Growing Makua in Thailand

[Somtham]

I have showed him the picture of the plants you pulled up. He doesnt like the look of the mottled yellow on the leaves. That is not what he was expecting. Closer picture if possible.

There is little differance between Karate and Karate Zeon. Both will do okay.

No explination for why the plants fell over. Its usualy worm damage to the stem where it comes out the ground. Hes going to chew it over for a day or 2.

Here's front and back pics of the leaves and I would say almost all of the plants have leaves that look like this. The falling over of the plants is not unique to the makuas. Some of the chile plants have done the same thing. Remember I had mentioned that I was watering for an hour each day and MIL says "way to wet". So I went back to the place I bought the sprinkler heads and they told me the output was 400L/hr. Possibly the root systems weren't strong or deep enough back when I was doing 1 hour watering. Just a guess because the plants still look like the other ones.

rgds

Oh yeh, the wife and MIL pump the fresh daily speak. The restaurants all want the farang makuas and chiles!

[chownah]

Could it be that you tilled the soil so it is really soft and now when you get it really wet it gets so soft that stuff just falls over?....you could test the soil with a finger, hand, or foot around the base of some plants and see if the soil seems so soft as to not be giving enough support.....just a wild guess.

Did you have some windy weather recently?

For alot of vegetables it is best to water and then wait for the ground to dry somewhat....as the top layers of soil dry out a bit the roots will go deeper to get water and you will develop an extensive root system which should enable larger and healthier plants.....at least this is the common wisdom for organic gardening...I don't know what non-organic gardening methods would say about this.

Chownah

[Somtham]

Could it be that you tilled the soil so it is really soft and now when you get it really wet it gets so soft that stuff just falls over?....you could test the soil with a finger, hand, or foot around the base of some plants and see if the soil seems so soft as to not be giving enough support.....just a wild guess.

Did you have some windy weather recently?

For alot of vegetables it is best to water and then wait for the ground to dry somewhat....as the top layers of soil dry out a bit the roots will go deeper to get water and you will develop an extensive root system which should enable larger and healthier plants.....at least this is the common wisdom for organic gardening...I don't know what non-organic gardening methods would say about this.

Chownah

The land was jungle previous to last summer. We had a 85hp Ford "scrape" away the luceana trees and grasses and then disc harrow. After that a small Kubota came in and disc'd again in two directions and then rototilled. I think that yes, maybe the ground was getting too wet when the soil was very soft and affected both the makua and chile plants.

The weather was a bit windy yesterday but not the reason for the plants laying down. It did make me postpone spraying the Karate until today though.

Do you think it's good to let the dirt around the chiles to dry out a bit before watering? They're still producing but looks like they could be healthier. Put fertilizer down yesterday so hopefully that will help.

thanks

[pallasaide]

Somtham

Tim says he knows little about chillies other than they are quite okay to "inter-row" with makua.

No, does not belive the soil is too loose. Just doesn't know why some have fallen over, but he wants to know this.

How have you laid your sprinklers out?

What pressure are they running at?

How much water per hour does each sprinkler deliver?

Keep it simple, he is not up to doing all sorts of fancy calculations, just rough answers for the above will be fine.

Tim thinks you might be over watering in some places and underwatering in others, and that what you have been told by the Thai people who have commented may be correct. This is almost certain if the sprinkler layout pattern is not exactly as the manufacturer suggests for the water pressure they are been used at, and even if it is done exactly like the manufacturer suggests, in reality they still do not work properly and will be almost certainly deliverying a lot of water in the last 25%-30% of the radius and less inside closer to the sprinkler. That means if you have a full radius overlap with another sprinkler then you will be getting bad distribution patterns.

A simple way to check water distribution is to take some containers with a big opening (plastic drums cut down to about 6" high) and to spread them out on the field.

1. The first test is a radius test. Place 1 at 2 meters from the sprinkler one, one about half way across the radius and one near the end of the throw. Run your sprinklers as normal and then go and collect the water from each drum and see by how much it differs. All 3 should be within about 10%-15%.

2. Next day repeat the test using a different sprinkler, and then a gain another day using another sprinkler at a different location, but keeping the same distances from the sprinkler each time.

When thats done you may wish to try it at different distances from the sprinkler.

The more variations you try, the more accuarte will be your graph.

There is just one problem. He reackons that nearly all sprinklers in Thailand are run below the correct working pressure, and there is nothing that can be done to correct distrabution patterns if a spinrkler is run at a low a pressure. The only thing to do then is to put in a valave and shut off a few sprinklers and run half for a certain amount of time, shut them off and run the other half.

Tim says you should know the total area of the land your sprinklers are distributing water over, how many sprinbklers you have and how much water is in each drum after each watering. If the amounts are within 10%-15% then you can work out an average per square meter over time and convert to mm or ml precipertation.

Remember your high-school math. Drums are round so you will need to convert the surface area of a circle to how many times it fits into the field surface area. He says "basic" but admitts he wouldnt have a clue how to calculate it at the moment.

In summary what he wants you to establish is within about 10% just how much water the field is getting and how well is it spread.

Here is another trick to do in the morning before you switch on a sprinkler.

Dig a small hole 2" or 3" anywhere in the field and take out about 100grams of soil. Put it in a bowl and weigh it (know the weight of the bowl before hand. You want exactly 100grams of soil. Do not pack it tight leave it loose.

Put the bowl in a micro wave at low heat for a botu 10 minutes to evapourate the moisture from the soil. Take it out and reweigh. Repeat the exercise (always at low heat) untill the weight ceases to drop.

Compare the before and after weights. If you started with exactly 100grams you will be able to calculate the mositure percentage level of the soil at root level by weight.

Depedning on the density of the soil as little as 10% could mean saturation or as much as 80% could mean dry. By weight is relative to soil density, so the question then is what type of soil are your makua plants planted in? Is it sandy, is it laomy, is it clayish, is it stoney, is it dark or light.

The subject gets complicated and the above is a very basic look at a subject that can be discussed for hours with all sorts of factors to qualify it, but having an idea of the soil type and how much water is in it before watering wil give a pretty good idea if too much water is been applied.

If there is a relationship between the position of the plants with leaves like those in the photos you have sent and the results of the above experiment (water distrabution) then that is almost certainly the problem. But it is not distribution or too much water per say. It is because a lot of water is on the actual leaves and could be encouraging bacteriual of fungus growth.

It mean mean changing the position of the sprinklers, the sprinkler nozzel or the pressure they are run at.

The problem with sprinklers, even if they are laid out perfectly, is that they water the whole field. About 80% of the water that hits the ground gets used up by grass and weeds and only about 20% feeds the crop. Nothing you can do about that.

If you go through the above you will achieve to things: get some insight into just how good or bad the water distribution is, and establsih if there is a relationship between the areas which receive a lot of water and the areas which have plants with the leaf patterns you have shown.

Good luck, and pleas keep him posted.

