Potassium and irrigation water salinity on the formation of sour passion fruit seedlings¹

Potássio e salinidade da água de irrigação na formação de mudas de maracujazeiro-azedo

HIGHLIGHTS

Potassium does not attenuate the deleterious effects of salt stress on the formation of seedlings of sour passion fruit.

Water salinity increases the percentage of cell membrane damage in sour passion fruit seedlings.

Salt stress inhibits growth of sour passion fruit but water with up to 3.5 dS m^-1 can be used for formation of its seedlings.

Key words:
Passiflora edulis Sims; attenuation; salt stress

ABSTRACT

The high concentration of salt in the waters of the semi-arid region of Northeast Brazil is a limiting factor for agricultural production in the region. In this context, the objective of this study was to evaluate the percentage of cell membrane damage, contents of photosynthetic pigments and growth of sour passion fruit seedlings, cv. BRS RC, under irrigation with saline water and potassium fertilization. The experiment was conducted in a greenhouse, adopting a randomized block design in a 5 x 2 factorial arrangement, with five values of electrical conductivity of irrigation water (0.3; 1.1; 1.9; 2.7 and 3.5 dS m^-1) and two potassium doses - KD (50 and 100% of the fertilization recommendation for pot experiments), with two plants per plot, and four replicates. The dose referring to 100% of the recommendation corresponded to 150 mg of K₂O kg^-1 of soil. Water salinity from 0.3 dS m^-1 promoted reduction in the chlorophyll synthesis and growth of seedlings of sour passion fruit cv. BRS RC. Despite the reduction in growth, water with electrical conductivity of up to 3.5 dS m^-1 can still be used to form passion fruit seedlings with acceptable quality for the field. Potassium does not attenuate the deleterious effects of salt stress on the formation of seedlings of sour passion fruit cv. BRS RC.

Key words:
Passiflora edulis Sims; attenuation; salt stress