TREE CROPS - MACADAMIAS, CITRUS, PECANS - From litres per hectare to litres per minute.

As explained in the previous post, spreadsheets can't be inserted or attached. Here's the link showing calibration and determining the volume per planted hectare using a set of existing nozzles. 

http://chemiconsa.blogspot.com/2014/10/nut-and-fruit-trees-mist-blower.html  

The image below is the print out of the spreadsheet covering the mistblower calibration starting off with a pre-determined volume per planted hectare.  You still have to enter the data to determine speed and inter-row spacing.  Just send an email to chemiconteejet@gmail.com and I'll send you the files. 

In my opinion, this is the correct way to undertake spray-applications.  The problem is that farmers are sold spray-rigs with an ex-works set of nozzles which are suitable for spraying Olives, Vines, Apples and Pears etc.  They eventually discover that this is not a plug and play unit especially when it can't cope with big trees. 

Once you have the spreadsheet you fill in the essential data as marked with **. Nozzle tip flow rates are taken from the suppliers information.

chemicon@multispray.com



Mobile Intl:    +27832890327

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NUT AND FRUIT TREES - MIST BLOWER CALIBRATION SPREAD SHEET

Greetings!

The weblog does not allow a spread sheet file to be inserted or attached.  If you need the spread sheet please email  chemiconteejet@gmail.com  and I'll send the file.

Here's the print out of the file.  The data entered is merely for illustrative purposes.  

Remember this calibration uses an existing nozzle-tip configuration. I will be presenting the calibration exercise IN FUTURE  starting off with a given spray-volume per planted hectare or litres per tree and then calculating the total nozzle-tip volume in litres per minute.  A nozzle-tip configuration then has to be worked out to match the total output. Simple.

DO YOU KNOW WHAT NOZZLE-TIPS YOU HAVE IN YOUR SPRAYER?  HAVE YOU GOT THE SPECIFICATIONS OF THE TIPS AT VARIOUS PRESSURES?  DO YOU KNOW HOW TO CALCULATE THE FLOW RATE AT PRESSURES NOT SPECIFIED?  I HAVE DISCUSSED THIS ASPECT IN PREVIOUS POSTINGS.  GOOD SEARCHING. 

chemicon@multispray.com

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MIST BLOWERS, AIR BLAST SPRAYERS - IMPORTANT POINTS

MIST BLOWERS, AIR BLAST SPRAYERS  - a "pre-flight" check.

Before you even calibrate a sprayer or attempt a spraying application make sure you check the following.

PRESSURE   Do not use the pressure setting at the pump.  Make sure that  you have a good quality guage fitted at a nozzle position furthest from the pump.  In most cases there is a 25%........ yes 25% variation between the two guages.  20 bar at the pump and 15 bar at the boom/nozzle guage.

On the right,  showing various adaptors to secure the guage to a nozzle body.

CHECK THE FLOW RATE OF EACH NOZZLE-TIP.  Use a hose and capture the liquid in a calibrated measuring cylinder or jug.   Any tip with a flow rate variation of more than 5% from the specified flow rate and pressure, will need replacing.  If more than 2 are worn replace the set.

FILTERS OR IN-LINE STRAINERS.  Check for damaged or blocked filter elements. Refer to my earlier posting regarding mesh sizes. Blocked filter elements will starve the pump and reduce the flow.  Broken elements will result in blockages at the nozzle.  Use slotted strainers with all  disc and core combinations irrespective of materials used.

Here's a image showing a common problem. The element was placed into the filter bowl and then screwed onto the filter head. As you can see the element frame has been crushed.

A SIMPLE RIBBON TEST

Make a few ribbons and attach them to the nozzle assemblies to get an idea of where the wind in taking the spray cloud.

Where possible adjust the air deflector vanes.

Be very careful.  Even though the nozzles are facing up the air stream can still force the spray-cloud in the wrong direction.

