthracnose in banana). The essential oils were obtained by hydrodistillation and analyzed by GCMS/FID. To evaluate the antifungal activity, the essential oils and their major compounds were tested at different concentrations (0.1; 0.3; 0.4; 0.5; 0.7; 1.0; 3.0, and 5.0 mL/L). The major compounds found in the essential oils were nerolic acid, linalool, geraniol, citral, and (E)-nerolidol. The essential oils of the plants MYRO-154, MYRO-165, and MYRO-015 had the minimum inhibitory concentration (MIC) (0.3 mL/L) for F. pallidoroseum and the lowest minimum fungicidal concentration (MFC) (0.7 mL/L), for C. musae. Geraniol and citral had the lowest MFC (0.5 mL / L) for the two fungi tested. For F. pallidoroseum, the essential oils of the chemotypes were more effective than their major compounds. Conversely, the major compounds geraniol of the chemotype MYRO-156 (74.37%) and citral were more effective than their respective essential oils for C. musae. (E)-nerolidol and geraniol of the chemotype MYRO-015 (33.15%) were responsible for the antifungal activity of the essential oils of their respective chemotypes.

Effect of pulsed light on postharvest disease control-related metabolomic variation in melon (Cucumis melo) artificially inoculated with Fusarium pallidoroseum

Pulsed light, as a postharvest technology, is an alternative to traditional fungicides, and can be used on a wide variety of fruit and vegetables for sanitization or pathogen control. In addition to these applications, other effects also are detected in vegetal cells, including changes in metabolism and production of secondary metabolites, which directly affect disease control response mechanisms. This study aimed to evaluate the possible applications of pulsed ultraviolet light in controlling postharvest rot, mainly caused by Fusarium pallidoroseum in yellow melon ‘Goldex’, in natura, and its implications in the disease control as a function of metabolomic expression to effect fungicidal or fungistatic. The dose of pulsed light (PL) that inhibited F. pallidoroseum growth in melons (Cucumis melo var. Spanish) was 9 KJ m-2. Ultra performance liquid chromatography (UPLC) coupled to a quadrupole time-of-flight (QTOF) mass analyzer identified 12 compounds based on the MS/MS fragmentation patterns. Chemometric analysis by Principal Components Analysis (PCA) and Orthogonal Partial Least Squared Discriminant Analysis (OPLS-DA and S-plot) were used to evaluate the changes in fruit metabolism. PL technology provided protection against postharvest disease in melons, directly inhibiting the growth of F. pallidoroseum through upregulation of specific fruit biomarkers such as pipecolic acid (11), saponarin (7), and orientin (3), which acted as major markers for the defense system against pathogens. PL can thus be proposed as a postharvest technology to avoid chemical fungicides and may be applied to reduce the decay of melon quality during its export and storage.

Harmful Effects of Parthenium hysterophorus and Management Through Different Approaches”- A review

Parthenium hysterophorus is commonly known as congress grass or carrot weed in India. It belongs to Asteraceae family and native to subtropics of North and South America. It is an invasive plant species that disturbs cultivated areas, roadside vegetation, gardens etc. P. hysterophorus is considered as one of the worst weeds responsible for causing health problems in animals and humans viz., dermatitis, asthma and bronchitis besides loss to agriculture and ecosystem. Nowadays, it has become one of the major weeds in almost all types of agricultural lands and other areas. Many control methods ranging from preventive, physical methods by manual uprooting, burning and allelopathic management through competitive plants like Cassia tora, Cassia uniflora Cassia sericea, have been recommended for management of P. hysterophorus. Likewise, insect Zygogramma bicolorata has proven successful in managing P. hysterophorus. Further, microorganisms like Alternaria alternata, Scerotiia sclerotiorum, Fusarium Pallidoroseum, Ralstonia solanacearum, Xanthomanas campestris are reported to infest P. hysterophorus. Use of chemical herbicides mainly glyphosate @ 2.5 kg a.i.ha-1,atrazine @ 2.6 kg a.i.ha-1,2,4-D amine @ 3 l/ ha-1, Paraquat 0.5 l/ ha-1 were proved effective in managing P. hysterophorus. No single option is suitable to control this invasive weed. Successful control of this weed can only be achieved by an integrated weed management approaches.