Growing Cassava In Thailand

[Khonwan]

Hi JR Texas / Tejas

As I have indicated on various occasions over the past couple of years, weekly cassava prices for all cassava-growing areas in Thailand are published and archived here: http://www.thaitapiocastarch.org/market.asp

The same pages can now be accessed in English courtesy of Google: http://translate.google.co.th/translate?hl....asp%3Fid%3D256

Weather patterns in Chonburi? Why not talk to Chonburi farmers?? Alternatively: http://www.tmd.go.th/EN/province_stat.php?...ionNumber=48459

EDIT: The Google translation link I've provided is for 19th Jan 2010; click on "Cassava Weekly" to go to the archive. The archive goes back to 2005.

Hi Steve

“I did meet one very smart farmer who follows the same sort of 18-20 month plan you recommend and he gets 15-20 tons/rai!! I have had this confirmed from the village poo yai. He does however spend a lot on fertilizer applying it 5 times over the cycle as well as using chicken manure ploughed in before planting.”

Interesting (it beggars belief) but more details would be very beneficial. What fertiliser is he using (in addition to chicken manure)? How many kilograms per rai (chemical and manure)? Is he irrigating?

Also useful to know which variety he is growing.

Rgds

Khonwan

Edited January 26, 2010 by Khonwan

[somo]

Hi Khonwan

Yeah I found it a little suprising to say the least but my wife told me he is well known for it and I could believe him but as the saying goes seeing is believing. Our poo yai confirmed but Thais don't like contradicting anything so???

I live in Bangkok and just met him as he dropped by when I was in Chayapoum for the new year. If I lived up there I would have visited his fields and pumped him further for info..I thought he was exagurating the price of stems for May delivery at 8000 Baht but have had that confirmed by 3 other sources one of whom may be buying 3 rai of me.

I just asked if he used chicken manure as well as the fertilizer and the normal amount is 50 bags/rai. I did ask what fertilizer

and he said "number 1" the most expensive but later mentioned something like 15.10. 26 can't rember the exact numbers. He also mentioned using 0.0.60 at some point. I assume 50kg/rai but didn't ask specifically.

My Thai is about average and once the locals start gabbling fast in Lao I get lost so need the wife to translate and she feels rude cross examaning people which I understand.

As far as I know he doesn't irrigate but didn't ask specifically. I assume he doesn't because he did say it was important to plant as soon as the rains start so as to get two full seasons of rain.

Somebody else told me that he crushes the setts at the end before planting. Not sure how but think he just bashes them with the blunt side of the machete before planting. This apparently means he gets more tubors growing off each plant but this is secondhand info.

Might be worth a try on a 1/2 rai or so next planting. Have you heard of this before?

Apparently he grows a number of varieties but mostly huey bong (spelling?) then cmr and rayong 72

On the subject of free gov handouts I mentioned above I can confirm that we have recieved 12000 Baht in MIL bank account.

I still am not sure if this is truly free although everyone assures me it is. Maybe the gov are trying to buy a few votes. I will let it sit till next year and if no one wants it back will donate it to the beer fund

Steve

[Khonwan]

His fertilizer choices are very good, Steve.

I certainly believe that stems can fetch B8,000. I cut 1 rai of Rayong 9 locally last year for B4,000 and was told yesterday that the local price is now B6,000.

I don’t crush the sett ends – have never heard of this. I would have thought it increased the risk of disease but maybe I’ll experiment with a small plot this June.

Rgds

Khonwan

[Khonwan]

I wrote in my OP that cassava in Thailand is relatively free from pests and diseases with economic consequences – that was true when I wrote it. 2009 saw an end to that, as we know.

These are CIAT’s recommendations as far as they affect farmers:

• Select pest and disease-free plants in the field for collection of stems as planting material

• Store stems for planting in a cool, dry place, and if necessary dip in a systemic insecticide such as Thiamethoxam

• Avoid application of foliar pesticides – they can affect beneficial biological control agents

• Restrict the movement of cassava planting stakes, especially from infected areas and restrict the movement of related species such as jatropha

The press release in full:

Cassava under threat

Pest and disease outbreaks put SE Asia on high alert

CIAT scientists and their partners in Southeast Asia have issued urgent preliminary guidelines to tackle deadly pest and disease outbreaks that have crippled cassava production in parts of the region.

