Artículos de revistas sobre el tema "Sudden wilt"
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1
Pratama, Rahmat, Ahmad Muslim y Suwandi Suwandi. "FIRST REPORT OF NEW WILT DISEASE ON Mangifera indica CAUSED BY Ceratocystis fimbriata IN INDONESIA". BIOVALENTIA: Biological Research Journal 9, n.º 1 (10 de julio de 2023): 36–40. http://dx.doi.org/10.24233/biov.9.1.2023.377.
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Ceratocystis wilt and canker disease has severely compromised the profitability of Mangifera indica plantations in the world. In 2022, wilt and sudden death were observed on Mangifera indica. Identification was performed by sequence analysis of the concatenated β-tubulin gene regions. Sequencing of the PCR product confirmed this pathogen was Ceratocystis fimbriata sensu stricto. This is the first report of C. fimbriata causing sudden death disease in M. indica in Indonesia.
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Cohen, R. "Response of Melofon Breeding Lines to Powdery Mildew, Downy Mildew, Fusarium Wilt, and Sudden Wilt". Plant Disease 79, n.º 6 (1995): 616. http://dx.doi.org/10.1094/pd-79-0616.
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Cohen, R., S. Pivonia, Y. Burger, M. Edelstein, A. Gamliel y J. Katan. "VARIOUS APPROACHES TOWARD CONTROLLING SUDDEN WILT OF MELONS IN ISRAEL". Acta Horticulturae, n.º 510 (marzo de 2000): 143–48. http://dx.doi.org/10.17660/actahortic.2000.510.24.
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Ploetz, R. C. "Sudden Wilt of Passionfruit in Southern Florida Caused byNectria haematococca". Plant Disease 75, n.º 10 (1991): 1071. http://dx.doi.org/10.1094/pd-75-1071.
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Cohen, Ron, Yonatan Elkind, Yosef Burger, Rivka Offenbach y Haim Nerson. "Variation in the response of melon genotypes to sudden wilt". Euphytica 87, n.º 2 (1996): 91–95. http://dx.doi.org/10.1007/bf00021880.
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Salaria, Pooja, Sandeep Jain, Ritu Rani y Salesh Kumar Jindal. "Evaluation of chilli germplasm for resistance against sudden wilt syndrome". Plant Disease Research 37, n.º 2 (2022): 169–72. http://dx.doi.org/10.5958/2249-8788.2022.00028.2.
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Pivonia, S., R. Cohen, U. Kafkafi, I. S. Ben Ze'ev y J. Katan. "Sudden Wilt of Melons in Southern Israel: Fungal Agents and Relationship with Plant Development". Plant Disease 81, n.º 11 (noviembre de 1997): 1264–68. http://dx.doi.org/10.1094/pdis.1997.81.11.1264.
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Fungi belonging to five genera, Monosporascus sp., Pythium aphanidermatum, Rhizoctonia solani, Olpidium sp., Fusarium solani, and F. proliferatum, were the species most frequently isolated from the root systems of wilted melon. Diseased plants were collected from 24 fields in the northern and central Arava region of southern Israel during the fall seasons of 1994 and 1995. In pathogenicity tests conducted under field conditions, in artificially inoculated microplots, the first wilt symptoms were observed at various stages of fruit maturation. High mortality levels (73 to 97%) were recorded for inoculation combinations in which Monosporascus sp. was involved. Inoculations with the other fungi listed resulted in lower incidences of wilt. The combination of F. solani and P. aphanidermatum resulted in higher mortality than that caused by each pathogen alone. Monosporascus sp. seems to be the primary pathogen, although other fungi could also induce wilt. The dry weight of plants grown in naturally infested soil ceased to accumulate 33 days after transplanting, in contrast to plants grown in methyl bromide-treated soil. At this stage, the first wilt symptoms were observed. Fruit load affected wilt incidence. At the end of the growing season, 98% mortality was recorded for plants having the normal fruit load (2.5 fruits per plant) compared with 75 and 12% for plants that had their fruits thinned to one or zero per plant, respectively.
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Cohen, R., S. Pivonia, D. Shtienberg, M. Edelstein, D. Raz, Z. Gerstl y J. Katan. "Efficacy of Fluazinam in Suppression of Monosporascus cannonballus, the Causal Agent of Sudden Wilt of Melons". Plant Disease 83, n.º 12 (diciembre de 1999): 1137–41. http://dx.doi.org/10.1094/pdis.1999.83.12.1137.
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Sudden wilt (vine decline) of melon, caused by Monosporascus cannonballus, is a worldwide problem in arid and semi-arid regions. Soil disinfestation by fumigation with methyl bromide before planting is a common treatment for disease management but, because methyl bromide is expected to be banned from use within the next 10 years, alternative measures for disease suppression are needed. The efficacy of 29 fungicides against M. cannonballus was evaluated in vitro. Among the fungicides tested, fluazinam and kresoxim methyl were the most effective and both totally inhibited the growth of M. cannonballus in culture at concentrations of 10 μg a.i /ml. Because fluazinam also was effective in inhibition of Pythium aphnidermatum, which also may be involved in sudden wilt syndrome, and kresoxim methyl was not, fluazinam was chosen for further tests. The effective dose of fluazinam for M. cannonballus that reduced mycelial growth by 50% was 0.09 μg a.i./ml. Fluazinam efficacy was evaluated in three field experiments conducted in the spring and in the late summer cropping seasons. In two of the experiments, applications of fluazinam resulted in approximately 87% wilt reduction, whereas in the third experiment it was only 32%. The mobility of fluazinam in soil was determined in samples taken from the field. Fungicide mobility in soil was relatively limited; most of the compound was adsorbed to soil particles, resulting in a zone of high concentration that decreased with depth and distance from the application site. Nevertheless, rates measured even at a depth of 25 cm were sufficient to control M. cannonballus. This study shows that fluazinam may be used as one component in an integrated approach for suppression of sudden wilt of melons.
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JAYASINGHE, C. K. y W. P. K. SILVA. "Foot canker and sudden wilt of Hevea brasiliensis associated with Nattrassia mangiferae". Plant Pathology 43, n.º 5 (octubre de 1994): 938–40. http://dx.doi.org/10.1111/j.1365-3059.1994.tb01639.x.
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Pivonia, S., Z. Gerstl, A. Maduel, R. Levita y R. Cohen. "Management of Monosporascus sudden wilt of melon by soil application of fungicides". European Journal of Plant Pathology 128, n.º 2 (16 de junio de 2010): 201–9. http://dx.doi.org/10.1007/s10658-010-9644-7.
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Sako, Isamu, Hiroshi Nagae, Mikio Sekiguchi y Tsutomu Yonekawa. "Control of Sudden Wilt of Watermelon by Chloropicrin Soil Fumigation using Irrigation System". Annual Report of The Kansai Plant Protection Society 47 (2005): 79–81. http://dx.doi.org/10.4165/kapps.47.79.
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Edelstein, M., R. Cohen, Y. Burger, S. Shriber, S. Pivonia y D. Shtienberg. "Integrated Management of Sudden Wilt in Melons, Caused by Monosporascus cannonballus, Using Grafting and Reduced Rates of Methyl Bromide". Plant Disease 83, n.º 12 (diciembre de 1999): 1142–45. http://dx.doi.org/10.1094/pdis.1999.83.12.1142.
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Sudden wilt of melons induced by Monosporascus cannonballus is a worldwide problem, mainly in arid and semi-arid regions. Soil disinfestation by fumigation with methyl bromide is a common and very effective treatment for disease control. However, methyl bromide is expected to be banned from use within the next 5 to 10 years; therefore, alternative measures for disease management are urgently needed. In this study, the efficacy of methyl bromide at a reduced rate (15 g/m2 instead of 50 g/m2) and grafted plants, alone or in combination, was examined. Experiments were conducted in the 'Arava region in southern Israel in naturally infested fields. First, various rootstock accessions were tested in three experiments. Of the eight rootstocks evaluated, cv. Brava (Cucurbita maxima) was selected to serve as a rootstock in the subsequent experiments due to its effects on wilt reduction (63 to 100% reduction in two experiments and 35% reduction in one experiment) and its horticultural performance. Next, integration of grafting and a reduced rate of methyl bromide was tested in two experiments. The reduced methyl bromide rate suppressed disease, but results were variable (32 and 91% reduction in the two experiments). Grafting, when used alone, significantly reduced wilt incidence by 84 to 87% compared to untreated plots. Integration of the two control measures provided adequate and reliable results and wilt incidence was always significantly lower (75 to 100% reduction) than incidence in untreated plots. Because control by each measure alone varies, integrated application is preferable.
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Hassan, Zohaib Ul y Nadeem Nazami. "POTENTIAL RISK TO MANGO ORCHARDS: MANGO SUDDEN DECLINE CAUSED BY CERATOCYSTIS FIMBRIATA". Pakistan Journal of Phytopathology 29, n.º 1 (12 de julio de 2017): 181. http://dx.doi.org/10.33866/phytopathol.029.01.0330.
