Articles
EFFECT OF BLEACHING, SHADING AND WATER SPRINKLING ON THE COVER IN THE TEMPERATURE AND OTHER CLIMATIC PARAMETERS OF GREENHOUSE, IN SUMMER.
Article number
357_26
Pages
268 – 268
Language
Abstract
The effect of some techniques on the temperature, visible radiation and transpiration in tomatoe plants was estimated in metallic greenhouses like simple tunnels (8 x 25 x 3,20 m) located in the Agriculture Experimental Station of the INTA in San Pedro, Buenos Aires province, Argentina.
The techniques were: lime bleaching with two densities: 95 and 34 g lime/m2; shading with an agrotextile mesh at 65% in 2 positions: horizontal laying, at 15 cm above the top of the greenhouse and leaned on the cover; and water sprinkling on the cover with two lines with micro water sprinklers providing a rain of water of 4 mm/hour.
Bleaching and shading allowed a significant decrease of temperature at the ground, environment, cover and tomatoe plants in relation to the control.
Water sprinkling on the cover rapidly reduced the temperature of it, though there was no influence on the inside temperature of the inside, neither was there on the visible radiation.
In the control, the temperature was registered flush with the soil, being followed in a decreasing order by the temperatures of the cover, plants and environment (stratification at different levels was observed). In the bleached and shaded greenhouses, no significant differences are given among these positions.
No agrotextile for shading in relation to its effectiveness at reducing the temperatures of the ground, environment and plants.
The visible radiation was significantly affected by the density of bleaching.
The transpiration in tomatoe plants was reduced almost proportionally to the decrease in visible radiation in the bleached and shaded greenhouses.
None of the showed a significant effect on the temperature of greenhouses during the night.
The techniques were: lime bleaching with two densities: 95 and 34 g lime/m2; shading with an agrotextile mesh at 65% in 2 positions: horizontal laying, at 15 cm above the top of the greenhouse and leaned on the cover; and water sprinkling on the cover with two lines with micro water sprinklers providing a rain of water of 4 mm/hour.
Bleaching and shading allowed a significant decrease of temperature at the ground, environment, cover and tomatoe plants in relation to the control.
Water sprinkling on the cover rapidly reduced the temperature of it, though there was no influence on the inside temperature of the inside, neither was there on the visible radiation.
In the control, the temperature was registered flush with the soil, being followed in a decreasing order by the temperatures of the cover, plants and environment (stratification at different levels was observed). In the bleached and shaded greenhouses, no significant differences are given among these positions.
No agrotextile for shading in relation to its effectiveness at reducing the temperatures of the ground, environment and plants.
The visible radiation was significantly affected by the density of bleaching.
The transpiration in tomatoe plants was reduced almost proportionally to the decrease in visible radiation in the bleached and shaded greenhouses.
None of the showed a significant effect on the temperature of greenhouses during the night.
Authors
Ing. Agr. Nora Francescangeli, Ing. Agr. Jorge Ferratto, Dr. Antonio Rosania, Ing. Civil Hugo Levit
Keywords
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