scholarly journals First Report of Nattrassia mangiferae Root and Stem Rot of Cassava in West Africa

Plant Disease ◽  
1997 ◽  
Vol 81 (11) ◽  
pp. 1332-1332 ◽  
Author(s):  
W. Msikita ◽  
J. S. Yaninek ◽  
M. Ahounou ◽  
H. Baimey ◽  
R. Fagbemissi
Keyword(s):  
West Africa ◽  
Plant Height ◽  
Hot Water ◽  
Day Length ◽  
Stem Rot ◽  
Fusarium Spp ◽  
First Report ◽  
Cassava Root ◽  
Nattrassia Mangiferae ◽  
Number Of Shoots

During part of the dry season in 1996 (November to December), surveys were made for incidence of root and stem rot in 99 fields of cassava (Manihot esculenta Crantz) randomly selected between latitudes 6°36′N and 7°49′N in Benin (79 fields) and Nigeria (20 fields). Root rot was observed in 65 fields in Benin and 15 fields in Nigeria. Disease incidence ranged from 0 to 54%. A total of 201 samples of wilted and/or dead plants were collected for laboratory analysis. Infected root and stem portions (0.5 to 1 cm) were cut out, surface disinfested (10 min) in 10% bleach (0.6% sodium hypochlorite), rinsed in sterilized distilled water, and cultured on potato dextrose agar acidified to pH 4.5 with 0.4% (vol/vol) lactic acid. Cultures were incubated at 25°C, under 12-h day length provided by cool-white fluorescent lamps. After 1 week, mycelia, conidiophores, and conidia were observed at ×30 to ×40 magnification under a compound microscope. Out of the 169 symptomatic samples collected from Benin, nine fungal genera were isolated: Aspergillus spp. (1% of fungi observed), Botryodiplodia theobromae Pat (7.7%), Fusarium spp. (11.8%), Macrophomina phaseolina (Tassi) Goidanich (14.2%), Nattrassia mangiferae (Syd. & P. Syd.) B. Sutton & Dyko (56.2%), Penicillium spp. (0.6%), Pythium spp. (2.9%), Rhizopus spp. (1.7%), and Trichoderma spp. (2.4%). One percent of the fungi isolated did not sporulate in culture and were not identified. Out of the 32 samples collected from Nigeria, four fungal genera were identified: N. mangiferae (40.6%), B. theobromae (28.1%), M. phaseolina (18.7%), and Fusarium spp. (12.5%). Since N. mangiferae was isolated with the highest frequency, its pathogenicity was tested on cassava (cultivars Agric, Ben 86052, Dessa 88, Tchukunochi, and TMS 30572). Two weeks prior to the experiment, inocula for pathogenicity tests were prepared by incubating 5-mm-diameter mycelial plugs of N. mangiferae with 500 ml of autoclaved rice seed for 10 days at 25°C, followed by air drying in a laminar flow hood for 2 days. Five 30-cm-long stem portions were cut from healthy plants of each cassava cultivar, surface disinfested in hot water (52°C, 5 min), and transplanted into sterilized (autoclaved, 1 h) sand in 1-liter pots to which 10 ml of the N. mangiferae-colonized rice inoculum had been added. There were five control stems for each cultivar, similarly treated, but not inoculated. Plants were maintained in a greenhouse under natural light at 28 to 30°C. Thirty days after planting, plant height, lesion length, and number of shoots and roots were recorded. For all five cultivars, N. mangiferae significantly (P < 0.05) reduced plant height and number of shoots and roots, compared with control plants. Lesions (3 to 15 cm long) formed on the lower stem portions of all inoculated plants, resulting in variable degrees of wilting of the infected plants. Two of the cultivars (Agric and Ben 86052) died 3 weeks after planting. Control plants remained asymptomatic. N. mangiferae was consistently reisolated from infected plants, and the identification was independently confirmed by the International Mycological Institute, Surrey, UK. Scytalidium sp., a synamorphic state of N. mangiferae (2), was reported to cause up to 85% cassava root yield loss in South America (1). This is the first report of N. mangiferae causing cassava root and stem rot in West Africa. References: (1) Anonymous. Annu. Rep. Cassava Prog., CIAT Working Doc. No. 116:97, 1992. (2) B. C. Sutton and B. J. Dyko. Mycol. Res. 93:466, 1989.

