Growing Cassava In Thailand

[Mikki]

hi now i read all of it and i know that the 15-7-18 is same as in my country.....not "same , same but diffrent" mikki

[Khonwan]

Hi Konwan,

following your advices i decided harvesting next october (18 months).

Question: do i have to put more fertilizer or it's enough the coming rain?

Tks Regards

Giustino

Hi Giustino

Having applied 100kg 15-7-18 last year, I don't intend to apply more during the second year of growth. I can't say that further application wouldn't at this time, in my case, make a positive difference but am inclined to believe it is not necessary since academic research suggests feeding the tubers in the early days (as indicated in my OP) rather than throughout the growing period.

Rgds

Khonwan

[Khonwan]

Hi, we planted 27rai with cassava 1st june last year.Luckilly we got rain the next day after 2 weeks of drought.

We spaced at 80cmsX120cms to allow kubota to go between the rows. Lnd was ploughed twice then ridged .Stems were 10cms planted 10cms deep.we had a small problems getting stems and ended up using two varieties : gan deang(kasertsart)? and huay bong.

First fertilizer application was after 30 days 15-7-18 @ 50kgs/rai.weeding was carried out by hand and kubota as required .second application of fertilizer at 3 months 0-10-30 @50kgs/rai.

In january we were back and my wife dug up plants at various points on the land . the weight of tubers was averaging 5kgs per plant.Maximum, was 7kgs and minimum 3kgs.

It was obvious that the best plants were the gan deang variety.

Some plants have growns over 2 meters high while some are less.,the advisor at TTDI said this was due to different variations in the soil in different parts of the land.

We were also advised to"go fo killo,not starch"

We plan to harvest in november ,which will be 18 months after planting.

I am concerned about the factory pricing system .It seems that the govt ,subsidy price can be got by making a contract with the factory.it is 2baht per killo in sikhiu.

BUT they will only take from each supplier ONE lorry load per day,and you cant send another load until your first has been tipped and that could be in two or three days after queing.Maximum of 170 tonnes per supplier.

However if you accept a non-contact factory price of 1.45 baht per killo ,then you can send in as much as you like ,when you like ,and no queing!!!

My thanks for all the advice i have taken on board from khonwan and the rest of the posters here .ill keep posting as i get more info

Hi Dave

Nice to read a positive post. Congrats on your results.

Rgds

Khonwan

[Khonwan]

Regards to you Khonwan , very informative reading.

I have som questions to you. what do you think or know about insert the fertilizer during the preparation of the soil so its already there before planting the stems

The difference between "15-15-15" and "15-7-18" fertilizer. And current price.

We shall plant about 50 rai in Petchabun. Last crop was corn. Have been recomended to use 100kgs/3rai with "15-15-15" the first time. But it seems to me like alot.

regards Mikki

Hi Mikki

15-7-18 (= N-P-K %) has less (but enough) P and more (which is good!) K than 15-15-15. I believe P is more expensive than K. 15-7-18 is cheaper than 15-15-15 and (in the absence of a soil-analysis proving otherwise) and better.

Who recommended 100kg/3rai (=33kg/rai)? I suspect a poor farming neighbour. If based on soil analysis, then great, otherwise I would stick with my OP and recommend 100kg/rai.

Rgds

Khonwan

[Khonwan]

hi now i read all of it and i know that the 15-7-18 is same as in my country.....not "same , same but diffrent" mikki

Same in every country since these N-P-K references just expresses the percentages of nitrogen, phosphate and potassium (in basic terms - a more complicated, though unnecessary for us, understanding involving oxides of the latter two, necessary for conversion to weight of the basic elements can easily be obtained via Google).

[Khonwan]

I was amused, surprised, a little annoyed (not sure which) to come across my own article (my OP in this thread) plagiarized by Asia Burapa Tapioca Co., Ltd, a tapioca starch manufacturer based in Kanchanaburi. It has been reprinted in whole on their website http://www.asiaburapa.com/Cassava%20Planting.htm without credit to me as the author or reference to this forum as the source. Hmmm! I have only just come across it this evening.

My purpose in posting about it here is to prevent confusion by any other reader who may also come across it and perhaps wonder if I plagiarized it from them – not so.

Khonwan

[giustino]

hi Khonwan

Tks.Giustino

[sandyrow]

Hi, I have read a lot og good things on this board and so am turning to you all for help. My wifes family have been farming Cassava for many years, however this year they, and as far as i can see all the small farms around them, have been hit by a mealybug invasion which has more or less wiped out their crop. they replanted but the crop is infected again. I have asked around in the village and no one seems to have seen anything like this before and they do not know how to control it, they have tried insecticides but they do not seem to have worked. I was wondering if anyone out there had any idea of the best way to beat this problem as it is threating to destroy all the small farmers in the village.

