No abstract

Adequate nutritional status is fundamental for the fruiting process of mango trees (Mangifera indica L.). In this context, plant biostimulants are substances that promote physiological and nutritional changes, benefiting production. The present study evaluated the effect of biostimulants on the nutritional status and fruit production of ‘Kent’ mango trees. The experiment was carried out in the Brazilian semiarid region over 2 consecutive years, 2016 and 2017. Leaf treatments with biostimulants were applied in three phases (preflowering, beginning of flowering, and full flowering) during both seasons. The treatments were as follows: T1) control (without biostimulants); T2) biostimulants containing nutrients and L-α-amino acids; T3) biostimulants containing nutrients and Lithothamnium algae extract; T4) biostimulants containing nutrients and sucrose; and T5) biostimulants containing nutrients, free amino acids, and Lithothamnium algae extract. The results show that there was no effect of the biostimulants for chlorophyll a, b, and total indices or for total leaf soluble carbohydrates. Some of the treatments affected the leaf concentrations of N, K, Mn, Fe, and Zn, whereas only T2 in 2016 and T5 in 2017 increased the number of fruits per panicle if compared with nontreated plants. In 2016, the production per tree was higher in T5 compared with the other treatments, whereas it was greater in 2017 in both T2 and T5 with increases of 37.4 and 23.1 kg per tree, respectively, compared with the control treatment. Biostimulants containing soluble nutrients, L-α-amino acids, free amino acids, and Lithothamnium algae extract benefit the nutritional status and increase the fruit production of mango ‘Kent’.

The grapevine cultivated in tropical regions, such as the Sub-medium of the São Francisco Valley, exhibits a strong bud dormancy and high apical dominance, thus presenting the need for the utilization of products that promote the dormancy breaking of the buds. The aim of the present work was to evaluate the efficiency of the application of hydrogenated cyanamide and the practice of cane torsion over the breaking of bud dormancy, bud burst and yield of grapevine cv. Italia Muscat in the conditions of the Sub-medium of the São Francisco Valley. The experiment was conducted in Petrolina, PE state, during two production cycles (2015-2016). The adopted design was in randomized blocks, with treatments distributed in a 2 x 2 factorial scheme, referring to the torsion of canes (with and without) and the different doses [D1: hydrogenated cyanamide (H2CN2) 2.45%; D2: hydrogenated cyanamide (H2CN2) 2.94%], with four replicates. The use of the hydrogenated cyanamide associated to the torsion of canes influences in a distinct manner the studied variables, in the different production cycles, although increments in production and yield occur in both. Therefore, the use of 2.94% of H2CN2 along with the torsion of canes is a recommended practice for the increase in the bud burst rate and yield of grapevine cv. Italia Muscat, cultivated in the region of the Sub-medium of the São Francisco Valley.