The move follows a CIAT investigation into reports from Thailand’s eastern and northeastern regions, of damaged and stunted cassava plants with low root yields.

Cassava is an essential pro-poor crop in the region, where it is grown by around 5 million smallholders, mainly to supply the starch processing and animal feed industries. In Thailand alone, the industry is worth US$1.5 billion annually, and the country accounts for three-quarters of the world’s cassava exports.

CIAT entomologist, Dr Tony Bellotti, was part of the investigation team that traveled from CIAT headquarters in Colombia to the region: “When we arrived at the plantations in Thailand, I was stunned. Straight away I realized we’ve got real problems.”

A drive around the Korat region, about three hours from the capital, Bangkok, confirmed the worst: the road was flanked by field-after-field of affected plants.

One troubling discovery was the large number of mealybugs – well-known cassava pests in Latin America and Africa, but rarely a problem for cassava producers in SE Asia. The sap-sucking insects weaken plants, resulting in leaf distortion, and lower root yields.

The Thai fields were also found to be infested by tropical whitefly and red mites, while Cassava Bacterial Blight (CBB) and Brown Leaf Spot disease were also widespread. Although seen before, none of these pest and disease problems had previously caused significant losses in Thailand.

Some analysts now predict a cut in Thai cassava output by at least 30% this season; some farmers face losses as high as 80%. Some have already abandoned their crop.

Dr. Tin Maung Aye, a cassava specialist in CIAT’s Asia office said: “These pests and diseases will place a huge strain on Thailand’s cassava production. Not only will the incomes of smallholder farmers be greatly affected, but so will those of the many laborers employed in the cassava industry. There will be widespread economic and social implications.”

Double-trouble

Then, more bad news as farmers in neighboring Vietnam began to report problems in their cassava crops. The team again found mealybugs, tropical whitefly and red mites, but the main problems were not pests, but diseases.

“The CBB was incredible,” said CIAT pathologist Dr Elizabeth Alvarez. “The disease was just oozing from the stems. I’ve worked with cassava for 30 years and I’d never seen anything like it.”

They also found symptoms known as “Witches’ Broom”, still new to Vietnamese farmers. This is typified by discoloration and distortion of cassava leaves, and shortening of the branches and stems. When the affected cassava is uprooted, the roots are thinner and smaller.

Further investigations are underway, and CIAT is now investigating reports that fields in Cambodia, Laos and the Philippines have also been affected.

“It’s no surprise if these problems are spreading quickly,” continued Tony Bellotti. “If the mealybug, for example, can find its way from its native Latin America, across the Atlantic to Africa, and then to Asia, it can find its way around the Mekong region and beyond.

“We can be fairly sure that China and Myanmar will be hit soon, and in time, Indonesia too,” he said.

“Cassava production in SE Asia has enjoyed an extended honeymoon period. That period is now over.”

Taking control

CIAT Asia is working with national partners to provide cassava management guidelines. “This is a red alert,” said Tin Maung Aye. “We’re still coming to terms with the scale of the problem, but without decisive action, we expect a huge slump in cassava output in SE Asia. That would be devastating for rural livelihoods in the region.

“The spread is almost certainly caused by the movement of infected planting material,” Tin continued. “One of the first responses is for the authorities in affected countries to impose strict quarantine regulations on the movement of cassava, especially the stems used as planting material, and of related species, like jatropha.

“Farmers also need to be trained to select and safely store clean planting material, and to identify pests and diseases. Establishing an effective surveillance and monitoring system with a Geographic Information System (GIS) database is essential.

“We will also need to develop an Integrated Pest and Disease Management (IPDM) strategy, based primarily on biological control. With sufficient and well-focused donor support, the current attempts to develop an effective IPM strategy could be strengthened very quickly, which will help protect next season’s crop. Over the medium to longer term, the biological control and IPDM strategy would be strengthened and include release of natural enemies to control pests and the insects that carry the diseases. Breeding of cassava varieties with greater pest and disease resistance would become a priority.

“As a result of generous, long-term support from the Nippon Foundation, CIAT and partners have had an extremely positive impact on cassava production in SE Asia, and the livelihoods of cassava farmers. We are therefore well-placed to provide solutions to the current pest and disease outbreaks,” he continued.