[Lickey]

Hi Sandyrow, I think i have been the only one to have this problem before with cassava, [see posts 7 & 9 on this pinned topic' ]

The biggest problem, believe it not is ants, these buggers look after the mealy bugs, even hibernate them when new growth is scarce, once new tender leaves appear, the ants carry the bugs to the plants and then live off the excrement [sugary] the mealy bugs give, when 1 plant is near dead, ants will take them to another and so on, The young buding cassava suffers a lot, with little or no growth, once they are over waist high [1mtr] its not such a serious problem, but a problem all the same,

The chemical in the pic is chlorpyrifos,its a nasty smelling chem that will kill all insects and natural predators too, to control the ants, you can use Furidan mini=pellettes, this will kill ants andagain most other insects in contact with it.

Please exercise care if using the above, always spray downwind, if not possible, spray the 6/7 rows to your right, never spray in front of you, and if using furidan, wait for a breeze, through a fist-full in the air and cover the field like this, use as much protective gear as possible, and dont scratch an itch however uncomfortable, try to pass this on to your thai farmer friends, and also what the dillution rate is, that is what it is, No More.

Lickey..

[sandyrow]

Hi Sandyrow, I think i have been the only one to have this problem before with cassava, [see posts 7 & 9 on this pinned topic' ]

The biggest problem, believe it not is ants, these buggers look after the mealy bugs, even hibernate them when new growth is scarce, once new tender leaves appear, the ants carry the bugs to the plants and then live off the excrement [sugary] the mealy bugs give, when 1 plant is near dead, ants will take them to another and so on, The young buding cassava suffers a lot, with little or no growth, once they are over waist high [1mtr] its not such a serious problem, but a problem all the same,

The chemical in the pic is chlorpyrifos,its a nasty smelling chem that will kill all insects and natural predators too, to control the ants, you can use Furidan mini=pellettes, this will kill ants andagain most other insects in contact with it.

Please exercise care if using the above, always spray downwind, if not possible, spray the 6/7 rows to your right, never spray in front of you, and if using furidan, wait for a breeze, through a fist-full in the air and cover the field like this, use as much protective gear as possible, and dont scratch an itch however uncomfortable, try to pass this on to your thai farmer friends, and also what the dillution rate is, that is what it is, No More.

Lickey..

HI Lickey, thanks for the info, I will pass this info on to the family and do my best to see that they take care will using these chemicals. I think small farmers are having a tough enough time of it this year without this added problem. price down to 1.20 at the moment.

[DaveD]

Hi Sandyrow, I think i have been the only one to have this problem before with cassava, [see posts 7 & 9 on this pinned topic' ]

The biggest problem, believe it not is ants, these buggers look after the mealy bugs, even hibernate them when new growth is scarce, once new tender leaves appear, the ants carry the bugs to the plants and then live off the excrement [sugary] the mealy bugs give, when 1 plant is near dead, ants will take them to another and so on, The young buding cassava suffers a lot, with little or no growth, once they are over waist high [1mtr] its not such a serious problem, but a problem all the same,

The chemical in the pic is chlorpyrifos,its a nasty smelling chem that will kill all insects and natural predators too, to control the ants, you can use Furidan mini=pellettes, this will kill ants andagain most other insects in contact with it.

Please exercise care if using the above, always spray downwind, if not possible, spray the 6/7 rows to your right, never spray in front of you, and if using furidan, wait for a breeze, through a fist-full in the air and cover the field like this, use as much protective gear as possible, and dont scratch an itch however uncomfortable, try to pass this on to your thai farmer friends, and also what the dillution rate is, that is what it is, No More.

Lickey..

HI Lickey, thanks for the info, I will pass this info on to the family and do my best to see that they take care will using these chemicals. I think small farmers are having a tough enough time of it this year without this added problem. price down to 1.20 at the moment.

hi guys ,our cassava is 11 months old and my wifes father reports what looks to be meally bug infestation,but im not 100% sure .What will happen to the plants at this stage ,and what is the best remedy? what happens if left untreated. can these stems be saved for reuse in a subsequent planting?

regrds

Dave

[Lickey]

Hi Dave,

Dont know if you intend to harvest now but we harvested at 10/11 months, we got ri-infested with mealy bugs at about 9months, we asked the local agri office about this and they said dont worry, the plant is fully developed and you will harvest soon, True enough, the plants were un-affected, But if you are growing the full 2year term, im not sure what will happen, hopefully the heavy rain will wash the bugs off and deter the ants a bit, plus new growth elsewhere might distract the ants,

It made me wonder last year that a lot of the farm was sprayed with herbicide, so no new growth for ants to take there mealy bug mates too, so they pick on cassava or papaya ect,

Cheers, Lickey..

