scholarly journals Doenças do álamo

FLORESTA ◽  
2000 ◽  
Vol 30 (12) ◽  
Author(s):  
LOUISE LARISSA MAY-DE MIO ◽  
LILIAN AMORIM
Keyword(s):  
Leaf Spot ◽  
Root Rot ◽  
Colletotrichum Gloeosporioides ◽  
Pests And Diseases ◽  
Leaf Spots ◽  
Melampsora Medusae ◽  
The World ◽  
Alternaria Tenuis ◽  
Summer Time ◽  
Important Disease

A cultura do álamo no Brasil, assim como no resto do mundo, enfrenta sérios desafios em relação a pragas e doenças. No que se refere a doenças, a ferrugem das folhas, causada por Melampsora medusae, é a mais importante da cultura. A doença provoca pústulas nas folhas, aonde são produzidos urediniósporos em grande número, responsáveis pela disseminação, podendo ocasionar epidemias no verão. Com o avanço da doença, a queda das folhas é antecipada, interferindo no crescimento da árvore e armazenamento de energia para o próximo ciclo. Além da ferrugem, outras manchas foliares como as causadas por Septoria, Alternaria tenuis e Colletotrichum gloeosporioides já foram detectadas no Brasil. A mancha de Septoria é a mais importante pois o patógeno causa cancros nos galhos e tronco das árvores. Também são relatadas na literatura manchas foliares causadas por Marssonina spp, Taphrina spp e Venturia spp, além de diversos cancros e algumas podridões radiculares. Abstract The poplar crop in Brazil, as in the rest of the world, has been attacked by a number of pests and diseases. The leaf rust, caused by Melampsora medusae is the most important disease. It causes pustules in leaves, which produces uredinospores in large quantities which spreads the disease causing epidemics in the summer time. After several cycles of the pathogen, the plant is early defoliated, grows poorly and retains less energy for the next year. Besides this disease, other leaf diseases caused by Septoria, Alternaria tenuis and Colletotrichum gloeosporioides have already been detected in Brazil. Leaf spot caused by S. musiva is the most important because the pathogen causes cankers in stems and branches. Other diseases have already been mentioned in different publications such as leaf spots caused by Marssonina spp, Taphrina spp, and Venturia spp, as well as several cankers and some root rot.

scholarly journals Diseases and Insect Pests associated with Cashew (Anacardium occidentale L.) Orchards in Ghana

2021 ◽  
Vol 3 (5) ◽  
pp. 23-32
Author(s):  
A. Muntala ◽  
S. Kwadwo Gyasi ◽  
P. Mawuenyegan Norshie ◽  
S. Larbi-Koranteng ◽  
F. Kwekucher Ackah ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Colletotrichum Gloeosporioides ◽  
Insect Pests ◽  
Anacardium Occidentale ◽  
Curvularia Lunata ◽  
Oecophylla Smaragdina ◽  
Isolation And Identification ◽  
Pests And Diseases ◽  
Kernel Infection ◽  
Colletotrichum Gloeosporioides Species Complex

Cashew (Anacardium occidentale L.), a recently recognized cash crop in Ghana, is an economically export oriented crop that plays a helping role in the Ghanaian economy in diverse ways. Owing to its importance, surveys were conducted in some major cashew producing communities in Dormaa and Berekum West District of the Bono region to assess the problems of insect pests and diseases associated with this economic tree across the study area. Diseased samples showing varying degrees of symptoms were taken for isolation and identification using morphological method. Insect pests were also assessed and identified. The results showed Colletotrichum gloeosporioides species complex to be associated with anthracnose, leaf lesions or spots, gummosis of twigs and stems and regressive die-back; Lasiodiplodia theobromae was found to cause stem and twig gummosis, blight, die-back of twigs and inflorescence; Pestalotia sp. was associated with Pestalotia leaf spot. Others, such as Penicillium sp., powdery mildew, Curvularia lunata, Cephaleuros sp. (red rust- algal leaf spot), mushroom and lichens were also found to be associated with the cashew orchards in the study area. Anthracnose, gummosis, algal leaf, and stem spots (red rust) and cashew kernel infection by Curvularia lunata constituted the major diseases of cashew in ascending order in the study area. The insect pests identified included Oecophylla smaragdina, Anoplocne miscurvipeson, Pseudotheraptus devastans, Pachnoda cordata, Pachnoda marginata, Helopeltis bug, Helopeltis schoutedeni, Planococcus sp., Lamida moncusalis, Odontotermes sp., Aphis sp., Analeptes trifasciata. Some unidentified pathogens, pests and other abnormalities were also observed.

