|
Field operation Field operation.
The Frazier chassis unit is capable
of working at speeds in excess of 16 km/h, however, these sort of
speeds are very rarely suitable for crop spraying operations. Speeds
considerably higher than those used for conventional tractor spraying
can normally be used however, due to the excellent boom stability of
the Frazier sprayer. For most spraying operations you should be able
to spray at between 10 and 12 km/hr. When deciding working speeds,
the following factors must be taken into consideration:
a). Size, shape, contours of field
and obstacles - can you maintain your target speed?
b). Ground conditions - if the
whole field is wet or there are wet patches - again, can you maintain
your target speed? - you may have to consider taking smaller tank
loads if conditions are bad. c). Application volume / spray quality - make sure you can get the required spray quality if you are using large jets and a high speed to get your required application rate.
d). Spray drift - Ensure that you
don't use too high a pressure with an undersized nozzle to get your
required application rate at a high speed.
e). Target - don't forget the whole
object of the crop spraying operation is to hit the target weed or
crop with the chemical. If the crop is dense and the target is weeds
in the bottom of the crop, then don't go too fast or the spray will
not penetrate.
f). Boom stability - It is most
important that the boom is stable whilst spraying. A boom that is
bouncing or yawing will cause uneven application, particularly at the
boom tips. This will be more noticeable with booms over 12 metres wide.
When you have decided your working
speed, have calibrated the sprayer and have become fully acquainted
with the operation of the chassis unit and the sprayer, it is
recommended that you practice in a suitable field with clean water
only. This is particularly important if you have not driven a
self-propelled sprayer before - there are an awful lot of new things
to get used to! When spraying at relatively high speeds, it is very important that your working speed is maintained to avoid under or over dosing. It is important that two bouts are sprayed around the headland, when using a 12 metre boom, to give yourself plenty of time to turn the sprayer on and off. Maintain your working speed as you travel on to the headland and turn the sprayer off before you start turning. After turning, straighten up and accelerate to your target speed before switching on again. If you turn whilst spraying you will get considerable overdosing at the outside of the inner boom.
For the same reasons always reverse
into corners and accelerate as quickly as possible as you switch the
sprayer on - the motorised valves fitted on the sprayer tend to be
little slow building up to full pressure which, of course, is a
definite advantage in this situation.
If the sprayer is fitted with an
automatic spray rate controller,(RDS Delta 3/4) it is still important
to keep as near to your target speed as possible or the spray quality
will vary considerably. When spraying potatoes and other dense crops with row crops fitted, always try to travel in the same direction each time you spray the field. The tops will then tend to grow in that direction with very little damage caused. If you change direction each time, you will find the tops are dragged back the other way, causing considerably more damage.
|