[Lickey]

Dave, forgot, no problem with the sticks for re-plant, Lickey..

[DaveD]

Hi,Lickey and thank you.Certainly reasuring words.My wife called TTDI in Dankuntote and spoke to the lady we met when we visited.

She said that this bug problem occurs during the dry season only and that at the moment it is widespread in the korat area.Ok,she also said ,that if we want to take cultivars from our existing plants,then we have to soak them in some stuff (forgive me) for 24 hours .This part i dont understand ,im feel .prolonged soaking will destroy the culitar??????? so im looking to be corrected .I done know if it means full immersion or just the tips of the stems.I am aware of khonwans advice regarding innoculation against fungus and a few minutes in a bath is all that is required. Has anyone else experienced this problem before.

Our neighbour ,has just harvested a small plot of cassava, 50 sq wah,he got 7.5 tonnes,i dont have info yet as regards factory.i didnt hear anything yet about any government sub here.if you look in my previous posts you will see how this has worked out here.

[DaveD]

Dave, forgot, no problem with the sticks for re-plant, Lickey..

Hi Lickey .and please see post,we intend to harvest that crop around november ,which will be around 17 months.Now ,my wife will begoing back to thailand and the plan is to plant a furthur 13 rai .using stems cut from th present crop.

She wants to try the different spacings of diagonal 1 meter and using 50 cm stems(anyone else read the thai guy who did this ?) then applications of fertilizer.

So? what about using these stems,for replanting? and what about killing ,and preventing future bugs /fungus?

regards

Dave

[Lickey]

Sis in law planted about 3 weeks ago, that was also from a bug infested previous crop, this area always dips the planting end of the sticks in a powder, which i would think is an anti-fungal thing, perhaps the same method as Khowan mentioned, but different, im not sure about that?

To be very honest Dave, it was our first and last time growing cassava, once bitten is twice shy, we just had a spare 9 rai and tried it, lost 18k bht, and speaking to a the neighbour farmer who regulary grows 60rai, he lost money as well, hes re-planted cassava, but they wont get weedkiller,fertilizer or anything else, he reckons he might break even next harvest, he has an idea next harvest that 2 men with strimmers will top the casaava, 2 more men will gather and stack the sticks,2 more will pull and cut the root, when the strimmer men have done a few rows, they will basket the tubers into the trailer, whatever way he plans it, its still labour intensive but he might make a few bht??

The idea of 1 mtr sq planting is normally for a 2 year crop, allowing the tubers to expand more, its done often in this area, but as usual, thais cant wait to sell, so whether it gets bigger yields or not, i really dont know, but worth a try if the family can wait,

Good Luck, Lickey..

[David006]

Govt. to develop Northeast as hub of energy crops

July 24th, 2008 - 2:11 pm ICT by Amrit Rashmisrisethi

The Ministry of Agriculture and Cooperatives launches a strategy to develop the Northeast as a hub of energy crops second to Brazil.

Deputy Minister of Agriculture and Theerachai Saenkaew (ธีระชัย แสนแก้ว) says the Northeast has a high potential to effectively produce energy crops such as sugar cane and cassava. The two crops produce key substances to ethanol production which can reduce the country’s import of oil.

However, Mr Theerachia says the ministry will not expand the plantations of the two energy crops but will increase the produce per rai to meet the demand of both consumption and ethanol production. He says further that the ministry has instructed the Department of Agriculture to promote the plantation of good sugar cane, cassava, and oil palm strains among farmers.

Source : National News Bureau, Public Relations Department of Thailand

khonwan,

My father in law has every year about 200-250 rai of Cassava.

He owns 500 rai but cultivates sugar canes also.

I know you are the cassava specialist,

but do you know if there are automatic sugar cane harvesters in Thailand.

Or is there info from the thai government available.

I found them via internet in Brasil,

but I need plans so that our machine supplier can make the machine.

We have every year more and more problems with workers and staff.

The labor is getting to hard, costs too high,...

automisation is necessary.

The same will come for the cassava:

we will need automatic harvests machines.

We are thinking already of modifying automatic potato harvesters from Europe....

But a solution has to be found because labor problems are getting bigger each year and more costly...

Suggest you search on Australian web sites ..i've heard the harvester was invented there in Queensland and probably farming Aussie blogs would help..good luck

[radeon]

I would like to thank khonwan for his contribution. He helped me a lot on letting me know what to do. Hope if he ever is online again he could answer my questions in the private message i sent to him.