scholarly journals First Report of Macrophomina phaseolina Causing Pre-harvest Cassava Root Rot in Benin and Nigeria

Plant Disease ◽  
1998 ◽  
Vol 82 (12) ◽  
pp. 1402-1402 ◽  
Author(s):  
W. Msikita ◽  
B. James ◽  
H. T. Wilkinson ◽  
J. H. Juba
Keyword(s):  
Plant Height ◽  
Root Rot ◽  
Macrophomina Phaseolina ◽  
Hot Water ◽  
Stem Rot ◽  
Rice Seed ◽  
First Report ◽  
Cassava Root ◽  
Number Of Leaves ◽  
Lower Stem

In diagnostic surveys conducted in parts of Benin and Nigeria to determine the incidence of pre-harvest cassava root and stem rot during the dry season, Macrophomina phaseolina (Tassi) Goidanich constituted 14.2 and 18.7% of the total fungi (n = 201) associated with cassava root and stem rot from Benin and Nigeria (1). Pathogenicity of M. phaseolina on cassava was tested with cv. Agric. Inocula for pathogenicity tests were prepared by incubating 5-mm-diameter mycelial plugs for each of five isolates (Mp 1 to Mp 5, all collected from Benin) with 500 ml of autoclaved, sterilized, dehusked rice seed for 14 days at 30°C. Five 30-cm-long stem portions per isolate were cut from healthy cassava, surface disinfested in hot water (52°C, 5 min), and planted into 1-liter pots containing autoclaved, sterilized sand mixed with 10 ml of air-dried inoculum. Five plants per isolate similarly treated but not inoculated served as controls. Plants were watered once a week, and maintained in a greenhouse under natural light at 28 to 30°C. Lower leaves of inoculated plants gradually wilted, usually preceded by chlorosis, and brown to black lesions formed on the lower stem portions of some roots. Control plants remained asymptomatic. Plant height and percentage of leaf wilt (determined by counting the number of leaves wilted per plant and dividing by the total number of leaves per plant) were measured on a weekly basis for 8 weeks for each of the control and inoculated plants. At the end of 8 weeks, lesion length on the lower stem was measured. There were significant differences (P < 0.05) in length of the lesions and percentage of leaf wilt induced by the different isolates of M. phaseolina. Isolate Mp 1 induced the longest lesion (7.2 cm), followed by Mp 4 (4.1 cm), Mp 3 and Mp 5 (3.8 cm each), and Mp 2 (1.2 cm). Mp 4 induced the highest percentage of wilted leaves (53%), followed by Mp 1, Mp 3, and Mp 5 (30%), and Mp 2 (10%). All five M. phaseolina isolates (except Mp 3) reduced plant height, compared with control treatments. M. phaseolina was isolated from all infected plants, and the identification was independently confirmed by the International Mycological Institute, Surrey, UK. This is the first report of M. phaseolina causing pre-harvest cassava root rot in Benin and Nigeria. Reference: (1) W. Msikita et. al. Plant Dis. 81:1332, 1997.

scholarly journals Prevalence and Severity of Nattrassia mangiferae Root and Stem Rot Pathogen of Cassava in Bénin

Plant Disease ◽  
2005 ◽  
Vol 89 (1) ◽  
pp. 12-16 ◽  
Author(s):  
W. Msikita ◽  
B. Bissang ◽  
B. D. James ◽  
H. Baimey ◽  
H. T. Wilkinson ◽  
...  
Keyword(s):  
West Africa ◽  
Root Rot ◽  
Rainy Season ◽  
Disease Incidence ◽  
Macrophomina Phaseolina ◽  
Dry Season ◽  
Stem Cuttings ◽  
Storage Roots ◽  
Fusarium Spp ◽  
Nattrassia Mangiferae