“But there is no time to lose.”

*

CIAT’s main recommendations at this stage are:

• Select pest and disease-free plants in the field for collection of stems as planting material

• Store stems for planting in a cool, dry place, and if necessary dip in a systemic insecticide such as Thiamethoxam

• Avoid application of foliar pesticides – they can affect beneficial biological control agents

• Restrict the movement of cassava planting stakes, especially from infected areas and restrict the movement of related species such as jatropha

• Train extension staff and farmers in the identification of the various pests and diseases and develop a network of trained professionals in the region and a GIS-based system to monitor pests and diseases

• Initiate research into the identification and control of all observed pests and diseases, and their vectors

• Initiate a breeding programme to develop resistance to pests and diseases.

http://ciatlibrary.blogspot.com/2010/01/ca...der-threat.html

[somo]

I am getting reports of "bacteria" as my wife calls it from Chayapoum. Only a little on our plants but a lot of growers are reporting big problems.

Not sure what it is but the top leaves of the plants curl in on each other in a bunch and inside are the white eggs. Is this mealy bug?

We had a bit last summer and sprayed them with some chemical our local store recomended and it did the trick. The infestation didn't seem to effect the plant too much and I think it may be sufficient to just break off the the bunches and burn them.

Will be going up there in a couple of weeks to investigate.

[Khonwan]

Hi Steve

Yes, mealy bug. I would certainly not delay treatment by two weeks!

If only a very few trees, break off and place immediately in a plastic bag to be burned. Be very vigilant though as you could lose most of your normal yield if it takes hold.

Rgds

Khonwan

[somo]

Thanks for the advice khonwan.

Have got some people on it.

Steve

[Khonwan]

Hi Khonwan.

Hope you don't mind me messaging you but know don't check in so often now and need some info soonest.

Mealy bug seems to be everywhere now in Chayapoum and the husband and wife team that do all my weed killing etc tell me that the chemicals available in our local shops are not killing the buggers. People have resorted to creating their own remedies which range from spraying the infected crops with a mix of coffee/ tobacco solution to a concoction made from washing up liquid and lemon juice. I have a fear these may be a waste of time but who knows!

My question is do you know of any sure way of getting rid of it?

If chemical spray please let me have full details.

Regards

Steve

Hi Steve

We discovered 12 rai of Rayong 9 infested with mealybug 3 weeks ago so sprayed the undersides of the leaves with a solution of only dishwashing liquid (one litre per 200 litres water) – no more mealybugs. We are going to spray again with the same solution in the next few days just to make sure none were overlooked.

Avoid largely useless insecticides when treating cassava - they do more damage to useful insects than the pests that affect cassava. Stick to natural solutions using dish-washing liquid, or white oil, or vinegar. I reckon that the coffee, tobacco and lemon solutions may also be useful. All these natural remedies basically get rid of the pests - they don't actually kill them though it may well be that the pests then die for lack of food.

Our Huay Bong 60 were not infested – I’m hearing now that mealybugs do not like this variety or one of its “parents”, Kasetsart 50.

Kind regards

Khonwan

Ps If you don't mind, I'll post your query and my reply in the thread in case of use to others.

Hi

That is good news. Sounds like we are doing the right thing. Our sprayers have finished 15 rai and are waiting a few days to see if it is working. They used the washing up liquid (not sure what concentration) + a very sour fruit juice of some kind (nam som sai choo) Apparently the clear liquid with the not so hot chilis floating in it given to you eat quatio at street stalls.

Also 'look men' which I think is what we call moth balls and smells of menthol crushed up.

Reckon if I was a mealy bug I'd do a runner with that lot being sprayed over me!

I will be up there this weekend. It may be too soon to see any results but as I say it seems like we are on the right track.

I have heard that once the rains come the bugs should disappear as they hatch out and fly off.

Do you know if that is correct?

My wife confirms that Huay Bong seems safe from them but now because of that it is hard to come by now.

Regards

Steve

PS By all means copy and paste this lot into your cassava thread. For sure there are others interested.