DON'T, FOR A MINUTE, THINK BECAUSE YOU SEE SOME MIST THAT ITS GETTING TO THE TARGET. YOU COULD BE WASTING MASSIVE AMOUNTS OF MATERIAL OR NOT PUTTING DOWN ENOUGH.

NEXT POSTING: A SPREAD SHEET TO SORT OUT ALL THE LITTLE SUMS FOR CALIBRATION. YOU JUST PLUG IN THE NUMBERS!!!

chemicon@multispray.com




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TOWER SPRAYERS COMING UP.  THAT MIST IS GOING TO DRIVE SOME CRAZY.

BIG MACS - BIG VOLUMES BUT WHERE IS IT GOING?

BIG MACS,   BIG VOLUMES BUT WHERE IS IT GOING?

Spaced at just over 7 metres inter-row and a tad over 3 metres intra-row. By my reckoning that puts the density at 448 trees per hectare. The trees have been opened up by selective pruning. There are still branches in the way.

This tree gives you an idea of the crown density. The trees are about 7 to 8 metres high.

The problem as expressed by many growers is that the Stinkbugs sit in the top and are not contacted by the insecticde spray.

To see where the spray was going, a six metre PVC pipe with Water Sensitive cards placed at 1 metre intervals was inserted into a dense tree.

The standard spray-rig as supplied was used.   Here are the important data:

Number of nozzle-tips : 26

Total delivery at 15 bar (1500kPa) : 91 litres per minute.  Pressure recorded at the nozzle!

Speed: 92 seconds per 50 metres. Kilometres per hour : 1.96 km/hr

Calibrated volume per hectare : 3'845  l/ha ....3'800 l/ha close enough

Volume per tree : 8.58 l/tree ........... 8 l/tree close enough.

Here are the pics of the WS cards from the bottom up.

The spray-rig.

This pic actually shows the two Adjustable Conejets at the top and the Air Induction AITX's on the right bank. Low resolution pic; sorry.

CHANGING NOZZLES

The top two positions were replaced with the big Adjustable Conejets (AC) to overcome the limited effective height. The remaining right nozzle bank was replaced with Air Induction AITX8004VK Hollowcone tips.

The rig spraying without the trees.

Looks very impressive with all the mist and then the trees spoil the fun.

Note the dramatically reduced drift from the AITX's on the right nozzle bank. No doubt there will be issues with operator safety in the future and there appears to be a move to the air induction nozzles.

It is obvious that where the foliage is exceptionally dense the spray cannot get through.

The Adjustable Conejets - Cone angle adjustment and tip insert size selection will be critical to ensure that the spray gets to the top of 8 and 9 metre high trees.

The left AC should be adjusted to slightly widen the angle.

The real world. Things get tricky.

And another problem! Restricted airflow. 

Once again, notice the reduced drift from the AITX's. Also notice the right top AITX not spraying.....my mistake; turned the wrong cap.

HOT TIP! To improve the angle the right AC should actually be spraying to the left and the left AC to the right. You saw it here first!

More results from the AC and AITX's THIS TIME FROM 2 METRES AND UP AT 1 METRE INTERVALS. REMEMBER; VERY DENSE TREE.

Note : Something to consider.

Somewhere out there in the ether is a graph showing wind speed vs distance from the sprayer outlet. If my memory serves me well the speed drops off dramatically. So just how far does a 100 micron droplet go on a dry hot day? If you have this information or a link to the information it will be appreciated.

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chemicon@multispray.com

NUT AND FRUIT TREE CROPS. MACADAMIAS - A practical calibration.

NUT AND FRUIT TREE CROPS. MACADAMIAS - A practical calibration.

There are many lessons to be learned from this practical calibration exercise so spend some time digesting  the observations. Do the calculations and see if my litres per tree are correct.

The mistblower used is equipped with a set of ceramic hollow-cone tips all of the same size. This is fine when spraying vines and small trees up to 4 or 5 metres. The Macs in this situation are about 8 to 9 metres high. I will return to this aspect further on.