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This review addresses one of the most emerging threats to Mango (Mangifera indica L.) production known as the Mango Sudden Decline (MSD), also referred as Mango Quick Wilt. Manifestation records of MSD/ Mango Quick Wilt have been reported from major Mango growing countries like Brazil, Oman and Pakistan where the disease is presently known to occur in mango. Fungus Ceratocystis fimbriata from family filamentous Ascomycetes vectored by Hypocryphalus mangiferae (Stebbing) bark beetle is the main cause of the disease (MSD) in Pakistan and other Mango growing regions as well. Different type of symptoms for MSD have been reported like gummosis, canker formation, bark splitting, drying of twigs, branches and curling of leaves. Hemicriconemoides mangiferae nematode has also been reported as a vector of this MSD causing fungus. This species of Ceratocystis that roots the disease on mango was first reported in Brazil after that in Oman and Pakistan. Currently, different mating types of the causative agent have also been reported making this problem a significant one. Applications of different doses of nutrients have been reported in reduction of MSD. But there is need to apply knowledge and management strategies with particular emphasis to overcome MSD causes and vectors.
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Gado, Emad y Karima Helmy. "Using Protein(s) Marker to Differentiate Between Resistant and Susceptible Cantaloupe Plants to Sudden Wilt Disease". Egyptian Journal of Phytopathology 39, n.º 2 (30 de diciembre de 2011): 123–32. http://dx.doi.org/10.21608/ejp.2011.229826.
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Santhanam, Rakesh, Van Thi Luu, Arne Weinhold, Jay Goldberg, Youngjoo Oh y Ian T. Baldwin. "Native root-associated bacteria rescue a plant from a sudden-wilt disease that emerged during continuous cropping". Proceedings of the National Academy of Sciences 112, n.º 36 (25 de agosto de 2015): E5013—E5020. http://dx.doi.org/10.1073/pnas.1505765112.
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Plants maintain microbial associations whose functions remain largely unknown. For the past 15 y, we have planted the annual postfire tobaccoNicotiana attenuatainto an experimental field plot in the plant’s native habitat, and for the last 8 y the number of plants dying from a sudden wilt disease has increased, leading to crop failure. Inadvertently we had recapitulated the common agricultural dilemma of pathogen buildup associated with continuous cropping for this native plant. Plants suffered sudden tissue collapse and black roots, symptoms similar to aFusarium–Alternariadisease complex, recently characterized in a nearby native population and developed into an in vitro pathosystem forN.attenuata. With this in vitro disease system, different protection strategies (fungicide and inoculations with native root-associated bacterial and fungal isolates), together with a biochar soil amendment, were tested further in the field. A field trial with more than 900 plants in two field plots revealed that inoculation with a mixture of native bacterial isolates significantly reduced disease incidence and mortality in the infected field plot without influencing growth, herbivore resistance, or 32 defense and signaling metabolites known to mediate resistance against native herbivores. Tests in a subsequent year revealed that a core consortium of five bacteria was essential for disease reduction. This consortium, but not individual members of the root-associated bacteria community which this plant normally recruits during germination from native seed banks, provides enduring resistance against fungal diseases, demonstrating that native plants develop opportunistic mutualisms with prokaryotes that solve context-dependent ecological problems.
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Awad, Hosam M. "Evaluation of Plant Extracts and Essential Oils for the Control of Sudden Wilt Disease of Watermelon Plants". International Journal of Current Microbiology and Applied Sciences 5, n.º 5 (10 de mayo de 2016): 949–62. http://dx.doi.org/10.20546/ijcmas.2016.505.100.
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Utsuzawa, Shin, Kenji Fukuda y Daisuke Sakaue. "Use of Magnetic Resonance Microscopy for the Nondestructive Observation of Xylem Cavitation Caused by Pine Wilt Disease". Phytopathology® 95, n.º 7 (julio de 2005): 737–43. http://dx.doi.org/10.1094/phyto-95-0737.
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The development of xylem cavitation caused by pine wilt disease was visualized nondestructively with a compact magnetic resonance (MR) microscope system. A T1-weighted spin-echo sequence clearly visualized the water-filled xylem of Japanese black pine (Pinus thunbergii) as white zones, whereas cavitated xylem was represented as dark areas. Cavitated areas in the xylem were first observed 6 to 9 days after inoculation with the pinewood nematode (Bursaphelenchus xylophilus), and enlarged gradually over several days. After 11 to 18 days, cavitated areas rapidly increased in size, fused, and reached the cambium. This drastic expansion in cavitation coincided with and appeared to explain the sudden wilting of the seedlings. The development of cavitation observed through MR microscopy corresponded well with previous descriptions of disease progression.
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Khaytbayeva, N., M. Sattorova, U. Rakhimov y N. Tillyakhodjaeva. "Principles of the distribution of wheat with fusariois disease, its effect on yield, harm and disease measures in the case of Uzbekistan". E3S Web of Conferences 258 (2021): 04043. http://dx.doi.org/10.1051/e3sconf/202125804043.
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This paper shows the role of Fusarium fungi in the farms of Kibray district of Tashkent province, which cause sudden yellowing of wheat fields before ripening, reducing the symptoms of the disease and the yield. The amount of grain in a diseased plant is reduced by 42% compared to the grain in a healthy plant, and the weight is reduced by 57.1%. Pure cultures of microorganisms were isolated from samples taken from diseased fields. The article is based on the results of scientific experiments and contains 2 tables and figures. The information presented in the article will serve as a scientific basis for further study of the prevalence and harm of wheat fusarium wilt.
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Al-Sa'di, A. M., M. L. Deadman, F. A. Al-Said, I. Khan, M. Al-Azri, A. Drenth y E. A. B. Aitken. "First Report of Pythium splendens Associated with Severe Wilt of Muskmelon (Cucumis melo) in Oman". Plant Disease 92, n.º 2 (febrero de 2008): 313. http://dx.doi.org/10.1094/pdis-92-2-0313c.
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Muskmelon (Cucumis melo L.) is one of the most important vegetable crops in Oman. In the fall of 2004, sudden wilt was observed in muskmelon grown in a field at Sultan Qaboos University, Muscat. The disease was characterized by rapid collapse of vines and muskmelon plants at the fruit production to maturation stage, associated with brown-to-dark brown rotted primary and secondary roots. The disease resulted in death of more than 85% of muskmelon plants in that field. On potato dextrose agar (PDA), with published methods (1), Pythium spp. were consistently isolated from crowns and roots of plants showing wilt symptoms. Further identification of five isolates of Pythium with sequences of the internal transcribed spacer (ITS) of the ribosomal DNA (1) using ITS1 and ITS4 primers produced a nucleotide sequence 806 bp long, which was identical among all isolates. Comparison with sequences deposited at the National Center for Biotechnology Information revealed 100% nucleotide similarity to a previously published sequence (Accession No. DQ381808) of isolate P091 of P. splendens from cucumber from Oman, for which identification has also been confirmed by morphological characteristics. The sequence of one isolate of P. splendens (P222) was assigned GenBank Accession No. EF546436 and deposited at CBS under Accession No. CBS121855. In pathogenicity tests conducted in a greenhouse, P. splendens induced damping-off symptoms on 7-day-old muskmelon seedlings and also reproduced the same wilt symptoms observed in the field when 2-month-old muskmelon plants were inoculated with 3-day-old P. splendens grown in PDA. To our knowledge, this is the first report of association of P. splendens with wilt of muskmelon in Oman. Reference: (1) A. M. Al-Sa'di et al. Plant Pathol. 56:140, 2007.
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Babbitt, S., M. Gally, B. A. Pérez y D. Barreto. "First Report of Nectria haematococca Causing Wilt of Olive Plants in Argentina". Plant Disease 86, n.º 3 (marzo de 2002): 326. http://dx.doi.org/10.1094/pdis.2002.86.3.326a.
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Death of 8- to 12-month-old olive plants (Olea europaea L. ‘Arbequina’, ‘Arauco’, and ‘Picual’) has been observed since 1998 in northwestern Argentina. No mycelium or perithecium was observed when examining rotting roots of greenhouse-collected plants. Root segments of diseased plants were plated on potato dextrose agar. Cultures developed a white mycelium after 2 to 3 days, producing microconidia, macroconidia, and chlamydospores identified as Fusarium solani (1). After 15 days of incubation at 23 ± 2°C, reddish perithecia developed infrequently on root segments and adjacent substratum. Single-septate ascospores were hyaline and turned light brown with longitudinal striations at maturity. Microscopic measurements agreed with Nectria haematococca (1). To conduct Koch's postulates (two experiments, two treatments including inoculated and controls, 10 replicates per treatment), young rooted cuttings (6- to 12-month-old) were transferred to pots with a soilless mix and F. solani-colonized oat grains (10:1 vol/vol) and placed in growth chamber (25 to 28°C). First symptoms of the disease were leaf drooping and apex bending after 5 days. At approximately 9 days, leaves turned brownish, developed wilting from the tip downward, and plant death. Controls remained healthy. The fungus was reisolated, and perithecia of N. haematococca developed. F. solani has been reported causing wilt and sudden death in olive previously (2,3). To our knowledge, this is the first report of perithecial development associated with F. solani on olive. References: (1) C. Booth. The Genus Fusarium. CAB International, Wallingford, UK, 1971. (2) R. L. Munjal et al. Studies on diseases of olive in himachal pradesh. Pages 437–440 In: Improvement of Forest Biomass. Symposium Proceedings. Indian Society of Tree Scientists. P. K. Kosla, ed. Sdan, India, 1982. (3) B. A. Pérez et al. (Abstr.) Phytopathology 91 (suppl):S71, 2001.
