Effect of Seaweed Aqueous Extracts and Compost on Vegetative Growth, Yield, and Nutraceutical Quality of Cucumber (Cucumis sativus L.) Fruit

The objective of this research was to evaluate the production and phytochemical quality of cucumber (Cucumis sativus) fruits, in response to the foliar application of different seaweed extracts. This study was carried out under shadow mesh conditions in the autumn-winter agricultural cycle at the Instituto Tecnologico de Torreon, Torreon, Coahuila, Mexico. The experimental design was completely random, using six treatments with six repetitions each. The treatments evaluated were: Macrocystis pyrifera, Bryothamnion triquetrum, Ascophyllum nodosum, Grammatophora spp., Macrocystis integrifolia, and a control treatment with inorganic fertilization. The substrate used was a mixture of sand and vermicompost. The yield, commercial size, and phytochemical compounds of the fruit were evaluated. Results showed that the yield using Steiner solution (6.75 kg m(-2)) was higher than that obtained with Bryothamnion triquetrum algae (6.07 kg m(-2)). Regarding the phenolic content, the extracts surpassed the control treatment, with Macrocystis pyrifera and Macrocystis integrifolia being statistically equal, with values of 47.37 and 43.73 mg equiv. of Ac. Gallic 100 g fresh weight, respectively. The antioxidant capacity by ABTS+ and DPPH+ methods was higher using the treatment with Macrocystis pyrifera algae with 149.4 and 454.mu M equiv Trolox/100 g fresh base, respectively. This treatment also presented the highest value of vitamin C with 5.07 mg/100 g fresh base, being 27% greater than the control treatment. Algae extracts increased the quality of the fruits by obtaining the highest antioxidant capacity, making their use a viable option to minimize the application of conventional fertilizers, thereby attenuating the effects on the environment and improving the health of the population.