This invention relates to a method of removing undesirable material from bunches of grapes while hanging on a vine.
A bunch of grapes growing on a vine will often contain a significant amount of necrotic plant matter. Such matter may arise when potential grapes fail to form and as a result die alongside healthy grapes. The necrotic plant matter can lead to diseases such as botrytis infecting healthy grapes and significantly reducing a harvest. It is accordingly an object of a preferred form of the present invention to go some way towards addressing this problem, or to at least provide the public with a useful choice.
According to one aspect of the invention there is provided a method of removing undesirable material from grapes comprising the steps of:
Preferably the blower comprises an air outlet having a fixed inner flap formed of flexible material which is caught by air flowing through the outlet and caused by such air flow to flap up and down within the outlet to facilitate the substantially disrupted air flow.
Preferably the flap is anchored substantially mid way up the air outlet.
Preferably the flap comprises a strip of synthetic material, for example rubber or webbing, arranged such that the wide surfaces of the strip extend in a transverse direction with respect to the air outlet.
Preferably the air outlet has an air inlet end and an air outlet end wherein the air outlet end is substantially wider than the air inlet end.
Preferably the air outlet is divided into a number of sub air outlets and each sub air outlet has a flap arranged as set out above.
Preferably the disrupted air flow comprises a series of vortexes.
Preferably there is a brief period of relative calm between at least some of the vortexes.
Preferably the blower is transported along a series of grape vines at no more than 5 km/hr with air blowing onto the bunches of grapes as the blower moves alongside them.
Some preferred embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, of which:
With the blower 1 fitted as described above the tractor 6 can be driven between rows of grape vines with air blowing out of the two outlet ducts 3, 4 in a sideways manner with respect to the tractor. More specifically the air flow 8, 9 is directed to bunches of grapes (not shown) hanging on the vines to dislodge necrotic plant matter from the bunches. The necrotic plant matter is left to drop to the ground and this reduces the risk of the grapes becoming infected with botrytis or other similar diseases.
It has been found that directing a substantially linear airflow onto the bunches of grapes can be less than effective in removing the necrotic plant matter. It has however been discovered, surprisingly, that a flow of disrupted air directed onto the bunches can more effectively remove necrotic plant matter. To this end the blower 2 incorporates means for disrupting air flow. Referring to
Each duct 3, 4 is divided into three sub ducts 14, 15 and 16 and each sub duct incorporates a flexible flap 17. Each flap 17 is anchored to a horizontal cross bar 18 about mid way up the corresponding sub duct with its broader face aligned across that sub duct. When no air is flowing each flap 17 hangs downwards from the cross bar 18. However when air flows through each sub duct the flap therein is lifted by the moving air and flaps up and down. This results in substantial disruption to the air flow causing such flow to be less than linear when it contacts the grapes. In one embodiment of the invention the flaps 17 cause the air flow to assume a series of vortexes which contact and dislodge necrotic plant matter. In preferred embodiments of the invention there is a brief calm between each wave of turbulent air to facilitate the release of the necrotic plant matter from the grapes.
In one prototype of the invention exceptionally good results were obtained with an air flow of approximately 30 m/sec from three sub ducts each spaced approximately 70 mm apart and having the internal dimensions of 70 mm wide, 490 mm long, 195 mm high at the narrow end and 300 mm high at the wide end. The flaps 17 were each fixed at the vertical mid point of their corresponding sub duct at approximately 360 mm from the outlet end 10. In this case the tractor was driven along rows of grape vines at 1-2 km/hr with the blowers 3, 4 spaced approximately 100-150 mm from the bunches of grapes. It will of course be appreciated that any or all of the above parameters can be altered within reason to arrive at similar result.
While some preferred forms of the invention have been described by way of example it should be appreciated that modifications and improvements can occur without departing from the scope of the appended claims.
Number | Date | Country | Kind |
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577176 | May 2009 | NZ | national |