Germinação de sementes e produção de mudas de Physalis peruviana L. Sob estresse salino.

Abstract

Physalis peruviana L., considered an exotic fruit vegetable with considerable value in the market, has aroused interest in being an excellent alternative for the small and medium producer, being able to increase profitability, since it has high added value and adaptability in several regions of the country. However, to produce in semi-arid regions due to the scarcity of water resources, it can often be subject to irrigation with water that has high concentrations of salts. In this context, the objective was to evaluate seed germination and seedling production of Physalis peruviana L. under conditions of saline stress. . The experiment was carried out in three trials at the Federal University of Campina Grande - UFCG, Pombal - PB. In the first experiment, under different shading conditions, different substrates and containers were tested in the production of physalis seedlings with a randomized block design in a 5 x 6 factorial (containers x substrate) with four replications, where R1 = of 55 cm³; R2 and R3 = 50 and 18 cm³ expanded polystyrene trays, respectively; R4 = biodegradable polyethylene bags 400 cm³ and R5 = 200 cm³ polypropylene containers. The containers were filled with the following substrates: S1 = soil; S2 = basaplant® commercial substrate; S3 = soil + sand + cabornizada rice husk + bovine manure (1: 1: 1: 2); S4 = soil + sand + carbonized rice husk + goat manure (1: 1: 1: 2); S5 = soil + commercial substrate basaplant® (1: 1); and S6 = soil + sand + commercial substrate basaplant® (1: 1: 1). Substrate S4 and containers R4 and R5 met the requirements of Physalis peruviana L. for most of the studied variables, providing higher quality and development of seedlings. In the second experiment, carried out in the laboratory, the induction of tolerance to saline stress during the germination of physalis seeds through osmoconditioning was done. The design was completely randomized with four replicates of 50 seeds in a 4x4 factorial scheme corresponding to four osmo-conditioning treatments with PEG 6000 for 120 hours in osmotic potentials -0.2; -0.4; -0.6 and -0.8 MPa, besides the control (seeds not osmoconditioned); and four levels of electrical conductivity of irrigation water (0.3, 1.2, 2.1, and 3.0 dS.m-1). Osmoconditioning of the seeds at the osmotic potential up to -0.4 MPa promoted better results for the germination variables. The salinity reduced the average speed and increased the germination time, not affecting the total percentage of germination of Physalis peruviana L. In the third experiment, the production of Physalis peruviana L. seedlings in the R4 container and substrate S4 defined in the first test under saline stress was analyzed using non - osmoconditioned and osmoconditioned seeds in PEG 6000 (- (Water supply), 1.2, 2.1, and 3.0 dS m-1) were used for 120 hours and four levels of electrical conductivity of the irrigation water. The treatments were distributed in a randomized complete block design in a 4 x 2 factorial scheme and four replications. Osmoconditioning did not inhibit but attenuated the deleterious effect of water salinity on emergence and leaf expansion on physalis. The use of osmoconditioned seeds with PEG 6000 solution (-0.4 MPa) provides greater growth of seedlings than those not submitted to osmoconditioning.