Checking the air flow. I used 2 metre ribbons attached to the nozzle bodies. The top centre-right is suspect. This method gives you a pretty good idea where the air is going.

Water sensitive paper. It is easy to say: 'staple water-sensitive paper directly onto the leaves at the periphery and inside the canopy at the top, in the center and lower part of the trees.'    In practice there are two problems; one is getting there (mac leaves are tough and prickly and the branches are brittle) and two; how many cards and exactly where to place them at "random" to get a good idea of the spray distribution. If you are undertaking a foliar feed or a light cover application it won't be necessary to place the cards in the tree centre.

If the target pest is an insect like stinkbugs on the macs then you would want a fullcover spray and it would be essential to get to the tree centre.   I decided to use a 5 metre aluminium 25mm square tube and attach the ws-paper at 1 metre intervals. This was then fed into the tree as close to the tree centre as possible. When testing different nozzle arrangements one can use the same position and the same tree.

A 5 m  25mm aluminium square tube  accurately marked at 1 metre centres.  

Here are the results. The ceramic hollow-cones produced a heavy coverage at 2 and 4 metres while the AITX's (Air Induction ceramic tips) appear to give a coaser droplet but more evenly distributed. The mistblower was not very effective above 4 metres.

ATR tips distribution above.  Water sensitive paper placed at 1 metres centres ; No 1 on left.

AITX tips distribution.  

Speed. 50 metres was accurately marked and the time recorded with a stopwatch.  Tape on the ground lower left in image.  In this case it took 1 min and 12 secs to cover the 50 metres. Speed in km/hr?

Nozzle arrangement.*** Nozzles fitted ATR's each deliver 3.6 litres per minute at 20 bar. 12 were used and 4 were shut off. Total delivery in l/min?   It would have been better to have tips of different sizes to achieve better coverage. In my opinion I would aim for 30% to the top third, 45% to the middle 1/3rd and 25% to the lower 1/3rd of the tree.   Each farmer will decide what's best.

Tree density. In this case the inter-row is 10 m and the spacing intra-row is 2.5 m. There 41 trees per 100 m and 10 rows per hectare. Trees per hectare?

*** Special notes relating to the nozzles.   It is clear that this mistblower is not going to cope with the tree height. The problem with this particular nozzle-body is that the capnut thread is 18mm metric so it was not possible to test other nozzle types especially the Adjustable Conejet. To increase the volume per tree, the rollover valves will have to be replaced to allow for other higher volume nozzle-tips.

So how much spray went onto each tree???

According to my calculations, the ATR ceramic tips achieved 2.53 litres per tree.

The AITX 8004VK's each delivering 4.06 litres per minute increased the volume marginally to only 2.85 litres per tree.

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Crocodile River.

Also Hippos!  Eyes open.

  

TREE CROPS AND CALIBRATION - theory is theory and practice is practice and never the twain shall meet.

TREE CROPS AND CALIBRATION - theory is theory and practice is practice and never the twain shall meet.

Off to the farm "R U NUTZ" belonging to R J "Ozzie" Beaumont to see if I can come up with some answers to the calibration problem in tree crops. Of late I hear talk of "2000 litres per hectare". Where does that come from?

The first thing I notice is there are orchards with different varieties, varying tree-heights and widths. Crown densities vary according to the variety. It is clear that there is no standard spray-volume per hectare. I decide to look at the sprayer used.

Ozzie uses a mistblower or as some refer to it as an airblast sprayer. I take note of the nozzle-tips used and find out that all products are applied at 20 bar pressure.

Anyway we decide to use a "practical" example to see if we can come up with a volume per tree. Here's the data used for the calculations.

Crop: Macadamia

Orchard : Tree density Inter-row 10 metres and intra-row 2.5 metres

Trees per 100 metre row: 41

Tree rows per hectare : 10 (Actually 11 rows but you're only spraying half of the two outer rows)

Trees per hectare : 410

Mistblower nozzles: 16 in total or 8 per side.