For Tim

D.Valentine

[chownah]

Could it be that you tilled the soil so it is really soft and now when you get it really wet it gets so soft that stuff just falls over?....you could test the soil with a finger, hand, or foot around the base of some plants and see if the soil seems so soft as to not be giving enough support.....just a wild guess.

Did you have some windy weather recently?

For alot of vegetables it is best to water and then wait for the ground to dry somewhat....as the top layers of soil dry out a bit the roots will go deeper to get water and you will develop an extensive root system which should enable larger and healthier plants.....at least this is the common wisdom for organic gardening...I don't know what non-organic gardening methods would say about this.

Chownah

The land was jungle previous to last summer. We had a 85hp Ford "scrape" away the luceana trees and grasses and then disc harrow. After that a small Kubota came in and disc'd again in two directions and then rototilled. I think that yes, maybe the ground was getting too wet when the soil was very soft and affected both the makua and chile plants.

The weather was a bit windy yesterday but not the reason for the plants laying down. It did make me postpone spraying the Karate until today though.

Do you think it's good to let the dirt around the chiles to dry out a bit before watering? They're still producing but looks like they could be healthier. Put fertilizer down yesterday so hopefully that will help.

thanks

How often to water depends on the plant and the soil and the weather....the water is pretty much the same everywhere (hahahahaha). When my pepper plants get well established, watering them heavily once a week is adequate or even maybe every two weeks in cooler weather. When you look at the soil you are seeing only the top surface....dig down about 10 cm and see if the soil is wet down there....if so then your plants will be doing fine. If you are worried about not watering enough then try not watering a few plants and examine them closely every day....see how long it takes to be able to detect the first signs of wilting. This will slow down the growth of the plant a bit but if you check it carefully every day you need not worry about killing the plant...a pepper plant can have a few days of wilt without suffering permanent damage...after the wilt experiment when you start giving water again they will be just fine...at least the pepper plants I've grown in organically farmed soil can wilt without permanent damage...I don't know about how plants grown using artificial fertilizers and pesticides would react.

Chownah

Edited January 9, 2007 by chownah

[Somtham]

Somtham

How have you laid your sprinklers out?

The basic layout is mini spriklers set at 4m spacing and stagered row to row also at 4m. There is a 2" main water line that seperates the field in half. There are 20 ball valves off the main that feed 1" PVC lines. The risers are 1/2" diameter. Here's a pic of the layout.

What pressure are they running at?

I normally open 6 valves at a time which would feed between 42-45 sprinkler heads. Today I removed 1 sprinker head and attached a pressure gauge. Here's what I got:

Valves open Pressure Spray radius

6 4 psi 2m+

4 7 psi 4m

3 11 psi ~5m

FYI I use a 2hp pump with a Qmax at 400 LPM and Hmax at 18m.

How much water per hour does each sprinkler deliver?

The place where I bought them told me 400 LPH but did not state at what pressure that was.

A simple way to check water distribution is to take some containers with a big opening (plastic drums cut down to about 6" high) and to spread them out on the field.

...

This one is going to take me a few days to do. No big plastic drums around here. All I could find was empty beer Chang bottles. Will check and post when I have the data.

Dig a small hole 2" or 3" anywhere in the field and take out about 100grams of soil. Put it in a bowl and weigh it (know the weight of the bowl before hand. You want exactly 100grams of soil. Do not pack it tight leave it loose.

Put the bowl in a micro wave at low heat for a botu 10 minutes to evapourate the moisture from the soil. Take it out and reweigh. Repeat the exercise (always at low heat) untill the weight ceases to drop.

Compare the before and after weights. If you started with exactly 100grams you will be able to calculate the mositure percentage level of the soil at root level by weight.

Depedning on the density of the soil as little as 10% could mean saturation or as much as 80% could mean dry. By weight is relative to soil density, so the question then is what type of soil are your makua plants planted in? Is it sandy, is it laomy, is it clayish, is it stoney, is it dark or light.

Did the 100g test and after the microwave the soil weighed in at ~90g. 10% moisture. I tested one area of the soil and it is 91% sand, 6% silt, and 3% clay which would put it in the "Sand" classification. A bit OT but this is why the fish farmer I bought the place from went broke. I brought in 50 dump truck loads of clay to seal the fish ponds! I will run this test again as the soil varies from area to area. Here's a pic from the soil test:

If there is a relationship between the position of the plants with leaves like those in the photos you have sent and the results of the above experiment (water distrabution) then that is almost certainly the problem. But it is not distribution or too much water per say. It is because a lot of water is on the actual leaves and could be encouraging bacteriual of fungus growth.

It mean mean changing the position of the sprinklers, the sprinkler nozzel or the pressure they are run at.

The bacteria and/or fungus growth may well be a problem as I am using the source for the sprinkler system is fish pond water. Changing pressure, layout, heads, etc is no problem. The entire sprinkler system was a mere B5,200.

Thanks for all the help and am still praying for Tim's recovery.

rgds

[pallasaide]

Sotham

Tim says if you want a job, let him know: he did not realise you had gone to that effort and says he is impressed with what you have done and the effort you put into it. There is no need to change anything in the layout and there is no need to change the pressure. The answer is quite simply: too much water.

You are never going to be able to apply the exact right amount of water. Its impossible and frankly there is little to be gained from doing so, but you can apply too much or too little and from what you have side about the the soil density and the mositure content versus when that test was done over when you last irrigated, his opinion is that you can try the following.

Irrigate once a day early evening or sunset, and reduce the irrigation time down to 10-15min.

Give time for everything to "settle" and then run the mositure again after 3 or 4 days. Do it one morning (meaning you have allowed over night for the water to soak in)

You are looking for something around 12 - 15% by weight at around 10cm depth.

If it's anything over 16% then knock 2 or 3 minutes off the irrigation time, and irrigate at the reduced time schedule for another 3 or 4 days, and then repeapt the mositure test. Likewise, if its too, dry add a couple minutes to the watering time.

Soil water tension fluctuates considerably in sandy type soil. Immeidatly after irrigation it is can be 100% saturated, but it will drop rapidly as the water disperses. The oppisite is true of course for clay type soils. The objective becomes trying to find as good a balance as possible. Try keeping a x, y graph, x (vertical) been % and y (horizontal) been days.

Draw a horizontal line across the graph and mark that as 12-15% and along the bottom draw a set of equally spaced vertical lines for every 3 days.

Divide the space above the horizontal line into about 10 eqally spaced lighter lines and do the same below the main line.

Then mark the graph every 3days as you do the moisture.

If you are willing to go to the effort of keeping keeping a second graph (total pump liters/surface area) you will quickly build up a very accurate picture of exactly how much water is going into the soil and just what it is doing for the plants.

May sound OTT, but you will look back on it next year and be really glad you done it. If becomes a very valuable "tool" from dry season to wet season.

Someone else commented that a bit of stress on the plants wont do them much harm. That is correct, it wont do them much harm, but it will effect your crop yield in the long run.

