Abstract

Nitrogen is necessary for the synthesis of chlorophyll that is involved in the process of photosynthesis. Vegetation indices measure spatial and temporal plant photosynthetic activity variations and are widely used due to their simplicity. Vegetation indices are dimensionless radiometric measurements, and combine different wavebands. Leaf analysis is an effective approach to monitor the nutritional status of strawberries and help to diagnose crop deficiencies. An application was developed for the smartphone, that acquire an image from a strawberry leaf and after processing it, displayed its nitrogen concentration. In this study, it was observed that with a decrease in the NO3 content, the R and G values increased, together with an increase in the R/G ratio, with values that reached 0.9 and 1.2 in the vegetative indices. The high degree of similarity between the R678 and R500 reflectance bands and the smartphone R and G color bands allow the application of these devices.

Keywords:Strawberry leaf image; Nitrate; LAQUAtwin; Smartphone application; Vegetation indexs