scholarly journals Anthracnose and leaf spot diseases of Aloe vera L. from Bangladesh

2013 ◽  
Vol 22 (2) ◽  
pp. 103-108
Author(s):  
Anita Rani Shutrodhar ◽  
Shamim Shamsi
Keyword(s):  
Aspergillus Niger ◽  
Aspergillus Flavus ◽  
Leaf Spot ◽  
Colletotrichum Gloeosporioides ◽  
Aloe Vera ◽  
Fungal Species ◽  
Pathogenicity Test ◽  
Diseased Leaf ◽  
Leaf Spots ◽  
Nigrospora Oryzae

Characteristic symptoms of anthracnose and leaf spot were recorded from diseased leaf samples of Aloe vera L. A total of 8 fungal species, namely Alternaria pluriseptata (Karst. & Har.) Jorstad, Aspergillus flavus Link, Aspergillus niger Van Tieghem, Cladosporium oxysporum Berk. & Curt., Colletotrichum gloeosporioides (Penz.) Sacc., Nigrospora oryzae (Berk. & Br.) Petch, Penicillium sp. and Pestalotiopsis guepinii (Desm.) Stay. were found to be associated with healthy and diseased leaf samples. In addition to above 8 fungi, Curvularia brachyospora Boedijn, Epicoccum purpurascens Ehrenb. ex Schlecht and Sclerotium sp. were also associated with diseased leaf samples of the plant. The prevalence of the fungi ranged 1.43 - 13.35% on healthy leaves and 1.43 - 62.16% on infected leaves. The frequency of C. gloeosporioides was the maximum and that of Aspergillus and Penicillium was the lowest. Pathogenicity test revealed that C. gloeosporioides causes anthracnose and E. purpurascens and P. guepinii cause leaf spots of A. vera. Dhaka Univ. J. Biol. Sci. 22(2): 103-108, 2013 (July)

scholarly journals Pathogenicity of Phoma betae isolates from red beet (Beta vulgaris) at seed farms in Canterbury, New Zealand

2019 ◽  
Vol 72 ◽  
pp. 21-26
Author(s):  
Nitesh Chand ◽  
E. Eirian Jones ◽  
Seona Casonato
Keyword(s):  
New Zealand ◽  
Beta Vulgaris ◽  
Leaf Spot ◽  
Root Rot ◽  
Economic Importance ◽  
The Other ◽  
Fodder Beet ◽  
Leaf Spots ◽  
Red Beet ◽  
Phoma Betae

Phoma betae is an economically important pathogen of red beet causing preemergence seedling damping, leaf spot and root rot. However, the pathogenicity of P. betae is unknown in New Zealand despite the economic importance of this pathogen. Twenty-five isolates were collected from a survey of red beet seed farms in Canterbury, New Zealand during 2016/2017 and three of these PB101 (from seeds), PB103 (from roots) and PB106 (from leaves) were used for pathogenicity testing of two red-beet cultivars. Isolate PB106 was further used to investigate its effects on spinach and fodder beet as well as red beet under greenhouse conditions. All three P. betae isolates were pathogenic on both red-beet cultivars tested, causing leaf-spot symptoms. Isolates PB101 and PB106 produced significantly larger leaf-spot lesions (P<0.001) compared with PB103. Phoma betae isolate PB106 was pathogenic to both red-beet cultivars, spinach and fodder beet but fodder beet was less susceptible than the other species tested. Regardless of cultivar, <i>P. betae </i>is an important pathogen of beets and is capable of causing leaf spots.

