University of Seville

About: University of Seville is a education organization based out in Seville, Andalucía, Spain. It is known for research contribution in the topics: Population & Model predictive control. The organization has 20098 authors who have published 47317 publications receiving 947007 citations. The organization is also known as: Universidad de Sevilla.

Fleets of robots for environmentally-safe pest control in agriculture

Abstract: Feeding the growing global population requires an annual increase in food production. This requirement suggests an increase in the use of pesticides, which represents an unsustainable chemical load for the environment. To reduce pesticide input and preserve the environment while maintaining the necessary level of food production, the efficiency of relevant processes must be drastically improved. Within this context, this research strived to design, develop, test and assess a new generation of automatic and robotic systems for effective weed and pest control aimed at diminishing the use of agricultural chemical inputs, increasing crop quality and improving the health and safety of production operators. To achieve this overall objective, a fleet of heterogeneous ground and aerial robots was developed and equipped with innovative sensors, enhanced end-effectors and improved decision control algorithms to cover a large variety of agricultural situations. This article describes the scientific and technical objectives, challenges and outcomes achieved in three common crops.

Microscopic and transcriptome analyses of early colonization of tomato roots by Trichoderma harzianum.

Abstract: The capacity of the fungus Trichoderma harzianum CECT 2413 to colonize roots and stimulate plant growth was analyzed. Tobacco seedlings (Nicotiana benthamiana) transferred to Petri dishes inoculated with T. harzianum conidia showed increased plant fresh weight (140%) and foliar area (300%), as well as the proliferation of secondary roots (300%) and true leaves (140%). The interaction between strain CECT 2413 and the tomato-root system was also studied during the early stages of root colonization by the fungus. When T. harzianum conidia were inoculated into the liquid medium of hydroponically grown tomato plants (Lycopersicum esculentum), profuse adhesion of hyphae to the plant roots as well as colonization of the root epidermis and cortex were observed. Confocal microscopy of a T. harzianum transformant that expressed the green fluorescent protein (GFP) revealed intercellular hyphal growth and the formation of plant-induced papilla-like hyphal tips. Analysis of the T. harzianum-tomato interaction in soil indicated that the contact between T. harzianum and the roots persisted over a long period of time. This interaction was characterized by the presence of yeast-like cells, a novel and previously undescribed developmental change. To study the molecular mechanism underlying fungal ability to colonize the tomato-root system, the T. harzianum transcriptome was analyzed during the early stages of the plant-fungus interaction. The expression of fungal genes related to redox reactions, lipid metabolism, detoxification, and sugar or amino-acid transport increased when T. harzianum colonized tomato roots. These observations are similar to those regarding the interactions of mycorrhiza and pathogenic fungi with plants.

Synthesis, characterization and photocatalytic properties of iron-doped titania semiconductors prepared from TiO2 and iron(III) acetylacetonate

Abstract: Specimens of iron-doped titania containing different amounts of Fe (0.5–5%) were prepared from TiO2 (Degussa P-25) and Fe(III) acetylacetonate by the wet impregnation method. Samples were characterized by X-ray diffraction analysis, specific surface area (BET) measurements, SEM-EDX, atomic absorption and IR and diffuse reflectance spectra. From the structural point of view, the samples were similar to those obtained with Fe(NO3)3 · 9H2O as the precursor, but with a more homogeneous distribution of iron for each mixed oxide sample on the particle surfaces but not between particles. The photocatalytic activity of these samples under near-UV irradiation was better for oxalic acid degradation than for EDTA, and similar for both types of mixed oxide samples. Mixed oxides showed however lower activity than TiO2. Some photodegradation under visible irradiation, not occurring with TiO2, could be observed for oxalic acid when using 5% Fe-containing samples.