Mangoes not flowering, advice please

Smithson · December 13, 2019

We planted four mangoes of different varieties about 10 years ago, they are a decent height now. They have rarely flowered and when they do it's only a few clumps which ends up with only a couple of mangoes. Does anyone have advice on how to encourage flowering and fruit. I was think about spreading biochar composted with chicken manure, adding a layer straw and then watering with a compost tea. My wife read that giving them a decent trim this time of year is good, but I'm a little skeptical. I also read something about smoke triggering flowering?

In general things grow well here, however many of the trees we planted are not flowering or fruiting, however bananas grow fine. Any advice is much appreciated.

Laza 45 · December 13, 2019

I don't know much about it but my wife's family have a mango plantation.. they prune every year. She says they fertilize with chicken manure.. always lots of mangos. They spray a lot too.. I'm not sure but I think it is for fungal disease.. good luck..

Smithson · December 13, 2019

48 minutes ago, Laza 45 said:

I don't know much about it but my wife's family have a mango plantation.. they prune every year. She says they fertilize with chicken manure.. always lots of mangos. They spray a lot too.. I'm not sure but I think it is for fungal disease.. good luck..

Thanks, any idea what time of year they prune and fertilize?

Grumpy John · December 13, 2019

Here in Noen Maprang district at this time of year the trees are overflowing with fruit. No one is pruning until late March or April. Over watering could be your problem. We water every fortnight till the dam is empty.....probably till end of January. If you water every day or every second day the tree may not switch to flower mode. It senses the dry and that's when it can start the process of fruit production. The tree thinks it is producing seeds for new trees...we think it is fruit for us to eat! Plus we spray home made hormones to stimulate flower development. It's easy to make....but for 4 trees best to buy a small bottle from the shop. During the year April, if it rains, we add 1 bag 46-0-0 and 3 bags of 15-15-15 Then in July 15-15-15 and this year Epsom salts then more Epsom salts September or October the in November 13-13-24. Plus every 12 days folar spraying trace elements usually with hormones.

Laza 45 · December 13, 2019

1 hour ago, Smithson said:

Thanks, any idea what time of year they prune and fertilize?

I'll ask my wife when she gets back from work and get back to you.. I'd only be guessing now..

Crossy · December 13, 2019

48 minutes ago, Grumpy John said:

It senses the dry and that's when it can start the process of fruit production.

That's what Madam tells me about ours, got in trouble for letting one get wet ????

Laza 45 · December 13, 2019

1 hour ago, Smithson said:

Thanks, any idea what time of year they prune and fertilize?

I just did a google search and came up with this old TV forum post.. some good information here I think..

Smithson · December 13, 2019

I haven't been watering or adding fertilizer to the soil, mainly because I've read the roots need to be dry to flower, or something similar. I'd also heard mangoes need a cold period to flower. So I thought the cause was floods and the disappearing Thai winter, as many mangoes in our area also don't flower.

Is it a good idea now to compost, mulch and water it in? My wife read that now is a good time to prune, but I don't think that's correct.

JungleBiker · December 13, 2019

Could there be a high water table from which the roots are able to get plenty of water throughout the dry season?

Smithson · December 13, 2019

2 hours ago, JungleBiker said:

Could there be a high water table from which the roots are able to get plenty of water throughout the dry season?

That is something I hadn't considered, but definitely a possibility. We are a few 100 meters from the foot of Khoa Yai. The water in our pond is around 2m - 3m below ground thru the dry season, this is the water table height. However during very dry years there was no flowering, which I put down to lack of cool weather.

Nonetheless I'd like to try something. Is it too late for watering and fertilizing?

Grumpy John · December 16, 2019

On 12/13/2019 at 1:16 PM, Crossy said:

That's what Madam tells me about ours, got in trouble for letting one get wet ????

Plus the cool evening help with fruit set. Watering fortnightly we allow 1 litre for every fruit (It's a rough count ) we can see and 100 litres for the big tree, 75 for medium And 50 for small. It's probably not enough but our dam is small and we want to be able to water into January. The good prices disappear by February so if production falls it's not a disaster as we have sold tons of mangoes at good prices.

Grumpy John · December 16, 2019

On 12/13/2019 at 6:15 PM, JungleBiker said:

Could there be a high water table from which the roots are able to get plenty of water throughout the dry season?

The water table is dropping. Probably only a small amount each year but dropping never the less.

Thian · December 16, 2019

Don't fertilize with nitrogen after oktober...wait untill after harvest with that....but do fertilize with phosphorous and potassium.