scholarly journals Molecular Identification and Management of Rhizoctonia Fragariae the Pathogen of Black Root Rot of Strawberry Plant

2017 ◽  
Vol 5 (2) ◽  
pp. 172
Author(s):  
Brwa Azad Aziz ◽  
Qasim Abdulla Marzani
Keyword(s):  
Root Rot ◽  
Pcr Amplification ◽  
Management Options ◽  
Black Root Rot ◽  
Pests And Diseases ◽  
Yield Value ◽  
Polymerase Chain ◽  
Crown And Root Rot ◽  
And Control ◽  
Important Disease

Strawberry plants are susceptible to a large number of pests and diseases and this can affect the quality and yield value of the fruit. Black root rot is an important disease of strawberry caused by a complex of fungi including Rhizoctonia. The most recognizable species of Rhizoctonia are R. solani and R. fragariae which are multinucleate and binucleate species, respectively. This work is aimed to isolate, identify and control the strawberry root rot caused by R. fragariae. Infected strawberry samples were collected from Erbil, Slemani, Duhok and Garmiyan Provinces. The identification of isolated fungi was achieved by using traditional methods along with molecular methods using polymerase chain reaction (PCR). In the later method, specific primers were designed and used to identify Rhizoctonia species. Several disease management options, including biological by using two species of Trichoderma, and chemical methods using Pristine fungicide, were also investigated. Sampling of strawberry plants revealed that the disease is prevalent in Kurdistan region and the isolated fungi, R. solani, Rhizoctonia sp., and R. fragariae, were pathogens of the disease causing crown and root rot of strawberry. PCR amplification was confirmed the identification of the species of Rhizoctonia. The results of control methods revealed that the most effective treatments were achieved using the fungicide followed by the use of the combination of T. harzianum and T. viride.

scholarly journals Molecular Phylogenetic Diversity and Biological Characterization of Diaporthe Species Associated with Leaf Spots of Camellia sinensis in Taiwan

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1434
Author(s):  
Hiran A. Ariyawansa ◽  
Ichen Tsai ◽  
Jian-Yuan Wang ◽  
Patchareeya Withee ◽  
Medsaii Tanjira ◽  
...  
Keyword(s):  
Camellia Sinensis ◽  
Leaf Spot ◽  
Phylogenetic Trees ◽  
Fungal Infections ◽  
Elongation Factor ◽  
Fungal Species ◽  
Tea Leaves ◽  
Phenotypic Characters ◽  
Leaf Spots ◽  
Molecular Phylogenetic

Camellia sinensis is one of the major crops grown in Taiwan and has been widely cultivated around the island. Tea leaves are prone to various fungal infections, and leaf spot is considered one of the major diseases in Taiwan tea fields. As part of a survey on fungal species causing leaf spots on tea leaves in Taiwan, 19 fungal strains morphologically similar to the genus Diaporthe were collected. ITS (internal transcribed spacer), tef1-α (translation elongation factor 1-α), tub2 (beta-tubulin), and cal (calmodulin) gene regions were used to construct phylogenetic trees and determine the evolutionary relationships among the collected strains. In total, six Diaporthe species, including one new species, Diaporthe hsinchuensis, were identified as linked with leaf spot of C. sinensis in Taiwan based on both phenotypic characters and phylogeny. These species were further characterized in terms of their pathogenicity, temperature, and pH requirements under laboratory conditions. Diaporthe tulliensis, D. passiflorae, and D. perseae were isolated from C. sinensis for the first time. Furthermore, pathogenicity tests revealed that, with wound inoculation, only D. hongkongensis was pathogenic on tea leaves. This investigation delivers the first assessment of Diaporthe taxa related to leaf spots on tea in Taiwan.