There is no question about how well you have set it up, nows the time to start fine tuning it to get the best out of it.

Please keep Tim posted, but dont feel under pressure to rush anything, especially when it comes to fine tuning the irrigation. It will leads to errors and having to start all over again. You are well on the way to making a success of it.

Tim207, how is your Makua project coming on?

You tried potatoes as well did you not?

What variety and how have you planted them?

There is a good local market for potatoes, if you can get them to grow, which in Thailand on any scale seems to be successful only in the highland areas? Tim tried once but despite following everything to the book it was a complete faliure. He done it all exactly how he was advised but the one thing he could not control was the climate, and the temperature (not the rainfall) ruined the project.

D.V.

[chownah]

I think that with your sandy soil and your daily watering the problem with the plants falling over very well might be that the soil when saturated simply is too soft to hold them up. Use some small bamboo stakes to tie them up or maybe watering less or even compacting the soil around the plants with your foot (carefully of course).

As another issue...with sandy soil adding organic material can make a big difference. The organic material will hold more water allowing less frequent watering. Sandy soils usually respond well and quickly to applying an organic mulch on the surface. The mulch will greatly slow surface evaporation and as the mulch contacting the soil decomposes the nutrients will readily move down through the loose sandy soil to the plant roots. When applying mulch you should keep the mulch away from the stem of the plant unless you have established that mulch contacting the plant will not be a problem. You can determine if its a problem by experimenting with a few plants...put some mulch right up to the stem and see if it causes a problem. I've been using rice hulls as a mulch...also rice straw. Rice straw has the potential to harbor rodents so I'm not recommending thick applications across the board but a thin layer should not provide habitat for rodents. Do remember that applying a large amount of carbon containing material without also adding some nitrogen containing material may tie up what nitrogen is available temporarily so remember to add some manure in conjunction with adding the hulls or straw. This is not so critical for mulches which lie above ground but when you till the mulch into the soil you must be sure that there is adequate nitrogen containing material (manure) added to avoid a temporary lack of available nitrogen.

Chownah

[Somtham]

Sotham

Tim says if you want a job, let him know: he did not realise you had gone to that effort and says he is impressed with what you have done and the effort you put into it. There is no need to change anything in the layout and there is no need to change the pressure. The answer is quite simply: too much water.

Sorry, I had to laugh at this opening line. Tell Tim thanks for the offer but I was only doing what needed to be done to answer his questions. Garbage in, garbage out as the saying goes. Just wanted to get good data. Also let him know that I am retired and haven't had this much kwam suk in a long long time. Not sure I would trade my existing life for anything but as I mentioned in the PM if he needs help on the farm just let me know.

The last soil moisture test that showed 10% moisture was done 30 hours after watering. I had watered Tuesday morning and then did the test Wed afternoon before watering again. I understand the moisture graph that he's suggesting and will try to generate.

DV - thanks for spending so much of your time passing on these messages and typing up the replies. I really do appreciate it. Maybe Tim should author a book "Step by Step Makua Growing in LOS"....edited by DV :-)

rgds

[pallasaide]

Somtham

K/Zeon will work with any fruit or vegetable plant, and will deal with just about any pest insect.

It is the only insecticide Tim uses. It works by switching off part of the nerve and sensory system of the insect which tells it that it is thirsty and must drink water (which they do by way of eating your crop). They can absorb it through their skin or shell directly or through ingestion by way of eating a plant that has already absorbed it systemically. I think I am conveying this correctly. Anyway. they stop eating and die of dehydration over a period of about 24hrs.

But as you will have discovered, it is not the cheapest insecticide. It's up with the best 5 avaliable anywhere in the world but what makes it expensive is its mode of action, which is not insect selective. Tim reccomended it because it would save you having to store different insecticides and having to apply different insecticides at different times.

Specifically, if you have a problem with just one type of insect and nothing else, you could probably deal with that insect with a far cheaper insecticide that is more specific. The potential downside is that if something else comes along 2 or 3 weeks later you may then have to apply insecticide all over again, and quite possibly a different type of insecticide.

Another potential problem is multiple resistance, not so much an issue over the life of a plant like vegetables but certainly in the case of fruit trees where the application of an insecticide doesn't always kill all stages of the the target insect at the time application.

The mode of action described above in the case of K/Zeon is relatively new for an insecticide. A specific consideration in its developement at a biochemical level was the slowness of animals to adapt (develope resistance) at a nerve level. A lot of study has been put into watching for resistance developement to Karate/Z by insects. Non of usual indicators have yet been identified.

How often should you have to apply it?

In theory as far as Tim recalls it is something like 8-10weeks, but in practise he has never had to use it more than 2 or 3 times a year.

By far the best way to apply it is through drippers straight into the ground and root system. it takes 2 or 3 days to get sucked up and disperse throughout the plant, but the advantage is that it deals with anything living in or on the plant and getting to it via the roots or stems, as well as leaves and fruit (worms and boring insects). Its a much quicker action if sprayed (overnight to 36hrs), but then its dispersal into new growth over the next 3-6 weeks is not as comprehensive as it is through the roots.

How are you buying your K/Zeon, is it in granular or liquid form?

You can mix it as much as 25%-20% below reccomended concentration and it will be just as effective.

D.V.

[Somtham]

Somtham

K/Zeon will work with any fruit or vegetable plant, and will deal with just about any pest insect.

It is the only insecticide Tim uses. It works by switching off part of the nerve and sensory system of the insect which tells it that it is thirsty and must drink water (which they do by way of eating your crop). They can absorb it through their skin or shell directly or through ingestion by way of eating a plant that has already absorbed it systemically. I think I am conveying this correctly. Anyway. they stop eating and die of dehydration over a period of about 24hrs.

But as you will have discovered, it is not the cheapest insecticide. It's up with the best 5 avaliable anywhere in the world but what makes it expensive is its mode of action, which is not insect selective. Tim reccomended it because it would save you having to store different insecticides and having to apply different insecticides at different times.

Specifically, if you have a problem with just one type of insect and nothing else, you could probably deal with that insect with a far cheaper insecticide that is more specific. The potential downside is that if something else comes along 2 or 3 weeks later you may then have to apply insecticide all over again, and quite possibly a different type of insecticide.

Another potential problem is multiple resistance, not so much an issue over the life of a plant like vegetables but certainly in the case of fruit trees where the application of an insecticide doesn't always kill all stages of the the target insect at the time application.

The mode of action described above in the case of K/Zeon is relatively new for an insecticide. A specific consideration in its developement at a biochemical level was the slowness of animals to adapt (develope resistance) at a nerve level. A lot of study has been put into watching for resistance developement to Karate/Z by insects. Non of usual indicators have yet been identified.

How often should you have to apply it?

In theory as far as Tim recalls it is something like 8-10weeks, but in practise he has never had to use it more than 2 or 3 times a year.

