XAVIER, Adnelba Vitória Oliveira.
Resumo:
In the Northeast region, guava has great socioeconomic importance, being widely cultivated,
due to its great demand and acceptance by consumers, but its cultivation in areas that have high
levels of salts in the water is a limiting factor due to its sensitivity to salt stress. Thus, the search
for strategies capable of mitigating the deleterious effects on guava is of paramount importance
for the expansion of irrigated cultivation, highlighting the foliar application of salicylic acid. In
this sense, the objective of this study was to evaluate the growth, physiological indices, and
quality of 'Paluma' guava seedlings irrigated with saline water and foliar application of salicylic
acid during the rootstock formation phase. The research was conducted under greenhouse
conditions, belonging to the Center of Technology and Natural Resources of the Federal
University of Campina Grande (CTRN/UFCG), located in the municipality of Campina Grande,
PB. The design used was randomized blocks in a 5 × 5 factorial arrangement, with five levels
of electrical conductivity of water (0.6, 1.5, 2.4, 3.3, and 4.2 dS m-1) and five concentrations of
salicylic acid (0, 0.8, 1.6, 2.4, and 3.2 mM), with four replications and two plants per plot.
Salicylic acid up to a concentration of 1.3 mM increased the relative water content and
decreased intercellular electrolyte leakage from the leaf blade of 'Paluma' guava seedlings.
Foliar application of salicylic acid at a concentration of 1.7 mM attenuated the effects of salt
stress on chlorophyll a of guava seedlings irrigated with water of up to 1.6 dS m-1. The
concentrations of 1.6 and 1.5 mM of salicylic acid increased the levels of chlorophyll b and
chlorophyll total, respectively. The harmful effects of salt stress on carotenoid concentration
and quantum efficiency of photosystem II were not attenuated by the application of salicylic
acid. The concentrations of salicylic acid applied via foliar spray did not attenuate the harmful
effects of irrigation water salinity on the growth and quality of 'Paluma' guava seedlings.