[ChanatS]

Dear Khun Khonwan and all,

As i post on page 6, now my cassava plantation is 3 month old with the size of 100 rai the progress as in the vdo. Start from picture of 1st month, the 2nd month show the soil cracking and recently just 3 month we checking on the roots. This is in DarnKhunTod NaKornRachChaSiMa province start planting from 1st april to before SongKran holiday. With mix varieties.

[http://www.youtube.com/watch?v=zeaCUPNQ5zk]

Welcome on any comment and suggestion.

Regards,

Chanat S.

Edited July 13, 2009 by ChanatS

[cowellandrew]

i have been growing tapioca in Kanchanburi for 12years

i would say very good report,as for the pests there are a couple

(tune) is thai for a large type of mole this eats tapioca tubers, it can be traped and eaten as i mincemeat.

there is one more pest and that is termites, these eat the roots

and i dont know what is best to control them,

from andrew

[stanfordmagnets]

Cassava (Manihot esculenta Crantz)

About the author's cassava experience:

I've been growing cassava on small parts of my 200 rai (1 rai = 0.4 acres = 0.16 hectares) for some 10 years now; I operated a cassava, mungbean, maize rotation system in the past but alternated the pattern so that I always had all crops growing each year in different fields. My main interest, however, was breeding cattle, then fattening pigs. Despite my lack of firm attention, and fairly minimal fertilisation, my cassava harvests normally yielded 3-4 tonne per rai. With better practices this year, I expect to achieve 5 tonne per rai at next harvest.

I do not consider myself an expert but I'm happy to share my knowledge based on both my experiences and research. The following represents an intentionally brief outline of how to grow the crop. There is an abundance of information to be had on the Internet should you Google "cassava" or "tapioca".

Other names:

Cassava is also known as tapioca, manioc, yucca, etc. It is known as มันสัปหลัง man sapalang in Thai.

Common varieties:

Refer to www.doa.go.th/fieldcrops/res/0949-3.pdf for a list and description. I have grown Rayong 5, Rayong 7, Kasertsat 50, and Huay Bong 60. I expect I will also grow Rayong 9 next year since it is reported to produce higher starch yields that are more suited to ethanol production..

Required soil conditions:

Cassava will grow in most soils but it prefers slightly acidic, loose soil with good drainage. The tubers shall certainly rot if planted in low-lying areas prone to flooding.

Planting season:

This crop can be planted anytime. For most varieties, artificial irrigation is only indicated if planted in the dry season. It is best to get the plant established before the major rains start to counter soil erosion: the developing roots help to anchor the plant and reduce soil erosion common on slopes; the emerging leaves help to reduce the impact of heavy rain around the vicinity of the plant, which otherwise hastens erosion. I normally plant 11-month crops April/May but intend to switch to 18-month crops with mungbean (ถั่วเขียว tùa kĭeow) rotation. I have grown the crop over 22 months (see attached photo of me with a 23kg example taken some 4/5 years ago) before but the first-line processors (who chip the tubers and sun dry them before selling them on) are starting to measure the starch content. 18 months is optimum for tuber weight and starch content (dry matter percentage). It is therefore likely that I'll start to plant mungbean in March (it has a propagation to harvest timeframe of 95-105 days) and then plant cassava in June. The cassava shall then be harvested in December of the following year. I shall plant only half my land in this fashion during the first year, and the other half the following year (the other half during the first year will be planted in April for an 11-month crop).

As a nitrogen fixer, mungbean (there are other crops you could choose from) puts around 23kg of nitrogen back into the soil per rai (equivalent to one 50kg bag of urea, 46-0-0, per rai costing nearly 1,000 baht these days). The beans are harvested (normally at a profit) and the plants are ploughed back into the soil, releasing the nitrogen and improving the soil structure by adding bio-mass. Should you not wish to grow the mungbeans yourself, it is common practice to allow someone else to do so for free – your land benefits, whilst they make the investment and take the risks.

This two-year cycle of growing cassava reduces the workload nearly in half, and consequently your costs. You should at least double your yield compared to a one-year cycle and more than double your profit compared to a one-year cycle.

One problem using this cycle presents itself: if you harvest in December you cannot use the stems six months later (they have a useful life of up to 3 months). This can be resolved by cutting the required stems in June from the other half of your land, which should now be 12 months old. The plant has another 6 months to recover from this – it has very little effect on the yield. You may be able to sell the December stems.

