The green bean ( Phaseolus vulgaris L.) is a very widely grown food crop that contributes significantly to human dietary needs in many countries due to its high content of protein. This study evaluates foliar applications of ZnSO ₄ versus that of zinc oxide nanoparticles (ZnO NPs) to leaves of the green bean cv. ‘Strike’ and records the plant responses in terms of Zn uptake and concentrations of photosynthetic pigments and bioactive compounds. The experiment was conducted under greenhouse conditions in Chihuahua, Mexico, with a completely randomised experimental design with 10 replicates. The two treatments were foliar applications of either an aqueous solution of ZnSO ₄ or an aqueous suspension of ZnO NPs (both 150 mg · L ⁻¹ ). The application of ZnO NPs significantly increased concentrations of Zn ²⁺ in the leaflets, roots, stems and pods of chlorophylls a and b (values 15.40 μg · g ⁻¹ and 11.64 μg · g ⁻¹ , respectively). Sucrose concentration was also increased by Zn ²⁺ applications, but no differences were found in total phenols (TP), total flavonoids (TFl) or antioxidant capacity (AC). In the pods and seeds, Zn ²⁺ application left sucrose and TFl concentrations unchanged, but the TP increase was significant. The AC was affected by both zinc sources and only in the pods. The applications of ZnSO ₄ or ZnO NPs significantly increased the biomass accumulation (79.10 g · p ⁻¹ and 84.70 g · p ⁻¹ DW) and yield (55.64 g · p ⁻¹ and 53.80 g · p ⁻¹ FW). These results suggest that the application of ZnO NPs could represent a worthwhile biofortification strategy in the commercial production of green bean cv. ‘Strike’.

Mexico is the centre of origin and domestication of the dahlia, which has the widest distribution worldwide as an ornamental plant; however, due to changes in eating habits in some sectors of the population (vegetarians and vegans), it has also been incorporated as an ingredient in the gastronomic field. The aim of this research was to determine the attributes of physicochemical quality, antioxidant capacity and nutritional value of ligulate flowers of some wild dahlia species. A completely randomized experimental design with five repetitions was used. Fresh weight, total titratable acidity (TTA), total soluble solids (TSS), ascorbic acid (AA), colour, total phenols (TP), total flavonoids (TFl), total anthocyanins (TAn), antioxidant capacity (AC) and proximate composition were evaluated. The highest fresh weight was observed in D. × hortorum , with similar values among its different flower colours. Likewise, D. merckii and D. coccinea stood out for their high TTA value; however, D . coccinea also had the highest AA content (0.77-0.9 mg g ⁻¹ FW), TP (12.87-19.92 mg GAE g ⁻¹ FW), TFl (6.78-11.32 mg QE g ⁻¹ DW) and AC (47.28-60.43 mg AAEVC g ⁻¹ FW). On the other hand, D . campanulata was notable for its high levels of moisture, fat and raw fibre; similarly, D . coccinea stood out for its high amounts of dry matter and total carbohydrates. The ligulate flowers of wild dahlias have a high concentration of bioactive compounds and a nutritional composition with beneficial contributions to health care, so they could be used for consumption as fresh products.

Changes in nutrient concentration and oxidative metabolism in pecan leaflets at different doses of zinc | Damaris Leopoldina Ojeda-Barrios, Martha Irma Balandran-Valladares, Oscar Cruz-Alvarez, Ofelia Adriana Hernández-Rodríguez, Juan Luis Jacobo-Cuellar, María Antonia Flores-Córdova, Rafael Ángel Parra-Quezada, Esteban Sánchez-Chávez | Agricultural Journals

Revista de investigación de Agronomía-Horticultura

The ripening of fruits is a determinant factor on the composition of phytochemical compounds such as phenolic compounds. In this study the phenolic profile of quince fruits was determined as a function of its maturity index. Based on the total soluble solids (TSS) and the acidity (TA) of the fruits, four maturity indexes were established (12.55, 14.56, 21.86 and 24.77), using the ratio of TSS/TA. The phenolic profile of quince fruits with different maturity indexes were obtained by a reversed-phase HPLC-DAD and HPLC-DAD/MS. A PCA loading plot was generated to explain the relationship between physicochemical parameters and the phenolic compounds. The phenolic compounds identified in the quince fruits were 3-0-caffeoylquinic acid, catechin, 4-0-caffeoylquinic acid, 5-0-caffeoylquinic acid, coumaric acid, quercetin-3-0-rutinoside and quercetin-3-0-glycosides. The maturity index increase caused in general a reduction of phenolic compounds, these compounds were also influenced by pH and acidity of fruits. Quince is a valuable source of natural phenolic antioxidants, and can be used as raw material to elaborate diverse food products, providing important functional properties.

Several studies indicate that nitrogen fertilization is one of the main constraints in obtaining higher yields and better nut quality in pecan (Carya illinoensis [Wangenh] K. Koch). Therefore, the aim of this research was to evaluate a single and split application of nitrogen in 'Western Schley' variety pecan, as well as its effect on leaf nutrient concentration, yield and nut quality. A randomized complete block design with six replicates was established. N doses were 100, 150 and 200 kg·ha-1; the single application was made in March and the split one in March and June. The leaf concentration of total N, P, K+, Ca2+, Mg2+, Fe2+, Mn2+, Zn2+ and Cu2+, yield (kg·tree-1), quality (nuts per kilogram and kernel percentage) and nitrogen use efficiency (NUE) were determined. Significant interaction between factors was detected for the Zn2+ concentration and the single applied dose of 200 kg·ha-1. With the single application of 100 kg·ha-1, the highest yield (44.60 kg·tree-1) and nuts per kilogram (194.83) values were recorded, where the kernel percentage remained constant. The maximum NUE was obtained with 100 kg·ha-1 applied in a single and split application (31.10 and 30.10 kg of nuts produced per kg of N applied, respectively). Increased yield and nut quality is the main objective in applying optimal N doses; however, ways of reducing the economic and environmental impact caused by its excessive application should also be sought.