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P. H. Ghante, S. S. Gote, V. S. Mete U. A. Asalkar y A. A. Kamble. "In-vitro Efficacy of Plant-Extract against Sudden Death Syndrome (wilt) of Soybean caused by Fusarium oxysporum f. sp. virguliforme". International Journal of Current Microbiology and Applied Sciences 10, n.º 2 (10 de febrero de 2021): 2802–7. http://dx.doi.org/10.20546/ijcmas.2021.1002.310.
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Gote, SS, PH Ghante, VS Mete, AA Kamble y SK Deshmukh. "In-vitro efficacy of fungicide against sudden death syndrome (wilt) disease of soybean caused by Fusarium oxysporum f. sp. virguliforme". International Journal of Chemical Studies 9, n.º 2 (1 de marzo de 2021): 133–39. http://dx.doi.org/10.22271/chemi.2021.v9.i2b.11741.
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Babli, Abhishek Rathod, Shivangi Tiwari Dharmendra Mishra, Ravi Patel Kamlesh Choubey y Jyoti Kurmi Dwarka. "Isolation of Causal Organism of Wilt and Collar Rot of Lentil and its Pathogenicity Tests". International Journal of Current Microbiology and Applied Sciences 10, n.º 12 (10 de diciembre de 2021): 276–82. http://dx.doi.org/10.20546/ijcmas.2021.1012.032.
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The disease appears in the field in patches at both seedling and adult stages. Seedling wilt is characterized by sudden drooping, followed by drying of leaves and seedling death. The roots appear healthy, with reduced proliferation and nodulation and usually no internal discoloration of the vascular system. The fungus Fusarium oxysporum f. sp. lentis is septate, profusely branched growth on potato sucrose / dextrose agar at 25ºC, initially white turning light buff or deep brown later and fluffy or submerged. The growth becomes felted or wrinkled in old cultures. Various types of pigmentation (yellow, brown, whitish /cream, crimson dark purple, light orange) may be observed in culture on solid medium. Microconidia were usually borne on simple and short conidiophores, which arise laterally on the hyphae. They are oval to cylindrical, straight or curved and measure 2.5 - 3.5 x 5 - 11µm. Macroconidia are borne on branched conidiophore, thin walled, 1 to 6 septate, fusoid, pointed at both ends and measures 3.5 -4.5 x 25 - 65µm. Chlamydospores are formed in old cultures, which are smooth or rough walled, terminal intercalary and may be formed singly or in pairs or in chains. The pathogen causes a lesion localized at or about the collar between the stem and the root. The lesions develop around the stem eventually forming a "collar" region.
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P. H. Ghante, S. S. Gote, U. A. Asalkar V. S. Mete y S. K. Deshmukh. "In-vitro Efficacy of Bio-agents against Sudden Death Syndrome (wilt) Disease of Soybean Caused by Fusarium oxysporum f. sp. virguliforme". International Journal of Current Microbiology and Applied Sciences 10, n.º 2 (10 de febrero de 2021): 2808–12. http://dx.doi.org/10.20546/ijcmas.2021.1002.311.
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Stirling, G. R., L. M. Eden y M. G. Ashley. "Sudden wilt of capsicum in tropical and subtropical Australia: a severe form of Pythium root rot exacerbated by high soil temperatures". Australasian Plant Pathology 33, n.º 3 (2004): 357. http://dx.doi.org/10.1071/ap04030.
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Triky-Dotan, Shachaf, Miriam Austerweil, Bracha Steiner, Yitzhak Peretz-Alon, Jaacov Katan y Abraham Gamliel. "Accelerated Degradation of Metam-Sodium in Soil and Consequences for Root-Disease Management". Phytopathology® 99, n.º 4 (abril de 2009): 362–68. http://dx.doi.org/10.1094/phyto-99-4-0362.
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We studied the development of accelerated degradation (AD) of methyl isothiocyanate (MITC) following repeated applications of its parent compound, metam-sodium (MS). Laboratory studies and four sets of field experiments were conducted during 2002–04 in three commercial fields in Israel. Repeated applications of MS to the three soils in the laboratory under controlled conditions demonstrated AD of MITC in some soils. In a peanut field, MS significantly reduced the incidence of Pythium pod rot and improved pod quality after a single application but its effectiveness was greatly reduced after two applications. In a second experiment, MS was significantly effective after a single application in controlling Verticillium wilt in potato but its efficacy diminished after three consecutive applications. In an additional experiment, fumigation with MS following single or double applications was more effective in reducing Verticillium wilt severity of potato compared with triple applications. Soils which did not develop AD of MITC were also recorded. Preplant MS fumigation of melon fields was effective at reducing sudden wilt following a single and two consecutive applications. Our study shows that development of AD of MITC might occur following repeated applications of MS in commercial fields. The data on MITC dissipation in soil following repeated MS applications under controlled conditions indicate the chemical's potential loss of activity under regular agricultural practices and the need for a management strategy to prevent such a development.
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Adebayo, O. S. y E. J. A. Ekpo. "Biovar of Ralstonia solanacearum Causing Bacterial Wilt of Tomato in Nigeria". Plant Disease 89, n.º 10 (octubre de 2005): 1129. http://dx.doi.org/10.1094/pd-89-1129c.
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A survey of southwestern Nigeria showed an outbreak of wilt disease caused by Ralstonia solanacearum in 80% of tomato (Lycopersicon lycopersicum) fields in the production area of Ogun State (7°15′N, 3°25′E) in June 1996. Subsequent surveys conducted in Edo (6°45′N, 5°30′E), Delta (5°15′N, 5°45′E), Lagos (6°30′N, 3°40′E), Oyo (8°40′N, 3°30′E), and Osun (7°50′N, 4°E) states between May and November 1998 identified 60 to 80% infected fields per state. Observations made at the experimental plots of the National Horticultural Research Institute (NIHORT) at Ibadan (7°23′N, 2°50′E) also showed similar infections. Affected plants exhibited initial wilting of terminal leaves followed (within 2 days) by sudden and permanent wilt. For further identification of the causal organism, 10 tomato plants showing wilt symptoms were collected from each of five fields in the vegetable blocks of the NIHORT at Ibadan and 20 farmers' fields in Ogun State. The 10 plants per field were thereafter bulked as one composite sample. Creamy bacterial sap from these samples was plated on tetrazolium chloride media, and plates were incubated at 30°C for 48 h (2). Colonies that were fluidal and white with pink centers were used for biovar determination. Basal media was prepared to include one of three disaccharides (cellobiose, lactose, or maltose) or three hexose alcohols (dulcitol, mannitol, or sorbitol). A loopful of bacterial cells of all 25 isolates was inoculated individually to each of the six media. Cultures were incubated at 30°C for 28 days and monitored daily for color changes. The pathogenicity of the 25 isolates was tested using 10 4-week-old seedlings each of eggplant cv. black beauty, tomato cv. Ibadan local, sweet pepper cv. California wonder, and potato cv. Kufri. Each inoculum was prepared by adjusting the concentration to 107 CFU/ml with a colorimeter at a wavelength of 600 nm (optical density of approximately 0.3). Plants were inoculated by pouring 10 ml of inoculum around the base of each plant. Ten uninoculated seedlings of each cultivar served as the control. Plants were assessed for wilt severity 30 days after inoculation. All isolates utilized the three disaccharides and three hexose alcohols, and according to Hayward's classification, all isolates were biovar 3 (1). Furthermore, the isolates caused rapid wilting of all four test plants. R. solanacearum was easily reisolated from the vascular bundles of the test plants. To our knowledge, this is the first report of this biovar of R. solanacearum affecting tomato crops in Nigeria. References: (1) A. C. Hayward. J. Appl. Bacteriol, 27:265, 1964 (2) A. Kelman. Phytopathology 44:693, 1954.
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Molinero-Ruiz, M. L. y J. M. Melero-Vara. "First Report of Stem Rot and Wilt of Sunflower Caused by Sclerotinia minor in Spain". Plant Disease 86, n.º 6 (junio de 2002): 697. http://dx.doi.org/10.1094/pdis.2002.86.6.697d.