By far the best way to apply it is through drippers straight into the ground and root system. it takes 2 or 3 days to get sucked up and disperse throughout the plant, but the advantage is that it deals with anything living in or on the plant and getting to it via the roots or stems, as well as leaves and fruit (worms and boring insects). Its a much quicker action if sprayed (overnight to 36hrs), but then its dispersal into new growth over the next 3-6 weeks is not as comprehensive as it is through the roots.

How are you buying your K/Zeon, is it in granular or liquid form?

You can mix it as much as 25%-20% below reccomended concentration and it will be just as effective.

D.V.

I bought the Karate in liquid form at B220 for 500ml. The directions called for 20-30ml/20l of water. Not to expensive. I've yet to set up a venturi system for applying fertilizer and insecticide so for I just sprayed the leafs with the Karate and put the fertilizer on the ground under the plants. If the Karate is to soak into the roots how much would need to be applied per plant? Would you just keep spraying the ground around the plant until it was saturated or would that be to much?

rgds

PS - found the E-W seeds and planted today in the potting trays with decent soil.

[pallasaide]

Hello Somtham

Tim reackons if you are going around bucket and cup in hand to apply, then 200ml will be fine.

It is best applied to dry soil (i.e. before you switch on your sprinkler system), so that it soaks in well. Then about half an hour later you can switch on your sprinklers. However, if you have already sprayed, then there is little point in applying now for at least another month or so.

If you are spraying, then below is the sort of sprayer you are best off using. It is a mist type sprayer using a blast of air to sprayer a fine mist right into the thick foilage. The coverage it gives is far more comprehensive then a convetional type sprayer which do not tend to penetrate foilage very well. In the process to uses the insecticide much more efficiently (about half the amount of a conventional sprayer for the same amount of area).

Honda market a model in Thailand that costs something like $100 -$150.

They also last longer because they have a much simplified high pressure system, and are more forgiving when abused by labourers who dont maintain equipment properly!

This morning, for what it worth, independant "confirmation". Tim had a friend from John Deere Ag visit him (as you may know he was part of the John Deere team in South East Asia many years ago). He looked at the leaf photos and said straight away "water" (i.e. excess).

What variety of EW seeds have you planted -Tiger/Stripe? Dont forget to put the netting up while they grow in the seed trays, and leave them in the seed tray till they are a good 15"-20" high. About 5 days before you transplant them to the field give each seedling a good dose of K/Zeon. Just flood each tray with a couple pints of mix and let it soak in (you cant overdose them with K/Zeon). It will keep the insects off for the first few weeks while they establish themselves in the field.

For Tim

D.V.

[Somtham]

Honda market a model in Thailand that costs something like $100 -$150.

Right now I just use one of those green backpack hand pump sprayers. At B5k the Honda is going to have to wait until the price of makua goes up. Right now that's 500kg of crop to pay for it!!

This morning, for what it worth, independant "confirmation". Tim had a friend from John Deere Ag visit him (as you may know he was part of the John Deere team in South East Asia many years ago). He looked at the leaf photos and said straight away "water" (i.e. excess).

This is a good news bad news situation. It's ok now because I can control how much water the plants get. Not sure what's going to happen come June. Might be another very good reason for planting in the buckets.

What variety of EW seeds have you planted -Tiger/Stripe? Dont forget to put the netting up while they grow in the seed trays, and leave them in the seed tray till they are a good 15"-20" high. About 5 days before you transplant them to the field give each seedling a good dose of K/Zeon. Just flood each tray with a couple pints of mix and let it soak in (you cant overdose them with K/Zeon). It will keep the insects off for the first few weeks while they establish themselves in the field.

I bought the Chaopraya again. Seems to be quite popular locally for making gaeng. I have the seed trays on a south facing patio table with a cover. They get about 2 hours of direct sunlight in the morning and the indirect light the rest of the day. My wife is watering them daily with a mist sprayer.

rgds

[chownah]

Somtam,

Have you reduced your watering and have the leaves stopped turning yellow like the picture? It is my experience that it is not uncommon for the bottom leaves on a plant to start to look like your photo sort of and it doesn't seem to necessarily be a problem.....the problem occurs if this process starts to work its way up the plant and a greater percentage of the leaves become disfunctional.

The rains might be manageable. At least you've got really sandy soil so the rain water will drain away quickly. Is it possible to dig (plow) drainage ditches in the rows?...I guess that depends on row spacing.

Chownah

[Somtham]

Somtam,

Have you reduced your watering and have the leaves stopped turning yellow like the picture? It is my experience that it is not uncommon for the bottom leaves on a plant to start to look like your photo sort of and it doesn't seem to necessarily be a problem.....the problem occurs if this process starts to work its way up the plant and a greater percentage of the leaves become disfunctional.

The rains might be manageable. At least you've got really sandy soil so the rain water will drain away quickly. Is it possible to dig (plow) drainage ditches in the rows?...I guess that depends on row spacing.

Chownah

Yes I have cut back on the watering and the plants appear to be doing better. I may only be my imagination but it looks there are fewer yellow leaves and none have progressed up the plant.

The field has drainage ditches. If you take a look at the sprinkler layout jpg above the "white spaces" between the shaded colors are the drainage ditches. There's somewhat of a slope to the plot so the water runs left to right and then drains into a 8" dia cement pippe that flows to the klong behind the place. Some days we get a lot of rain and it takes a while to drain the field. Looks like more "chawp" work before June!!

rgds

[chownah]

Somtam,

If you have a 2 wheel tractor or can hire someone who does you could have them run the length of the planting strips and have them plow the dirt up into raised berms with deep furrows between for the areas you indicate as for future planting. You should be able to get enough height on the berms to keep the plants up out of the wet I think. Is this what you have done already?

I looked at your plot plan and it looks like you have some big ditches and some small ones...is this right?....also it looks like you have some irrigation lines running down the ditches and some running down the center of the planting strips....is this right? Also do you have one row of plants down the center of each planting strip or is it two rows per planting strip...and the planting strip is about 2.6 metres wide?

Chownah

[Somtham]

Somtam,

If you have a 2 wheel tractor or can hire someone who does you could have them run the length of the planting strips and have them plow the dirt up into raised berms with deep furrows between for the areas you indicate as for future planting. You should be able to get enough height on the berms to keep the plants up out of the wet I think. Is this what you have done already?

Yes it is already that way.

I looked at your plot plan and it looks like you have some big ditches and some small ones...is this right?

No, that's just a lack of precision in my sketch :-) They're all pretty much the same depth and width.

....also it looks like you have some irrigation lines running down the ditches and some running down the center of the planting strips....is this right?

Yes, that's the way I set it up to get the 4m spacing on the sprinkler system.

Also do you have one row of plants down the center of each planting strip or is it two rows per planting strip

2 rows per strip.

...and the planting strip is about 2.6 metres wide?

Haven't measured but I would guess ~ 2m wide.