[catwho]

The wife lastweek had to go korat for some goverment thing about how to look after crops and what to advise farmers on fertilizer, as we have had our little farming shop now 6 months,

we went into pak chong yesterday to buy tobacco, coconot oil,cream,and coffee which we did not get, she said not your normal instant coffee,they recomended this for something else, or maybe mealy bug,i did not ask too much about it till i saw this post,

and all the organic things i look up o the net always recomend the dish wash sol, for many bugs.

So the gov is in there trying which is good.

cat

[somo]

Just returned from Chayapoum and not too inmpressed with the results of spraying with washing liquid etc.

Have decided to cut the heads of all the infected plants and burn them. No problem with that as all my plants are well developed but saw lots of recently planted cassava totally infected and dying.

I have been told that once the rains come the mealy bug should go. Is that right???

[involver]

I am a Malaysian and I have an EM with me right now. This EM can turn cassava residue into a very good animal feeds for pig, cattle, goat, chicken, duck, and etc (experiments have been carried out on these and it shown a very good result). This new developed EM has not yet launch in Thailand, therefore, I'm now finding some ways to bring this EM into Thailand market. I believe it will generate a good result in Thailand's market.

Now, let me introduce the product to you. This EM is focus on 3 major benefits. Below is the general explanation of the benefits of the Effective Microbe.

1.) The EM + cassava residue can be used as animal feeds to feed animals. Since the cassava residue is much cheaper than the normal animal feeds in the market nowdays, thus, when the farmers use the Effective Microbe + cassava residue to feed the animals, it will reduce the cost of the farmers (for example, 70% normal feeds + 30% cassava residue, to feed the animals).

2.) Beside that, the Microbe can improve the health of the animals. The animals will not get sick easily after having the EM within its body. By this, the farmers can once again save money on the animals medication.

3.) Lastly, after having EM + cassava residue, the animals will have same growing rate, or even faster than the animals feeded fully with normal feeds.

*This product is totally safe and natural. The Microbes inside are retrived from natural sources. It does not contain any chemicals with it.

For additional information, the toxin, such as alpha toxin, contained in the cassava residue will be removed by the Microbe during the fermentation process. Therefore, it is safe to let the animals taking the cassava residue in a larger amount than usual.

This EM not only can be applied into cassava residue, but also others side products such as rice bran, soybean residue and etc.

Anyone who is interested or want to have further information, please kindly contact me. I can be reached on my email at [email protected].

Best regards,

Mr. Lim

[Khonwan]

Cassava waste (the total above-ground part of the tree) has been recognized as an excellent food source for livestock for many years - I used it for my cattle and ducks in the past. EM has been sold in Thailand for many years now also, for many purposes including this one you now suggest.

[Khonwan]

Hi Steve

Mealybugs are usually washed away by heavy rains but the damage to the cassava may well be irreversible should you await rain only.

I don’t know why dishwashing liquid did not work for you – it works perfectly well for others (me included). I wonder if you have been looking at the mealybug residue after spraying and mistaken it for the pests.

Rgds

Khonwan

[somo]

Hi Khonwan.

They sprayed 15 rai and the report back was that it had worked 50% whatever that meant. I went up about 5 days after and for sure ther was still plenty of the mealy bug about but it may have died since then.

I had about another 23 rai to treat so decided to go with beheading all the plants and burning them. At least this way for sure the bugs will die and it actually works out a lot cheaper to do it this way. They have just finished this job so will now keep a close eye out for any return.

I think part of the problem with spraying is that it is very difficult to open the leaves up and spray the eggs and it seems simpler to just break the lot off and burn it. I appreciate I cant do this with young plants but most of mine are at leaast 7 months old now so a bit of pruning shouldn't do them any harm.

The other problem I have been facing is that adjacent plots of land owned by others are also infested so they will reinfect mine but hopefully the rains will help soon.

Steve

[Robroy]

Hi all,

I'm new here. I work for an NGO in Cambodia which owns a cassava starch factory (in Battambang province opposite Sa Kaeo in Thailand).

The Thai mealybug infestation has concerned me since mid-2009 when I first saw it mentioned in the scientific websites (e.g. IITA).

I am not a cassava grower, but can pass on what theoretical knowledge I have - before asking some questions in return.

The only sure way to eliminate mealybug is via 'biological control' - specifically the predator A. lopezi, which eliminated the mealybug problem that had all but destroyed the African cassava industry in the 1980s.