Spray the tree's with 4% potassiumnitrate (13-0-46) dissolved in water..so 40 gram a litre. If no flowers after 21 days do it again.

After harvest you can soil drench the soil with pactrobutrazol after harvest so next season the tree will flower in time and give extra large flowers. google that for info if you like.

keep the tree's healthy by spraying seaweed extract during the season, lazada sells it but also thaiwatsadu and so. Once every week or month will do.

when the tree is blooming you water it and also during fruit set and after that.

If it blooms well check the flowers for diseases/fungus....if so you can spray with copper or another fungus killer...the shops can help you, just show them a picture of it.

If they really won't bloom at all you can hammer the trunk a bit with the back of an axe or hammer....don't damage it but just bruice it slightly. You can also cut a ring of 5mm wide around the trunk if nothing works...that should work. Just take the bark away for 5mm.

Or buy a chocanan mangotree, that's the most easy one which will fruit all year. You need grafted tree's, don't grow seeds but for chocanan you can do it...

Grumpy John · December 17, 2019

23 hours ago, Thian said:

Don't fertilize with nitrogen after oktober...wait untill after harvest with that....but do fertilize with phosphorous and potassium.

Spray the tree's with 4% potassiumnitrate (13-0-46) dissolved in water..so 40 gram a litre. If no flowers after 21 days do it again.

After harvest you can soil drench the soil with pactrobutrazol after harvest so next season the tree will flower in time and give extra large flowers. google that for info if you like.

keep the tree's healthy by spraying seaweed extract during the season, lazada sells it but also thaiwatsadu and so. Once every week or month will do.

when the tree is blooming you water it and also during fruit set and after that.

If it blooms well check the flowers for diseases/fungus....if so you can spray with copper or another fungus killer...the shops can help you, just show them a picture of it.

If they really won't bloom at all you can hammer the trunk a bit with the back of an axe or hammer....don't damage it but just bruice it slightly. You can also cut a ring of 5mm wide around the trunk if nothing works...that should work. Just take the bark away for 5mm.

Or buy a chocanan mangotree, that's the most easy one which will fruit all year. You need grafted tree's, don't grow seeds but for chocanan you can do it...

What area are you in? That sounds like professional grower advice! As a professional maybe you could give me some advice: As an outside looking in I think being a mango grower is probably one of the dumbest career paths to take in farming. What can I say to the wife to sell her on growing something more profitable and requiring less work? Look at Durian, get in with Chinese buyers and your set! But this area is no good for Durian. Your thoughts.....

Thian · December 17, 2019

7 minutes ago, Grumpy John said:

What area are you in? That sounds like professional grower advice! As a professional maybe you could give me some advice: As an outside looking in I think being a mango grower is probably one of the dumbest career paths to take in farming. What can I say to the wife to sell her on growing something more profitable and requiring less work? Look at Durian, get in with Chinese buyers and your set! But this area is no good for Durian. Your thoughts.....

I'm a hobby fruit grower and live in BKK...today i bought 2 mangotree's though because i killed some other tree's that won't fruit...one was a large lamut yak from malaysia....doesn't fruit so byebye...

If i were you i would grow something that the thai don't know...and sell it on the or-tor-kor market to bangkoks richest chinese thai which go there every day.

You need a novelty...and yes i have plenty of those, imported from all over the world for a decade now.

Durian Musang King fetches a very high price, so does XO...those are very expensive in Singapore and also MAlaysia. I have only seen the tree's in thailand, not the fruit..those also have a bitter taste in the palate, like coffee/chocolate.

But it all depends where you grow it (i bet durian can grow also where you live if you water it)...and also if you can transport it to the wealthy people...there's no need selling expensive fruit to the farmers in Isan me thinks.

Yes i studied a lot about mango tree's...spraying potassium nitrate is simple, safe, easy and works....that's also how you can get offseason mango's...potassium nitrate to a longan tree also makes it bloom, just pour it to the soil of the longan but for mango you should spray it.

Thian · December 18, 2019

http://era.daf.qld.gov.au/id/eprint/1647/4/3gro-mango.pdf

Smithson · December 20, 2019

Thanks very much for the comprehensive info. Does anyone know if potassium nitrate is commonly available by another name in rural areas?

petermik · December 20, 2019

8 hours ago, Smithson said:

Thanks very much for the comprehensive info. Does anyone know if potassium nitrate is commonly available by another name in rural areas?

I think if you look for bags with 13-04-46 on it will be what you want....I,ll be looking for the same