Land preparation:

Having used only the 7-disc plough (ผานเจ็ด pan-jèt), along with a ridger (ผานยกร่อง pan-yoke-man) for several years, my soil below resembles a layer of concrete. This assists erosion on slopes since water cannot easily be absorbed by this compacted layer. It also reduces the reservoir of moisture available to the plants in the dry season. On flat level areas, it reduces the effective drainage thereby increasing the risk of tuber-rot. The shallow tillage with such a compacted layer also acts as a physical obstruction to the growth of the tubers. The solution is to plough first with a 3-disc plough (which cuts deeper), then follow up (after a few days to allow weeds to die) by cross-ploughing with the 7-disc plough. (These disc sizes pertain to large tractors such as my Ford 6600.) However, I think it best to use the 3-disc plough (ผานสาม pan-sarm) only every second crop-season to prevent the compacted layer occurring.

Slopes should be counter ridged to prevent soil erosion. Water gullies shall still occur – you can try to minimize these by placing objects (e.g. stakes) in the gullies to slow (not to prevent) the water-flow. Whatever you do, slopes are going to present a challenge if consisting of sandy soil. Integration with crops such as mungbean, peanuts, etc. or even strips of grass will help, but they too reduce the area for cassava cultivation or (when confined to between normal-spaced ridges) compete with cassava for nutrients, reducing the cassava yield.

Propagation:

Stems are cut from mature cassava trees and then cut into pieces measuring approximately 20cm – these cut stems are called setts. These setts should preferably have at least 5 nodes. Stick them into the top of the (normally) ridged soil either vertically or at an angle. Of the 20cm, stick 10-15cm into the ground. Make sure the nodes are pointing up (just as they were whilst in the ground before cutting). Better results (in terms of sett survival rates) can be obtained by immersing the setts in a solution of water containing a root promoter the night before planting (normally utilizing a 200-litre drum).

Spacing:

The Thai recommendation is 80-100cm x 80-100cm. I follow local practice by planting approximately 50cm x 95cm (I say approximately because we don't bother to use measuring sticks – the exact spacing is not that relevant). The total yield per rai is not affected. The closer spacing helps to reduce weeds (because of a greater leaf canopy), and soil erosion on slopes (the greater canopy reduces the impact of rainfall on the soil and the more extensive roots help hold the soil in place).

Weeding:

It is vital to keep your crop weed-free during the first 3-4 months. Cassava is a slow grower initially and cannot compete with weeds. Weeds will certainly reduce your cassava yield. You can spray the newly planted area during the first three days with a pre-emergence herbicide (I've never done so to-date) then spray paraquat around one month after planting and again as often as required during the first 3-4 months (keep the nozzle low to avoid spraying the cassava leaves).

Fertiliser:

50kg of "15-7-18" per rai one month after planting, and another 50kg of "15-7-18" three months after planting. This first application of fertiliser (ปุ๋ย bpŭI) can be replaced, if you wish, by 1,000kg of aged-manure before planting – whilst better, it is impractical for most farmers and more expensive. Of course, any amount of aged-manure or compost before planting in addition to the chemical-fertiliser (ปุ๋ยเคมี bpŭi kây-mee) after planting as described can only help improve the soil.

Pests & Diseases:

Unlike other parts of the world, cassava in Thailand is not seriously afflicted by pests or diseases. I've not yet had a problem – never known anyone to have a problem.

Harvest:

Where the tree stems are to be used or sold for planting, they should be cut and handled fairly carefully (so as to avoid damaging the nodes), de-branched (leaving the leaves and branches to be ploughed in later), bundled (tie with string), and transported to a site where you can safely keep them for up to 3 months. They should be untied and stood on the ground (nodes up), ensuring that each stem is actually in contact with the soil. Ploughing that small area of soil immediately before standing the stems will make moisture available to the stems. Although not vital, standing them where they can benefit from some shade, e.g. on the north side of a tree, should increase their storage life-span. The sooner you plant them, the higher the survival rate, the fewer replacements needed. You can occasionally slightly wet the soil should you think the stems are drying out too much.

To now harvest the tubers, use a tractor with a mouldboard plough attached to the 3-point hitch at the back (ผานขุดมัน pan kood man) to loosen the tubers from the soil. Do not expose more tubers than can be collected that day – the starch content rapidly reduces once the tubers are exposed. You will need one person per tonne per day to follow behind the tractor, haul the tubers out, separate them from the woody stem-base with a machete, and load them into your transport. The tubers should then immediately be transported to the processor. The processor shall weigh your loaded vehicle before and after unloading the tubers – you shall receive a ticket indicating both weights and the agreed price, and will probably have to come back after a couple of days (some times a week) to receive payment.

