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Friday, September 12, 2014

MACADAMIAS - THE SMALLER GROWER AND A SECOND LOOK AT SPRAYING WITHOUT AIR ASSISTANCE.

MACADAMIAS - THE SMALLER GROWER AND A SECOND LOOK AT SPRAYING WITHOUT AIR ASSISTANCE.

Here's the link to the previous posting.




These pictures show the inter-row spacing and the foliage density.

On the previous occasion the AIC -05 and -06 capacities were tested .
(REFER PAGE 10 - TEEJET CAT 51A-M OR PG 8 CATALOGUE 51 -M)

This time, smaller capacity Air Induction flat-fans were tested and these failed to penetrate the canopy. The maximum pressure achieved was 10 bar. 

THE PROBLEM'S NOT OUTSIDE IT'S INSIDE.

Not much getting through. See the pics below. The WS cards were placed at 1 metre centres on aluminium tubes starting 1 metre above ground level.







Ignore the spot on the card at 5 metres; probably the sweat from my brow.

Two points worth mentioning. When placing the aluminium tubes extremely dense trees were selected.

The pump, a Wanner Hydracell D10 with an X camshaft capable of pressures up to 70 bar delivers only 30 liters per minute at 1450 rpm. UNFORTUNATELY THIS SETUP PROVED TO BE TOO SMALL TO TEST A FULL SET OF BIGGER CAPACITY SPRAY-TIPS.

THE AIM WAS TO TEST AIR INDUCTION NOZZLE-TIPS TO SEE IF THE CANOPY COULD BE PENETRATED.

Because the smaller capacity AIC's failed to penetrate the canopy I decided to test the big Adjustable Conejets. Here's the link.


Here are a few pics showing the arrangement and the spraying.



NOTE: GIVEN THE PUMP LIMITS, THE ADJUSTABLE CONEJETS (AC) WERE SPACED ON THE VERTICAL BOOM AS PER THE PICTURES. THE SPLIT-EYELETS ON THIS WET BOOM ARRANGEMENT ARE SPACED AT 50 CM CENTRES. THE INITIAL PRESSURE WAS SET AT 10 BAR AND THE CONEJETS ADJUSTED TO JUST ABOUT THEIR MAXIMUM ANGLE.

A general shot of the spraying. It is clear one would need additional AC's in this particular orchard where trees are planted 5.5 m x 3m. The left  picture shows good overlap but the lower nozzle-tip size is too small in my opinion.  The pressure was reduced to 8 bar from 10 bar and the AC adjusted (right pic)to create bigger droplets and improve penetration.  



Here the overlap is adequate with good canopy penetration. Selection of the nozzle-tip sizes will be critical. Pressure on the guage -- 10 bar.





The pressure was reduced to 8 bar and lowest AC adjusted or "opened" to reduce the angle and increase the droplet size to achieve better penetration with less drift. The overlap is inadequate.


Inter-row spacing is a major problem. INTERNAL DISTRIBUTION WILL BE UNEVEN BECAUSE THERE IS NOT ENOUGH OVERLAP. See the results below. These however are minor problems.

THE RESULTS - Intial set-up at 10 bar.







THE RESULTS

SUMMARY:

AIR INDUCTION FLAT FANS Without air assistance the smaller capacity Air Induction Flat Fans operating at 10 bar(AIC - 02 through -04) did not adequately penetrate the dense Macadamia canopy.

ADJUSTABLE CONEJETS         MOVING IN THE RIGHT DIRECTION!

These need to be mounted on a vertical STEEL DRY BOOM EQUIPPED WITH HOSE SHANK NOZZLE BODIES AND CLAMPS which will allow for variable spacing.


WARNING : WITHOUT AIR ASSISTANCE JUST BE CAREFUL WHEN USING SMALL CAPACITY CONE TIPS AT HIGH PRESSURES (20 BAR OR MORE) AS THEY PRODUCE ALOT OF FINE DROPLETS WHICH DO NOT APPEAR TO PENETRATE THE DENSE MACADAMIA CANOPY. THE FOLIAGE APPEARS TO ACT AS A "SOLID" BUFFER ZONE. I.E. THE DROPLETS FLOW WITH THE LEAST LINE OF RESISTANCE. JUST AN OBSERVATION.

Next time I'll take a look at other conejets and arangements..

Tel Intl. +27 83 289 0327

Tel Natl.  083 289 0327

chemicon@multispray.com




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