Flow rate at 20 bar : 3 litres per minute per nozzle or 48 litres per minute for 16 nozzles.

Speed: This varies but we settle on a slow 50 metres per minute or 100 metres per 2 minutes or 3 km per hour.

Given this speed the mistblower will spray 96 litres on 41 trees in 2 minutes. Spraying both sides = 1 tree. So the litres per tree 96 ÷ 41 = 2.342 l/tree. Wow! To the third decimal place.

There are 410 trees per field hectare so the volume per hectare is 2.342 x 410 = 960 l/ha.

IF WE LOOK AT A SPRAYRIG AND NOTE THE NOZZLE-TIPS WE CAN CALCULATE THE TOTAL VOLUME OUTPUT AT A SPECIFIC PRESSURE AND GIVEN THE SPEED WE CAN CALCULATE THE VOLUME PER HECTARE FOR EACH ORCHARD TREE DENSITY.

Let's see if we use our old faithful formula to calculate litres per hectare --- l/ha

l/ha = 600 x litres per minute ÷ speed km/hr x spacing in metres

l/ha = 600 x 48 ÷ 3 x 10 = 960 l/ha Hey! That looks the same.

WATCH OUT; THIS IS FOR BOTH SIDES. NOTE THE VOLUME IS FOR THE WHOLE SPRAYER OUTPUT.

GETTING BACK TO THAT 2'000 LITRES PER HECTARE.

If Ozzie wants to double the volume ("2'000 l/ha") the sprayer has to travel at virtually 1.5 km/hr. Yawn!! When are we getting there?

Given the "2'000 litres per hectare", what must the total volume output in litres per minute be?

l/min = l/ha x speed km/hr x swath or row spacing in metres ÷ 600

l/min = 2'000 l/ha x 3km/hr  x 10row spacing ÷ 600 = 100 litres per minute for all nozzles. OR 6.25 l/min per nozzle.

As I drive away leaving a rather bewildered Ozzie with a Teejet catalogue and some questions about coverage and those 8 metre high trees, I reach for the speed dial on my smart phone ................ HOUSTON; WE HAVE A PROBLEM.

TEL INTL: +27137449928

TEL NATL: 013 744 9928 

chemicon@telkomsa.net

SUGARCANE - ROW APPLICATION l/ha and l/min calculations

SUGARCANE - ROW APPLICATION

Cane or sugarcane is planted locally in rows at 1.5 or 1.9 metre centres. When it comes to liquid fertiliser applications the rate per hectare is known. For example a product may be applied at 100 litres per treated hectare. The speed at which it is applied will vary due to the equipment and the terrain. When dealing with high fertiliser concentrates it may be better to apply the product to standing crops in a single or multiple solid stream pattern to minimise leaf-burn.

PRACTICAL EXAMPLE.

FERTX at 100 l/ha. Speed 6 km/hr. Cane row spacing 1.9 metres. Application as a single solid stream. Refer to page 45 in Catalogue 51M. We need to determine the flow rate of a nozzle-tip in litres per minute??

l/min = l/ha x speed in km/hr x swath or rather row spacing in metres ÷ 600

l/min = 100 l/ha x 6 km/hr x 1.9m ÷ 600 = 1.9 litres per minute

That was quite handy ...600 divided by 600 leaves 1.9. For an explanation of the 600 constant refer to the previous posting.

With a bit of algerbraic jiggery-pokery you can reverse the process and given the flow rate you can determine the litres per hectare:

l/ha = 600 x l/min ÷ km/hr x m 

l/ha = 600 x 1.9 ÷ 6 x 1.9 = 100 l/ha

Looking in the catalogue on page 45 you'll find a H1/4U SS 0006 or a TP0006-SS. At 2 bar or 200 kPa this tip delivers 1.93 litres per minute. Close enough for the real world!

