L. Damerow, C. Seehuber and M. Blanke
University of Bonn, Germany
Abstract for o r a l
Thinning is a pre-requisite in the majority of fruit crops worldwide in order to overcome or prevent alternate bearing (change of years with large and low yields) and to provide regular yields of high quality in terms of size, color and constituents. Fruits of higher quality develop in the periphery of fruit trees, while shaded, green, undesired undersized fruit develop around the tree trunk in the inner canopy. The widely-used chemical thinning works randomly viz affects both desired and undesired fruit to a similar extent.
Hence, a new device was developed to achieve a wide variety of three-dimensional thinning motions in such biosystems, which consists of three variable horizontal rotors with rotating tines. The number and position of tines ware varied, while the rotor number, speed and angle and vehicle velocity were kept constant. The objective was to detect or remove flowers precisely viz not evenly within a tree, but selectively, e.g. more inner canopy flowers towards the tree trunk with undesired flowers, which would otherwise develop into small, hard, green and unripe fruit. To achieve this selective thinning , e.g. to remove particularly this inner flowers, tines of the outer canopy were stepwise detached from the rotors. Six- year-old apple cv. ‘Pinova’ trees on M9 rootstock 3.5 m x 1. m spacing near Bonn, Germany were mechanically blossomed-thinned in the periphery.
Overall, the success of the selective thinning depended on the branch angle; branches facing (45°) the thinning device were more severely thinned. Detachment of tines led to selective in the flowers, where progressively eliminated towards the tree trunk reduction of the tines for the outer canopy by 33- 66% increased the portion of the desired singlets, i.e. flowers bunches with one single flower with less fruit to fruit competition for assimilates.
The removal of tines destined for the outer peripheral tree canopy improved the quality of apple fruit in terms of fruit size and fruit colouration, which constituted a packout of class I from 70% to 86%. While apple served as a model crop here in this original study, the results can be transferred to the majority of tree fruit crops such as pears, plum, apricots and both cultivation systems, IP (integrated fruit production ) and bio-organic.
.
L. Damerow, C. Seehuber and M. Blanke
University of Bonn, Germany
Abstract for o r a l
Thinning is a pre-requisite in the majority of fruit crops worldwide in order to overcome or prevent alternate bearing (change of years with large and low yields) and to provide regular yields of high quality in terms of size, colour and constituents. Fruits of higher quality develop in the periphery of fruit trees, while shaded, green, undesired undersized fruit develop around the tree trunk in the inner canopy. The widely-used chemical thinning works randomly viz affects both desired and undesired fruit to a similar extent.
Hence, a new device was developed to achieve a wide variety of three-dimensional thinning motions in such biosystems, which consists of three variable horizontal rotors with rotating tines. The number and position of tines ware varied, while the rotor number, speed and angle and vehicle velocity were kept constant. The objective was to detect or remove flowers precisely viz not evenly within a tree, but selectively, e.g. more inner canopy flowers towards the tree trunk with undesired flowers, which would otherwise develop into small, hard, green and unripe fruit. To achieve this selective thinning (, e.g. to remove particularly this inner flowers), tines of the outer canopy were stepwise detached from the rotors. Six- year-old apple cv. ‘Pinova’ trees (on M9 rootstock 3.5 m x 1. m spacing) near Bonn, Germany were mechanically blossomed-thinned in the periphery.
Overall, the success of the selective thinning depended on the branch angle; branches facing (45°) the thinning device were more severely thinned. Detachment of tines led to selective in the flowers, where progressively eliminated towards the tree trunk reduction of the tines for the outer canopy by 33- 66% increased the portion of the desired singlets, i.e. flowers bunches with one single flower with less fruit to fruit competition for assimilates.
The removal of tines destined for the outer peripheral tree canopy improved the quality of apple fruit in terms of fruit size and fruit colouration, which constituted a packout of class I from 70% to 86%. While apple served as a model crop here in this original study, the results can be transferred to the majority of tree fruit crops such as pears, plum, apricots and both cultivation systems, IP (integrated fruit production ) and bio-organic.
.