Root rot pathogens were found through diagnostic surveys in all departments (regions) of Bénin, West Africa, to affect 86 to 100% and 96 to 100% of cassava fields during the dry and rainy seasons, respectively. Disease incidence in individual fields ranged between 0 and 53%, and averaged 16 to 27% per department. Nattrassia mangiferae was consistently the most frequently isolated root rot pathogen (56% in the dry season and 22 to 52% in the rainy season). Pathogenicity of N. mangiferae was confirmed on four cultivars of cassava using stem cuttings and storage roots. For all four cultivars, N. mangiferae significantly reduced the number of roots. Lesions (3 to 15 cm long) formed on the lower stem portion of all inoculated plants, whereas control plants remained symptom free. On storage roots, the disease profile was similar to that formed on stem cuttings. Other root rot pathogens detected during the dry season were Macrophomina phaseolina (14.2%), Fusarium spp. (11.8%), Botryodiplodia theobromae (7.7%), and Pythium spp. (2.9%). During the rainy season, Fusarium spp. were the second most commonly isolated root rot pathogens in three departments (Atlantique, Borgou, and Mono). In Oueme and Zou, B. theobromae was the second most isolated root rot pathogen (ranging between 24 and 28%) during the rainy season. During the same season, Pythium spp. were pronounced in Borgou (18%), followed by Mono (11%), Atlantique (9%), Atacora (8%), Oueme (5%), and Zou (6%). Results of the study are discussed with a view to creating awareness of the destructive power of N. mangiferae, a hitherto poorly recognized root rot pathogen of cassava in Bénin and West Africa in general.

scholarly journals First report of Phytophthora sp. causing a root and basal stem rot of narrowleaf lupin in Australia

2001 ◽  
Vol 50 (6) ◽  
pp. 811-811 ◽  
Author(s):  
A. Nikandrow ◽  
R. L. Gilbert ◽  
D. A. Gunning ◽  
M. A. C. B. Lawler ◽  
K. D. Lindbeck ◽  
...  
Keyword(s):  
Stem Rot ◽  
Basal Stem Rot ◽  
First Report

scholarly journals First Report of Stem Rot on Potato Caused by Dickeya chrysanthemi in Minnesota

Plant Disease ◽  
2018 ◽  
Vol 102 (1) ◽  
pp. 238-238 ◽  
Author(s):  
R. R. McNally ◽  
R. D. Curland ◽  
B. T. Webster ◽  
A. P. Robinson ◽  
C. A. Ishimaru
Keyword(s):  
Stem Rot ◽  
First Report

scholarly journals First Report of Common Bean (Phaseolus vulgaris) Stem Rot Caused by Colletotrichum spaethianum in China

Plant Disease ◽  
2019 ◽  
Vol 103 (1) ◽  
pp. 151
Author(s):  
L. Yang ◽  
X. H. Lu ◽  
Y. L. Jing ◽  
S. D. Li ◽  
B. M. Wu
Keyword(s):  
Phaseolus Vulgaris ◽  
Common Bean ◽  
Stem Rot ◽  
First Report

scholarly journals First Report of Root and Stem Rot Caused by Phytophthora nicotianae on Peperomia tetraphylla in China

Plant Disease ◽  
2010 ◽  
Vol 94 (9) ◽  
pp. 1171-1171 ◽  
Author(s):  
D. X. Zeng ◽  
X. L. Wu ◽  
Y. H. Li
Keyword(s):  
Southern China ◽  
Aerial Mycelium ◽  
Its Region ◽  
Soil Extract ◽  
Phytophthora Nicotianae ◽  
Stem Rot ◽  
Molecular Characteristics ◽  
Its Sequence ◽  
First Report ◽  
Pure Cultures

