ASABE Technical Library - Abstract

Abstract. Wild blueberry is high value cash crop in North Eastern North America. In last two decades, crop characteristics were changed due to improved management practices. Currently, wild blueberry industry is facing increased harvesting losses (15-25%) due to changes in crop conditions. Four wild blueberry fields were selected in Atlantic Provinces of Canada to examine the effect of fruit characteristics on berry losses during mechanical harvesting. Four different categories of fruit yield (FY) and fruit zone (FZ), i.e. high fruit zone-low fruit yield, high fruit zone-high fruit yield, low fruit zone-low fruit yield and low fruit zone-high fruit yield were selected for berry loss data collection in each field. Nine yield plots (0.91 × 3 m) for each combination of FY and FZ were selected randomly at experimental fields. A 3 × 3 factorial design with 4 blocks was set to identify the combined effect of ground speed (1.2, 1.6 and 2.0 km h^-1) and header revolutions (26, 28 and 30 rpm) on berry losses at each category of fruit characteristics. Fruit zone and fruit diameter (FD) were recorded manually and FY was collected in the bucket at the back of the harvester from each selected plot. A real-time kinematics global positioning system (RTK-GPS) was used to map the field boundaries, bare spots, weeds and yield plots. The pre-harvest berry losses were collected from each plot prior to harvest and after harvest loss i.e. shoot loss (SL), ground loss (GL) and blower loss (BL) were collected from each plot within selected fields. Analysis of covariance (ANCOVA) showed that the interaction of ground speed and header rpm was significant (p=0.05) in each category of fruit characteristics. Results revealed that there was an effect of FZ and FY on berry loss during mechanical harvesting. It is concluded that the lower combinations of ground speed and header RPM of the harvester produced minimum losses, while higher ground speed in conjunction with higher header RPM resulted in substantially higher losses during mechanical harvesting. Results also revealed that a suitable combination of ground speed and header rpm in each category of fruit characteristics can minimize the berry losses during harvesting, which can increase the harvestable yield.