Post-harvest:

You can chip and sun-dry the tubers yourself on a large area paved with concrete – don't bother. It is not worth the effort. The extra risks and labour involved do not justify the slight extra financial gain.

Local Thai knowledge/wisdom:

A lack of money tends to be the average Thai farmer's only obstacle to improving cassava yields. They too know that deep ploughing is preferable and that 100kg of chemical fertiliser yields more than just 25-50kg but most of them can't afford the extra outlay due to years of depressed prices. There is very little I can teach the average Thai cassava farmer. The best cassava research comes from Thailand, and the information is disseminated to the farmers quite well

Finally:

Please feel free to comment or correct me on any point above – as I stated at the outset, I'm not a cassava "expert"….just another cassava farmer in the land of smiling debt-ridden farmers (who now thankfully have a golden opportunity to clear their debts thanks to ethanol/petroleum biofuels).

Khonwan

PS. The attached Excel spreadsheet should give you a good idea of your likely expenses. Play with the figures: change the yield from 4 tonne (assumes 11 months) to 8 tonne (assumes) 18 months. I recently harvested at 2,270 baht/tonne but I believe the figure likely to reach 3,000 baht next harvest.

Good post, thank you.

[Pamela12]

Cassava (Manihot esculenta Crantz)

About the author's cassava experience:

I've been growing cassava on small parts of my 200 rai (1 rai = 0.4 acres = 0.16 hectares) for some 10 years now; I operated a cassava, mungbean, maize rotation system in the past but alternated the pattern so that I always had all crops growing each year in different fields. My main interest, however, was breeding cattle, then fattening pigs. Despite my lack of firm attention, and fairly minimal fertilisation, my cassava harvests normally yielded 3-4 tonne per rai. With better practices this year, I expect to achieve 5 tonne per rai at next harvest.

I do not consider myself an expert but I'm happy to share my knowledge based on both my experiences and research. The following represents an intentionally brief outline of how to grow the crop. There is an abundance of information to be had on the Internet should you Google "cassava" or "tapioca".

Other names:

Cassava is also known as tapioca, manioc, yucca, etc. It is known as มันสัปหลัง man sapalang in Thai.

Common varieties:

Refer to www.doa.go.th/fieldcrops/res/0949-3.pdf for a list and description. I have grown Rayong 5, Rayong 7, Kasertsat 50, and Huay Bong 60. I expect I will also grow Rayong 9 next year since it is reported to produce higher starch yields that are more suited to ethanol production..

Required soil conditions:

Cassava will grow in most soils but it prefers slightly acidic, loose soil with good drainage. The tubers shall certainly rot if planted in low-lying areas prone to flooding.

Planting season:

This crop can be planted anytime. For most varieties, artificial irrigation is only indicated if planted in the dry season. It is best to get the plant established before the major rains start to counter soil erosion: the developing roots help to anchor the plant and reduce soil erosion common on slopes; the emerging leaves help to reduce the impact of heavy rain around the vicinity of the plant, which otherwise hastens erosion. I normally plant 11-month crops April/May but intend to switch to 18-month crops with mungbean (ถั่วเขียว tùa kĭeow) rotation. I have grown the crop over 22 months (see attached photo of me with a 23kg example taken some 4/5 years ago) before but the first-line processors (who chip the tubers and sun dry them before selling them on) are starting to measure the starch content. 18 months is optimum for tuber weight and starch content (dry matter percentage). It is therefore likely that I'll start to plant mungbean in March (it has a propagation to harvest timeframe of 95-105 days) and then plant cassava in June. The cassava shall then be harvested in December of the following year. I shall plant only half my land in this fashion during the first year, and the other half the following year (the other half during the first year will be planted in April for an 11-month crop).

As a nitrogen fixer, mungbean (there are other crops you could choose from) puts around 23kg of nitrogen back into the soil per rai (equivalent to one 50kg bag of urea, 46-0-0, per rai costing nearly 1,000 baht these days). The beans are harvested (normally at a profit) and the plants are ploughed back into the soil, releasing the nitrogen and improving the soil structure by adding bio-mass. Should you not wish to grow the mungbeans yourself, it is common practice to allow someone else to do so for free – your land benefits, whilst they make the investment and take the risks.

This two-year cycle of growing cassava reduces the workload nearly in half, and consequently your costs. You should at least double your yield compared to a one-year cycle and more than double your profit compared to a one-year cycle.

One problem using this cycle presents itself: if you harvest in December you cannot use the stems six months later (they have a useful life of up to 3 months). This can be resolved by cutting the required stems in June from the other half of your land, which should now be 12 months old. The plant has another 6 months to recover from this – it has very little effect on the yield. You may be able to sell the December stems.