By now you must be asking what do these tip numbers mean? The HU type refers to a spray-tip with a 1/4" thread male inlet, the SS stands for Stainless Steel and the 0006 refers to the angle and flow rate. The first 2 digits (00) refer to the angle and in this case it is zero degrees (solid steam)  and the 06 refers to the rated flow rate in United States gallons per minute at a specific pressure. A USGal is 3.7854 litres. An Imperial gal is 4.54 litres. (Customs officials helped themselves to the difference when they imported Scotch from across the pond) Neat little excise duty as the story goes. Anyway the 06 means 0.6 gal per minute or 2.27 litres per minute at 40 pounds per square inch or about 2.8 bar pressure.

BE CAREFUL! THE SPACING IN THE CATALOGUE IS 75 CM OR 0.75 METRES.

If you are not happy with these formulas refer to the postings covering calibration.

The real world.  Overall or broadcast application at 8'000 litres per hectare. Speed 7 km/hr. Swath 1.5 m. Flow rate?

chemicon@multispray.com

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FERTILISERS AND FUMIGANTS. METERING OR FLOW REGULATION - ORIFICE PLATES

FERTILISERS AND FUMIGANTS.   METERING OR FLOW REGULATION - ORIFICE PLATES - TREATED HECTARES AND WATCH OUT FOR PRODUCT SG (SPECIFIC GRAVITY.)

Here are a few examples of orifice plates which are placed in-line to accurately meter or regulate the flow of soil fumigants or fertilisers.

This tractor with a five-tine implement is applying a sub-surface fumigant as an overall application.

A single or double tine setup could be used per row.

This will have a dramatic impact on the usage per field hectare. 

Also note, in this case the fumigant must be applied as supplied i.e. in its concentrated form.    Remember the specific gravity for water is 1 (1litre weighs 1 kilogram) and the SG for this product is 1.2.       20% heavier than water.

A beautiful image of the orifice plate showing how it should be mounted in the nozzle assembly. Inlet on the left and outlet on the right.

NOTE THAT THE NUMBERED SIDE OF THE ORIFICE PLATE MUST FACE THE OUTLET.

IF  NOT TOO SURE ABOUT TREATED HECTARES AND FIELD HECTARES PLEASE REFER TO THE POSTS COVERING CALIBRATION AND AREA.

PRACTICAL EXAMPLE:

Overall fumigant application using the 5-tine setup. The fumigant is to be applied at 60 litres per hectare. The tines are spaced at 50 cm or 0.5 metre centres on the drawbar. Speed is 5 kilometres per hour. We need to calculate the flow rate in litres per minute.

l/min = (60 litres / ha x 5 km per hour x swath or spacing of tine 0.5 metres) ÷ 600

= 0.25 litres per minute

Oh dear! Where does the 600 come from?  It's a constant which pops up as there are 60 seconds in a minute and 60 minutes in an hour, 1'000 metres in a kilometre and the swath is used in metres instead of centimetres.

So we need to find an orifice plate that matches the flow rate of 0.25 l/min or 250 ml per minute. Refer to page 44 of the TeeJet 51M catalogue. The CP4916-25 will do the trick at 2 bar or 200 kPa.

BUT!! Watch out for the SG of the product. In this case the SG is 1.2 (1 LITRE WEIGHS 1.2 KG) and the conversion factor is 1.1 so merely multiply 0.25 l/min x 1.1 = 0.28 l/min. Check the table again and you'll see that you have merely to increase the pressure to 2.5 bar or 250 kPa.

Ok! So you could have multiplied the product rate of 60 l/ha by 1.1 and come out with the same result. Six of one half dozen of another.

Next post I'll look at row application in Sugarcane.

REAL WORLD.  WHAT ABOUT THE TEMPERATURE OF THE PRODUCT AND WHAT ABOUT WHEEL SLIPPAGE?  THE WORLD ISN'T FLAT.  

Tel Intl : +27 83 289 0327

Tel Natl : 083 289 0327

chemicon@multispray.com