Data/hora: 06/06/2024 20:24:57

Biblioteca(s): | Embrapa Soja.
Data corrente: | 30/06/2005
Data da última atualização: | 22/05/2006
Autoria: | YORINORI, M. A.; KLINGELFUSS, L. H.; PACCOLA-MEIRELLES, L. D.; YORINORI, J. T.
Título: | Effect of time of spraying of fungicide and foliar nutrient on soybean powdery mildew.
Ano de publicação: | 2004
Fonte/Imprenta: | Journal of Phytopathology, Berlin, v. 152, n. 3, p. 129-132, Mar. 2004.
Idioma: | Inglês
Conteúdo: | With the objective of determining the effects of initial infection level (% leaf area infected, % l.a.i.) at the time of fungicide and foliar nutrient application for the control of powdery mildew, a study was carried out under greenhouse conditions at Embrapa Soja, Londrina, P.R. The fungicide tebuconazole (100 g a.i./ha/application) and sulphur fungicide (2.0 kg a.i./ha/application), sprayed at 20, 30, 40 and 50% l.a.i. (growth stages V3 and V5, between R5.1 and R5.3), and three applications (at V3, V4 and R5.1, beginning at 20% l.a.i.) of tebuconazole were compared with sulphur foliar nutrient (sulphur at the dose of 125 g a.i./ha/application). The highly susceptible BR-16 cultivar was used in a completely randomized design with 11 treatments, five replications (pots) and five plants per pot. The parameters evaluated were: % l.a.i., % yellowing leaf when the control reached growth stage R7.2 (between 50 and 75% yellow/mature leaves), % defoliation (% defol.) when the control plants reached R8.2 (pre-harvest maturity), number of pods and seeds and seed weight (s.w.) per plant. The area under the disease progress curve (AUDPC) was determined based on disease progress. The % l.a.i. and AUDPC of the control (98% and 65.41) differed from other treatments (3.564.2% l.a.i. and 13.5740.59 AUDPC). The % l.a.i. for the sulphur fungicide treatment (41.964.2%) and sulphur foliar nutrient (49.8%) were greater than for tebuconazole (3.528%). The % defol. of the control (90%) differed from tebuconazole applied at 30% initial infection (48%), with three applications (45%), and from sulphur foliar nutrient (47%). The s.w./plant of the control (2.23 g) was lower than that of tebuconazole treated at 40% IL (3.03 g) and at 20% IL (3.35 g) and for sulphur foliar nutrient (3.7 g). The initial disease severity (2050% l.a.i.) did not affect the level of powdery mildew control and the sulphur foliar fertilizer resulted in greater number and higher s.w./plant.
Thesagro: | Doença de Planta; Fungicida; Fungo; Soja.
Categoria do assunto: | --
Registro original: | Embrapa Soja (CNPSO)
Exemplares: | CNPSO - (25242-1) - UPC - SP - -- - 9926 -  - 9926 - DIS