Fertilizing Fruit Trees

[thaipod]

I would like to know if you can tell me when and how much and type NPK fertilizer to distribute aroung small, medium to large fruit trees ( rose apple ,jack fruit ,star fruit , mango ma-praang etc).

Also the best time of the year or when eg, after flowering , to apply for good fruit production , being the rainy season at the moment i guess it would not be effective

Thanks

[drtreelove]

Did somebody say trees?

The short answer is to use 15-15-15 granular, distributed evenly throughout the root zones (dripline and a little beyond) at a rate of about 6 kilos per 100 sq meters. I'm basing that application rate on about 1 kilo of actual nitrogen per 100 sq meters. This is real loosly about half of an annual rate. General purpose chemical fertilization standard is 2 to 4 pounds of actual nitrogen per 1000 square feet per year (ANSI A300 - tree fertilization). 15-15-15 has 15% actual N. You can fertilize now, and it will be effective, but you will lose some nitrogen due to leaching from the heavy rains. You can fertilize again at this rate at the beginning of the growing season in late February or March if you are irrigating. If you are not irrigating then wait for the beginning of the rainy season in May.

A better answer is to use real compost or composted manure and use mulch in the entire root zone. Manure is high nitrogen, don't overdo it. Mulch will help with weed control and reduce competition for nutrients. This will help to build soil fertility and will retain nutrients with a gradual breakdown, and minimize leaching. Raising organic matter content and mulching will also help your trees get through the dry season by retaining moisture.

Another aspect to consider is to send soil samples for scientific soil analysis. Then you can (with the help of a soil scientist or horticultural advisor in the know about these things) devise a prescription fertilization program based on actual deficiencies, not guess work.

Other members who are growers may have better specific information about timing and special formulations. My answer is for very general tree health purposes. If you don't have deficiencies and you are just looking for maintenance, then you may be able to reduce that rate. Too much nitrogen can overproduce vegetative growth and reduce flowering and fruit. As far as fruit production in general, healthy trees with adequate water and nutrient uptake produce good fruit.

[thaipod]

Thanks for that , i have asked a couple of locals and getting conflicting reports one say's 15 kilo per tree another says around 20 I was a little shocked thinking that will cook the root system for sure .

The trees have not been maintained for many years and the fruit is smaller and not as juicy as they should be ( quite dry and sour ) . About 6 months ago I pruned them and airated the soil and put about 1 kilo around the drip line and they seemed to show signs or picking up , flowering and the fruit has more flavor and juicy.

At the moment we are working on compost bins from the abundant amount of weeds to use to dig into the soil which is very much clay and mulch .

It's only a hobbie at this time but getting a lot of satisfaction with the progress.

[fredge45]

Would the same, or similar, advice given apply to an old longan/lomyai orchard drtreelove?

Been getting lots of conflicting information from the locals and I would like to get it as right as possible, w/o using much if any chemical fertilizers. I shudder when the use of a strong dash of Potassium Chlorate is suggested to shock the tree but a lot of people are doing just that. I notice that an application kills off anything growing around the tree so it must not be doing the tree all that much good...

Presently each tree gets a bag of cow manure spread along the drip line after harvest and then a mulching of 4 - 6" of rice straw when that comes available. Sprinkler irrigation during the dry season rather than the previously used flood irrigation.

They're a hobby for me but the mother-in-law likes the income when she gathers the troops and does the harvest.

