Yield maps in tree fruit production: analysis of spatial and temporal variability to establish homogeneous zones
Precision agriculture (PA) involves the use of information to manage field spatial and temporal variability and has advanced considerably, supported by electronic and computer technologies. Crop properties are analyzed to delimit field areas with homogenous characteristics called management zones. Although many crop properties could be evaluated, yield is one of the mainly used parameters, and yield maps can be considered as a key factor in PA. In this paper, spatial and temporal variability were analyzed in a 1.75-ha plot of 'Bartlett' pears over four seasons to evaluate if site specific management can be an alternative to improve productivity. The plot had 57 rows with 36 trees each. Crop rows were divided in sub-units of 12 trees with practical purpose for future yield monitors. Yield maps were obtained using a locally developed system, which geo-references the weight of the fruit during harvest. The data set was analyzed using GS+ software. A spherical variogram model was fitted and the interpolation was made using ordinary kriging. Plot spatial variability was shown on the resulting yield maps. Three management zones were delimitated based on average fruit production. Yield data were analyzed using ANOVA where fixed factors of the model were year, sector, and year × sector interaction. Temporal stability was also evaluated using a coefficient of temporal variation that indicates the variance over the time of a sub-unit yield relative to the field mean yield. As most years (2015-2017) showed non-significant year × sector interaction, production could be considered as relatively stable for all sectors. It is remarkable that spatial and temporal variability could be shown in a single yield map. Finally, possible causes of temporal and spatial variability were analyzed, and potential improvements were presented in order to increase fruit quality and yield.
Fernandez, D., Curetti, M., Benitez Piccini, E., Romitelli, M., Del Brio, D., Ocampo, S., Bramardi, S. and Magdalena, C. (2021). Yield maps in tree fruit production: analysis of spatial and temporal variability to establish homogeneous zones. Acta Hortic. 1303, 435-442
Pyrus communis L., 'Bartlett' pear, site-specific management, precision agriculture