A. lopezi has now been brought into Thailand by the Agriculture Ministry, & is being bred up & dispensed from three Ag Dept sites in Isaan.

More details if needed - but Dept of Ag are your best source.

I would like to hear:

1. How bad the mealybug infestation now is.

2. Whether anyone has used A. lopezi against it, & what the results have been.

Incidentally, we have just this week discovered cassava mealybug in Banteay Meanchey province here - breaking news.

Thanks,

John

[somo]

Hi John.

In my area of Chayapoum mealy bug is everwhere and many villagers are reporting their recently planted crops as destroyed.

The older plants look like they can survive with the help spraying/pruning but it is a bit of a losing battle.

One major problem is that most of the land is owned in small parcles so if your neighbour doesn't treat his then it just comes back to your plants.

Do you have any info on where the three Ag Dept sites in Isaan that are dispensing A. lopezi are located Maybe I can visit them and ask they treat our area or give me a bagful of it:)

As far as I know it has not been used in my area and this is the first I have heard of it.

Do you know how it is applied?

Steve

[Mikki]

Hi Steve I saw that around Sap Samo Thot there was mealy bugs on most fields in various grades of damage. But the farmers dident seem to worry, most said they will go away when the rains come. I hade about 2rais infected with mealy bugs when we harvested.

And i do worry about next crop because the problem of getting neigbours to take the mealy bug seriously.

regards mikki

[somo]

Hi.

I have heard the same ie when the rains come the bugs will go.

Not sure about that and even if true I reckon they will be back next dry season unless something is done.

I guess the thing to do is plant once the rainy season is well underway so if it is a dry season only thing then the plants will be able to withstand the next attack. For the life of me I don't understand the villagers that have been planting over the last few months. It seems they are too impatient to get things going rather than waiting for the rain and it is these guys who are now having their crops devastated.

I, as a farang beginner, am in no position to advise plus the villagers are a very independent lot and each thinks he knows best. I have never found two of them to agree on anything! It doesnt seem rocket science thinking is needed to conclude that planting once the rains have started is the way to go.

Oh well, cest la vie and all the best with your crop.

Steve

[Robroy]

I have heard the same ie when the rains come the bugs will go.

Hi again & thanks for the feedback.

I just want to stress that I've never grown cassava (tho my NGO's factory's growers do). This is all from what I've read (about 80 hours' reading so far), plus communicating with the world cassava mealybug experts at IITA, CIAT, CGIAT, etc, in various parts of the world. One of them is Dr Tony Bellotti, the guy who both identified the cassava mealybug & discovered A. lopezi, in 1981. Another is the chief entomologist at the African IITA centre which breeds A. lopezi (Benin). These are the guys who ended Africa's mealybug plague, so I figure they are worth listening to.

Firstly, yes, the rain is likely to 'collapse' mealybug populations. I do not, however, know how much rain is required (haven't had responses on that yet.) One study says that mealybug populations are at their lowest "at the end of the rainy season" - suggesting it may take a while to wash them out.

Spraying is possibly counterproductive because any A. lopezi mealybug-eating parasite wasps that are coming your way from the various Ag Dept dispersals (A. lopezi) will be killed too.

A. lopezi will likely get to you, wherever you are. It covered the entirety of Africa in 9 years; seems to move at maybe 25 km per month. When it does reach you it is likely to control mealybug levels to the point where they don't threaten the commerciality of your crop any more. I.e. it is very effective.

If you're an a hurry, you could contact the Ag Dept & ask where their 3 Isaan dispersal points are: sorry, I don't know.

The Ag Dept has a website with contacts etc.

(I've sent off a dozen emails about all this: no-one much has replied. Maybe they're all out in the field: this is a national emergency of sorts.)

Here in Cambodia, the mealybugs have just crossed into the northwest (three districts of Banteay Meanchey province), & are starting to eat cassava crops. I am trying to get some A. lopezi from Thailand. Tho the wasp will reach us eventually, may as well kill off the mealybugs now rather than wait for them to eat more cassava & spread further.

I'm happy to pass on anything more I have learned. Good luck.