[slapout]

45; hard to know where to start on the lamyai questions as the answers seem to depend on who you ask, day of week, mood of person (both sides) at that time (our lamyai are in Fang area). Potassium chlorate, it seems to be used by the majority of the growers in Lamphun area (lots of lamyai there) spread around drip line about January or Feb. 1 to 2 kilo/tree depending on age/size (this applies to 12 year trees) too much and yes it can kill and/or knock the tree for a year or so. Manure at pruning time, rainy season, (quantity depends on need of soil and prior harvest quantity). EX-M microorganism mixture spray and a leaf curl/fungi spray applied at end of rainy season. She who knows all, listens to the chemical sales people. Hit with 10-20-10 fertilizer about March/April and soak in with irrigation system. This method produced about 100 kilo/tree this year on 12+ year old trees, about 60 to 70% fruit potential??? as per boss. This method worked great 5 year ago and we got the same gross weight from our trees when they were 7 year old, When price hit 5 to 9 baht/kilo we only used manure and also had hail , complete screw up on irrigation at bloom one year, etc. What I am trying to say is, hel_l, I do not know what will happen from year to year, but this procedure comes from lots of advice, trial and error, etc. It will need to be time, quantity, adjusted depending on location and soil condition/need. Good luck

[drtreelove]

Would the same, or similar, advice given apply to an old longan/lomyai orchard drtreelove?

Been getting lots of conflicting information from the locals and I would like to get it as right as possible, w/o using much if any chemical fertilizers. I shudder when the use of a strong dash of Potassium Chlorate is suggested to shock the tree but a lot of people are doing just that. I notice that an application kills off anything growing around the tree so it must not be doing the tree all that much good...

Presently each tree gets a bag of cow manure spread along the drip line after harvest and then a mulching of 4 - 6" of rice straw when that comes available. Sprinkler irrigation during the dry season rather than the previously used flood irrigation.

They're a hobby for me but the mother-in-law likes the income when she gathers the troops and does the harvest.

Slapout has a lot more experience than I do, we only had our lamyai and mango orchards for 3 years when we had to move off the property.

Potassium chlorate is used to force the blossoming stage of a longan tree, causing it to produce fruit earliler to beat the market for higher prices. But like all extreme practices, there is a price to pay in the imbalances created. You can't over-do it or do that every year without a downside.

Your manure and mulch program sounds good and you probably won't need chemical fertilizers if you keep that up and build soil fertility by building organic matter content. In your older orchard, you may have too much canopy coverage to grow green manure, but if you have space between trees where sunlight gets in, a legume cover crop can help with the organic matter content too, and supplement your mulching when you cut and leave lay.

As Slapout mentions, irrigation is a real key, timing and amount. You have switched to sprinkers from flood irrigation, you must have your reasons. Sometimes sprinklers get more even coverage, it depends on other factors, slopes are hard to flood irrigate without extensive burms and terracing, and it takes more management. Sprinklers can get depth of water penetration, but usually they don't because they aren't run long enough. I like flood irrigation, maybe because I grew up where my father managed citrus orchards and deep flood irrigation was the method of operation; the results were deep rooting and longer moisture retention and therefore longer irrigation intervals were possible.

Pruning practices are often extreme in lamyai orchards and you will be advised to stub the trees back to a hat-rack to generate new growth. I have always rejected that kind of extreme practice and prefer to thin and drop-crotch. I started pruning orchards and landscape trees when I was 12 under my father's direction and this method has always served me well, and I think the trees apprecitate it too, at least they look a lot better on completion of pruning and in the results of regrowth and productivity. don

[drtreelove]

I've been looking for WIN, water insoluble nitrogen, nitroform, urea-formaldehyde and haven't been able to find it in Chiang Mai. Anybody out there seen it in Thailand?

[drtreelove]

I should mention, while I'm preaching against the stub-cut, hat-rack method of pruning, is that it leaves stems and scaffold branches exposed to drying of bark and sunburn; also the large cut ends of scaffold branches can decay and create long term stuctural weakness at the point of re-growth, so eventually the newly formed branch structure can break off more easily under wind load or weight of fruit crop. With big trees this can create hazardous condions for life ande property and is one reason to avoid topping.

[fredge45]

My many thanks for the informative replies and my apologies for the delayed response.

About 50% of the orchard got "hat-racked" before I realized that the 'experts' had no concept of pruning a tree. I've spent a lot of time and effort attempting to create some good trees after their attack! In the open spaces we've planted some ornamentals, avocado, mango etc etc. Now that the rains are so helpful sunn hemp seed has been broadcast for a green manure crop and to compete with some of the more aggressive weed varieties.

