Data/hora: 14/06/2024 16:56:42

Biblioteca(s): | Epagri-Sede.
Data corrente: | 02/05/2024
Data da última atualização: | 02/05/2024
Autoria: | CANALE, MC; CASTILHOS, R. V.; ANDRADE, M. V. S.; NESI, C. N.; ZAKEEL, M. C. M.
Título: | Unravelling the spatial dynamics and incidence of corn stunting disease complex in Brazilian maize fields.
Ano de publicação: | 2024
Fonte/Imprenta: | In: INTERNATIONAL EPIDEMIOLOGY WORKSHOP, 13., 2024, Foz do Iguaçú, PR. Abstracts... Viçosa, MG: UFV, 2024. p. 70
Idioma: | Inglês

Conteúdo:

Corn stunting disease complex poses a severe threat to maize production in Brazil, with
persistent outbreaks and substantial crop losses since 2015. This disease complex involves
two phloem bacterial pathogens, the maize bushy stunt phytoplasma (?Candidatus
Phytoplasma asteris?) and Spiroplasma kunkelii, both transmitted by the corn leafhopper
Dalbulus maidis (Hemiptera: Cicadellidae). Empirical studies to assess the epidemic
dynamics of this disease are scarce. This study aimed to comprehensively assess disease
incidence and progression in an experimental field in Chapecó, Santa Catarina, Brazil,
during the 2018/19 and 2019/20 cropping seasons. A meticulous visual evaluation of a total
of 2860 and 6336 maize plants was conducted, mapping binary data representing the
presence (1) or absence (0) of symptoms at 80 days after sowing. The observed corn
stunting disease incidence was 7.62% and 4.58% for the 2018/19 and 2019/20 seasons,
respectively. Statistical analyses revealed that the binomial distribution better described the
2018/19 data (log-likelihood ratio statistics, LRS = 2.24, df = 1, P > 0.05), while the
beta-binomial distribution was more suitable for the 2019/20 data (LRS = 7.82, df = 1, P <
0.05). However, the Fisher's indices of dispersion for both data, close to one, indicated a
relatively uniform distribution of diseased plants. Semivariogram analysis confirmed the
uniform distribution of diseased plants across the study fields. Geostatistical examination of
the large-scale distribution of diseased plants unveiled low spatial dependence, with an
index of aggregation around 1 and an intracluster correlation coefficient of &#8804; 0.03. The
absence of pronounced spatial clustering emphasizes the critical significance of a
widespread distribution throughout the field, highlighting the imminent risk of rapid plant
infestation and underscoring the necessity for prompt control measures to prevent potential
extensive damage. In conclusion, these findings deepen our understanding of the epidemic
dynamics of this disease, providing a basis for targeted interventions and effective
management strategies in Brazilian maize production.

Thesagro: | distribuição espaço-temporal; epidemia; molicutes.
Categoria do assunto: | X Pesquisa, Tecnologia e Engenharia
URL: | http://intranetdoc.epagri.sc.gov.br/producao_tecnico_cientifica/DOC_60785.pdf
Registro original: | Epagri-Sede (Epagri-Sede)
Exemplares: | Epagri-Sede - (109424-1) - UPC - PL - DD -  -  -  - DIS