Efeito da presença das plantas daninhas no microclima da cultura da cevada
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Data
1997-01-01
Autores
Souza, José Roberto P. de
Velini, Edivaldo Domingues [UNESP]
Marcondes, Daniel A. S. [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Sociedade Brasileira da Ciência das Plantas Daninhas
Resumo
Um experimento foi realizado com cevada (Hordeum vulgare L.) em condições de campo, com o objetivo de avaliar , durante um período de estiagem (82 e 89 dia após a emergência da cevada), o microclima formado pela cultura mantida na presença ou ausência de plantas daninhas desde o início do ciclo. Foram avaliados o teor de água do solo, umidade relativa, temperatura, tensão de vapor d'água, déficit de saturação de vapor d'água, potencial água e teor de água do ar nos períodos da s 8: 30 às 9:00, 11:30 às 12:00, 14:30 às 15:00 e 17:30 às 18:00 horas a 0,0m, 0,10m, 0,20m, 0,30m, 0,40m, 0,50m, 0,60m e 0,70m de altura na entrelinha da cultura. A presença das plantas daninhas na cultura durante o período de estiagem contribuiu para reduzir as perdas de água do solo para a atmosfera. Nos três primeiros períodos do dia e nas áreas mais próximas do solo, a cultura mantida no mato os menores valores de temperatura e déficit de saturação de vapor d'água do ar, e os maiores valores de umidade relativa, tensão de vapor d'água, potencial água e teor de água do ar, que proporcionaram redução do consumo de água do solo.
The objective of this research was to evaluateth e effects of the weeds on water consumption and the microclimate in a field of barley (Hordeum vulgare L.), during a drought period. It were evaluated the soil water contents, relative humidity, temperature, water vapor tension, water vapor saturation deficit, water potential, water content in the air at different times (8:30 to 9:00, 11:30 to 12:00, 14:30 to 15:00 and 17:30 to 17:00) and heights (0.0; 0.10; 0.20; 0.30; 0.40; 0.50; 0.60 and 0.70m). The weeds, at high population densities increased the water content in the air, the water vapor tension, the water potential and the relative humidity and decreased the temperature, the saturation déficit and the air movement in the plots. The highest water contents in the soil were observed in highly infested areas, showing that, in this condition, the weeds increased the amount of water available to the crop. In plots with median and low population densities of weeds the water contents in weedy and weed free plots were similar. In plots with low weed populations higher amounts of water were available to the crop in hand weeded plots.
The objective of this research was to evaluateth e effects of the weeds on water consumption and the microclimate in a field of barley (Hordeum vulgare L.), during a drought period. It were evaluated the soil water contents, relative humidity, temperature, water vapor tension, water vapor saturation deficit, water potential, water content in the air at different times (8:30 to 9:00, 11:30 to 12:00, 14:30 to 15:00 and 17:30 to 17:00) and heights (0.0; 0.10; 0.20; 0.30; 0.40; 0.50; 0.60 and 0.70m). The weeds, at high population densities increased the water content in the air, the water vapor tension, the water potential and the relative humidity and decreased the temperature, the saturation déficit and the air movement in the plots. The highest water contents in the soil were observed in highly infested areas, showing that, in this condition, the weeds increased the amount of water available to the crop. In plots with median and low population densities of weeds the water contents in weedy and weed free plots were similar. In plots with low weed populations higher amounts of water were available to the crop in hand weeded plots.
Descrição
Palavras-chave
Hordeum vulgare, planta daninha, água, temperaturas, Hordeum vulgare, weed, water, temperature
Como citar
Planta Daninha. Sociedade Brasileira da Ciência das Plantas Daninhas , v. 15, n. 2, p. 89-96, 1997.