Aerial Remote Sensing in Agriculture: A Practical Approach to Area Coverage and Path Planning for Fleets of Mini Aerial Robots

In this paper, a system that allows applying precision agriculture techniques is described. The application is based on the deployment of a team of unmanned aerial vehicles that are able to take georeferenced pictures in order to create a full map by applying mosaicking procedures for postprocessing. The main contribution of this work is practical experimentation with an integrated tool. Contributions in different fields are also reported. Among them is a new one-phase automatic task partitioning manager, which is based on negotiation among the aerial vehicles, considering their state and capabilities. Once the individual tasks are assigned, an optimal path planning algorithm is in charge of determining the best path for each vehicle to follow. Also, a robust flight control based on the use of a control law that improves the maneuverability of the quadrotors has been designed. A set of field tests was performed in order to analyze all the capabilities of the system, from task negotiations to final performance. These experiments also allowed testing control robustness under different weather conditions.

Species of Fusarium isolated from river and sea water of Southeastern Spain and pathogenicity on four plant species

Species of Fusarium were isolated from water samples collected from the Andarax River and coastal sea water of the Mediterranean in Granada and Almería provinces of southeastern Spain. In total, 18 water samples were analyzed from the Andarax River, and 10 species of Fusarium were isolated: Fusarium anthophilum, F. acuminatum, F. chlamydosporum, F. culmorum, F. equiseti, F. verticillioides, F. oxysporum, F. proliferatum, F. solani, and F. solani. When considering the samples by their origins, 77.8% of the river water samples yielded at least one species of Fusarium , with F. oxysporum comprising 72.2% of the total isolates. In the case of marine water, 45.5% of the samples yielded at least one species of Fusarium, with F. solani comprising 36.3% of the total isolates. The pathogenicity of 41 isolates representing nine of the species collected from river an sea water during the study ws evluated on barley, kohlrabe, melon, and tomato. Inoculation with F. acuminatum, F. chlamydosporum, F. culmorum, F. equiseti, F. verticillioides, F. oxysporum, F. proliferatum F. solani, and F. sambucinum resulted in pre-and post-emergence damping off. Pathogenicity of Fusarium isolates did not seem to be related to the origin of the isolates (sea water or fresh water). However, the presence of pathogenic species of Fusarium in river water flowing to the sea could indicate long-distance dispersal in natural water environments