Most of the land is sloping which lead me to using sprinkler irrigation. What I had seen of the flooding was that it was not very consistent in the amount of water/tree and the erosional gullies formed from lack of attention while flooding. By mulching I have been able to irrigate less while keeping the trees well watered. I have dug test holes to check the effectiveness of the sprinkler irrigation and find the I'm getting good penetration. Besides, I like the sound of the rainbird-type of sprinklers chugging away while they work... ;-)

Now I have a much better idea of timing for those nudges of fertilizer for more fruit thanks to your efforts.

[Thailand Noobie]

Hello. This is an old topic but I just like to know will same fertilizer works for every trees, mostly palm trees in Thailand?

Or do every trees have own 

fertilizer? I need to take care several brand of palm trees and other normal Thai trees.

[drtreelove]

On 8/29/2020 at 10:00 PM, Thailand Noobie said:

Hello. This is an old topic but I just like to know will same fertilizer works for every trees, mostly palm trees in Thailand?

Or do every trees have own 

fertilizer? I need to take care several brand of palm trees and other normal Thai trees.

Disregard my advise from 10 years ago. My approach to soil fertility and plant nutrition has evolved with study and intensive practical experience. I now discourage the use of high NPK chemical fertilizers, there are inherent problems created with the repeated use. I now advocate for soil testing based fertilization, or next best is general purpose COF (complete organic fertilizer) mineralized, slow release, NPK percentages under 10. Read the chapter on COF in The Intelligent Gardener by Steve Solomon. 

 

Soil testing is the best, with prescription soil amendments based on actual deficiencies found. Contact member Evolare about soil testing. bonemeal.net

 

Getting the Calcium level right, in proportion to Magnesium, is the most important and first thing to work on.

 

You can learn to make your own, but the only reasonably good COF that I know of being sold in Thailand is a bokashi from OrganicTotto in Samut Prakan. 

 

Bokashi fertilizer.docx

[drtreelove]

You will also need to attend to IPM, integrated pest management for your palms. There are killer pests that you don't want to get started or you will lose trees, one after another.

 

Preventive management is far better than waiting for an advanced infestation before attempting to control active pests. Coconut palms are particularly susceptible to several devastating pests, but some can go to ornamental palms too. Soil fertility that you are inquiring about is important for building resistance to pests, Calcium is an important transporter of other nutrients and is vital in building cell wall strength. Water management during dry season is the most important, not too much or too little.  Sanitation is equally important, cleaning up debris piles and fallen tree trunks, and netting of compost piles where rhinoceros beetles can breed. 

 

Search for the many forum discussions we have had on coconut rhinoceros beetle, red palm weevil and other palm pests. 

 

There is a Thailand Agricultural Dept biological control center in Chonburi that has been responsible for developing and releasing biological control agents for commercial and resort palm pests. This is something to consider as an alternative to chemical control. 

[Thailand Noobie]

On 9/3/2020 at 8:54 AM, drtreelove said:

Disregard my advise from 10 years ago. My approach to soil fertility and plant nutrition has evolved with study and intensive practical experience. I now discourage the use of high NPK chemical fertilizers, there are inherent problems created with the repeated use. I now advocate for soil testing based fertilization, or next best is general purpose COF (complete organic fertilizer) mineralized, slow release, NPK percentages under 10. Read the chapter on COF in The Intelligent Gardener by Steve Solomon. 

 

Soil testing is the best, with prescription soil amendments based on actual deficiencies found. Contact member Evolare about soil testing. bonemeal.net

 

Getting the Calcium level right, in proportion to Magnesium, is the most important and first thing to work on.

 

You can learn to make your own, but the only reasonably good COF that I know of being sold in Thailand is a bokashi from OrganicTotto in Samut Prakan. 

 

Bokashi fertilizer.docx 58.72 kB · 0 downloads

Thanks for your reply.

I do not have time for any testing. So I prefer good fertilizer from the shop.