Parametric study of hand-held mechanical bloom thinner in cherry orchards

摘要

The wholesale market returns a premium price for high quality, large sweet cherries. Some sweet cherry cultivars require the removal of bloom to achieve high yields of high quality large cherries. Removal of bloom - or bloom thinning, has traditionally been done by hand in a manual operation. The demand for large numbers of people and the associated employment expenses results in a high risk situation. Mechanical thinning could increase efficiency and therefore reduce the risks associated with higherlarge numbers of people for short periods of time. While previous research has proved the practicability of using hand-held mechanical thinners to thin flowers, there is still a need to gain a better understanding on how can some of the mechanical parameters of the thinner affect its effectiveness under different operation conditions. This parametric study was to investigate the influence of those parameters in typical WA sweet cherry orchard environments to obtain critical information to support the effective use of a hand-held thinner. Results indicated that thinning efficacy could be predicted when strings with small bending stiffness were installed (M4 and M5). Rotating speed of the thinning spindle had positive correlation to thinning efficiencywith correlation coefficients of 0.669 and 0.719 corresponding to M4 and M5, respectively. With the guideline provided to operators, precision thinning can be achieved.