Goiabeira 'paluma' irrigada com água salina e tratada com fertilizantes de efeito bioestimulante

• Ano de defesa: 2023
• Autor(a) principal: Silva, Helton de Souza
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal da Paraíba; Brasil; Agricultura; Programa de Pós-Graduação em Agronomia; UFPB
• Palavras-chave em Português: Psidium guajava; lignosulfonato; extrato de algas; salinidade; CNPQ::CIENCIAS AGRARIAS
• Link de acesso: https://repositorio.ufpb.br/jspui/handle/123456789/29664

The ‘Paluma’ guava tree has a high productive potential and can reach 100 t ha-1, however, in the fruit-growing centers of the northeastern semi-arid region, the strong limitation of this productivity is caused by saline stress. Lately companies in the agricultural sector have launched products with the promise of mitigating the effect of saline stress on plants and of acting as a soil improver. In this theme, the objective of this work was to evaluate the application of Codasal® and Aminoagro Raiz® on the physiological and nutritional aspects, the fruit quality and productivity, the root system and the chemical attributes of the soil, of a ‘Paluma’ guava orchard irrigated with saline water. For articles I, II, and IV, the experiment consisted of a 2 x 4 factorial, the first factor refers to spraying with Aminoagro Raiz® (Without and With) the second factor refers to the application of Codasal® and, or Amianoagro Raiz® via irrigation (Without, Codasal®, Aminoagro Raiz® and Codasal® + Aminoagro Raiz®), the treatments were distributed in randomized blocks with four replications. In article III, for the variables related to salinity and soil fertility, to the aforementioned treatments, the soil depth factor (0-20 and 20-40 cm) was added as a subplot, thus forming a 2 x 4 x 2 factorial. Article I: The determined variables were, chlorophyll a, b and total index and chlorophyll a/b ratio. Variables related to chlorophyll a fluorescence and variables related to gas exchange were also determined. It was found that there was no significant effect of fertilizers of biostimulant effect on these physiological parameters. Article II: It was determined the levels of N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, Zn and Na in leaves in two periods (flowering and fruit growth). In the fruits, the levels and export of N, P, K, Ca and Mg were determined. Fruit yield was also obtained. It was found that nutritional status and fruit yield were not improved by fertilizers of biostimulant effect. Article III: It was found that the salinity and fertility of the soil were not affected by the products. As for the depth sections, it was verified that the pH, P, K+, Ca+2 and Mg+2 exchangeable, Sum of Bases (SB), Cation Exchange Capacity (CEC) and Organic Matter (OM) were higher in the layer depth of 0-20 cm compared to soil depth of 20-40 cm. For the salinity parameters, it was verified that in the 0-20 cm layer the Electrical Conductivity of the saturation extract (ECse) the contents of SO4-2, Cl-, K+, Ca+2 and Mg+2 soluble, were higher than the contents of the 20-40 cm layer. Additionally, it was found that soil fertility was compromised by the evolution of salinity during the experimental period. The dry mass of the root was evaluated, and with the SAFIRA software, the determination of length, volume and area. Root density was also determined. It was evidenced that the fertilizers of biostimulant effect did not affect the guava root system. Article IV: Soluble solids (SS), titratable acidity (TA), ratio (SS/TA), vitamin C, pH, firmness, longitudinal length (LL), transverse length (TL), shape (LL/TL) and fresh mass of the fruits were evaluated. The foliar application of Aminoagro Raiz® favored the reduction of LL, resulting in the formation of less elongated fruits; fertilizers of biostimulant effect cause a reduction in the pH of guava fruits; Codasal® causes a reduction in the levels of soluble solids. Considering the overall quality of the fruits, it can be concluded that the products do not improve the quality of ‘Paluma’ guava fruits irrigated with saline water. Keywords: Psidium guajava; lignosulfonate; seaweed extract; salinity.