scholarly journals Photosynthesis of Blueberry Leaves as Affected by Septoria Leaf Spot and Abiotic Leaf Damage

Plant Disease ◽  
2004 ◽  
Vol 88 (4) ◽  
pp. 397-401 ◽  
Author(s):  
I. Roloff ◽  
H. Scherm ◽  
M. W. van Iersel
Keyword(s):  
Leaf Area ◽  
Disease Severity ◽  
Leaf Spot ◽  
Abiotic Factors ◽  
Lesion Size ◽  
Leaf Conductance ◽  
Yield Potential ◽  
Leaf Spots ◽  
Virtual Lesion ◽  
Septoria Leaf Spot

Leaf spots caused by fungal pathogens or abiotic factors can be prevalent on southern blueberries after harvest during the summer and fall, yet little is known about how they affect physiological processes that determine yield potential for the following year. In this study, we measured CO2 assimilation and leaf conductance on field-grown blueberry plants affected by Septoria leaf spot (caused by Septoria albopunctata) or by edema-like abiotic leaf blotching. Net assimilation rate (NAR) on healthy leaves varied between 6.9 and 12.4 μmol m-2 s-1 across cultivars and measurement dates. Infection by S. albopunctata had a significant negative effect on photosynthesis, with NAR decreasing exponentially as disease severity increased (R2 ≥0.726, P < 0.0001). NAR was reduced by approximately one-half at 20% disease severity, and values approached zero for leaves with >50% necrotic leaf area. There was a positive, linear correlation between NAR and leaf conductance (R2 ≥ 0.622, P < 0.0001), suggesting that the disease may have reduced photosynthesis via decreased CO2 diffusion into affected leaves. Estimates of virtual lesion size associated with infection by S. albopunctata ranged from 2.8 to 3.1, indicating that the leaf area in which photosynthesis was impaired was about three times as large as the area covered by necrosis. For leaves afflicted by edema-like damage, there also was a significant negative relationship between NAR and affected leaf area, but the scatter about the regression was more pronounced than in the NAR-disease severity relationships for S. albopunctata (R2 = 0.548, P < 0.0001). No significant correlation was observed between leaf conductance and affected area on these leaves (P = 0.145), and the virtual lesion size associated with abiotic damage was significantly smaller than that caused by S. albopunctata. Adequate carbohydrate supply during the fall is critical for optimal flower bud set in blueberry; therefore, these results document the potential for marked yield losses due to biotic and abiotic leaf spots.

What is an Ecodisaster?

1977 ◽  
Vol 4 (1) ◽  
pp. 66-68 ◽  
Author(s):  
John L. Cloudsley-Thompson
Keyword(s):  
Developed Countries ◽  
Standard Of Living ◽  
World Population ◽  
Human Species ◽  
Pests And Diseases ◽  
The Past ◽  
Environmental Deterioration ◽  
The World ◽  
Global Catastrophe ◽  
Near Future

The term ‘ecodisaster’ may be defined as ‘a global catastrophe of the human species’. Any ecodisasters occurring in the near future will, almost certainly, be caused, directly or indirectly, by the present overpopulation of the world, accompanied by unwise and irresponsible disregard of environmental deterioration.The suggestion is made here that Man's first and, it is to be hoped, last, ecodisaster may already have begun. Although not dramatic, it is taking the form of a steady decline in the standard of living nearly everywhere, coupled with massive pollution, and widespread malnutrition in the under-developed countries of the world. It will persist until world population eventually becomes adjusted to environmental resources.It is ironical that control of the pests and diseases which have inflicted so much misery on mankind in the past, should have helped to engender the present population explosion with all the hunger and privation that accompany it in the under-developed regions of the world.

Cochliobolus pallescens. [Descriptions of Fungi and Bacteria].