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In 2001, sunflower (Helianthus annuus L.) plants with symptoms of stem and root rot and wilt were observed in Soria, Spain. Light brown, water-soaked lesions developed on the collar of infected plants and extended along the stem, affecting the pith and causing early and sudden wilt. White mycelium and sclerotia (0.5 to 2 mm long) formed in the pith of stems. The sclerotia were disinfested in NaClO (10% vol/vol) for 1 min, transferred to potato dextrose agar (PDA), and incubated at 20°C. The fungus consistently obtained was identified as Sclerotinia minor Jagger (1). Pathogenicity was confirmed in a greenhouse experiment (15 to 25°C, 13 h light). Seven-week-old plants of six genotypes of sunflower (‘Peredovik’, HA89, HA821, HA61, RHA274, and HA337) were inoculated by placing one PDA disk with active mycelial growth adjacent to each basal stem just below the soil line and covering it with peat/sand/silt (2:2:1, vol/vol). Six plants of each genotype were inoculated without wounding, and another six were inoculated immediately after stem base wounding with a scalpel; six wounded and uninoculated plants were used as controls. First symptoms (wilting) appeared 4 days after inoculation in all genotypes. Two weeks after inoculation, the percentage of dead plants ranged from 33 to 92% (depending on cultivar), white mycelium was observed at the base of affected plants, and sclerotia were present in the pith of diseased plants. There was no effect of plant wounding on disease incidence or severity, and the fungus was reisolated from inoculated plants. To our knowledge, this is the first report of S. minor in Spain. Reference: (1) L. M. Kohn. Mycotaxon IX 2:365, 1979.
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Garibaldi, A., A. Minuto, G. Gilardi y M. L. Gullino. "First Report of Sclerotinia sclerotiorum on Gazania sp. Hybrid in Italy". Plant Disease 85, n.º 11 (noviembre de 2001): 1207. http://dx.doi.org/10.1094/pdis.2001.85.11.1207d.
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Gazania sp. hybrid is produced in pots in the Albenga Region of northern Italy for export to central and northern Europe. During fall 2000 to spring 2001, sudden wilt was observed in commercial plantings of this ornamental. Initial symptoms included stem necrosis at the soil level and yellowing and tan discoloration of leaves. As stem necrosis progressed, infected plants wilted and died. Wilt followed by soft rot occurred within a few days on young plants after the first leaf symptoms. Necrotic tissues became covered with white mycelia that produced dark, spherical (2 to 6 mm diameter) sclerotia. Sclerotinia sclerotiorum was consistently recovered from infected stem pieces of Gazania disinfested for 1 min in 1% NaOCl, plated on potato dextrose agar amended with streptomycin sulfate at 100 mg/liter. Pathogenicity of three fungal isolates was confirmed by inoculating 45- to 60-day-old plants grown in containers (14 cm diameter). Inoculum that consisted of wheat kernels infested with mycelium and sclerotia of each isolate was placed on the soil surface around the base of each plant. Noninoculated plants served as controls. All plants were maintained outdoors where temperatures ranged between 8 and 15°C. Inoculated plants developed symptoms of leaf yellowing, followed by wilt, within 7 to 10 days, while control plants remained symptomless. White mycelia and sclerotia developed on infected tissues, and S. sclerotiorum was reisolated from inoculated plants. To our knowledge, this is the first report of wilt of Gazania sp. hybrid caused by S. sclerotiorum in Italy. A crown rot of Gazania caused by S. sclerotiorum has been reported from California in the United States(1). Reference: (1) V. M. Muir and A. H. McCain. Calif. Plant Pathol. 16:1, 1973.
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Huang, Q., Y. Y. Zhu, H. R. Chen, Y. Y. Wang, Y. L. Liu, W. J. Lu y X. Y. Ruan. "First Report of Pomegranate Wilt Caused by Ceratocystis fimbriata in Yunnan, China". Plant Disease 87, n.º 9 (septiembre de 2003): 1150. http://dx.doi.org/10.1094/pdis.2003.87.9.1150b.
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Pomegranate (Punica granatum Linn.) is an important fruit crop in Yunnan Province, China. Recently, older pomegranate bushes in Mengzi County, Yunnan began dying. Initial symptoms were yellowing and wilting of leaves on one to several branches, followed by sudden death of the bush within 3 to 4 weeks. Roots of diseased bushes appeared brown to black, and irregularly shaped lesions were observed when the bark was removed. A species of Ceratocystis was consistently isolated from discolored roots, stem, and branch tissues from wilted bushes on potato dextrose agar (PDA) and was identified as Ceratocystis fimbriata Ellis & Halst, based on the morphology of perithecia, ascospores, conidia, and conidiophores. Perithecia were black with a globose base (130 to 300 μm) and a long neck (450 to 800 μm). Ascospores exuded from the apex of the perithecium neck in a long coil and were small, hyaline, and hat-shaped (3.8 to 5.0 μm long × 2.3 to 4.0 μm wide). Conidiophores were septate and hyaline to dark greenish brown. Hyaline conidia, 8 to 17 μm long × 6 to 15 μm wide, were usually produced in chains of 10 or more. Thick-walled endoconidia were globose to oval, olive brown, and 8 to 20 μm in diameter. Because of the increasing occurrence of the disease, surveys of the main pomegranate production areas in Mengzi County, including Xinan, Duofale, Caoba, Hongzhai, and Shilipu townships, were conducted from 10 to 20 August 2002. The disease was detected in 17 of 50 plantings surveyed. Disease was more severe in older plantings than in younger plantings. Disease incidence was 1% in 1- to 5-year-old bushes, 3.6% in 6- to 10-year-old bushes, and 6% in bushes more than 10 years old. Scolytid beetles were occasionally found on bushes, but we were unable to isolate the fungus from them as has been reported (1). Inoculations with an isolate of C. fimbrata were made by inserting mycelium with perithecia from 12-day-old cultures growing on PDA into root wounds made with a sterile scalpel on five pomegranate plants and then covering the wounds with Parafilm. Sterile medium was placed in an equal number of wounded bushes to serve as controls. Fourteen days later, symptoms began to appear in two bushes, and 5 days later, all bushes exhibited symptoms. No symptoms were observed on control bushes. The first visible symptom was a small area of blackened tissue near the point of inoculation. Lesions expanded slowly, but they expanded more rapidly upward than downward. The fungus was reisolated on PDA from roots of all artificially inoculated bushes. C. fimbriata has been previously reported as the cause of pomegranate wilt in India (2); however, to our knowledge, this is the first report of C. fimbriata on pomegranate in China. Because environmental conditions which favor the pathogen (temperatures ranging from 18 to 30°C and frequent rains) typically occur in many areas during late spring and summer, the disease has the potential to seriously impact pomegranate production in China. References: (1) Y. M. Somasekhara. Plant Dis. 83:400, 1999. (2) Y. M. Somasekhara, et al. Res. Crops 1(1):63, 2000.
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Rabaaoui, Amal, Chiara Dall’Asta, Laura Righetti, Antonia Susca, Antonio Francesco Logrieco, Ahmed Namsi, Radhouane Gdoura, Stefaan P. O. Werbrouck, Antonio Moretti y Mario Masiello. "Phylogeny and Mycotoxin Profile of Pathogenic Fusarium Species Isolated from Sudden Decline Syndrome and Leaf Wilt Symptoms on Date Palms (Phoenix dactylifera) in Tunisia". Toxins 13, n.º 7 (30 de junio de 2021): 463. http://dx.doi.org/10.3390/toxins13070463.
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In 2017–2018, extensive symptoms of sudden decline and fruit rot were observed on date palms in southern Tunisia. Samples of diseased plants were randomly collected in six localities. Based on morphological identification, Fusarium was the most frequent fungal genus detected. A sequencing of translation elongation factor, calmodulin, and second largest subunit of RNA polymerase II genes was used to identify 63 representative Fusarium strains at species level and investigate their phylogenetic relationships. The main species detected was Fusarium proliferatum, and at a much lesser extent, Fusarium brachygibbosum, Fusarium caatingaense, Fusarium clavum, Fusarium incarnatum, and Fusarium solani. Pathogenicity on the Deglet Nour variety plantlets and the capability to produce mycotoxins were also assessed. All Fusarium species were pathogenic complying Koch’s postulates. Fusarium proliferatum strains produced mainly fumonisins (FBs), beauvericin (BEA), and, to a lesser extent, enniatins (ENNs) and moniliformin (MON). All F. brachygibbosum strains produced low levels of BEA, diacetoxyscirpenol, and neosolaniol; two strains produced also T-2 toxin, and a single strain produced HT-2 toxin. Fusarium caatingaense, F. clavum, F. incarnatum produced only BEA. Fusarium solani strains produced MON, BEA, and ENNs. This work reports for the first time a comprehensive multidisciplinary study of Fusarium species on date palms, concerning both phytopathological and food safety issues.
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Garibaldi, A., A. Minuto y M. L. Gullino. "First Report of White Mold Caused by Sclerotinia sclerotiorum on Persian Buttercup (Ranunculus asiaticus) in Italy". Plant Disease 87, n.º 9 (septiembre de 2003): 1151. http://dx.doi.org/10.1094/pdis.2003.87.9.1151a.
