Ascorbic Acid Promotes Beneficial Effects on Yield Components and Postharvest Quality of Grafted Guava Under Salt Stress
Vitor Manoel Bezerra da Silva, Geovani Soares de Lima, Lauriane Almeida dos Anjos Soares, Hans Raj Gheyi, Jackson Silva Nóbrega, Jean Telvio Andrade Ferreira, Flávia de Sousa Almeida, Cassiano Nogueira de Lacerda, Larissa Fernanda Souza Santos, Valeska Karolini Nunes Oliveira, Reynaldo Teodoro de Fátima, Reginaldo Gomes Nobre, Saulo Soares da Silva, Smyth Trotsk de Araújo Silva, Allesson Ramos de Sousa, Weslley Bruno Belo de SouzaThis study aimed to evaluate the effects of foliar application of ascorbic acid on the yield and postharvest quality of guava fruits under irrigation with saline water during the post-grafting stage. The experiment was conducted under field climatic conditions using lysimeters in a randomized complete block design with a split-plot arrangement. Five irrigation water electrical conductivity levels (ECw: 0.9, 1.5, 2.1, 2.7, and 3.3 dS m−1) were assigned to the main plots, while four ascorbic acid concentrations (Asc: 0, 200, 400, and 600 mg L−1) were assigned to the subplots, with three replicates. Guava cv. Paluma was used as the scion, and BRS Guaraçá was used as the rootstock. According to the response surface models, foliar application of 600 mg L−1 Asc increased fruit diameter and yield performance of ‘Paluma’ guava under 0.9 dS m−1, whereas under 3.3 dS m−1, it increased average fruit weight and improved quality attributes, including pH, titratable acidity, vitamin C, and total sugars. In addition, salinity increased fruit soluble solids, while the MGIDI identified combinations involving 600 mg L−1 Asc as having the best multivariate performance. These results indicate the potential of Asc as a viable strategy for guava cultivation under saline conditions.