1990 ◽  
Author(s):  
A. Sivanesan
Keyword(s):  
Hong Kong ◽  
Sierra Leone ◽  
Papua New Guinea ◽  
Geographical Distribution ◽  
Leaf Spot ◽  
Solomon Islands ◽  
Ear Rot ◽  
Black Point ◽  
Leaf Spots ◽  
Windward Islands

Abstract A description is provided for Cochliobolus pallescens. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Common on many graminicolous and non-graminicolous hosts. Important cereals and grasses include Eleusine, Hordeum, Oryza, Panicum, Paspalum, Pennisetum, Poa, Saccharum, Setaria, Sorghum, Triticum and Zea economically important dicot hosts include Allium (59, 4867), Arachis (53, 1647), Brassica (66, 3075), Canna, Calendula, Calotropis (44, 1832; 66, 3587), Carica (61, 5129), Cinnamomum, Citrus (68, 843), Coriandrum, Dahlia, Fagopyrum (64, 2425), Gaillardia, Hevea (56, 1257; 67, 5560), Musa (54, 4051), Solanum (50, 3484). DISEASE: Leaf spots of cereals, black point of wheat (44, 102), leaf spot and on stems of rubber (56, 1257; 67, 5560), ear rot of barley (62, 1005), rot of garlic (59, 4867). GEOGRAPHICAL DISTRIBUTION: Australia, Bangladesh, Brunei, Burma, Canada, Colombia, Cuba, Denmark, Egypt, Ethiopia, Fiji, Ghana, Guinea, Hong Kong, India, Indonesia, Iran, Jamaica, Japan, Kenya, Malaysia, Malawi, Nepal, Nigeria, Pakistan, Papua New Guinea, Peru, Philippines, Sierra Leone, Singapore, Solomon Islands, Somalia, Sri Lanka, Swaziland, Sudan, Taiwan, Tanzania, Thailand, Trinidad, USA, USSR, Venezuela, Windward Islands, Zambia, Zimbabwe. TRANSMISSION: By wind-borne conidia and seed-borne.

Genetics of Cercospora Leaf Spot Resistance in Mungbean [Vigna radiata (L.) Wilczek] through Generation Mean Analysis

2021 ◽  
Author(s):  
Priyanka Choudhary ◽  
Ramesh Chand ◽  
Anil Kumar Singh
Keyword(s):  
Latent Period ◽  
Leaf Spot ◽  
Vigna Radiata ◽  
Generation Mean Analysis ◽  
Cercospora Leaf Spot ◽  
Progress Curve ◽  
High Heritability ◽  
Efficient Breeding ◽  
Important Disease ◽  
Selection Of

Background: Cercospora leaf spot (CLS) is a fungal disease of mungbean [Vigna radiata (L.) Wilczek] caused by Cercospora canescens and now emerged as an important biotic stress. A better understanding of the genetics of CLS resistance will help in formulating efficient breeding procedures in mungbean.Methods: The present investigation focused on genetics of CLS resistance through generation mean analysis (six parameter model) in two intra-specific mungbean crosses namely, Kopergaon × HUM12 and Kopergaon × ML1720. Four quantitative disease resistance components, viz., Area under disease progress curve (AUDPC), Incubation period (IP), Latent period (LP) and degree of sporulation (SP) were studied.Result: A high correlation of AUDPC with latent period (r = –0.68 to –0.79, P less than 0.0001) and SP (r = 0.72 to -0.81, P less than 0.0001) advocated that both are main contributor for CLS disease development. High heterosis along with high heritability in terms of AUDPC ( greater than 0.09) indicated the importance of genetic factor(s) in controlling CLS resistance. Generation mean analysis of both the crosses revealed duplicate epistatic interaction and involvement of two genes for CLS resistance in terms of AUDPC. This study supports oligogenic nature of inheritance, advocating AUDPC along with IP, LP and SP as important disease indicator for selection of CLS resistance in mungbean.

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