Fruit quality and nutritional analysis in ‘Pêra’ orange as affected by soil available water and different rootstocks

Abstract

The market of citrus fruits for fresh consumption is greatly influenced by the external aspect of the fruit, which needs to meet certain quality requirements. Therefore, this study aimed to evaluate fruit characteristics and leaf concentrations of nutrients, associating them with soil available water, for combinations of 'Pêra' orange with five different rootstocks, in two planting systems [conventional seedlings and direct seeding (DS) of rootstocks] in soil without subsoiling, in two sampling periods (wet and dry) of leaves and fruits. The attributes evaluated in the fruits were as follows: fruit length (FL), fruit diameter (FD) (cm), fruit weight (FW), juice yield, total soluble solids (TSS, in ºBrix), titratable acidity (TA, in g de citric acid mL −1 ), and ratio (TSS/TA). For nutritional evaluation of the plant, the contents of N, P, K, Ca, Mg, Fe, Cu, Mn, and Zn were determined in the leaves. The fruits produced in the rainy period showed better physical and chemical characteristics. Higher average ratios were found in 'Volkameriano' lemon, 'Índio' citrandarin and 'Cravo Santa Cruz' lemon. The planting system via DS led to higher values of FW, FD and FL. Leaf analysis indicated deficiency of N and Mn, excess of K and Fe; and P, Ca, Mg, Cu and Zn within the adequate range. The intensity of water stress, found in the dry period, increased the leaf concentrations of K, Ca, Mg and Cu. The preservation of the root system, promoted by DS, led to higher contents of N, Ca, Cu and Mn.

Transgenic Sweet Orange Expressing the Sarcotoxin IA Gene Produces High-Quality Fruit and Shows Tolerance to ‘Candidatus Liberibacter asiaticus’

“…The changes in the C Las-infected fruit led to abnormal growth development that regulated the fruit shape to a less oblate, typical of sweet oranges. The size and weight of the Pera sweet orange fruit found in our study were similar to those reported for this cultivar under field conditions ( Figure 5 ) [ 67 ]. Further investigation is certainly needed to evaluate the performance of the STX IA transgenic plants under field conditions.…”