Chownah

[chownah]

Somtham,

I'm wondering if plowing another furrow down the middle of each planting strip dividing it in two could be done....the idea not being to get better drainage necessarily (sounds like your layout is pretty good already) but to add a few more centimetres of height where the plants are...it might not be worth it....just a thought. I planted some pineapples this year and according to what I've read they are especially vulnerable to having their roots under water so I plowed the dirt (in my sandiest soil) up into berms raised about 40 to 50 cm above the trench bottoms which was what was recommended for converting paddy fields into pineapple fields. I've got one berm done (about 15m long) and planted...its doing well and I've got another constructed and will plant it with the suckers from the first berm if/when they appear. The problem with building such high berms is that you need really wide trenches to get enough dirt to get the height so you have alot of area in the trench....I'm trying to figure out if I can do some different crop in the trench bottom.

Anyway....if it just takes a few hours for the field to drain after a heavy rain then for many crops this is not a problem...I don't know about makua on this but maybe Maizefarmer knows.....of course his bucket method seems ideal in this respect....maybe you could put four cement blocks in a square with a nylon line tied around it and fill it with dirt...that would give you a 40 cm square raised by about 18 cm....the cost of the blocks might make it not worth it unless you could use the blocks later if/when a better solution is found.

Chownah

[pallasaide]

Hello Somtham

Without seeing the field and the “slope” it is hard to judge exactly what drainage is required.

Berms or building up soil around the base of the crop with row crops like makua can be a case of trading one problem off for another.

There are some considerations (long winded but hopefully giving you a good insight to as many different options as possible, and the issues associated with each).

The root structure of Makua is shallow and spread out to start with, the higher the moisture content of the soil the shallower will be the roots as they will grow like this to avoid water logging. This means that makua planted in raised beds will soon have their roots been exposed (through the side of the raised bed). The problem will be made worse as the soil compacts over time and with rainfall (and of course the older the plant becomes the more spread out will be the roots). An unusually large downpour of rain can wash down a lot of the soil packed around the plant, then exposing more roots and causing the plants to lean or fall over.

A second consideration is that as the crop is harvested daily, many workers are walking up and down each row every day. Not so much a problem with a crop that is picked once or twice a month, but with it occurring every day the built up soil is going to get trampled (however much care is taken, this will happen).

Come the dry season, you will find you will be having to irrigate SO MUCH more because of the increased surface area around the plants open to drying out (evaporation) and capillary effect under gravity (the tendency of the water to soak through to the land beneath).

In theory building up the soil can be a solution, in practise you will find the extra considerations it introduces are likely to negate what it offered in the first place.

There are though scenarios in which building up the soil around the base of the plants would be a viable (indeed very good) solution. That is if you had laid down a roll of black plastic sheeting over the built up bed before you planted the seedlings (through a small hole pierced through the plastic). Tim can’t remember if he mentioned this as a method, but says next to the bucket method, this has to be a good way of going about it.

The edges of the plastic can be covered with loose soil to hold them down. Using this method means you have to of course use drippers (which need to be laid down before you lay the plastic sheeting down).

The 2 good advantages this offers are: an almost total elimination of weeds and grass growing around the makua plants (so long as black plastic is used there will be insufficient sunlight to sustain photosynthesis and they will die within a day or 2 of germinating. So land maintenance (labour) is reduced to less than a quarter of what it currently is (labour is the single biggest expense in the long run, and anything down at the start to cut future aniticipated labour costs pays off handsomely). The second advantage is the reduction it offers in required irrigation and the cost of fuel (whether it is electricity or diesel), as evaporation is reduced enormously. The third advantage is the reduction in insect damage from worms and other ground insects. They don’t like settling down in soil underneath plastic (because of heat in the daytime).

But like all systems, this too is not perfect. Again, with workers walking up and down the rows each day it is only a matter of time before someone sticks their foot through the plastic sheeting (not to much of a problem, and nothing a bit of spray on adhesive and piece of black plastic cant sort out).

Still, on balance, it his in his opinion one of the best ways of growing flieds of makua after planting in buckets. Remember if you do then it is important to place the drippers right up near the near hole where the makua seedlings are planted. This gives easy access to changing any if they get blocked without having to make additional holes in the plastic.

Try one or 2 rows out using this method. You will notice the seedlings will grow about 20-30% faster and a lot larger over the same amount of time. Why? Firstly, because moisture tension in the soil does not fluctuate as much,and secondly the seedlings are not competing with grass and weeds for soil nutrient content, which usualy use up about 40%-60% of whatever fertiliser or nutirent is in the soil.

Remember as well (this is important) to build up each row or strip of soil to about 15”-20” height and leave it to settle (under the daily sprinkler irrigation) for about 3 weeks. This gives the soil time to settle and compact (which it will do naturally in any case). The advantage to doing this now and not planting the seedlings straight away, is that if you were to cover it with the plastic sheeting immediately you will find that after about 3 weeks to a month the plastic will be “loose” and flapping around a lot (because the soil has settled). So give the soil a few weeks to settle before covering (don't worry about the weeds or grass that grow in that period of time, they'll die off within a couple days of been covered with plastic).

Another consideration here (if you cover the rows with a roll of plastic) is not to have them running perpendicular to the land slope (across the land slope). They should run at an angle, any angle that gives around 3-5 degree slope. This will allow excess rainfall in the wet season to run off (slowly) without causing soil erosion between the rows. In fact you may even wish to lay down a seperate strip of plastic between each row and covering it with stone chip. You will have perfect run off and no matter how heavy the rain and zero erosion. Using this method rows can now without risk of erosion while still ensuring all excess run off, no mud, no soil damage, no water logging, and next to zero land maintenance.

Capital outlay, yes. But in the long term what it saves is recouped. With that all said, you will be thinking, why don’t I just go to buckets. And you are right. Tim is just trying to share with you different practical options that will go towards solving water logging problems, but solve it you are going to have to do one way or the other.

The last and probably the easiest and most practical method to address water logging (and if you have any water logging now at this time of the year, you can be absolutely 100% certain you will have a big problem with those same patches come the rain later this year) would be to dig 2 drainage trenches.

The first one should be dug across the field about half way, and the second one should be dug at the bottom of the field (meaning the lowest point). They must be dug across the slope, not with the slope irrespective of the row angles). What you have currently described as been in place is no where near what is required to drain your field. No where near.

The trenches will have to be a good 2’ or so wide and about 5’ deep. Remember, unless the water in the soil below the surface cannot drain away, then the water above it (at root level) has no-where to go, and that is what causes the root zone to become waterlogged. So the trenches should be really deep, 5’ or so. If there is no-where for the water to run out of the drainage trench then a submersible pump should used to drain out the ditch (to the kalong) when it starts filling. You will be amazed just how much water flows into these trenches in the wet season and how quickly they fill up. Tim has a few trenches dug to roughly the same dimensions, and about 130' long. It is not uncommon in the wet season for him to drain out the equivalent of 50 tons of water per week per trench! Each of those trnechs would be draining he reackons about 2 to 3 acres of land at most.

