Continuous canopy status monitoring is an essential factor to support and precisely apply orchard management actions such as pruning, pesticide and foliar treatment applications, or fertirrigation, among others. For that, this work proposes the use of multispectral vegetation indices to estimate geometric and structural orchard parameters from remote sensing images (high temporal and spatial resolution) as an alternative to more time-consuming processing techniques, such as LiDAR surveys or UAV photogrammetry. A super-intensive almond (Prunus dulcis) orchard was scanned using a mobile terrestrial laser (LiDAR) in two different vegetative stages (after spring pruning and before harvesting). From the LiDAR point cloud, canopy orchard parameters, including maximum height and width, cross-sectional area and porosity, were summarized every 0.5 m along the rows and interpolated using block kriging to the pixel centroids of PlanetScope (3 × 3 m) and Sentinel-2 (10 × 10 m) image grids. To study the association between the LiDAR-derived parameters and 4 different vegetation indices. A canonical correlation analysis was carried out, showing the normalized difference vegetation index (NDVI) and the green normalized difference vegetation index (GNDVI) to have the best correlations. A cluster analysis was also performed. Results can be considered optimistic both for PlanetScope and Sentinel-2 images to delimit within-field management zones, being supported by significant differences in LiDAR-derived canopy parameters.

Generally, when nitrogen effects on fruit properties are assessed, different samples harvested at different maturity stages are assayed. This method makes it difficult to investigate the direct effects of fertilization on the different quality parameters without the influence of the ripening stage. In this piece of work, the effects of three levels of nitrogen fertilization (0, 60 and 120 kg/ha) on polyphenol oxidase (PPO) activity and consistency of peach fruits at the same maturity stage were studied. The results showed that nitrogen application (regardless the dose) had a direct effect on the studied parameters, causing an increase of PPO activity and also an increase of fruit consistency. However, no significant differences were found between the application of 60 and 120 kgN/ha. This enhanced activity of the enzyme may represent a problem in peach postharvest handling and processing.