Produção de porta-enxerto de goiaba “Paluma” sob estresse hídrico e ácido salicílico.

Abstract

One of the factors for the guava tree to present low productivity in the semi-arid region is the local climate, being the water scarcity the main problem, but that can be supplied by an adequate management and methods that provide a better resistance of this problem to the plant. Aiming at this, the objective was to evaluate the effect of salicylic acid on water stress in the production of Paluma guava. The experiment was conducted in a greenhouse in the semi-arid region of Pombal-PB. As for the experimental design, a randomized block design with 4 replicates was used, with five irrigation slides (50%, 58%, 77%, 97%, 105%) and five doses of salicylic acid (AS: 0.00; , 29, 1.00, 1.71 and 2.00 mM L-1), totaling 9 combinations generated through the Central Composite Box (CCB). The stem diameter, number of leaves and height of the plants were evaluated at 150 days after sowing; for the gas exchanges were stomatal conductance, liquid photosynthesis, transpiration, Ci concentration, intrinsic efficiency of carboxylation and water use. The data were submitted to analysis of variance, and polynomial regression analysis was performed for the significant values, using the statistical program SAS University. The irrigation blade 105% of the field capacity provides greater growth of the 'Paluma' guava rootstock. The irrigation blade 105% of the field capacity provides greater growth of the 'Paluma' guava rootstock; the physiological variables A, EiCi and USA are influenced by the increase of the irrigation depth (105%), presented the highest averages; the 2.0 mM dose of salicylic acid provides higher means in the physiological variables A and EiCi; the total dried phytomass presents higher mean values when a larger dose of salicylic acid (2.0 mM) is applied and a larger lamina (105%) is applied.