Here is something else you may wish to consider, that does involve building up the soil, and which will work reliably in the long run. Really all it involves is supporting the side of the built up soil and to do that you simply use planks of wood laid down each side of the soil. They can be placed about 15” apart and the top edge of the plank should be about 8” (or more) above the surrounding ground level. This will reliably contain the soil preventing it from washing down and exposing roots, and if you wish to use palstic as well, well then you can tuck the sides of the plastic down the side of the plank. Perfect! (no waterlogging, no weeding and no insects getting into the soil, little to zero ground maintenance, redcued irrigation costs) Of course the problem here is the capital outlay.

Another possibility along the bucket method is to use large tins. Anything with a volume of 10 litres or more should work. They can be obtained for next to nothing from scrap yards (about Baht10 each Tim thinks). Small, yes, but you’d be surprised, with the correct soil and fertiliser regime, it is possible to get the makua plant to grow to same size as it would in the ground.

The above are all considerations to address drainage. Building up the soil around the plant would not be Tim’s first option without someway of supporting the sides and protecting the roots from exposure. But with support and covering, why not. Failing this you are going to be bogged down literally, in the wet season with both maintenance and damage caused by workers constantly walking up and down the rows each day. BUt whatever you decide on, if you have water logging now, you are going to have a problem on your hands come the rains in June, July and August, so youmust give some thought to how it is going to be dealt with. Drainage trenches would be your best option from a cost point of view. Building up the soil, and supporting the edges would be a good option as not only will it reduce water logging, if done properly at a row angle you will achieve good run off and significantly reduced long term labour and irrigation costs. And then of course their is the bucket or tin option, in which case what happens on the ground becomes a complete non-issue.

best Regards - for Tim

D.V.

[Somtham]

Hello Somtham

Without seeing the field and the “slope” it is hard to judge exactly what drainage is required.

Berms or building up soil around the base of the crop with row crops like makua can be a case of trading one problem off for another.

There are some considerations (long winded but hopefully giving you a good insight to as many different options as possible, and the issues associated with each).

The root structure of Makua is shallow and spread out to start with, the higher the moisture content of the soil the shallower will be the roots as they will grow like this to avoid water logging. This means that makua planted in raised beds will soon have their roots been exposed (through the side of the raised bed). The problem will be made worse as the soil compacts over time and with rainfall (and of course the older the plant becomes the more spread out will be the roots). An unusually large downpour of rain can wash down a lot of the soil packed around the plant, then exposing more roots and causing the plants to lean or fall over.

A second consideration is that as the crop is harvested daily, many workers are walking up and down each row every day. Not so much a problem with a crop that is picked once or twice a month, but with it occurring every day the built up soil is going to get trampled (however much care is taken, this will happen).

Come the dry season, you will find you will be having to irrigate SO MUCH more because of the increased surface area around the plants open to drying out (evaporation) and capillary effect under gravity (the tendency of the water to soak through to the land beneath).

In theory building up the soil can be a solution, in practise you will find the extra considerations it introduces are likely to negate what it offered in the first place.

There are though scenarios in which building up the soil around the base of the plants would be a viable (indeed very good) solution. That is if you had laid down a roll of black plastic sheeting over the built up bed before you planted the seedlings (through a small hole pierced through the plastic). Tim can’t remember if he mentioned this as a method, but says next to the bucket method, this has to be a good way of going about it.

The edges of the plastic can be covered with loose soil to hold them down. Using this method means you have to of course use drippers (which need to be laid down before you lay the plastic sheeting down).

The 2 good advantages this offers are: an almost total elimination of weeds and grass growing around the makua plants (so long as black plastic is used there will be insufficient sunlight to sustain photosynthesis and they will die within a day or 2 of germinating. So land maintenance (labour) is reduced to less than a quarter of what it currently is (labour is the single biggest expense in the long run, and anything down at the start to cut future aniticipated labour costs pays off handsomely). The second advantage is the reduction it offers in required irrigation and the cost of fuel (whether it is electricity or diesel), as evaporation is reduced enormously. The third advantage is the reduction in insect damage from worms and other ground insects. They don’t like settling down in soil underneath plastic (because of heat in the daytime).

But like all systems, this too is not perfect. Again, with workers walking up and down the rows each day it is only a matter of time before someone sticks their foot through the plastic sheeting (not to much of a problem, and nothing a bit of spray on adhesive and piece of black plastic cant sort out).

Still, on balance, it his in his opinion one of the best ways of growing flieds of makua after planting in buckets. Remember if you do then it is important to place the drippers right up near the near hole where the makua seedlings are planted. This gives easy access to changing any if they get blocked without having to make additional holes in the plastic.

Try one or 2 rows out using this method. You will notice the seedlings will grow about 20-30% faster and a lot larger over the same amount of time. Why? Firstly, because moisture tension in the soil does not fluctuate as much,and secondly the seedlings are not competing with grass and weeds for soil nutrient content, which usualy use up about 40%-60% of whatever fertiliser or nutirent is in the soil.

Remember as well (this is important) to build up each row or strip of soil to about 15”-20” height and leave it to settle (under the daily sprinkler irrigation) for about 3 weeks. This gives the soil time to settle and compact (which it will do naturally in any case). The advantage to doing this now and not planting the seedlings straight away, is that if you were to cover it with the plastic sheeting immediately you will find that after about 3 weeks to a month the plastic will be “loose” and flapping around a lot (because the soil has settled). So give the soil a few weeks to settle before covering (don't worry about the weeds or grass that grow in that period of time, they'll die off within a couple days of been covered with plastic).

Another consideration here (if you cover the rows with a roll of plastic) is not to have them running perpendicular to the land slope (across the land slope). They should run at an angle, any angle that gives around 3-5 degree slope. This will allow excess rainfall in the wet season to run off (slowly) without causing soil erosion between the rows. In fact you may even wish to lay down a seperate strip of plastic between each row and covering it with stone chip. You will have perfect run off and no matter how heavy the rain and zero erosion. Using this method rows can now without risk of erosion while still ensuring all excess run off, no mud, no soil damage, no water logging, and next to zero land maintenance.

Capital outlay, yes. But in the long term what it saves is recouped. With that all said, you will be thinking, why don’t I just go to buckets. And you are right. Tim is just trying to share with you different practical options that will go towards solving water logging problems, but solve it you are going to have to do one way or the other.

The last and probably the easiest and most practical method to address water logging (and if you have any water logging now at this time of the year, you can be absolutely 100% certain you will have a big problem with those same patches come the rain later this year) would be to dig 2 drainage trenches.

The first one should be dug across the field about half way, and the second one should be dug at the bottom of the field (meaning the lowest point). They must be dug across the slope, not with the slope irrespective of the row angles). What you have currently described as been in place is no where near what is required to drain your field. No where near.