Land preparation:

Having used only the 7-disc plough (ผานเจ็ด pan-jèt), along with a ridger (ผานยกร่อง pan-yoke-man) for several years, my soil below resembles a layer of concrete. This assists erosion on slopes since water cannot easily be absorbed by this compacted layer. It also reduces the reservoir of moisture available to the plants in the dry season. On flat level areas, it reduces the effective drainage thereby increasing the risk of tuber-rot. The shallow tillage with such a compacted layer also acts as a physical obstruction to the growth of the tubers. The solution is to plough first with a 3-disc plough (which cuts deeper), then follow up (after a few days to allow weeds to die) by cross-ploughing with the 7-disc plough. (These disc sizes pertain to large tractors such as my Ford 6600.) However, I think it best to use the 3-disc plough (ผานสาม pan-sarm) only every second crop-season to prevent the compacted layer occurring.

Slopes should be counter ridged to prevent soil erosion. Water gullies shall still occur – you can try to minimize these by placing objects (e.g. stakes) in the gullies to slow (not to prevent) the water-flow. Whatever you do, slopes are going to present a challenge if consisting of sandy soil. Integration with crops such as mungbean, peanuts, etc. or even strips of grass will help, but they too reduce the area for cassava cultivation or (when confined to between normal-spaced ridges) compete with cassava for nutrients, reducing the cassava yield.

Propagation:

Stems are cut from mature cassava trees and then cut into pieces measuring approximately 20cm – these cut stems are called setts. These setts should preferably have at least 5 nodes. Stick them into the top of the (normally) ridged soil either vertically or at an angle. Of the 20cm, stick 10-15cm into the ground. Make sure the nodes are pointing up (just as they were whilst in the ground before cutting). Better results (in terms of sett survival rates) can be obtained by immersing the setts in a solution of water containing a root promoter the night before planting (normally utilizing a 200-litre drum).

Spacing:

The Thai recommendation is 80-100cm x 80-100cm. I follow local practice by planting approximately 50cm x 95cm (I say approximately because we don't bother to use measuring sticks – the exact spacing is not that relevant). The total yield per rai is not affected. The closer spacing helps to reduce weeds (because of a greater leaf canopy), and soil erosion on slopes (the greater canopy reduces the impact of rainfall on the soil and the more extensive roots help hold the soil in place).

Weeding:

It is vital to keep your crop weed-free during the first 3-4 months. Cassava is a slow grower initially and cannot compete with weeds. Weeds will certainly reduce your cassava yield. You can spray the newly planted area during the first three days with a pre-emergence herbicide (I've never done so to-date) then spray paraquat around one month after planting and again as often as required during the first 3-4 months (keep the nozzle low to avoid spraying the cassava leaves).

Fertiliser:

50kg of "15-7-18" per rai one month after planting, and another 50kg of "15-7-18" three months after planting. This first application of fertiliser (ปุ๋ย bpŭI) can be replaced, if you wish, by 1,000kg of aged-manure before planting – whilst better, it is impractical for most farmers and more expensive. Of course, any amount of aged-manure or compost before planting in addition to the chemical-fertiliser (ปุ๋ยเคมี bpŭi kây-mee) after planting as described can only help improve the soil.

Pests & Diseases:

Unlike other parts of the world, cassava in Thailand is not seriously afflicted by pests or diseases. I've not yet had a problem – never known anyone to have a problem.

Harvest:

Where the tree stems are to be used or sold for planting, they should be cut and handled fairly carefully (so as to avoid damaging the nodes), de-branched (leaving the leaves and branches to be ploughed in later), bundled (tie with string), and transported to a site where you can safely keep them for up to 3 months. They should be untied and stood on the ground (nodes up), ensuring that each stem is actually in contact with the soil. Ploughing that small area of soil immediately before standing the stems will make moisture available to the stems. Although not vital, standing them where they can benefit from some shade, e.g. on the north side of a tree, should increase their storage life-span. The sooner you plant them, the higher the survival rate, the fewer replacements needed. You can occasionally slightly wet the soil should you think the stems are drying out too much.

To now harvest the tubers, use a tractor with a mouldboard plough attached to the 3-point hitch at the back (ผานขุดมัน pan kood man) to loosen the tubers from the soil. Do not expose more tubers than can be collected that day – the starch content rapidly reduces once the tubers are exposed. You will need one person per tonne per day to follow behind the tractor, haul the tubers out, separate them from the woody stem-base with a machete, and load them into your transport. The tubers should then immediately be transported to the processor. The processor shall weigh your loaded vehicle before and after unloading the tubers – you shall receive a ticket indicating both weights and the agreed price, and will probably have to come back after a couple of days (some times a week) to receive payment.

