Tolerância de genótipos de citros ao estresse hídrico na fase de porta-enxerto.

Abstract

The study was conducted in greenhouse conditions (bath-vegetation), Academic Unit of Agricultural Engineering (UAEAg) / CTRN UFCG in the city of Campina Grande in Paraíba State in geographical coordinates 7 15'18 "N S and 35 0 52'28 "W longitude, at an altitude of 550 m. The study aimed to evaluate the tolerance to water stress of 10 genotypes of citrus, with treatments consisting of two factors, water stress and genotypes of citrus. The water stress treatment consisted of EH1: witnesses, irrigated at 100% of fíeld capacity (CC); EH2: limited irrigation at 50% DC for 51 days and then 25% of CC. The genotypes used for the study were: 4 (LCR LVK x 019), 5 (LCR CTYM x 005), 6 (TSKC CTTR x 028), 7 (TSKC x CTSW 018), 11 (TSKFL CTTR x 017), 15 ( TSKC x CTARG 019), 16 (Citrange), 17 (TSKFL CWEB x 004), 20 (TSKC x CTSW 041), 25 (Rangpur SANTA CRUZ). Since the randomized block design with 3 replications, a 2 x 10, with experimental units consisting of 10 plants in polyethylene tubes of 288 ml, using a mixture of soil and substrate composed of vermiculite, pine bark and húmus 1:1. The water stress treatments were started with 125 days after sowing (DAS) conducted every 17 days, measurements of plant height, stem diameter and counting the number of leaves, obtained from these data the relative growth rate (RGR ). At 239 DAS transplant was performed in plastic bags filled with soil and with uniform weight of 6.5 kg. At the end of the experiment was made to obtain destructive analysis of matter, the parameter used in the classification of genotypes. The citrus genotypes studied can be classified according to water stress as follows: Tolerant: 6 (x TSKC CTTR 028), 7 (TSKC x CTSW 018), 15 (TSKC x CTARG 019), 16 (Citrange), 17 (TSKFL CWEB x 004) and 20 (TSKC x CTSW 041). Genotypes Moderately Sensible: 4 (LCR LVK x 018), 5 (LCR CTYM x 005), 11 (TSKFL CTTR x 017) and 25 (Rangpur SANTA CRUZ ). The genotype 17 (TSKFL CWEB x 004) stands out among the genotypes for their tolerance to water stress.