The trenches will have to be a good 2’ or so wide and about 5’ deep. Remember, unless the water in the soil below the surface cannot drain away, then the water above it (at root level) has no-where to go, and that is what causes the root zone to become waterlogged. So the trenches should be really deep, 5’ or so. If there is no-where for the water to run out of the drainage trench then a submersible pump should used to drain out the ditch (to the kalong) when it starts filling. You will be amazed just how much water flows into these trenches in the wet season and how quickly they fill up. Tim has a few trenches dug to roughly the same dimensions, and about 130' long. It is not uncommon in the wet season for him to drain out the equivalent of 50 tons of water per week per trench! Each of those trnechs would be draining he reackons about 2 to 3 acres of land at most.

Here is something else you may wish to consider, that does involve building up the soil, and which will work reliably in the long run. Really all it involves is supporting the side of the built up soil and to do that you simply use planks of wood laid down each side of the soil. They can be placed about 15” apart and the top edge of the plank should be about 8” (or more) above the surrounding ground level. This will reliably contain the soil preventing it from washing down and exposing roots, and if you wish to use palstic as well, well then you can tuck the sides of the plastic down the side of the plank. Perfect! (no waterlogging, no weeding and no insects getting into the soil, little to zero ground maintenance, redcued irrigation costs) Of course the problem here is the capital outlay.

Another possibility along the bucket method is to use large tins. Anything with a volume of 10 litres or more should work. They can be obtained for next to nothing from scrap yards (about Baht10 each Tim thinks). Small, yes, but you’d be surprised, with the correct soil and fertiliser regime, it is possible to get the makua plant to grow to same size as it would in the ground.

The above are all considerations to address drainage. Building up the soil around the plant would not be Tim’s first option without someway of supporting the sides and protecting the roots from exposure. But with support and covering, why not. Failing this you are going to be bogged down literally, in the wet season with both maintenance and damage caused by workers constantly walking up and down the rows each day. BUt whatever you decide on, if you have water logging now, you are going to have a problem on your hands come the rains in June, July and August, so youmust give some thought to how it is going to be dealt with. Drainage trenches would be your best option from a cost point of view. Building up the soil, and supporting the edges would be a good option as not only will it reduce water logging, if done properly at a row angle you will achieve good run off and significantly reduced long term labour and irrigation costs. And then of course their is the bucket or tin option, in which case what happens on the ground becomes a complete non-issue.

best Regards - for Tim

D.V.

As usual an a'maizing' amount of information. Thanks.

You need to know that right now, dry season, I do not have any drainage problems at all. The plot has a little more than a 1% slope to it and I never put down so munch water that it needs to drain down the ditches. Last year during the rainy season it would take the lower parts of the garden a half a day to drain. In addition to the ditches between the rows I do have one diagonal ditch that crosses all the rows about 2/3 of the way down the row and another ditch perpendicular to the rows at the very end which feeds the 8" drain pipe.

I'm glad this is just a 1 rai test plot because there is so much to learn and definately some mistakes to be made. Had I read this thread before starting all of this I would be much better off.

Although the plastic sheets would work for a start, like Tim, I don't think they are the solution for chiles and makuas which are picked daily. I saw a number of fields in CA last Nov that looked like a sea of plastic but they were growing seasonal crops like brocolli, lettuce, etc. and not having to walk on it daily to pick the crop. With the pickers, me, walking around everyday it wouldn't be long before the plastic was all tore up.

With all do respect the 5 foot deep trench sounds like a disaster waiting to happen for me. On occasion, I do like to wander around at night and check out the moon, stars and birds yacking away and mind you this is usually after a few Changs. Five foot deep ponds I can handle but a trench, well, I just might end up in it!! I think I'll put in a couple more 8" drainage pipes and give that a go first.

I still like the plastic bucket method the best and I think it would work with my sprinkler system so I wouldn't have to replace it with drippers for the time being. I've looked in the recycle shops and found a few at B20 each. So I will pursue that while the new plants are germinating.

Your quote "The root structure of Makua is shallow..." may be the reason why I have plants falling down. Before we got back from the US auntie, God bless her, helped us out by ho-ing around the base of all the plants. Maybe that tore up enough roots along with the over watering and sandy soil some of the plants just decided to lay down. Not sure, but sounds reasonable.

FYI the plants are responding good to the Karate. Yesterday I only saw one fruit picked that had worms and it was a fruit from a laying down plant that was resting on the dirt.

OK, one more thing. What the heck is going on at your farm while you're gone? Are your guys "dumping" the 20 rai harvest in KPP? Yesterday the restaraunt only wanted to give MIL B5/kg!! They said that's what they could buy them for at the talat soon. I told MIL either B8 or keep them for yourself and bring some gaeng by in the morning. She got the B8 but boy.... Today I didn't harvest the makua :-(

rgds

[pallasaide]

Somtham

He hasn't a clue what he's getting at the moment. Its the last thing on his mind (hes just dreaming cows!). Ing checks once a week and said last week the price was around B11 per kg. But you must remember only a small part of Tim's makua go to the local fresh market, most of it gets sent in an 8 wheel truck on a daily basis to the main wholesale market in Khon Khaen.

But has had periods when the price is even lower than B6 - 8. He doesnt sell them then, they get given to the cows to eat.

You need to be carefull on this pricing point. If the person who goes to market to get the daily makua price is someone everyone knows is asking on behalf of you, then they may deliberately be told a low price. Tim had this many years ago on several occassions untill he found out it was a setup to try and drive him out of business. Okay, the price does go down low at times and B6 is possible, but it wil go back up within a couple weeks. There is someone round your area who's plants flowered a few weeks back and all their makua are ready for picking.

Supply and demand. If it consistantly stays low, then you need to ask a few questions, because the market traders are not beyond to trying to buy for a little as possible. Send someone to check out the price that is not connected to you.

It will go up, dont worry.

If there is a sustained period of low pricing, Tim has all the flowers on his plants picked off.

[Somtham]

Wouldn't it be nice if there was a Thai commodity pricing website and then use that as a basis for negotiating? Anyway, the restaraunts we're selling to say "well I can buy them for..." at the talat. One of the restaraunts is owned by a relative and the other restaraunt employs a relative so maybe there's something fishy. Anyway, with the small quantity we're producing now it's no fret. For the time being B8 is ok.

Interesting that when I go to the talat and try to buy makua the price is always way high except for some of the folks that recognise me. I'll keep working on this as it seems to be the same when we're selling the fish.

How does Tim determine price? Does he just take what's offered when he gets to Kong Kaen or is his driver/worker doing some negotiating?

rgds

PS - talked to the lady that runs a recycle center near by and she's going to save me the 20L paint pails that I can pickup once a week. already got ~20 of them at B15 each. When the new seeds germinate and are 30cm tall they're headed for a life in the pail. So many advantages.

rgds

[pallasaide]

Somtham

He doesn't have much of an idea how the pricing works, and takes what he is given. He has random pricing checks conducted a few times a month, to compare what here is getting paid to what the wholesaler is retailling for, and consistantly he has found the differance to be about 25%-30%.

He has a good relationship with the wholesaler who he has worked with for 12 years.

