Efeito de reguladores vegetais na qualidade de frutos de melão rendilhado

• Main Author: Kohatsu, Douglas Seijum
• Publication Date: 2012
• Other Authors: Ono, Elizabete Orika [UNESP], Evangelista, Regina Marta [UNESP], Klein, Jeferson [UNESP]
• Format: Article
• Language: por
• Source: Repositório Institucional da UNESP
• Download full: http://www.dca.uem.br/V1N2.htm; http://hdl.handle.net/11449/137187
• topic: Cucumis melo L. var. reticulatus; Enzymes; Postharvest; Cucumis melo L. var. reticulatus; Enzimas; Pós-colheita

This work evaluated the effect of the pre-harvest application of plant growth regulators on the postharvest quality of ‘Galileo’ cantaloupe (Cucumis melo L. var. reticulatus) stored at room temperature. Plants were treated in the field with the following plant growth regulators: T1– control, T2– GA3 (gibberellic acid) 100 mg L-1, T3– IBA (indolebutyric acid) 100 mg L-1, T4– kinetin 100 mg L-1, and T5– GA3 + IBA + kinetin (5%) mixture at the beginning of the reproductive stage. Fruits were harvested (51 days after application) and transported to the Fruits and Vegetables Lab from the Department of Agroindustrial Technology and Management, São Paulo State University (UNESP), Botucatu, São Paulo State, Brazil. Fruits were evaluated at every five days during 20-day storage for firmness assessment. The remaining quality variables were analyzed at harvesting through analyses of pectinmethylesterase (PME) and polygalacturonase (PG) activities, besides soluble solids (SS), total sugars (TS), and titrable acidity (TA) and ratio (SS/TA). In addition, net CO2 assimilation rate (A) was measured in leaves before and after application. Gibberellic acid (T2) and the mixture of plant growth regulators (T5) led to a better fruit conservation through firmness maintenance. Also, T5 (GA3 + IBA + kinetin) increased PG activity during storage, whereas PME activity was higher in IBA-treated fruits. However, there was no correlation between enzymatic activity and fruit firmness loss. SS and TS levels besides net CO2 assimilation rate were negatively influenced by IBA treatment, whereas TA and ratio did not statistically differ.