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Persian buttercup (Ranunculus asiaticus L.) is grown in the Albenga Region of northern Italy for cut flower production and exportation to central and northern Europe. During the winter of 2003, sudden wilt was observed in commercial plantings of R. asiaticus. Initial symptoms included stem necrosis at the soil level and yellowing and tan discoloration of leaves. As stem necrosis progressed, infected plants wilted and died. Wilt occurred within a few days on young plants and was characterized by the presence of soft and watery tissues. Necrotic tissues became covered with whitish mycelium that produced dark, spherical sclerotia (1 to 4 mm in diameter). Sclerotinia sclerotiorum (Lib.) de Bary (1) was consistently recovered from infected stem pieces of R. asiaticus that were disinfested for 1 min in 1% NaOCl and plated on potato dextrose agar (PDA) amended with 100 ppm of streptomycin sulfate. Pathogenicity of three isolates obtained from infected plants of persian buttercup was confirmed by inoculating 30-day-old plants grown in containers. Inoculum that consisted of wheat kernels infested with mycelium and sclerotia of each isolate was placed on the soil surface around the base of each of five plants. Noninoculated plants served as controls. The inoculation trial was repeated once. All plants were kept at temperatures ranging between 8 and 22°C and watered as needed. Inoculated plants developed symptoms of leaf yellowing followed by wilt within 15 days, while control plants remained symptomless. White mycelium and sclerotia developed on infected tissues, and S. sclerotiorum was reisolated from inoculated plants. S. sclerotiorum has been previously reported on R. asiaticus in the United States (2) and Japan (3). To our knowledge, this is the first report of wilt of R. asiaticus caused by S. sclerotiorum in Italy and Europe. References: (1) N. F. Buchwald. Den. Kgl. Veterin.er-og Landbohojskoles Aarsskrift, 1949. (2) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St. Paul, MN, 1989. (3) T. Urushibara et al. Annu. Rep. Kanto-Tosan Plant Prot. Serv. 46:61, 1999.
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Santhanam, Rakesh, Riya C. Menezes, Veit Grabe, Dapeng Li, Ian T. Baldwin y Karin Groten. "A suite of complementary biocontrol traits allows a native consortium of root‐associated bacteria to protect their host plant from a fungal sudden‐wilt disease". Molecular Ecology 28, n.º 5 (marzo de 2019): 1154–69. http://dx.doi.org/10.1111/mec.15012.
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Cohen*, Roni, Yosef Burger y Menahem Edelstein. "Grafted Melons: The Phytopathological Aspect". HortScience 39, n.º 4 (julio de 2004): 873D—873. http://dx.doi.org/10.21273/hortsci.39.4.873d.
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The use of grafted vegetables as one of the alternatives to soil disinfestation with methyl bromide is increasing in Israel. Watermelon (Citrullus lanatus) and melon (Cucumis melo) plants are grafted mainly onto Cucurbita rootstocks for lessening losses due to soil-borne pathogens. The contribution of the rootstock to the grafted plant's resistance depends on the nature of the disease. In general, damage caused by non-specific root-rot pathogens such as Rhizoctonia solani, Macrophomina phaseolina, Monosporascus cannonballus, and Pythium spp. are effectively reduced by using Cucurbita rootstocks. However, these rootstocks provide only partial protection from vascular diseases such as fusarium wilt, in which case better protection can be achieved by grafting susceptible melons onto monogenic fusarium-resistant melon rootstocks. The performance of the grafted plants depends not only on the rootstock but also on the scion response to pathogens and on the effect of the environment on disease development. The response of grafted and non-grafted melons of different cultivars to sudden wilt disease caused by the fungus Monosporascus cannonballus was evaluated in field trials conducted in the fall and spring growing seasons. Significant differences in disease incidence were found among cultivars, between grafted and non-grafted plants, and between seasons. Grafting reduced plant mortality in the spring and fall experiments but prevention of yield losses was more effective in the spring. More emphasis should be given to finding suitable rootstocks and adjusting agrotechniques for successful commercial cultivation of grafted melons in the fall.
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Sieber, Thomas N. "Neomyzeten – eine anhaltende Bedrohung für den Schweizer Wald". Schweizerische Zeitschrift fur Forstwesen 165, n.º 6 (1 de junio de 2014): 173–82. http://dx.doi.org/10.3188/szf.2014.0173.
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Neomycetes – persistent threats to Swiss forests More than 40 neomycetes pathogenic to woody plant species were introduced to Switzerland during the last 100 years, and the number is increasing exponentially. A few neomycetes are invasive and cause serious diseases on forest and ornamental trees: Cryphonectria parasitica, causal agent of chestnut blight, Hymenoscyphus pseudoalbidus causing ash dieback, Ophiostoma novo-ulmi causing Dutch elm disease and Ceratocystis platani causing canker stain of plane. The causal agents of sudden oak death (Phytophthora ramorum) and collar and root rot of alder (P. alni ssp. alni) have been detected in Switzerland but have not reached epidemic levels. Ceratocystis fagacearum, causal agent of oak wilt, or Leptographium wageneri causing black stain root disease of conifers are absent from Switzerland, but are threats to Swiss forests and measures have been implemented to prevent their introduction. Prevention of threats by fungi which are harmless symbionts in their native range, e.g. endophytic fungi, is more challenging. The only way to avoid the endophyte problem is to grow trees from aseptic seed, saplings or meristem cultures. Additionally, setup of sentinel plantings in as many regions as possible all over the world could serve as early warning systems. To prevent the introduction of wilt and root diseases, only treated wood and treated potting media should be allowed for import. Natural regeneration prevents contamination of forest soils by Phytophthora species originating from nursery plants.
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Gote, SS, PH Ghante, VS Mete, AA Kmable y Gayakwad CS. "To evaluate in-vivo efficacy of fungicides, bio-agents and phyto-extracts against sudden death syndrome (wilt) of soybean caused by Fusarium oxysporum f. sp. virguliforme". International Journal of Chemical Studies 9, n.º 1 (1 de enero de 2021): 3281–83. http://dx.doi.org/10.22271/chemi.2021.v9.i1at.11740.
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Degani, Ofir, Danielle Regev, Shlomit Dor y Onn Rabinovitz. "Soil Bioassay for Detecting Magnaporthiopsis maydis Infestation Using a Hyper Susceptible Maize Hybrid". Journal of Fungi 6, n.º 3 (13 de julio de 2020): 107. http://dx.doi.org/10.3390/jof6030107.
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Magnaporthiopsis maydis is the causal agent of severe maize late wilt disease. Disease outbreak occurs at the maize flowering and fruit development stage, leading to the plugging of the plant’s water vascular system, resulting in dehydration and collapse of the infected host plant. The pathogen is borne by alternative hosts, infected seeds, soil, and plant residues and gradually spreads to new areas and new countries. However, no soil assay is available today that can detect M. maydis infestation and study its prevalence. We recently developed a molecular quantitative Real-Time PCR (qPCR) method enabling the detection of the M. maydis DNA in plant tissues. Despite the technique’s high sensitivity, the direct examination of soil samples can be inconsistent. To face this challenge, the current work demonstrates the use of a soil bioassay involving the cultivation of a hyper-susceptible maize genotype (Megaton cultivar, Hazera Seeds Ltd., Berurim MP Shikmim, Israel) on inspected soils. The use of Megaton cv. may facilitate pathogen establishment and spread inside the plant’s tissues, and ease the isolation and enrichment of the pathogen from the soil. Indeed, this cultivar suffers from severe dehydration sudden death when grown in an infested field. The qPCR method was able to accurately and consistently identify and quantify the pathogen’s DNA in an in vitro seed assay after seven days, and in growth-chamber potted plants at as early as three weeks. These results now enable the use of this highly susceptible testing plant to validate the presence of the maize late wilt pathogen in infested soils and to evaluate the degree of its prevalence.
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Garibaldi, A., A. Minuto y M. L. Gullino. "First Report of Sclerotinia sclerotiorum on Calendula officinalis in Italy". Plant Disease 85, n.º 4 (abril de 2001): 446. http://dx.doi.org/10.1094/pdis.2001.85.4.446c.
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Pot marigold (Calendula officinalis) has recently become popular as a potted ornamental plant in Italy. During the spring 1999, a sudden wilt of 120 day-old plants was observed in the Albenga region of Northern Italy, an area of intensive floriculture production. Initial symptoms included stem necrosis at the soil line and yellowing and tan discoloration of leaves. As stem necrosis progressed, infected plants wilted and died. Necrotic tissues resulted, covered with whitish mycelium that produced dark, spherical (2- to 6-mm diameter) sclerotia. Sclerotinia sclerotiorum was consistently recovered from symptomatic stem sections surface disinfested 1 min in 1% NaOCl and plated on potato dextrose agar (PDA), amended with 100 ppm streptomycin sulfate. Pathogenicity of three isolates was confirmed by inoculating 90-day-old pot marigold plants grown in containers. Inoculum that consisted of wheat kernels infested with mycelium and sclerotia was placed on the soil surface around the base of previously wounded or non-wounded plants. Non-inoculated plants served as controls. All plants were kept outdoors where temperatures ranged between 8 and 16°C, under 50% shade and were maintained moist. Inoculated plants developed symptoms of leaf yellowing, followed by wilt within 7 days, while control plants remained symptomless. Sclerotia developed on infected tissues and S. sclerotiorum was reisolated from inoculated plants. This is the first report of stem blight of C. officinalis caused by S. sclerotiorum in Europe. The disease was previously observed in the United States (1). Reference: (1) D. F. Farr et al. 1989. Fungi on Plants and Plant Products in the United States. American Phytopathological Society, St. Paul, MN.
