Water consumption of estevia (stevia rebaudian a (Bert.) Bertoni) estimate by automatic microlysimeter. / Consumo de água da cultura da estévia (Stevia rebaudiana (Bert.) Bertoni) estimado por microlisímetro automático.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2002

RESUMO

The aim of this work was to estimate the water consumption of stevia using two constant watertable microlysimeters and determine the irrigation levels response in the yield. The research was conducted at the Department of Agronomy and Agroecosystem Gestion experimental area of the Pisa University, in San Piero a Grado-Pisa/Itália. The reference evapotranspiration e was determined by the Penman-Monteith-FAO method. The data was daily coleected from June to October 2000. The two microlysimeters watertable had been maintained at 35 cm depth. The irrigation levls were 15%, 64%, 80%, 100% and 117% of evapotranspiration (ETP), measured by capillary ascension microlisymeter. The experimental design was entirely randomize with 4 repetitions and 20 plots. The soil water potential was measured by tensiometers installed at 10 cm, 20 cm, 30 cm and 40 cm. The crop evapotranspiration in the total cicle (80 days) was 464 mm. For the most water consumption phase, the crop evapotranspiration average was 5,44 mm.day-1. The crop coefficient values were 1,14 for the next period (from 26 to 50 days), and 1,16 for the latest one (from 51 to 80 days). The greatest yield was obtained by 117% ETE (538 mm) and 100% ETE (464 mm) irrigation levels, with 5130 Kg.ha-1 and 4931 Kg.ha-1, respectively. These values were 113% and 105% higher than the treatment without irrigation. The yield decreased according to increased the soil water tension. The different irrigation levels did not affect the esteviodeo content, with an average of 6,49%. Until 3 days between irrigation under the 117% ETE, the crops yield was not affected significatevily.

ASSUNTO(S)

water consumption consumo de água máquinas agrícolas hidríco rocking balanço hidríco estévia located irrigation irrigação localizada agricultural machines freáticos lençois lençois freáticos

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