scholarly journals Fungi on irrigated rice seeds produced in the pre-germinated system in the Alto Vale do Itajaí region, Santa Catarina state, Brazil

2020 ◽  
Vol 50 (8) ◽  
Author(s):  
Bruno Tabarelli Scheidt ◽  
Juliano Berghetti ◽  
Flávio Chupel Martins ◽  
Ricardo Trezzi Casa ◽  
Welliton Recalcatti ◽  
...  

ABSTRACT: The aim of this research was to identify and quantify fungi infecting irrigated rice seeds produced in the 2015/16, 2016/17 and 2017/18 harvests in the pre-germinated system in the Alto Vale do Itajaí Region, Santa Catarina State, Brazil. A total of 479 lots of eight cultivars were analyzed. Seeds were disinfected and sown in potato-sucrose-agar culture medium with incubation for seven days at 25ºC ± 2ºC and photoperiod of 12 hours. The main fungus detected in the three crops season was Microdochium albescens with 54.9% of average incidence, followed by Alternaria padwikii (7.7%) and Bipolaris oryzae (3.3%).

2020 ◽  
Vol 50 (2) ◽  
Author(s):  
Bruno Tabarelli Scheidt ◽  
Jaquelini Garcia ◽  
Ricardo Trezzi Casa ◽  
Cileide Maria Medeiros Coelho ◽  
Amauri Bogo ◽  
...  

ABSTRACT: The fungus Microdochium albescens is one of the main pathogens associated with irrigated rice seeds in southern Brazil. The objective of the present study was to quantify the transmission of M. albescens from naturally infected seeds to the crown, coleoptile, and first true leaf of the seedlings of six cultivars growing in pre-germinated cultivation system of irrigated rice. Seeding was carried out on a water-saturated substrate, using four untreated seed lots for each of the six cultivars. At 14 days after sowing, the crown, coleoptile, and first true leaf of the seedlings were carefully highlighted, and the samples were disinfected and plated onto potato-sucrose-agar culture medium. M. albescens was transmitted asymptomatically to crown, coleoptile, and first true leaf, at rates of 39.3%, 25.8%, and 5.4%, respectively (these values represent the average incidence of the six cultivars). This is the first report that proves that M. albescens is transmitted from infected seeds to irrigated rice seedlings in a pre-germinated seed system.


2021 ◽  
Vol 47 (1) ◽  
pp. 57-59
Author(s):  
Bruno Tabarelli Scheidt ◽  
Juliano Berghetti ◽  
Ricardo Trezzi Casa ◽  
Flávio Chupel Martins ◽  
Weliton Recalcatti ◽  
...  

ABSTRACT The aims of this study were to quantify the viability of Microdochium albescens in irrigated rice seeds stored during the time between harvests and to quantify its incidence in the seed structures. Samples of irrigated rice seeds of the cultivars SCS122 Miura and SCS121 CL were monthly collected and stored during the time between harvests 2018/19. Pathology analysis and viability quantification were performed in the laboratory. The location of the fungus in the seeds was determined by separating lemma, palea, endosperm and embryo, with subsequent disinfestation and sowing in culture medium. The fungus M. albescens showed 77.8% seed storage viability for nine months, considering the average of lots and cultivars. Average incidence was 48% in the lemma, 43.7% in the palea, 24.7% in the endosperm and 20.7% in the embryo. The fungus M. albescens remains viable in rice seeds between harvests, while mycelium is detected at a higher incidence in the external tissues of caryopsis.


2022 ◽  
Vol 52 (4) ◽  
Author(s):  
Bruno Tabarelli Scheidt ◽  
Evandro Zacca Ferreira ◽  
Flávio Chupel Martins ◽  
Juliano Berghetti ◽  
Marília Michalski De Pieri ◽  
...  

ABSTRACT: The fungus Microdochium albescens can interfere in the germination of seeds and in the death of rice seedlings; however, there is not technical indication for its control by seed treatment. This research evaluated the efficiency of fungicides in the treatment of pre-germinated and dryland rice seeds in the control of M. albescens. Seeds of the cultivars, Epagri 109, SCS116 Satoru, SCS121 CL and SCS122 Miura were treated with the following fungicides (g a.i./100 kg of seeds): fluazinam + thiophanate methyl (9.45 + 63), pyraclostrobin + thiophanate methyl (5 + 45), carboxin + thiram (60 + 60), metalaxyl-M + thiabendazole + fludioxonil (3 + 22.5 + 3.75), carbendazim + thiram (45 + 105), carbendazim (45). Seeds without fungicide treatment constituted the control. The treated seeds were sown in potato-sucrose-agar (PSA) culture medium and incubated at 25 ± 2 °C and photoperiod of 12 hours for 14 days. Treated seeds were also submitted to the germination test. Fluazinam + thiophanate methyl and metalaxyl-M + thiabendazole + fludioxonil showed greater control of M. albescens, not differing statistically between them, in the five cultivars and in the two cultivation systems. The tested fungicides provided seed germination above 90% in the four cultivars.


