Optimizing stress management in stone fruit plots using Crop-Scan™
Monday, 24 November 2014
Field Experience | Frut trees | Crop-Scan®
Modern day techniques for the diagnosing of nutritional and crop stresses that are available to the producer are limited by the size of the plot, thus yielding scarcely representative results due to the difficulties inherent in examining a large number of samples.
Crop-Scan™ is a high resolution Tele detection system which collects thermal and multi specter images of the plots being over flown, obtaining precise, rapid information of all trees in a single large plot. This makes the early, pre-visual diagnostic of the crop’s situation possible, in order to carry out all necessary preventive action for the correction of stress.
In an example of its use in extra-early nectarines, we observed marked differences in the water content in trees (Figure 1)- which presented visually uniform and proper development. But, when harvesting time came, the trees yielded fruits of a size inferior to what was expected (caliber 51/56 instead of the commercially desirable >61).
Depending on these calibers, the difference in prices paid to the farmers for these fruits may vary by 0.5 €/kg (1.25 to 0.75 €/kg), and it may even affect the commercialization of the fruit of that plot because of the lack of sufficient caliber after maturation.
Thanks to the use of CROP-SCAN™, we can observe in detail the effects of water deficiency in these new variants for which it is difficult to find the optimal dose of Kc, especially when taking into account that this fruit develops in February, March and April, which are months of constant meteorological changes.
Figure 1. Image depicting the water mosaic of part of the plot. We can observe important differences between individual trees.
The NDVI parameter, which indicates the crop’s vigor, also revealed significant differences. This parameter provides us with a good hint of the final caliber and therefore of the crop’s quality. Although in this case the caliber was limited by the water supply, the NDVI (Figure 2) would allow us to have an early detection of the less vigorous trees which would yield smaller caliber fruits because of nutritional deficiencies and/or other stress factors. By means of the rapid and precise diagnostic through Crop-Scan™ we could correct these deficiencies in time in order to obtain a top quality crop.
Figure 2. Image belonging to the NDVI map showing plant vigor. To the left we can see the scale with the different index values.