ASABE Technical Library - Abstract

Abstract

Knowledge of spatial variability in fruit yield, crop characteristics, fruit loss, and slope of the field is critical for planning and implementing the operational recommendation for mechanical harvesting. Improved management practices have caused significant changes in crop conditions, which reduce the picking performance of the harvester as the harvester was designed in early 1980s. The goal of this work was to characterize and quantify the spatial pattern of variability in crop characteristics, fruit yield, and slope the field in relation to fruit loss during mechanical harvesting. Completely randomized experiments were designed and plots (0.91 x 3 m) were constructed in selected fields. Total fruit loss (pre- and post-harvest) and fruit yield were collected from each plot within selected fields. Slope, plant height, and fruit zone were also recorded from each plot to examine the impact of their spatial variability on fruit loss.

The coefficient of variations (CVs) for fruit yield, berry loss, slope, plant height, and fruit zone suggested moderate to high variability (CV>15%) within selected fields. Correlation analysis showed higher fruit loss in high yielding areas and vice versa. Fruit yield, berry loss, slope, plant height, and fruit zone had large spatial variation (range of influence ~20 to 50 m) within selected fields. Kriged maps revealed substantial variation in these parameters. Variability in fruit loss corresponding with the spatial variations in crop characteristics, fruit yield, and slope suggested that the fruit loss during mechanical harvesting were influenced by the spatial variations in these parameters. Adjustments in operational settings (ground speed, head revolutions, head height, etc.) of the harvester in accordance with the spatial variations have the potential to increase profit margins for blueberry industry.