Antonio J. de Lima-Neto1, Lourival F. Cavalcante2, Francisco de O. Mesquita3, Antônio G. de L. Souto1, Gaudêncio P. dos Santos2, Juliana Z. dos Santos2, and Evandro F. de Mesquita4
Water used for irrigation in semiarid regions of the world is not always of good quality, and may contain salts levels that inhibit plants growth. This study was conducted to evaluate the growth of papaya (Carica papaya L.) ‘Golden’ seedlings irrigated with saline water in soil with and without bovine biofertilizer produced by anaerobic fermentation of a mixture of fresh bovine manure and water. The experiment was carried out in Areia County, Paraiba State, Brazil. Treatments were distributed in randomized blocks using a factorial design 5 × 2 relative to five salinity levels in irrigation water of 0.5, 1.0, 2.0, 3.0 and 4.0 dS m-1 in soil with and without bovine biofertilizer, corresponding to 10% of the substrate volume. At 90 d after emergence (DAE), both the electrical conductivity (EC) in soil saturation extract, biometric growth and DM production of papaya seedlings were evaluated. Increased salinity from 0.5 to 4.0 dS m-1 raised, within 90 DAE, soil EC of saturation extract (ECse) from 1.19 to 3.95 dS m-1 and from 1.23 to 3.63 dS m-1 in treatments with and without bovine biofertilizer, respectively. Also, the increase in water salinity from 0.5 dS m-1 to the estimated maximum values ranging from 1.46 to 2.13 dS m-1 stimulated seedling height to 11.42 and 18.72 cm in soil with and without bovine biofertilizer, respectively. Higher salinity levels in irrigation water increased soil salinity levels to values that inhibited both growth and quality of papaya seedlings, but with less severity when treated with bovine biofertilizer.
Key words: Carica papaya, growth, humic substances, organic fertilization, salt stress.
1Universidade Federal de Viçosa (UFV), Departamento de Fitotecnia, Av. Peter Henry Rolfs, s/n, Centro, 36570-000, Viçosa-MG, Brasil. *Corresponding author (email@example.com).
2Universidade Federal da Paraíba (UFPB), Centro de Ciências Agrárias (CCA), Rodovia PB-079, 58397-000, Areia-PB, Brasil.
3Universidade Federal Rural do Semi-Árido (UFERSA), Departamento de Ciências Ambientais e Tecnológicas, Av. Francisco Mota, nº 572, Costa e Silva, 59625-900, Mossoró-RN, Brasil.
4Universidade Estadual da Paraíba (UEPB), Centro de Ciências Humanas e Agrárias, Sítio Cajueiro, Zona rural, 58884-000, Catolé do Rocha-PB, Brasil.