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Marbudi Pangaribuan, Freddy Iston Hasil. "PENGARUII CORPORATE GOWRNANCE TERIIADAP STRUKTUR MODAL DAN KINERJA PERUSAHAAI\: STUDI EMPIRIS PADA FAMILY BASINESS GROUP YANG TERDAFTAR DI BURSA EFEK JAKARTA". Jurnal Riset Manajemen dan Bisnis 2, n.º 1 (1 de junio de 2007): 23. http://dx.doi.org/10.21460/jrmb.2007.21.107.
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The aim of this research is to examine the effect of corporate governancet's internal mechanism that ls institutionii o*r"rriip, oi both firm performance and firm capital structure. To the extent, the moderating effect of managerial ownership on the relationship between institutional ownership,-fir* performance and capital structure wilt be examined as well.The sample of this research is drar,vn fro* companies within the big six family,owned business in Indonesia, which are listed at The Jakarta Stock Exchange fro* 1998 until 2005. Using the Moderated Regression Analysis (MRA),. the result shows that both institutional and managerial ownership fail to demonstrate the direct and moderated effect on both performance and capital structure. These findings suggest that the froil of economic, social and political circumstances create the "short term-focused" toward investment return. Moreover, the slow achiqement of collusion, corruption, and nepotism (KI< I) eradication has resulted in sudden-withdrawal of investor's investment. Hence, the internal control mechanism of corporate governance which is long-term focused and associated with KKI{ eradi cation cannot b e su cc es sfully impl em ent ed.Keywords: Institutional ownership, managerial ownership, performance,capital structure
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Auger, J., I. Pérez, R. A. Fullerton y M. Esterio. "First Report of Verticillium Wilt of Gold Kiwifruit, Actinidia chinensis Cv. Hort 16A, Caused by Verticillium albo-atrum in Chile". Plant Disease 93, n.º 5 (mayo de 2009): 553. http://dx.doi.org/10.1094/pdis-93-5-0553b.
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Gold kiwifruit, Actinidia chinensis Planch cv. Hort 16A, was first planted in Chile in 2003 and vines started dying within 2 years. By the end of the 2007–2008 growing season, as much as 80% of the plants in several orchards had died. The disease was characterized by a conspicuous reddish brown discoloration of the xylem and the sudden wilting and dieback of plants any time during the growing season. In the spring, entire plants or parts of plants failed to break buds. In others, the buds broke, but juvenile leaf clusters then wilted and died. On severely affected plants, scion watershoots wilted and died. The disease was often accompanied by shallow cracking of the bark and slight sponginess of the underlying cortex. The disease was apparently most severe in sites that had been planted to Gold kiwifruit immediately after removal of apple, pear, citrus, or grape. Orchards planted following long-term maize, wheat, or grass culture were almost disease free. A fungus was consistently isolated from symptomatic vascular tissue disinfected in 1% sodium hypochlorite and plated on potato dextrose agar. Conidiogenous cells were arranged in verticels; conidia were hyaline, elliptical, single celled, and measured 3.5 to 8.5 × 1.8 to 4.3 μm (average 5.5 × 2.5 μm). Dark, resting mycelium developed after 1 to 2 weeks of incubation. On the basis of these morphological characteristics, the fungus was identified as Verticillium albo-atrum Reinke & Berthier. Identification was confirmed by sequencing part of the internal transcribed spacer (ITS) region with primers ITS1 and ITS4. The sequence of a representative isolate showed high homology (98% identity over a length of 494 bp) with a DNA fragment (NCBI Accession No. 108476) of V. albo-atrum from alfalfa. To complete pathogenicity tests, 20 healthy, 1-year-old Hort 16A kiwi vines grafted on Hayward kiwifruit (A. deliciosa Chevalier) seedlings were inoculated by injection of 20 μl of 106 conidia/ml into stems of the scion. Twenty control plants were injected with an equal volume of sterile distilled water. Plants were held in a controlled environment facility at 24°C with 16 h of light per day. Eight weeks after inoculation, typical wilting and dieback symptoms developed on 90% of the plants. Control plants injected with water remained healthy. Verticillium wilt has never been reported on kiwifruit (A. deliciosa) in Chile. V. albo-atrum has a rather narrow host range and is mainly reported as a pathogen on alfalfa, hop, soybean, tomato, and potato (1). To our knowledge, this is the first report of V. albo-atrum causing wilt and dieback on Gold kiwifruit (A. chinensis) cv. Hort 16A. The fungal isolates have been deposited in the Plant Pathology Laboratory of the Sanidad Vegetal Department of Agricultural Sciences Faculty of University of Chile under the name Actinidia chinensis/V. albo-atrum No. 1 to 8. Reference: (1) E. K. Ligoxigakis et al. Phytoparasitica 30:511, 2002.
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Lops, F., F. Cibelli, M. L. Raimondo y A. Carlucci. "First Report of Stem Wilt and Root Rot of Schlumbergera truncata Caused by Fusarium oxysporum f. sp. Opuntiarum in Southern Italy". Plant Disease 97, n.º 6 (junio de 2013): 846. http://dx.doi.org/10.1094/pdis-11-12-1092-pdn.
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Schlumbergera truncata (Haw.) Moran, belonging to the Cactaceae, is a very common ornamental cactus in southern Italy. In November 2011, sudden stem wilt and root rot was observed in about 45% of vegetatively propagated plants cultivated as potted ornamental plants in a commercial greenhouse in Cerignola (Foggia Province, Apulia, Italy). The roots and collars of the plants showed brown rot. Yellow sunken lesions that were similar to cortical cankers were detected at basal level of the stem. Ten plants with these symptoms were analyzed by fungal isolation techniques. Small (0.5 cm) tissue portions from root, collar, and basal stem were plated on potato dextrose agar (PDA) after disinfection with 75% ethanol for 1 to 2 min, 0.2% NaOCl for 1 to 2 min, and a wash with sterile distilled water. A fungal isolate that was morphologically similar to Fusarium sp. was isolated from 85% of these tissue samples. It had nucleotide sequences of the internal transcribed spacer region (ITS1-5.8S-ITS2) of ribosomal DNA (GenBank Accession No. KC196121) 100% identical to those of the comparable sequences of Fusarium oxysporum (HQ651161). The nucleotide sequences of its translation elongation factor 1-α (EF-1α) gene (KC196120) showed 100% identity to sequences of F. oxysporum f. sp. opuntiarum (DQ837689, AF246881) retrieved from GenBank. Pathogenicity tests were performed at 22 ± 3°C on 18 45-day-old plants of S. truncate by adding of a 5-ml aliquot of conidial suspension adjusted to 5 × 106 conidia/ml to soil of each plant. Six non-inoculated plants were used for a control treatment and sprayed with 5 ml of sterilized water. Plants were maintained in greenhouse at 22 ± 3°C. After 10 days, nine of the inoculated plants showed wilting, and after 45 days, all of them were dead, with root and collar rot and lesions on the basal stem. Control plants were symptomless. Koch's postulates were fulfilled as the pathogen was reisolated from all of the symptomatic tissues and identified as Fusarium sp. On the basis of 3-septate macroconidia (mean 31.75 × 3.21 μm; range, 26 to 35 μm long, 3.0 to 4.2 μm wide), aseptate microconidia, single chlamydospores, and monophialide conidiophores on carnation leaf agar, and molecular analyses, the fungus was identified as F. oxysporum f. sp. opuntiarum (Speg) (1,2,3). In Italy, F. oxysporum f. sp. opuntiarum was reported as basal stem rot of Echinocactus grusoni (4). To our knowledge, this is the first report of stem wilt and root rot of S. truncata caused by F. oxysporum f. sp. opuntiarum in Italy. References: (1) W. Gerlach. Phytopathol. Z. 74:197, 1972. (2) W. L. Gordon. Can. J. Bot. 43:1309, 1965. (3) P. E. Nelson et al. Fusarium Species: An Illustrated Manual for Identification. Pennsylvania State University Press, University Park, 1983. (4) G. Polizzi et al. Plant Dis. 88:85, 2004.
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Garibaldi, A., A. Minuto y M. L. Gullino. "First Report of Sclerotinia sclerotiorum on Campanula carpatica and Schizanthus × wisetonensis in Italy". Plant Disease 86, n.º 1 (enero de 2002): 71. http://dx.doi.org/10.1094/pdis.2002.86.1.71a.
