Data/hora: 18/06/2024 10:31:22

Biblioteca(s): 	Epagri-Sede.	
Data corrente: 	29/12/2021	
Data da última atualização: 	29/12/2021	
Autoria: 	CASTILHOS, R. V.; SILVA, M. C. C. R.; MATIOLO, G.	
Título: 	INCIDENCE OF Dalbulus maidis (HEMIPTERA: CICADELLIDAE) IN MAIZE AFTER SPRAYING WITH BIOLOGICAL AND CHEMICAL INSECTICIDES AND IMPACT ON MAIZE RAYADO FINO DISEASE.	
Ano de publicação: 	2021	
Fonte/Imprenta: 	In: REUNIÃO SUL-BRASILEIRA DE PESQUISA DE MILHO E SORGO, 2., 2021, Pato Branco . Resumos... Sete Lagoas, MG: ABMS, 2021.	
Idioma: 	Inglês	
Conteúdo: 	The foliar application of insecticides in the early stages of maize is a recommended practice in cases of high infestation of the leafhopper Dalbulus maidis (Hemiptera: Cicadellidae). In this work we evaluated the efficacy of biological and chemical foliar sprayed insecticides in the management of D. maidis and mitigation of maize rayado fino (MRF) disease (Maize rayado fino virus MRFV) in a second growing season maize. The trial was conducted in 2019/20 agricultural year, in Chapecó, SC, with the P4285 VYHR maize genotype, sown in plots of 120m2 (8 x 15m), in a density of 62.000 plants ha 1. The insecticides evaluated were: Octane (Isaria fumosorosea) 500mL/ha; Connect (imidacloprid + beta cyfluthrin) 750mL/ha and Talisman (bifenthrin + carbosulfan) 600mL/ha, all in a spray volume of 200L/ha, whereas the control plot did not receive any treatment. Insecticides were sprayed twice, at V2 and V5 stages. D. maidis were counted in five points in the plots, being each point composed by 10 plants, at three and seven days after first spray (DA1S) and three, seven and ten days after second spray (DA2S). At R2 stage, all plants in the plots were visually evaluated and the proportion of MRF disease was calculated (n. symptomatic plants / total n. plants). At maturation, cobs from 1m section of the four central lines of each plot were collected to obtain productivity/plant. Data were subjected to ANOVA and means compared by Tukey test at 5% probability. The respective amount of leafhoppers/plant at 3DA1S, 7DA1S, 3DA2S, 7DA2S and 10DA2S ranged from 1.22 to 2.36 in control; 1.22 to 2.42 in Octane; 1.12 to 2.26 in Connect; 1.46 to 2.78 Talisman. At the conditions of this particular study, the insecticides evaluated were not effective in reducing D. maidis incidence, since the number of leafhoppers in the treated plots was not significantly lower than control in all evaluations. The observed proportion of MRF symptomatic plants was 0.33, 0.29, 0.26 and 0.21 in the control, Octane, Talisman and Connect, respectively, with a reduction in MRF incidence of 13.8% for Octane, 23.8% for Talisman and 36.5% for Connect, in relation to the control. The grain productivity/plant was 150g in control, 155.5g in Octane, 152.1g in Connect and 138.1g in Talisman (not significant difference). Chemical control of D. maidis with foliar application of insecticides is difficult because of the great emigration of this pest from adjacent areas. Also, during the conduction of this study, the temperature and humidity were not favorable for appropriate Octane performance. All insecticides reduced MRF incidence, and the spray of biological and chemical insecticides, alone or in combination, should be considered as complement of seed treatment in D. maidis management.	
Palavras-Chave: 	integrated pest management; maize leafhopper; vector transmitted virus disease.	
Categoria do assunto: 	O Insetos e Entomologia	
URL: 	http://intranetdoc.epagri.sc.gov.br/producao_tecnico_cientifica/DOC_50539.pdf	
Registro original: 	Epagri-Sede (Epagri-Sede)	
Exemplares: 	Epagri-Sede - (106599-1) - UPC - PL - DD -  -  -  - DIS