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Ever-growing concerns and governmental restrictions related to the use of pesticides in modern agriculture has driven the need for more adept decision-making tools to minimize unnecessary treatments whilst still efficiently preventing a spread of infection. To this effect, a network of cost-effective, laser-based holographic detectors were developed and placed in vineyards in Switzerland and France with the objective of detecting and identifying airborne spores of downy and powdery mildew before they have the potential to infect crops. The data collected are remotely sent to a server where image processing techniques and artificial intelligence classify the spores and determine the quantitative intervention thresholds. Knowledge on the quantitative development of fungal diseases has been successfully used to temporally and spatially identify the primary infection of downy mildew which was confirmed by a visual evaluation of symptoms within the parcel. This data coupled with the current risk prediction models provide farmers with a powerful decision-making tool to optimise strategies in the management of grapevine diseases.

We deploy a network of autonomous stations measuring meteorological and soil parameters, as well as the airborne particle size distribution with a focus on the size of Plasmapora Viticola (PV). They provide early warning and detection of PV spore outbursts with high spatial and temporal resolution. We evidence the high spatial inhomogeneity of this pathogen, potentially allowing to limit treatments to the specific times and locations where infection risk is detected.

At relative humidities above 70%, femtosecond laser filaments generate aerosol particles and water droplets in the atmosphere. The water vapour condensation and droplet stabilization are assured by soluble species produced in the laser plasma.

The consideration of the higher-order Kerr effect (HOKE) drastically improves the quantitative agreement between measured and simulated harmonic yield as well as intensity and electron density in laser filaments generated by pulses below a few hundreds of fs. In longer pulses, the plasma defocusing plays a much more important role.

We report experimental and theoretical results on mid-infrared femtosecond pulse filamentation in different gases. Highly efficient generation of a three-octave-wide spectral continuum in argon, covering the main atmospheric transparency windows, is demonstrated and explained.