Aplicação de eliciadores em pós colheita de uva cultivares “Bordô” e “Niágara Rosada” para redução dos danos causados por Glomerella cingulata

Abstract

The grape stands out as one of the most planted perennial crops in Brazil, contributing significantly to income generation and employment in the agribusiness sector, making it an excellent opportunity for the small producer, especially in the southern region of the country.Its production is intended for several purposes, which are mostly dependent on transport and storage, compromising the quality of the product, which is extremely sensitive to post-harvest diseases, especially the ripe grape rot caused by the fungus Glomerella cingulata. The chemical control of the pathogen is not very effective, besides leaving residues in the fruits that modify the flavor, can cause serious damages to human health and to the environment.In order to overcome this problem, the induction of resistance causes that when subjected to an atypical situation, whether it is caused by a biotic or abiotic factor, the plant produces defense compounds, in this sense the objective of this work is to verify the elicitor effect of Acibenzolar- S-methyl (ASM), and Lasiodiplodana, a 1 → 6) -β-D-glucan that is extracted from the fungus asiodide Lasiodiplodia theobromae, applied in post-harvest grapes to reduce the damage caused by the fungus G. cingulata.In order to reach the proposed objective, an experiment was carried out with two cultivars: Niagara rosada and Bordô, submitted to 3 treatments (Witness (distilled water), ASM [Bion 500Wg, Syngenta] 500 mg L-1, and Lasiodiplodana 200 mg L- 1), under two conditions: with and without injury, submitted to two applications: distilled and sterilized water and the treatment in which the clusters were challenged by the pathogen: G. cingulata, with 5 replicates, totaling 120 experimental units. The analyzes were carried out as soon as the first symptoms of the fungus were manifested, the phytopathological evaluations were then performed, for further calculation of the AACPD, biochemical analyzes of phenolic compounds, protein content and determination of the activity of the enzyme phenylalanine ammonia-lyase only in the cultivar map, for both cultivars physical-chemical analyzes, color, pulp firmness, total soluble solids, pH analysis were performed. It was observed that there was a significant reduction in the AACPD of the cultivar board for the treatment with the Lasiodiplodana, whereas to cultivate pink niagara there was difference in the two elicitors, however, the ASM was not different from the control treatment. The physical-chemical analysis showed that there was no reduction in fruit quality when comparing the treatments with and without elicitors. However, despite the better performance of the treatments with Lasiodiplodana, it can not be affirmed that the positive results were obtained through elicitation, because there was no significant difference in the phenol content and also in the activity of the PAL enzyme.