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The production of potted ornamental plants is very important in the Albenga Region of northern Italy, where plants are grown for export to central and northern Europe. During fall 2000 and spring 2001, sudden wilt of tussock bellflower (Campanula carpatica Jacq.) and butterfly flower (Schizanthus × wisetonensis Hort.) was observed on potted plants in a commercial greenhouse. Initial symptoms included stem necrosis at the soil line and yellowing and tan discoloration of the lower leaves. As stem necrosis progressed, infected plants growing in a peat, bark compost, and clay mixture (70-20-10) wilted and died. Necrotic tissues were covered with whitish mycelia that produced dark, spherical (2 to 6 mm diameter) sclerotia. Sclerotinia sclerotiorum was consistently recovered from symptomatic stem pieces of both plants disinfested for 1 min in 1% NaOCl and plated on potato dextrose agar amended with streptomycin sulphate at 100 ppm. Pathogenicity of three isolates obtained from each crop was confirmed by inoculating 45- to 60-day-old C. carpatica and Schizanthus × wisetonensis plants grown in containers (14 cm diameter). Inoculum that consisted of wheat kernels infested with mycelia and sclerotia of each isolate was placed on the soil surface around the base of previously artificially wounded or nonwounded plants. Noninoculated plants served as controls. All plants were maintained outdoors where temperatures ranged between 8 and 15°C. Inoculated plants developed symptoms of leaf yellowing, followed by wilt, within 7 to 10 days, while control plants remained symptomless. White mycelia and sclerotia developed on infected tissues and S. sclerotiorum was reisolated from inoculated plants. To our knowledge, this is the first report of stem blight of C. carpatica and Schizanthus × wisetonensis caused by S. sclerotiorum in Italy. The disease was previously observed on C. carpatica in Great Britain (2) and on Schizanthus sp. in the United States (1). References: (1) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St. Paul, MN, 1989. (2) J. Rees. Welsh J. Agric. 1:188, 1925.
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DUTTA, RAM, AMRITA BANERJEE, GAJANAN T. BEHERE, K. JINA DEVI, SATISH CHANDRA y S. V. NGACHAN. "PCR detection of Ralstonia solanacearum: A new approach for rapid detection of bacterium from infected plants". Indian Journal of Agricultural Sciences 85, n.º 8 (5 de agosto de 2015): 1007–11. http://dx.doi.org/10.56093/ijas.v85i8.50815.
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Ralstonia solanacearum (Smith) is a soil-borne plant pathogen responsible for causing bacterial wilt and having wide host range which includes monocots, dicots, annual plants/trees and shrubs. It is a most destructive disease of solanceaous crops and ginger in north eastern region of India. The pathogen is primarily present in soils as saprophytic bacterium and it has ability to survive for long periods of time in various natural habitats. The bacterium causes sudden wilting in plants and difficult to detect at the initial level as similar symptom may also occur with many fungal organisms like Fusarium spp. and Verticillium spp. An attempt was made to develop a PCR-based rapid method for detection of this pathogen. This method requires only 3-5 hours against the conventional methods which generally require minimum 3 days to detect the pathogen. The PCR uses previously reported primer pairs for fliC gene (Rsol_fliC), which amplify 400bp region of fliC gene. The bacterial ooze from infected tissues was directly used as a source of DNA. The amplified product was cloned and sequenced for confirmation. The PCR based method developed in this report is very simple, robust and inexpensive and was successfully tested on four infected samples and further validated on over 50 samples of tomato which were infected by R. solanacearum.
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Wright, E. R., M. C. Rivera, G. Chiesa y D. Morisigue. "Occurrence of Sclerotinia Stem Rot of Osteospermum sp., Felicia amelloides, and Ranunculus asiaticus in Argentina". Plant Disease 89, n.º 9 (septiembre de 2005): 1014. http://dx.doi.org/10.1094/pd-89-1014b.
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Three ornamental species, Osteospermum sp. (L.), Felicia amelloides (L.) Voss, and Ranunculus asiaticus L., cultivated in greenhouses on the outskirts of Buenos Aires, showed sudden wilt and death during October 2002. These species are new ornamentals in Argentina. The diseased plants were cultivated in plastic containers filled with commercial potting mix. Soft rot was observed at the base of the plants. Stem lesions became covered with whitish mycelium that produced large, black sclerotia (5 to 7 mm in diameter) characteristic of Sclerotinia sclerotiorum (Lib.) de Bary (1). The fungus was consistently recovered from infected stem pieces that were disinfested for 1 min in 0.2% NaOCl and plated on potato dextrose agar (PDA), pH 7. Pathogenicity of the three isolates obtained from infected plants was confirmed by inoculating 10 3-month-old healthy plants of each species in 14-cm-diameter plastic pots. Each isolate was inoculated on the host from which it had been isolated. Inoculum consisted of three mycelial plugs from 7-day-old PDA cultures that were placed on the substrate at the base of the plants. Control plants were treated with sterile agar plugs. Inoculated and noninoculated plants were covered with transparent plastic bags for 2 days and incubated in a growth chamber at 20 to 24°C with a 12-h photoperiod. All inoculated plants developed symptoms of leaf yellowing and wilt. Soft and watery tissues were observed at the base of the plants, soon followed by the appearance of white mycelium. Disease symptoms were similar to those observed on the original infected plants and appeared 6, 5, and 3 days after inoculation on Osteospermum sp., F. amelloides, and R. asiaticus, respectively. All inoculated plants died within 3 weeks, and control plants remained healthy. S. sclerotiorum was reisolated from inoculated plants of each species, fulfilling Koch's postulates. To our knowledge, this is the first report of the occurrence of Sclerotinia stem rot on these three plant species in Argentina. Reference: (1) J. E. M. Mordue and P. Holliday. No. 513 in: Descriptions of Pathogenic Fungi and Bacteria. CMI, Kew, Surrey, UK. 1976.
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Oszust, Karolina, Michał Pylak y Magdalena Frąc. "Trichoderma-Based Biopreparation with Prebiotics Supplementation for the Naturalization of Raspberry Plant Rhizosphere". International Journal of Molecular Sciences 22, n.º 12 (14 de junio de 2021): 6356. http://dx.doi.org/10.3390/ijms22126356.
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The number of raspberry plants dying from a sudden outbreak of gray mold, verticillium wilt, anthracnosis, and phytophthora infection has increased in recent times, leading to crop failure. The plants suffer tissue collapse and black roots, symptoms similar to a Botrytis–Verticillium–Colletotrichum–Phytophthora disease complex. A sizeable number of fungal isolates were acquired from the root and rhizosphere samples of wild raspberries from different locations. Subsequent in vitro tests revealed that a core consortium of 11 isolates of selected Trichoderma spp. was the most essential element for reducing in phytopathogen expansion. For this purpose, isolates were characterized by the efficiency of their antagonistic properties against Botrytis, Verticillium, Colletotrichum and Phytophthora isolates and with hydrolytic properties accelerating the decomposition of organic matter in the soil and thus making nutrients available to plants. Prebiotic additive supplementation with a mixture of adonitol, arabitol, erythritol, mannitol, sorbitol, and adenosine was proven in a laboratory experiment to be efficient in stimulating the growth of Trichoderma isolates. Through an in vivo pathosystem experiment, different raspberry naturalization-protection strategies (root inoculations and watering with native Trichoderma isolates, applied separately or simultaneously) were tested under controlled phytotron conditions. The experimental application of phytopathogens attenuated raspberry plant and soil properties, while Trichoderma consortium incorporation exhibited a certain trend of improving these features in terms of a short-term response, depending on the pathosystem and naturalization strategy. What is more, a laboratory-scale development of a biopreparation for the naturalization of the raspberry rhizosphere based on the Trichoderma consortium was proposed in the context of two application scenarios. The first was a ready-to-use formulation to be introduced while planting (pellets, gel). The second was a variant to be applied with naturalizing watering (soluble powder).
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Garibaldi, A., A. Minuto y M. L. Gullino. "First Report of Sclerotium rolfsii on Jerusalem Cherry (Solanum pseudocapsicum) in Europe". Plant Disease 84, n.º 9 (septiembre de 2000): 1048. http://dx.doi.org/10.1094/pdis.2000.84.9.1048b.
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Jerusalem cherry (Solanum pseudocapsicum) has recently become popular as a potted ornamental plant in Italy. During the summer of 1999, a sudden wilt of 60-day-old plants was observed in the Albenga region (Northern Italy), an area of intensive floriculture. Initial symptoms included stem necrosis at the soil line and yellowing and tan discoloration of leaves. As stem necrosis progressed, infected plants wilted and died. Necrotic tissues were covered with whitish mycelium that differentiated into reddish brown, spherical (1 to 2 mm diameter) sclerotia. Sclerotium rolfsii was consistently recovered from the surface of symptomatic stem sections that were disinfected for 1 min in 1% NaOCl and then plated on potato-dextrose agar (PDA) amended with 100 ppm streptomycin sulfate. Pathogenicity of three S. rolfsii isolates was confirmed by inoculating 90-day-old S. pseudocapsicum plants grown in pots. Inoculum consisted of mycelium and sclerotia of the pathogen placed on the soil surface around the base of each plant. Noninoculated plants served as controls. All plants were kept in a growth chamber at 18 to 28°C and RH > 85%. Inoculated plants developed symptoms within 7 days, while control plants remained symptomless. Sclerotia developed on infected tissues and S. rolfsii was reisolated from symptomatic tissues. The disease has been observed in the United States (1), but this is the first report of stem blight of S. pseudocapsicum caused by S. rolfsii in Europe. Reference: (1) S. A. Alfieri, Jr., K. R. Langdon, C. Wehlburg, and J. W. Kimbrough, J. W. Index Plant Dis. Florida Bull. 11:215, 1984.
