Severidade de ocorrência das manchas de alternária e septoriose em girassol semeado em diferentes épocas no Rio Grande do Sul

Loose, Luís Henrique; Heldwein, Arno Bernardo; Maldaner, Ivan Carlos; Lucas, Dionéia Daiane Pitol; Hinnah, Fernando Dill; Bortoluzzi, Mateus Possebon

doi:10.1590/s0006-87052012005000012

Cited by 6 publications

(7 citation statements)

References 11 publications

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“…These results corroborate the ones of Loose et al (2012), who verified higher occurrence of diseases in the sowings performed in January and February, and by Leite et al (2006), who found higher yield and lower severity of alternaria leaf blight for the sowing dates in October and November, in Londrina-PR.…”

Section: Resultssupporting

confidence: 90%

“…The cultivation of sunflower in the different productive regions in Brazil is influenced by some factors that lead to yield reduction, such as the occurrence of diseases (Leite & Amorim, 2002;Loose et al, 2012) and periods of water deficit in the soil (Maldaner, 2012).…”

Section: Introductionmentioning

confidence: 99%

“…Tubaki and Nishihara, and septoria leaf blight, caused by Septoria helianthi Ellis and Kellerman (Leite et al, 2006;Loose et al, 2012). These diseases are favored by the climate of the state of Rio Grande do Sul, because of the frequency of occurrence of long periods of leaf wetting from the beginning of the spring until late October.…”

Section: Introductionmentioning

confidence: 99%

“…These diseases are favored by the climate of the state of Rio Grande do Sul, because of the frequency of occurrence of long periods of leaf wetting from the beginning of the spring until late October. On the other hand, this period is recommended for crop establishment, in order to avoid the coincidence of the period with the highest probability of water deficit and the most critical period for the crop regarding water stress (Maldaner, 2012).…”

Section: Introductionmentioning

confidence: 99%

“…Another sowing period that has stood out in the last years is the late season (from late January to late February), especially in irrigated areas, but it favors the occurrence of diseases due to the high temperature and relative air humidity in the beginning of the autumn (Loose et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

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Irrigation and fungicide application on disease occurrence and yield of early and late sown sunflower

Maldaner

Heldwein

Bortoluzzi

et al. 2015

Rev. bras. eng. agríc. ambient.

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A B S T R A C TThe objective of this study was to evaluate the effect of irrigation and fungicide application on the occurrence of diseases and cypsela yield of two genotypes of sunflower. The experiments were carried out in Santa Maria-RS, during the regular season in 2007 and the late season, in 2008. Plants were sown on 04/09/2007 and 21/01/2008, in a completely randomized design, with four replicates. A 2 x 6 factorial scheme was used, with the sunflower genotypes Aguará 03 and Hélio 358 and six fungicide application schemes, which were determined by the FAST forecasting system, as follows: FAST 16, FAST 22 and FAST 28, without irrigation, FAST 16 IRR under irrigated condition, in addition to irrigated control (CONTROL IRR) and control (CONTROL). Disease progress was analyzed based on weekly observations of the severity of the symptoms. It was verified that irrigation increases sunflower cypsela yield in the regular season, provided that weather conditions are not favorable for the occurrence of alternaria and septoria leaf blights or that fungicides are applied. In the late season, under irrigated condition, fungicide application is necessary to control alternaria and septoria leaf blights.Irrigação e aplicação de fungicidas na ocorrência de doenças e na produtividade do girassol em períodos de safra e safrinha R E S U M O Objetivou-se, neste trabalho, avaliar o efeito da irrigação e da aplicação de fungicidas na ocorrência de doenças e na produtividade de cipselas de dois genótipos de girassol. Os experimentos foram conduzidos em Santa Maria, RS, nos períodos de safra de 2007 e safrinha de 2008. As semeaduras foram realizadas em 04/09/2007 e 21/01/2008, sendo utilizado o delineamento inteiramente casualizado, com quatro repetições. Foi utilizado um esquema fatorial 2 x 6, constituído pelos genótipos de girassol Aguará 03 e Hélio 358 e seis esquemas de aplicação de fungicida, determinados em função do sistema de previsão FAST, os quais foram: FAST 16, FAST 22 e FAST 28, sem irrigação, FAST 16 IRR, em condição irrigada, além das testemunhas irrigada (TEST IRR) e não irrigada (TEST). O progresso da doença foi analisado com base nas observações semanais da severidade dos sintomas da doença. Verificou-se que a irrigação aumenta a produtividade de cipselas de girassol no cultivo de safra desde que as condições meteorológicas não sejam favoráveis para a ocorrência de mancha de alternaria e septoria ou que se apliquem fungicidas. Na safrinha em condição irrigada, a aplicação de fungicidas é necessária para o controle de mancha de alternaria e septória.

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Section: Resultssupporting

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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