Peperomia tetraphylla, an evergreen herb, is becoming increasingly popular as a potted ornamental plant in southern China. In the summer of 2008, in some commercial flower nurseries in Shenzhen, Guangdong Province, P. tetraphylla showed extensive black stem and root rot, with leaves dropping from the rotten stem. Small pieces (approximately 3 mm2) of stems and leaves were excised from the margins of the black lesions, surface disinfected for 30 s to 1 min in 0.1% HgCl2, plated onto potato dextrose agar (PDA), and incubated at 25°C in the dark. All the plated samples yielded Phytophthora, and microscopic examination of pure cultures grown on PDA plates showed arachnoid colonies with abundant aerial mycelium, chlamydospores, and a few sporangia. Numerous sporangia were formed in sterile soil extract. Sporangia were ovoid or obpyriform, noncaducous, with prominent solitary papillae, and measured 31 to 52 μm (average 38 μm) × 21 to 34 μm (average 27 μm). Chlamydospores were spherical and 21 to 34 μm in diameter (average 28 μm). The internal transcribed spacer (ITS) region of rDNA of a single isolate was amplified using primers ITS4/ITS5 and sequenced (2). The ITS sequence, when submitted for a BLAST search in the NCBI database, showed 100% homology with the sequences of two reference isolates of Phytophthora nicotianae (Accession Nos. AY833526 and EU433396) and the consensus ITS sequence was deposited in the NCBI as Accession No. GQ499373. The isolate was identified as Phytophthora nicotianae on the basis of morphological and molecular characteristics (1). Pathogenicity of the isolate was confirmed by inoculating 1-year-old plants of P. tetraphylla growing in pots. The isolate was grown for 7 days on PDA plates and mycelial plugs, 5 mm in diameter and taken from the advancing margins of the colonies, were buried approximately 1 cm deep near the base of the stem in such a way that the mycelium on the plugs was in contact with the surface of the stem, which had been wiped earlier with 70% ethanol and gently wounded with a needle. Plants treated the same way but inoculated with sterile PDA plugs served as control plants. Three plants in each pot were inoculated and there were five replications each for the treatment and the control. All plants were kept in a greenhouse at 22 to 32°C. After 6 to 7 days, the inoculated plants showed black lesions around the mycelial plugs; symptoms of root and stem rot developed rapidly thereafter and the plants collapsed within 2 weeks. All symptoms on the inoculated plants were identical to those observed in naturally diseased plants, whereas the control plants remained healthy. The same fungus was consistently reisolated from the inoculated plants. To our knowledge, this is the first report of Phytophthora nicotianae on P. tetraphylla in China. References: (1) D. C. Erwin and O. K. Ribeiro. Phytophthora Diseases Worldwide. The American Phytopathological Society, St. Paul, MN, 1996. (2) J. B. Ristaino et al. Appl. Environ. Microbiol. 64:948, 1998.

The Effect Of Giving Banana Stem Compos With EM4 Concentration Variation And Urea Fertilizer On The Growth Of (Pepper nigrum L.) Cuttings Of Malonan 1 Variety

2021 ◽  
Vol 10 (1) ◽  
pp. 59-64
Author(s):  
Fredrick belawan Ngo
Keyword(s):  
Plant Height ◽  
Block Design ◽  
Urea Fertilizer ◽  
Concentration Variation ◽  
Randomized Block Design ◽  
Number Of Leaves ◽  
Banana Stem ◽  
Experimental Garden ◽  
Number Of Shoots

This research was conducted at the Experimental Garden of Widya Gama Mahakam University Samarinda, Faculty of Agriculture, Jalan KH. Wahid Hasyim. The study was conducted in January - April 2020. This study used a factorial randomized block design (RBD) with 2 treatment factors and 3 replications. The first factor was the application of banana stem compost with various concentrations of EM4 consisting of 4 levels, namely P0 = banana stem compost without EM4, P1 = banana stem compost with EM4 concentration of 50 ml L-1 water, P2 = banana stem compost with EM4 concentration of 75 ml. L-1 water, P3 = banana stem compost with a concentration of EM4 100 ml L-1 water and the second factor is the dose of urea fertilizer which consists of 4 levels, namely, D0 = control, D1 = 1 g urea / polybag, D2 = 2 g urea / polybag, D3 = 3 g urea / polybag. The results of the research giving banana stem compost with variations in the concentration of EM4 and the dose of urea fertilizer and the interaction of the two treatments had a very significant effect on plant height at the age of 20, 40, 60 and 80 DAS, with the best treatment P3 = 28.67 cm, D3 = 28, 21 cm and P3D3 = 32.33 cm, then had a very significant effect on the number of shoots at the age of 60 and 80 DAS with the best treatment P3 = 6.67 fruit, D3 = 6.17 fruit and P3D3 = 8.33 fruit, and very influential significant on the number of leaves at the age of 40, 60 and 80 DAS with the best treatment P3 = 8.58 strands, D3 = 8.83 strands and P3D2 = 10.67 strands.

scholarly journals First Report of Mucor spp. Causing Root Rot of Radix pseudstellariae in Guizhou Province of China

Plant Disease ◽  
2020 ◽  
Author(s):  
Hongmiao Wu ◽  
Jiachun Wu ◽  
Feng Li ◽  
Ling Zheng ◽  
Jingkai Fan ◽  
...  
Keyword(s):  
Root Rot ◽  
Disease Incidence ◽  
Acid Soils ◽  
Its Region ◽  
Significant Loss ◽  
Day Length ◽  
Guizhou Province ◽  
First Report ◽  
Chinese Medicinal Plants ◽  
Branched Chains