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Fu, C. H., Y. P. Huang y F. Y. Lin. "First Report of Southern Blight of Iresine herbstii Caused by Sclerotium rolfsii in Taiwan". Plant Disease 96, n.º 11 (noviembre de 2012): 1692. http://dx.doi.org/10.1094/pdis-04-12-0372-pdn.
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Widely cultivated commercially, Iresine herbstii Hook is a potted herbaceous plant popular for its foliage, which varies from a dark red to brownish maroon. In the summer of 2010, a sudden wilt of I. herbstii plants was observed at a recreational farm in Taipei City in northern Taiwan. The initial symptoms were water-soaked lesions that became soft and then rotted. Necrotic areas on the stems were covered with fans of white mycelium as well as abundant spherical, brown sclerotia. A fungus was isolated from both infected tissue and sclerotia and maintained on potato dextrose agar (PDA) plates incubated at 25°C without light. Colonies were white and cottony, often forming mycelial fans. Pure cultures were prepared by transferring single hyphal tips to PDA. Sclerotia formed after 7 days. Sclerotia were initially white becoming dark brown with age and were 0.8 to 1 mm in diameter at maturity. These are typical features of Sclerotium rolfsii. Koch's postulates were performed by inoculating five healthy, potted I. herbstii plants with 10 fresh sclerotia placed on the soil surface around the base of each plant. In a second test, five healthy potted plants were inoculated with a single 10-mm-diameter mycelial agar plug placed at the stem base of each plant. Five noninoculated plants served as controls. All plants were incubated in a growth chamber at 25 to 35°C. Basal stem rot and wilt developed within 4 days on plants inoculated with sclerotia or mycelial plugs. All plants were dead by 7 days after inoculation whereas the controls remained healthy. The fungus was reisolated from the symptomatic tissue and produced sclerotia and mycelium consistent with S. rolfsii. To confirm identity of the causal fungus, the complete internal transcribed spacer (ITS) rDNA region of the causal fungus was amplified using the primers ITS4 and ITS5 (3) and sequenced. The resulting sequence of 687 bp was uploaded in NCBI (Accession No. JN543691.1). The sequence was 98% similar to sequences of Athelia rolfsii (anamoprh S. rolfsii). This disease has been observed on many species of plants (1, 2). To our knowledge, this is the first report of I. herbstii caused by S. rolfsii in Taiwan or any other part of the world. References: (1) T. T. Chang. Bull. Taiwan For. Res. Inst. 9:191, 1994. (2) Y. N. Wang et al. J. Exp. For. Nat. Taiwan Univ. 20:45, 2006. (3) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.
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Jovicich, Elio y Daniel J. Cantliffe. "451 Transplant Depth can Overcome “Elephant's Foot” Disorder in a Hydroponic Greenhouse Sweet Pepper Crop". HortScience 35, n.º 3 (junio de 2000): 471D—471. http://dx.doi.org/10.21273/hortsci.35.3.471d.
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A physiological disorder, “Elephant's Foot”, can develop in greenhouse hydroponic sweet pepper (Capsicum annuum L.). In a plant with this disorder, the base of the stem becomes swollen below the cotyledon level and wounds develop at the base of the stem's epidermis, what might predispose it to a localized rot and result in a sudden permanent plant wilt. Salt accumulation at the base of the stem could be a possible cause of the epidermis wounds. The effects of soilless media type (perlite, coconut coir, pine bark, and peat–perlite–vermiculate mix), transplant depth, and amount of nutrient solution applied per day were studied to evaluate the development of “Elephant's Foot” on a summer–fall sweet pepper greenhouse crop in Gainesville, Fla. Seedlings grown in polyethylene containers were transplanted 29 June 1999 into 11.4-L pots at three transplant depths: a) at half of the cell height, discarding only the bottom of the container (TOP); b) at the cotyledon level (LEVEL), and c) at the second stem node (DEEP). Plants were irrigated with 2, 2.5, 3, 3.5, and 4 L/day per plant of solution. The percentage of plants with epidermis wounds at the base of the stem was highest (82.5%) on TOP plants, compared to LEVEL (5.8%) and DEEP plants (0%). TOP plants had higher values of electrical conductivity on the stem epidermis than LEVEL and DEEP plants. There was a positive linear relationship (r = 0.82) between the percentage of plants with epidermis wounds and the electrical conductivity. Early yield of extra large and large fruits was higher in DEEP (1.05 kg·m–2) than in TOP plants (0.82 kg·m–2). Transplanting sweet pepper with the cotyledonary node under the soilless media could minimize salt accumulation and epidermis damage at the base of the stem level.
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Jovicich, Elio y Daniel J. Cantliffe. "Salts Deposited on the Lower Stem of Bell Pepper Contribute to a Basal Stem Disorder in Soilless, Greenhouse-grown Plants". HortScience 39, n.º 1 (febrero de 2004): 36–39. http://dx.doi.org/10.21273/hortsci.39.1.36.
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A physiological disorder in greenhouse-grown pepper (Capsicum annuum L.) plants was observed in Florida, wherein the base of the main stem becomes swollen below the cotyledonary node level and crack-like wounds develop at the base of the stem's epidermis. The disorder may predispose the plant to a localized rot and result in a sudden plant wilt. The effects of soilless media type, transplant depth, and amount of nutrient solution applied per day were studied to evaluate the development of what was termed “Elephant's Foot” disorder, on a greenhouse-grown bell pepper crop in Gainesville, Fla. The percentage of plants with epidermal wounds at the base of the stem was highest (83%) on plants transplanted at half of the cell height (3.8 cm), compared to plants transplanted to the cotyledonary node level (6%) and the second leaf node (0%). Salts were washed from the surface of basal stem epidermis and electrical conductivity measured in the washing solution was expressed per unit area of epidermal sample (ECA). The ECA in the solutions from plants transplanted at half of the cell height was higher than that from plants transplanted to the cotyledonary node level and to the second leaf node. There was a positive linear relationship (r = 0.81) between the percentage of plants with epidermal wounds and the ECA of the solution obtained from washing the epidermal tissues. Salts deposited on the epidermis beneath the cotyledonary node provoked a tissue injury that may predispose the plant to a Fusarium infection. Simple management practices, such as transplanting deep, using cultivars with lower susceptibility to salt damage, and gradually moving back the emitter from the base of the plant after transplanting (to reduce humid conditions near the base of the stem) would help reduce the appearance of this basal stem disorder in soilless-grown peppers.
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Hsiao, W. W., C. H. Fu y C. Y. Chen. "First Report of Southern blight of Formosan Michelia Seedlings in Taiwan". Plant Disease 90, n.º 5 (mayo de 2006): 682. http://dx.doi.org/10.1094/pd-90-0682a.
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Formosan michelia (Michelia compressa (Maxim.) Sargent) is a native, giant evergreen tree in Taiwan. This species is used for afforestation, provision of shade in domestic situations, used in parks, and also for furniture. During the summer of 2004, a sudden wilt of 1-year-old plants was observed in a nursery of northern Taiwan. Initial symptoms included stem necrosis at the soil line, yellowing, and tan discoloration of leaves. As stem necrosis progressed, infected plants wilted and died. Necrotic tissues were covered with whitish mycelium that differentiated into reddish brown spherical (1 to 2 mm in diameter) sclerotia. Sclerotium rolfsii was consistently recovered from the surface of symptomatic stem sections that were disinfected for 1 min in 0.5% NaOCl and then plated on potato-dextrose agar amended with 100 ppm ampicillin. Pathogenicity of two S. rolfsii isolates was confirmed by inoculating 1-year-old Formosan michelia seedlings grown in pots. Inoculum consisted of mycelium and sclerotia of the pathogen placed on the soil surface around the base of each plant. Noninoculated plants served as controls. All plants were kept in a growth chamber at 25 to 35°C with relative humidity >95%. Inoculated plants developed symptoms within 14 days while control plants remained symptomless. Sclerotia developed on infected tissues, and S. rolfsii was reisolated from symptomatic tissues. This disease has been observed on many species of plants (1), but to our knowledge, this is the first report of southern blight of Formosan michelia seedlings caused by S. rolfsii in Taiwan. Reference: (1) Y. P. Tsai, ed. List of Plant Diseases in Taiwan. The Plant Protection Society of the Republic of China and The Phytopathological Society of the Republic of China, 1991.