[Robroy]

An email last night from one of the mealybug experts:

[The mites he refers to are the cassava green mite, red mites, & various others. CBB = cassava bacterial blight. All these are happening in different parts of SEA presently, & are probably on the way to eastern Thailand & western Cambodia. It seems that most can be successfully guarded against or beaten, but that's another post..]

"A reason for recent pests outbreaks may be attributed to a warmer climate or more prolonged dry periods. Both mites and mealybugs are dry season pests and populations are reduced during the rainy seasons often giving farmers a sense of false security.

CBB is more of a rainy season problem, especially where you have significant differences between day and night temperatures. The worst cases of CBB that I have seen in my 36 years working with cassava was in Vietnam in November of last year. Climatologists are indicating that the SE Asia region will have warmer temperatures and perhaps also longer dry periods. This could increase pest problems.

An additional problem is that the varieties being grown in the region have little or no resistance to these disease and pest problems. When it comes to pest problems on cassava Asian countries have been on a honeymoon and the honeymoon is over. The Americas and Africa have been dealing with these pest and disease problems for many, many years. We often speculated that the reason that cassava yields were higher in Asia than the Americas and Africa was because Asia did not have any of the major pest and disease problems."

[Khonwan]

Hi John

Thanks for your interesting contribution.

I would just like to clarify one point: whilst spraying of insecticide is definitely proscribed, spraying of natural solutions such as dish detergent, vinegar, white oil, etc. is definitely prescribed – these do not harm beneficial predatory insects.

Mealybug damage is quite widespread in my area. The economic damage is due in large part to poor education. Good monitoring and immediate treatment by spraying the underside of the leaves as above resolves the problem completely. Since poor education is not going to be rectified anytime soon, I welcome the introduction of A. lopezi.

It is worth noting again that Kasertsat 50 and Huay Bong 60 do not appear to attract mealybugs.

By the way, I’d be interested to know what your NGO-owned cassava-starch factory is currently paying for wholesale dried tapioca.

Rgds

Khonwan

PS. In my experience, Thai businesses and institutions rarely respond to English-language emails – phone calls work better.

[Robroy]

An update:

Cassava mealybug is now in 100,000 rai of land in Thailand.

From November 2009, the parasitoid wasp which kills the mealybug - A. lopezi - has been released in cassava fields near the Rayong Field Crop Centre.

Harvest estimates are down to 22.21 million tones for the 2009-2010 harvest, from an earlier forecast of 27.76m. That's a 20% drop.

A. lopezi has been tested with 10 Thai insect species: honey bee larvae, 2 species of lacewing larvae, 2 species of ladybird beetle larvae, 3 species of mealybugs found on cassava, diamondback moth, and rice moth. It only attacked the cassava mealybug (which is one of the '3 species of mealybugs found on cassava', & is the species causing all the trouble at present).

A. lopezi doesn't work well on unmulched sandy loam soils.

Slightly scatty data, but that's all I can get out of people as of today: Thailand's few entomologists are out in the field trying to fight the mealybug, & not spending much time in the office writing emails to me.

If A. lopezi has only been released in Rayong to date (as it seems), that means it could take 2-4 years to spread throughout Isaan (at a slightly wild guess - I'm going on the African figures). Though of course the extra rearing stations should come onstream well befor then, which will speed things up.

It seems A. lopezi is breeding fast in Rayong (enough have bred in the fields up for 6000 to be collected for a second breeding program), so anyone desperate enough could go there and ask a farmer if he can get some from his field. You'd need minimum 60-120, and to trasnport them pretty quickly in an aerated jar with some sugar to keep them alive for the trip, so fas as I understand.

Knonowan: You're right, of course dish detergent etc is fine, I'm sure. It's insecicide that kills A. lopezi & is thus counterproductive.

[Robroy]

Here is a pic of what I assume is A. lopezi: http://www.iita.org/medialib/displayimage....=82&pos=244

(It's not named, but the website is that of IITA, the org that found & dispersed A. lopezi in Africa.)

Attached is a pic of the 'pink cassava mealybug' that is now ravaging Isaan, courtesy of the Thai Dept of Agriculture.

(I assume this is the classical cassava mealybug, A. manihoti, & have sought to confirm this.)

I'm sorry for the slight lack of certainty: it's a hard time to get info out of people right now, as they're all out in the field.

