Eficiência do uso da água na mangueira sob diferentes tratamentos de irrigação.

Abstract

The main objective of this study was to determine the crop coefficient more appropriate and determine the water use efficiency to mango orchard growth in a region of the middle reaches of the San Francisco river valley. A field experiment was carried out at the production area of the farm “Boa Esperança S.A” which is located at the Km 183 of the BR-428, at Petrolina, Pernambuco state (latitude: 09o20’S; longitude: 40o27’W; altitude: 365.5 m above sea level). Experimental delineation was entirely randomized, with four treatments and four repetitions. The irrigation treatments were established based on the reference crop coefficient (Kcr) obtained by Silva (2000) as follows: treatment T1 (Kcr – 20%), treatment T2 (Kcr), treatment T3 (Kcr + 20%) and treatment T4 (control). The mango orchard evapotranspiration was obtained by soil water balance method and the production components such as yield, weight of fruits per plant and number of fruits per plant also were avaluated. It was used both evapotranspiration and irrigation to estimate the water use efficiency of the mango orchard. Soil water pressure suction was measured based on the twelve sets of mercury monometer tensiometers positioned under the canopy of individual trees. Measurements were recorded three times per week at 08:00, 12:00 and 16:00 h. Throughout the mango orchard fruiting cycle the means daily evapotranspiration were 3,0; 3,2; 3,6 and 4,1 mm/day under T1, T2, T3 and T4 treatments, respectively. The maximum and minimum yields were 31.1 and 28.1 t ha-1 under the T1 and T4 treatments, respectively. Results also showed that the productivity parameters of the mango orchard did not have significant difference statistically at 5% significance level by Turkey’s test. Despite its higher water level, the T4 treatment had the lowest yield.