ASABE Technical Library - Abstract

Abstract. North Eastern North America is the largest producer of wild blueberry crop. In the last two decades, improved management practices have changed crop characteristics. Currently, the wild blueberry industry is facing increased harvesting losses (15-25%) due to changes in crop conditions. This study was designed to examine the impact of plant characteristics on berry losses during mechanical harvesting of wild blueberry. Four wild blueberry fields were selected in Nova Scotia and New Brunswick, Canada. Plant height (PH) and plant density (PD) were classified into four different categories i.e. tall plant - low plant density, tall plant - high plant density, short plant - low plant density and short plant - high plant density, and stem thickness (ST) was used as a covariate. Nine yield plots (0.91m x 3 m) for each combination of PH and PD were selected randomly at each experimental field. The PH, PD and ST were recorded manually from each selected plot. Factorial experiments with four replications were designed 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 PH and PD. Berry losses were collected from each plot within the selected fields. Factorial analysis of covariance (ANCOVA) using general linear model (GLM) procedure showed that the interaction of ground speed and header RPM was significant (p<0.05) in each category of plant characteristics. Results of multiple means comparison showed that the lower ground speed and header RPM resulted in significantly lower losses when compared with higher ground speed and header RPM. The study findings also suggested a suitable combination of ground speed and header RPM for each class of plant characteristics to minimize the berry losses during harvesting.

Keywords. Ground speed, harvesting losses, header RPM, mechanical harvesting, plant characteristics and wild blueberry.