[Robroy]

Does the above pic look familiar to those of you who have mealybug?

Also, I'm trying to get some idea of the extent of mealybug's spread through the Isaan region.

One poster said it was in Rayong right in the south, another that it was in Chayapoum roughly in the middle; and the CIAT scientists who came out in Feb found it right through the Korat area in the mid-north.

That's about a 600 km north-south spread. Anyone care to fill in some details? For example is there anyone to the very far north, or as far west as Petchaburi, who has the mealybug? What about around Nahkon Phanom in the north-east near the Lao border?

(I can confirm it's the the east as far as (and beyond) the Cambodian border - around the Aranyaprathet area on your side.)

There is no government data on the extent of the spread, so some info on this would help put together a picture.

In Cambodia, rains are already starting to wash the mealybug away (as they do). We've already had 2 big downpours. When the rainy season begins properly, it should largely disappear - until the next dry season. But it is essential to get the A. lopezi parasite established, otherwise mealybug will come back again bigger than ever.

Best time is before the rainy season begins; second-best is when the next dry season begins.

[sandyrow]

Does the above pic look familiar to those of you who have mealybug?

Also, I'm trying to get some idea of the extent of mealybug's spread through the Isaan region.

One poster said it was in Rayong right in the south, another that it was in Chayapoum roughly in the middle; and the CIAT scientists who came out in Feb found it right through the Korat area in the mid-north.

That's about a 600 km north-south spread. Anyone care to fill in some details? For example is there anyone to the very far north, or as far west as Petchaburi, who has the mealybug? What about around Nahkon Phanom in the north-east near the Lao border?

(I can confirm it's the the east as far as (and beyond) the Cambodian border - around the Aranyaprathet area on your side.)

There is no government data on the extent of the spread, so some info on this would help put together a picture.

In Cambodia, rains are already starting to wash the mealybug away (as they do). We've already had 2 big downpours. When the rainy season begins properly, it should largely disappear - until the next dry season. But it is essential to get the A. lopezi parasite established, otherwise mealybug will come back again bigger than ever.

Best time is before the rainy season begins; second-best is when the next dry season begins.

[sandyrow]

Does the above pic look familiar to those of you who have mealybug?

Also, I'm trying to get some idea of the extent of mealybug's spread through the Isaan region.

One poster said it was in Rayong right in the south, another that it was in Chayapoum roughly in the middle; and the CIAT scientists who came out in Feb found it right through the Korat area in the mid-north.

That's about a 600 km north-south spread. Anyone care to fill in some details? For example is there anyone to the very far north, or as far west as Petchaburi, who has the mealybug? What about around Nahkon Phanom in the north-east near the Lao border?

(I can confirm it's the the east as far as (and beyond) the Cambodian border - around the Aranyaprathet area on your side.)

There is no government data on the extent of the spread, so some info on this would help put together a picture.

In Cambodia, rains are already starting to wash the mealybug away (as they do). We've already had 2 big downpours. When the rainy season begins properly, it should largely disappear - until the next dry season. But it is essential to get the A. lopezi parasite established, otherwise mealybug will come back again bigger than ever.

Best time is before the rainy season begins; second-best is when the next dry season begins.

[somo]

sandyrow

The idea is that you are suppose to write something below the quote

[sandyrow]

sandyrow

The idea is that you are suppose to write something below the quote

Most be doing something wrong, this is the fourth time I have written something and tried to upload it, I would say third time lucky but we have passed that already J Here in Ta phraya we have also been hit quite badly by the mealy bug infestation, and this is the second year. Last year we thought that the rains had saved the day but them have returned with the dry season. Tried a lot of things suggested on the board but none really worked, problem being that they spread from one plot to another in a relentless fashion. Are there any strains of cassava that are resistant? A lot of small farmers around here are now afraid to plant again as they cannot afford to be hit two seasons in a row.

[Khonwan]

........ Are there any strains of cassava that are resistant? ......

Have you read post #218 or #231???

[Khonwan]

Update as of this afternoon: Lopezi wasps still undergoing tests to ensure they cannot themselves become pests in our Thai environment. They are not yet available for general release; names of cassava farmers requesting wasps are not yet being accepted.

Rgds

Khonwan