Case Study 1

On a small block of land just outside Ashburton New Zealand, a farmer had a large infestation of Californian Thistles. The infestation was so thick, walking through it was a very painful experience, having been topped the grass and thistles were the same height.

Broadcast spraying was ruled out because of -

1-     Neighboring properties had sensitive fruit’s, vegetables etc, and being in a relatively high wind zone area there was a high chance of spray drift.

2-     There was very good clover and grass in this paddock which the farmer couldn’t afford to loose.

A Rotowiper® was chosen because -

1-     By using a selective herbicide (Tordon Gold in this case) the grass would be unaffected, and the clover would not be touched by either the roller or chemical.

2-     By using a Rotowiper® there was no concern over spray drift affecting neighboring properties.

The Paddock was wiped on the 16th February 2006, after about 5 days the results were starting to become obvious and by April the paddock looked like this!

One application is very unlikely to eradicate Californian thistle in one hit but the farmer is well on his way to eradication, His grass and clover were unharmed allowing him to use the paddock for winter feeding.


Crop Study

A paddock between Christchurch and Ashburton New Zealand was planted in carrots, although the paddock had been in grass for a few years, potatoes started coming up through the crop and smothering the carrot seedlings.

Broadcast spraying was ruled out because –

1-     As a gylphosate was going to be used, broadcast spraying was ruled out as the carrots would also be killed.

2-     The Canterbury planes are a high wind area which increases the risk of spray drift.

A Rotowiper® was used because –

1-     As a gylphosate was being used and the potatoes were higher than the carrots the height of the Rotowiper® was set to hit as much of the potatoes as possible without hitting the crop.

2-     A rotowiper® with its enclosed spray rail is not subject to windy conditions.

3-     A tractor mounted unit was used to utilize the current wheel marks.

As can be seen in the photo the potato plants are well on the way to dying but the carrot crop is still very healthy.


While it was not possible to kill every potato plant as they all had different growth rates, the kill rate was very good and helped yield a profitable crop for the farmer.