Eficiência do uso da água no cultivo do coentro e da salsa na presença de um polímero hidroabsorvente.

Abstract

The objective of the present work was to maximize productivity and efficiency of water usage applied in coriander and parsley cultivations by utilizing a hydrogel polymer named hidratassolo. Thus establishing a more appropriate method of irrigation management. The study was done in an experimental station built in the Tecnologia Rural Department of Universidade Federal Rural de Pernambuco, located in the municipal district of Recife-PE during September 2005 to May 2006. The parsley cultivation was done in a protected atmosphere, with two irrigation frequencies (2 and 4 days water replacement), and five hidratassolo doses (0; 5; 10; 15 and 20 dg.kg"1). The coriander cultivation was grown in a field atmosphere, with two irrigation leveis related to estimated evapotranspiration (Tank Class "A" method O.ó.ETo and 1.20.ETo in mm), applied on two day irrigation frequencies, and five hidratassolo doses (0; 4; 8; 12 and 16 dg.kg"1). The experiment design consisted of randomized blocks in split-plots, with simple regression analysis. The characteristics appraised were efficiency of water use, crop maximum evapotranspiration, crop coefficient, height of plants, and productivity. Hidratassolo leveis affected, in an isolated way, the vegetative characteristics studied in the parsley cultivations, in two harvests. The studied treatments affected the volumes of water consumed in the coriander cultivations, and the vegetative characteristics as well. In two instances of coriander planting, the appraised vegetative characteristics increased linearly with the elevation of hidratassolo dosage when minimum irrigation leveis were established, except for height of plants in the fírst planting. With application of maximum irrigation leveis, the appraised characteristics of the coriander, with significant interaction, reached maximum points with doses varying around 6.00 to 11.00 dg.kg"1. While the maximum dose provided a reduction when applied to a blank treatment. The observed averages of the maximum evapotranspiration and crop coefficients, during water balance periods, increased with the elevation of hidratassolo doses when the minimum irrigation leveis were used. These averages reached their maximum observed values with a hidratassolo dose of 8 dg.kg"1 at maximum irrigation leveis.