Effects of saline water and potassium fertilization on photosynthetic pigments, growth and production of West Indian Cherry

Efeito da água salina e adubação potássica nos pigmentos fotossintéticos, crescimento e produção da aceroleira

Abstract

Due to the scarcity of water in the semi-arid region of Northeast Brazil, in both quantitative and qualitative terms, the use of saline water in agriculture should be considered as one alternative for irrigated agriculture. This study therefore aimed to evaluate the photosynthetic pigments, growth and production of West Indian Cherry as a function of irrigation using waters with different salinity levels and potassium (K) fertilization, after grafting. The study was carried out in drainage lysimeters under greenhouse conditions, in a eutrophic Regolithic Neosol with sandy loam texture, in the municipality of Campina Grande, PB. The experiment was set in a randomized block design, to test two levels of irrigation water electrical conductivity - ECw (0.8 and 3.8 dS m^-1) and four K₂O doses - KD (50, 75, 100 and 125% of recommendation), with three replicates. The dose relative to 100% corresponded to 79.2 mg K₂O kg^-1 of soil. Irrigation with high salinity water stimulated the biosynthesis of chlorophyll b and carotenoids, while the chlorophyll a content and the growth of the cherry were reduced markedly in the post-grafting phase. The harmful effects of salinity on the total number of fruit and fresh mass of West Indian Cherry fruit were minimized with potassium fertilization.

Keywords:
Malpighia emarginata; potassium; salt stress.