Data/hora: 01/06/2024 22:47:31

Biblioteca(s): 	Embrapa Soja.	
Data corrente: 	13/05/1993	
Data da última atualização: 	27/10/2004	
Autoria: 	SCHMITTHENNER, A. F.	
Afiliação: 	The Ohio State University, Wooster, Ohio 44691, U.S.A.	
Título: 	Phytophthora root rot: detection, ecology and control.	
Ano de publicação: 	1989	
Fonte/Imprenta: 	In: CONFERENCIA MUNDIAL DE INVESTIGACION EN SOJA, 4., 1989, Buenos Aires. Actas... Buenos Aires: AASOJA, 1989.	
Volume: 	t.3	
Páginas: 	p.1284-1289.	
Idioma: 	Inglês	
Conteúdo: 	Phytophthora root rot of soybean caused by P. megasperma f. sp. glycinea (Pmg) was first found in the United States, where it can kill 100% of susceptible plants. Average loss is estimated at 5%. Although widely distributed, it has not yet been reported from Central and South America or Asia. Symtoms are seed rot, damping-off, root rot, stem rot, wilting and reduced vigor and stem lesions on older plants. Severity is dependent on cultivar tolerance (relative susceptibility). The pathogen survives for many years as oopsores in debris from diseased plants. Primary infection occurs from zoospores formed from oospores in soil. Flooded soil is required for severe infection, and highly tolerant cultivars may escape if no flooding occurs. Early infection periods are more damaging than late ones. Factors increasing severity are flooding rainfall, poorly drained soil, reduced tillage, high soil salts, and continous cropping of soybean. Phytophthora can be controlled by monogenic, race-specific resistance; 12 genes at six loci have been described. Twenty-five Pmg races have been reported , some of which are virulent to the latest resistance gene combination released. Alternative controls are application of metalaxyl to soil, which is most effective with the high tolerance, improved drainage, plowing or other tillage, metalaxyl seed treatment, and rotation.	
Palavras-Chave: 	Disease; EUA; Fitopatologia; Fungus; Phytopathology; Soybean; USA.	
Thesagro: 	Doença; Fungo; Phytophthora Megasperma; Soja.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Soja (CNPSO)