Radix pseudostellariae L. is one of the most common and highly-prized Chinese medicinal plants with various pharmacological effects, and mainly produced in acid soils in the Guizhou and Fujian provinces of southwestern and southeastern China, respectively (Wu et al. 2020). However, consecutive monoculture of R. pseudostellariae results in severe root rot and decline in biomass and quality of underground tubers. Root tubers of R. pseudostellariae are typically planted in December and harvested in next June. Root rot commonly starts developing in May. The disease incidence of root rot was ranging from 37 to 46% in root portions and basal stem of R. pseudostellariae under the consecutive monoculture fields in Shibing County, Guizhou Province, China (108°12ʹE, 27°03ʹN) (Li et al. 2017). Severe root rot was observed in Shibing County in May 2018. Infected plants displayed curly, withered, and yellow leaves, blight, retarded growth, root rot, and yield losses. Abundant whitish mycelia were observed on roots and surrounding soil. Two fungal isolates, designated GZ20190123 and GZ20190124, were obtained from symptomatic roots cultured on potato dextrose agar (PDA). The optimum temperature range for growth of the two isolates was 25 to 30°C. The optimum pH range for the growth of GZ20190123 was 5 to 5.5, whereas GZ20190124 grew better between pH 5 to 8.5. The mean mycelial growth rates of GZ20190123 and GZ20190124 at 30°C were 2.1 and 1.5 cm/day, respectively. Conidia of the two isolates were ovoid or obclavate and were produced in single or branched chains. The internal transcribed spacer (ITS) region was amplified with primers ITS1 and ITS4 (White et al. 1990). The sequences were deposited in GenBank as accession No. MN726736 for GZ20190123 and MN726738 for GZ20190124. Sequence comparison revealed 99% (GZ20190123) and 97% (GZ20190124) identity with previously reported isolate xsd08071 of Mucor racemosus Bull. (accession No. FJ582639.1) and isolate BM3 of Mucor fragilis Bainier (accession No. MK910058.1), respectively, which was confirmed by phylogenetic analysis. The two isolates were tested for pathogenicity on R. pseudostellariae. Six roots of R. pseudostellariae were surface-sterilized with 75% ethanol and stab inoculated with mycelia using a sterile toothpick for each isolate. Sterile distilled water was stab inoculated to twelve roots to serve as the control. Treated roots were incubated in a greenhouse with 16 h day length [light intensity 146.5 μmol/(m2·s)] and day/night temperature 26°C/18°C. The inoculated roots showed the expected symptoms on roots and sprouts 7 days after inoculation, whereas the control roots with sprouts did not show any symptom. The fungi were re-isolated from the diseased roots and confirmed as expected M. racemosus or M. fragilis based on the ITS sequences, which satisfied Koch’s postulates. Thus, isolate GZ20190123 was identified as M. racemosus and GZ20190124 as M. fragilis. Previously, M. racemosus and M. fragilis have been reported as a pathogen on tomato (Kwon and Hong 2005) and grape (Ghuffar et al. 2018), respectively. To our knowledge, this is the first report of M. racemosus and M. fragilis causing root rot of R. pseudostellariae in southwestern China, where the disease could cause a significant loss to production of this important medicinal plant.

scholarly journals First Report of Stem Rot of Dracaena Caused by Aspergillus niger in Iran

2008 ◽  
Vol 9 (1) ◽  
pp. 48 ◽  
Author(s):  
Mehrdad Abbasi ◽  
Faezeh Aliabadi
Keyword(s):  
Aspergillus Niger ◽  
Stem Rot ◽  
Local Market ◽  
Disease Symptoms ◽  
First Report ◽  
Dracaena Sanderiana

Specimen plants of Dracaena sanderiana showing stem rot symptoms were collected from a local market in Tehran. Aspergillus niger was isolated from all diseased plants. Healthy greenhouse plants were inoculated and developed disease symptoms. The authors were able to isolate A. niger from all inoculated plants. This is believed to be the first report of A. nigercausing stem rot of D. sanderiana in Iran. Accepted for publication 26 November 2007. Published 12 February 2008.

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