Post-harvest:

You can chip and sun-dry the tubers yourself on a large area paved with concrete – don't bother. It is not worth the effort. The extra risks and labour involved do not justify the slight extra financial gain.

Local Thai knowledge/wisdom:

A lack of money tends to be the average Thai farmer's only obstacle to improving cassava yields. They too know that deep ploughing is preferable and that 100kg of chemical fertiliser yields more than just 25-50kg but most of them can't afford the extra outlay due to years of depressed prices. There is very little I can teach the average Thai cassava farmer. The best cassava research comes from Thailand, and the information is disseminated to the farmers quite well

Finally:

Please feel free to comment or correct me on any point above – as I stated at the outset, I'm not a cassava "expert"….just another cassava farmer in the land of smiling debt-ridden farmers (who now thankfully have a golden opportunity to clear their debts thanks to ethanol/petroleum biofuels).

Khonwan

PS. The attached Excel spreadsheet should give you a good idea of your likely expenses. Play with the figures: change the yield from 4 tonne (assumes 11 months) to 8 tonne (assumes) 18 months. I recently harvested at 2,270 baht/tonne but I believe the figure likely to reach 3,000 baht next harvest.

i am impressed by your submission on cassava, am shifting to nigeria for some business, west africa where production of cassava are in large scale but

a good number consumed locally being a stable local food,

presently looking for ideal casssava starch producing machine

that can boost exportation and earning of foreign exchange.

looking forward to suppliers of such machine soonest , those

that can make business in nigeria.canony one help me out finding them?

[cassavaharvester]

Hello to all friends of cassavain Thailand!

If You are interested I can send fotos and videos of the INTERPLAN Cassava Harvester working in Brazil:

The harvester is working fast and with reduced losses of roots(100 -150 tons/day).

Greetings from Germany!

Diethelm Hammer

INTERPLAN Agropecuaria Ltda.

[email protected]

[radeon]

thank you khonwan for your tips.

[Khonwan]

thank you khonwan for your tips.

You're welcome, radeon. Since you can't PM me now, you can email me should you need to contact me: TigerPassCreek at gmail dot com.

Rgds

Khonwan

[somo]

Hi Khonwan.

Not seen you around much recently so hopefully you will see this.

I was wondering if you had as yet used the system of cutting stems from one year old cassava to plant

elswhere and leaving the tubors in the ground for later harvesting and how it worked out?

Specifically did the plants recover well and how was the harvest after the full 18 months?

Also did you cut the stems in the same way as if you were harvesting or did you leave a part of each branch you cut

on the main stem to help recovery.

It was mentioned to me it may be best to only cut branches off stems that have more than one branch and then to leave at least one fully grown branch on each stem.

Do you think this is necessary as it would take quite a bit more work.

Any advice on this matter would be helpful as I will need some new stems next spring and don't need the expense of buying them in just at the time when everyone is looking to plant.

I had thought of stretching the 18 months growing period out to 21 months (the extra 3 months would be in the dry season) then trying to store the stems in good conditions for 3 months but not sure it is a good idea??

Any comments/advice much appreciated.

Steve

PS Cassava has just hit 2 Baht/kilo in Chayapoum

[Mikki]

hi Somo and thanks....you have asked all my questions to Khonwan . we planted 50 rai with cassava in petchabun in may/june and everything looks fine . had some problems with ants on one and a half rai . intend to harvest some rai and leave the rest to december 2010 i also hope to hear from Khonwan

Regards Mikki

[Mikki]

hi again Somo Ive read a study about storing stems and it said if kept on prepared land and under sunshelter/roof up to 3 months the stems had an 80 percent growth capability. Greate importance that the stems have full contact with the soil.

if cut and planted the next day it was 98 percent

Regards Mikki

[somo]

Hi Mikki

Yeah this is the one hassle with harvesting around Dec. as you would have to store stems for arond 5 months if planting in May after some rain. This is why i am toying with the idea of harvesting in Feb but if there is no problem cutting branches from 1 year old stems that seems the way to go. Just don't want to make any expensive mistakes and ruin a crop so Khonwan's experience could be very helpful.

As a matter of interest I got about 6 tons/rai just leaving it 2 months longer ie a 14 month crop so quite optomistic for an 18/19 month crop

Steve

[Mikki]

Hi Somo well its the extra tons we want and 6 tons / 14 months sounds good to me .

We will plant another 60 rai next year so im very interessted in using stems from our own field and let the roots stay for another 6 months.

But as you wrote it would be nice to hear from anyone that have done it.

Mikki