Águas salinas e adubação potássica no cultivo de aceroleira ˜BRS 366 Jaburu enxertada

Resumo

Agricultural exploitation in the semi-arid region of Northeast Brazil depends on the use of irrigation to guarantee safe production of crops. Nevertheless, the waters commonly used in this region have high levels of salts and require management strategies that make their use possible in agriculture. In this context, the present study aimed to evaluate water relations, photosynthetic pigments and growth of grafted West Indian cherry as a function of saline water irrigation and potassium (K) fertilization. The study was conducted under greenhouse conditions in lysimeters filled with eutrophic Regolithic Neosol with sandy loam texture, in the municipality of Campina Grande-PB, Brazil. Treatments were distributed in randomized blocks and consisted of two factors: two levels of irrigation water electrical conductivity - ECw (0.8 and 3.8 dS m^-1) and four K doses (50, 75; 100 and 125% of the recommendation), with three replicates and one plant per plot. The 100% dose corresponded to 19.8 g of K₂O per plant per year. The West Indian cherry crop was sensitive to water salinity of 3.8 dS m^-1 in the post-grafting phase, resulting in a decline in photosynthetic pigment content and growth. Increasing K doses reduced the percentage of cell membrane damage and promoted increase in the synthesis of chlorophyll a and carotenoids in West Indian cherry plants. There was significant interaction between salinity levels and K doses for the leaf osmotic potential, water saturation deficit, percentage of cell membrane damage and chlorophyll b content in West Indian cherry plants.