2013 ◽  
Vol 31 (3) ◽  
pp. 413 ◽  
Author(s):  
André Becker Nunes ◽  
Gilson Carlos Da Silva

ABSTRACT. The eastern region of Santa Catarina State (Brazil) has an important history of natural disasters due to extreme rainfall events. Floods and landslides are enhancedby local features such as orography and urbanization: the replacement of natural surface coverage causing more surface runoff and, hence, flooding. Thus, studies of this type of events – which directly influence life in the towns – take on increasing importance. This work makes a quantitative analysis of occurrences of extreme rainfall events in the eastern and northern regions of Santa Catarina State in the last 60 years, through individual analysis, considering the history of floods ineach selected town, as well as an estimate through to the end of century following regional climate modeling. A positive linear trend, in most of the towns studied, was observed in the results, indicating greater frequency of these events in recent decades, and the HadRM3P climate model shows a heterogeneous increase of events for all towns in the period from 2071 to 2100.Keywords: floods, climate modeling, linear trend. RESUMO. A região leste do Estado de Santa Catarina tem um importante histórico de desastres naturais ocasionados por eventos extremos de precipitação. Inundações e deslizamentos de terra são potencializados pelo relevo acidentado e pela urbanização das cidades da região: a vegetação nativa vem sendo removida acarretando um maior escoamento superficial e, consequentemente, em inundações. Desta forma, torna-se de suma importância os estudos acerca deste tipo de evento que influencia diretamente a sociedade em geral. Neste trabalho é realizada uma análise quantitativa do número de eventos severos de precipitação ocorridos nas regiões leste e norte de Santa Catarina dos últimos 60 anos, por meio de uma análise pontual, considerandoo histórico de inundações de cada cidade selecionada, além de uma projeção para o fim do século de acordo com modelagem climática regional. Na análise dos resultados observou-se uma tendência linear positiva na maioria das cidades, indicando uma maior frequência deste tipo de evento nas últimas décadas, e o modelo climático HadRM3P mostra um aumento heterogêneo no número de eventos para todas as cidades no período de 2071 a 2100.Palavras-chave: inundações, modelagem climática, tendência linear.


Author(s):  
ACIR JOSÉ DIRSCHNABEL ◽  
JANAINA PITT ◽  
FRANCIELLE KAFER ◽  
CAMILA PEZZINI ◽  
LEA MARIA FRANCESCHI DALLANORA ◽  
...  

2018 ◽  
Vol 7 (2) ◽  
pp. 84-91
Author(s):  
Adil Laaziz ◽  
Souad Qjidaa ◽  
Yousra El Hammoudi ◽  
Abdelouahed Hajjaji ◽  
Amina Bouseta

The aim of this study was to evaluate the effect of three fungicides azoxystrobin (Ortiva), hexaconazole (Hexa) and pyrimethanil (Pyrus) for their ability to inhibit the radial growth and ochratoxin A (OTA) production by five ochratoxigenic strains of Aspergillus carbonarius and A. niger previously iso-lated from Moroccan grapes. Our results showed that, the addition of the fungicides to the Czapek Yeast Autolysate agar culture medium reduced the growth of the ochratoxigenic strains. Pyrimethanil caused total inhibition of spore germination and growth of the five strains, for all dose tested. Where-as hexaconazole totally inhibited the growth of 4 strains and gave growth for the MUCL 49227 strain (2.67 mm/day) at sublethal concentration. The reduction in radial growth was less marked for azoxystrobin, with growth rate varying between 0 and 6.37 mm/day depending on the strain and the azoxystrobin concentration. Analysis of variance showed that the effect of single factors (fungicides, concentration and strain) and their interactions on growth and OTA production were highly significant (P=0.000).These findings suggest that the use of tested fungicides have to potential for reduction in production of OTA.


Phytotaxa ◽  
2018 ◽  
Vol 364 (3) ◽  
pp. 275
Author(s):  
CASSIO RABUSKE DA SILVA ◽  
JOSIMAR KÜLKAMP

Valeriana iganciana, an endemic species from the Serra do Tabuleiro highlands of Santa Catarina state, southern Brazil, is described and illustrated. The new species shares morphological affinities with V. ulei, from which it is distinguished mainly by leaves with entire margin, by the cymose architecture of the inflorescence and by the triquetrous and elliptical fruits with annular to dentate calyx.


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