Biochemical responses in ‘Kent’ mango grown in Brazilian semi-arid region under different doses of triacontanol

ABSTRACT The management adopted for the mango crop requires that, at a certain stage, the irrigation depth should be reduced to promote a more uniform flowering. In regard to that, it is necessary to introduce new alternatives that mitigate the harmful effects of abiotic stress and that promote greater fruit yield. Therefore, the present study aimed to evaluate the influence of triacontanol on the levels of organic solutes, antioxidant enzymatic activity, and production of ‘Kent’ mango under Brazilian semi-arid conditions. The experiment was carried out for two consecutive years, 2018 and 2019, in a commercial orchard located at the DAN Farm, Petrolina-PE. The experimental design used was randomized blocks, with five treatments and four replications, evaluating four plants per plot. The treatments consisted of triacontanol doses: 0 (control treatment), 3.75; 7.50; 11.25, and 15.00 ppb per plant. Two consecutive harvests (2018 and 2019) were evaluated during the stages of branch maturation (2019 only), floral induction, full flowering, and initial fruiting. Foliar application of triacontanol positively favored the contents of total amino acids, free proline, total proteins, and activity of the enzymes superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT). There was an increase in production of 50.85% (dose - 11.25 ppb) and 64.95% (dose - 10.50 ppb) in the 2018 and 2019 crop years, respectively. RESUMO O manejo adotado para a cultura da manga exige que, em determinada fase, a lâmina de irrigação seja reduzida para promover uma floração mais uniforme. Nesse sentido, é necessário inserir novas alternativas que atenuem os efeitos deletérios do estresse abiótico e que promovam maior produtividade de frutos. Portanto, o presente estudo teve como objetivo avaliar a influência do triacontanol sobre os teores de solutos orgânicos, atividade enzimática antioxidante e produção de mangueira ‘Kent’ nas condições do semiárido brasileiro. O experimento foi realizado em duas safras consecutivas, 2018 e 2019, em um pomar comercial localizado na Fazenda Dan, Petrolina-PE. O delineamento experimental utilizado foi em blocos casualizados, com cinco tratamentos e quatro repetições, sendo avaliadas quatro plantas por parcela. Os tratamentos consistiram em doses de triacontanol: 0 (tratamento controle); 3,75; 7,50; 11,25 e 15,00 ppb por planta. Duas safras consecutivas (2018 e 2019) foram avaliadas durante os estágios de maturação do ramo (somente 2019), indu