The buckets will change the economics of the project significantly (your nett will go up significantly)

[Somtham]

Somtham

He doesn't have much of an idea how the pricing works, and takes what he is given. He has random pricing checks conducted a few times a month, to compare what here is getting paid to what the wholesaler is retailling for, and consistantly he has found the differance to be about 25%-30%.

He has a good relationship with the wholesaler who he has worked with for 12 years.

The buckets will change the economics of the project significantly (your nett will go up significantly)

Looking forward to planting in the buckets if.......the new seeds germinate which they haven't yet.

Anybody else out there trying the 1 rai makua experiment? What's your experience/problems? Wouls like to hear from you.

rgds

[Pond Life]

Whew, just re-read the Makua thread start to finish, who would have thought that such an innocent suggestion would spark off so much interest.

Im not specificly interested in Makua but the whole bucket & dripper idea has grabbed my attention, so a couple of questions.

1. What method do you use to connect your 1/2 inch black flexible dripper lines to the 3 inch blue rigid header pipe ? is there a standard off the shelf connector ?

2. If youve got to run your supply pipe a long distance. Say 100 m. Would it be cheaper or better to use 3 inch black flexible pipe from a coil rather than lots of 4 m sections of blue plastic joined together ?

3. If I try to gravity feed such a system from a big tank with approx 5m elevation (.5 bar, 7 psi) does anyone foresee problems ?

Thanks

[btate]

Pallasaide and Maizefarmer

I've noted on a couple of threads, including how to grow Makua, a mention of using a greenhouse. I am testing a couple of buckets of Makua to see how I do with them, I am also interested in anothere crop, no sense in all the eggs in one "bucket".

I am interested to know if Tim knows of a resource for using greenhouses in a tropical climate. I imagine cooling would be a major issue. I like his idea of cantelope production or even tomatoes intensly grown.

Thanks for any info.

[pallasaide]

Pond Life, some answers to your questions.

1. What method do you use to connect your 1/2 inch black flexible dripper lines to the 3 inch blue rigid header pipe ? is there a standard off the shelf connector ?

No, no that Tim knows of. He suggests you do one of the following: insert a 3" to 1" tee piece into the 3" pvc pipe and then use a hose clamp to connect the 1/2" black hosing to a section of 1/2" that has been fixed to the 1" end with a 1" to 1/2" adaptor (I think I have got that right, I am not very technically minded on this stuff). You have to use PVC adhesive to fix the 1! stub of pvc to the adaptor that can screw into or glue into the 1" end of the adaptor.

Thats the complicated way. the simple way is to drill a hole (anything aroun 1/2" - 1") into the 3" pvc piping and insert a 1/2" rubber spigot. It looks like a rubbe teat off a babys bottle and you can find them in dairy supply shops. They have a double flange on on end i.e. one parts fits insdie the rigid hose. They are flexible enough to be manipulated to get into the drilled hole. These are basically dairy spares and come in all sorts of sizes, so best get them first and then use you can see exactly what diameter hole to drill. If you are in luck the shop that sells the flexible black tubing for drippers may well also have the custom made "spiggots" to connect the hosing to the rigid pipe, which are usualy made by the same manufacturer as the black tubing. Just that they often dont have them in stock.

2. If youve got to run your supply pipe a long distance. Say 100 m. Would it be cheaper or better to use 3 inch black flexible pipe from a coil rather than lots of 4 m sections of blue plastic joined together ?

Yes and no, problem is how do you connect the flexible dripper tubing to your 3" mainsupply tubing, unless you cut it up into sections (to insert the 3" to 1" t-pieces). But other than that it should be fine.

3. If I try to gravity feed such a system from a big tank with approx 5m elevation (.5 bar, 7 psi) does anyone foresee problems ?

Over what length - 100m per section of balck dripper tubing? No, that should be fine as the flow rates of drippers as spread out over that length of tubing will not result in excessive end pressure drop. Best to get self regulating drippers rated for about 4-8liters per hour, then you should be okay. Okay the plants at the front may get 8 liters and the ones at the end 100m away may get about 6 or 7 litres, but other than for that deviation it wil be just fine.

BTATE

A resource for using greenhouses? Do oyu mean where they can be purchased from and who sells them in Thailand?

Makua will do fine in greenhouses, in fact he says they do bloody well. The advantage the greenhouse gives is protection from pests and instects, and offers a more stablised temp cycle from day to day, so your production sours and your costs drop siginifcantly )other than of course for the capital outlay).

The greenhouses mad ein Thailand and sold as "kits" (or built for you) come in 40 meter lenghts if Tim can recall correctly. They are supplied with ventilation, ususally 2 big ac fans on a humidity and temp controlled switch. They retail (setup and installed) for around B150000 per 40m. The supplier usualy builds aconcreate or brickwall base about 8"-10" high, and onthis the fix the galvanised frame to hold the tranparent PVC sheeting.

You can mix crops, and cantaloupes and tomatoes do excellently together in greenhouses as they are well protected from bugs and grow well in the humidity (keep the fans switched off).

He adds that a beehive located right up against the side of the greenhouse about 2' away from a hole cut and framded into the pvc sheeting will have a huge effect on crop production rates. The bees quickly learn there way into and out of the greenhouse, and the size of the opening does not present much of an entrance for other pests to get in. But don't put the hive inside the greenhouse, as bees dont like it at all, and they tend to start drinking water from the drippers, which you have any fertilsier or other chemicals mived in with the water supply can kill them.

Tim says get hold of Netafim Ltd in Thailand. He can't remember the contact name or the number but says they are on the 5th floor of the TPS building on Pattankarn road in Bangkok. Do a google search or go to Netafims website.

The other company you can contact is ChaiThai Seeds. they have a division that manufactures and supplies greenhouses to vegetable farms. These are the tunnel typ greenhouses whereas the Ntefim ones as far as he recalls are glass and cost about twice as much. But double check because perhaps Netafim also make tunnel type greenhouses.

For Tim

D. V.

[paulsmithson]

pallasaide,

Not makua connected---just how is Tim doing now and when will he be back home.Pass on my best wishes too please

[btate]

Pallasaide and Maizefarmer

Sorry, I wasn't too clear on what I was looking for. I'm interested in finding out the pitfalls etc. of using a greenhouse in tropical climates. I 'think' I understand some of the environmental plusses of a closed system for pest control. I will check the net on the two references from Tim and I thank him for that.

On another note, I read what I could find on the insecticide that Tim has recommended. It seems according to the literature that both require a 15 day window between application and sale/use. The way I read it, it wasn't tied to one method of application or another (spray vs. soil penetration)

Tim's thoughts on this are greatly appreciated.

As always, a speedy recovery and early return to home.

BT

[Pond Life]

Thanks for passing on the info DV.

Sounds like the rubber tits are the way to go.

Is there any reason why these couldn't be fitted to the 3" black flexible pipe ? wall to thick ?

Anyway I have other questions/ideas but I will go & open an irrigation thread so as not to hijack the Makua any further.