drtreelove

On 4/10/2024 at 9:12 PM, mahjongguy said:

Over-watering is harmful to many young trees, including pomelo. The roots need time to dry a little so they don't rot. Monty would say "they don't like wet feet", so water less often. Depending on the weather, this might be once a week. Cover the ground around the base with a good mulch to slow evaporation. 

 

Chicken manure seems a good choice as long as it is mixed into quality planting soil at something like 5 parts dirt to 1 part chicken sh*t.

 

This particular tree is badly stressed. It may or may not be too late.

Good advise!   Also, from the photo it appears that it was planted too deep, with the root crown buried and susceptible to crown rot from the over watering. 

 "...the trees in question haven't been fertilized or watered (the water table is quite high where we are, so I assume that they are getting adequate water)..."

How does that saying go? "To assume makes an ass out of you and me".  A high water table does not insure that trees are getting what they need, or are not getting too much. Soil surface watering is important in most cases because that's where the bulk of the absobing roots are, in the top few inches of the soil profile, and just as important is, that is where the beneficial soil biology is active (or should be active) in facilitating nutrient cycling and other important metabolic functions.

And sometimes the opposite is in effect, that a high water table is too much and predisposes root rot in trees that are highly susceptible, like durian and avocado. 

Also, regarding soil fertility, durian trees have a high foliage density and large structural wood formation, and large fruits, so there is naturally a need for high nutrient availability, and in the depleted soils of Issan, that usually means that well managed amendments are needed until soil biology can be restored. Calcium supplementation will be one of the most important, and in the CEC-based BCSR soil testing and cation balancing system, for large fruit formation, Potassium is upped to 5%, as well as other essential mineral considerations. SOM (soil organic matter) content, mulching or cover cropping, are also important management factors to consider. 

You are working with a highly unnatural planting, so you should not assume that natural forest conditions prevail, and that intelligent soil and water management is not vital. 

Also, trees planted from seed are not necessarily true to the parent variety that has been bred for adaptibility to the site specific conditions and desireable characteristics, so anything is possible. 

Adequate Calcium is also an important element to consider, in balance with other cations. 

Do a pH or "fizz-test" .  If your soil is alkaline then don't use lime. gypsum (calcium sulfate) is okay, but the problem is that what is sold as gypsum in Thailand is usually Calcium oxide, quicklime.  There are other sources of Ca. 

August 29, 2014 by Permakulturnik

The importance of Calcium for health and proper functioning of the plant

Calcium is one of the elements, which are essential for plants. They need it in very large quantities – in Good soil, giving the highest value of fruits and vegetables, calcium is more than all the other necessary elements combined plants. It performs many functions in the plant (Calcium functions):

§  Regulates the absorption of other minerals by plants

§  It stimulates the correct elongation of plant cells

§  Strengthens the structure of the cell wall, which are responsible for the proper form and shape of plants

§  Participates in the process of enzymatic and hormonal

§  It helps to protect plants from heat stress

§  Protects the plant by diseases – many fungi and bacteria secretes enzymes, that attack the cell walls of plants. Strong and rich in calcium, cell walls are better able to resist the invasion of pathogens

§  Affects the quality of the fruit

§  It is needed for the proper functioning of stomata

Can be briefly summarized as: “without lime there is nothing”!

LIME - More Than an Agent to Change Soil pH.pdf

Appropriate water management is a major factor.

Adequate and balanced mineral nutrients can be a factor. Large fruits require a lot of Potassium (among other nutrients) for the growth and ripening process. When I write a soil-test-based Rx for amendments with the cation balancing method, for K-hungry crops especially durian, papaya, bananas, citrus, I bump up the potash amendment to 5% of the BCSR instead of the normal 4%. (See the book The Ideal Soil by Michael Astera, or The Intelligent Gardener, Steve Solomon).  One of the best organic program compatible K sources is naturally mined Potassium sulfate 0-0-50, or Langbeinite (Sul-Po-Mag) 0-0-22.  Avoid Potassium chloride 0-0-60, as it is extremely harsh and detrimental for the beneficial soil biology.

As far as how much to apply, I wouldn't go out and dump a lot of K2SO4 on your soil, it should be a measured amount in relation to other nutrients. Without a soil analysis, the Langbeinite would be the safest.  Best Garden State in Nakhon Pathom and on FB may carry it. And they do soil testing with a much better method than local labs and universities in my opinion. 

https://downtoearthfertilizer.com/products/single-ingredients/langbeinite-0-0-22/

Langbeinite

Trees & Shrubs:
Spread ½ -1 lb per 1″ of trunk diameter around the base outwards to the drip line, mix into soil surface and water in well. 

Potassium sulfate

Without Soil Analysis (recommended rates for general use):
For foliar and spray applications, mix ½ – 1 tsp per gallon of water. Apply with even coverage directly to plant leaves. For soil drench applications, mix 1-2 Tbsp per gallon of water.

Over the years we have had many discussions on this forum regarding soil analysis.  I belive that there is a lot of incomplete and mis-information on the subject. Here is my attempt (with the help of AI - Chat GPT) to explain some of the different approaches and methods of soil testing, chemical farming oriented SLAN, organic farming BCSR and the latest soil biology oriented regen ag methods and materials. 

Regenerative Agriculture, as promoted by Kiss the Ground advocates, The Soil Food Web School and Advancing Eco Agriculture, as well as others, represents a modern movement away from pure chemical soil analysis toward a primary consideration of the soil biology and related processes, and how the microbiome is affected positively or negatively by management of growing methods and materials.

Don’t miss this key perspective on soil food web and regenerative agriculture:

John Kempf,  Changing Agronomy with Biology

https://www.youtube.com/watch?v=cHPOMBe2SUE

The "Integrity Grown" development is great news from the master Regen Ag advocate John Kempf, AEA (Advancing Eco Agriculture).

This program has the possibility of eliminating some of the limitations and weaknesses in "Organic" terminology and varied practices, misinformation, confusing consumer marketing hype, some outright misrepresentation and fraud, and certification program standards. 

Regan Ag movement is gaining traction worldwide, for good reasons. When will Thailand farmers get on board? 

This from the University of California, finally. 

Glenda Humiston 

Vice President

UC Agriculture and Natural Resources 

In January I’ve been participating in a variety of planning meetings to set priorities and objectives for UC ANR’s work in the new year. One discussion that will have ramifications for many of us, not just in the coming months but for years down the road, is the ongoing dialogue around defining “regenerative agriculture.”

Presently, the term represents a somewhat nebulous but undeniably significant movement toward agriculture that builds soil health, strengthens biodiversity and sequesters carbon for the benefit of people and planet. But more concrete language is necessary to guide future policy, practices and programs; encompass our state’s wide range of ecosystems and soils; and meet the needs of a wide range of stakeholders.

It is imperative we have a sensible, science-based definition. And it needs to work for farmers and ranchers of all sizes, tribes, scientists, businesses and environmental groups – as well as the broader public whose sustenance relies on strong and resilient food systems.

The California Department of Food and Agriculture and the State Board of Food and Agriculture are collecting comments at RegenerativeAg AT cdfa.ca.gov and hosting listening sessions in February, April and May on this crucial topic. I encourage you to attend an upcoming session – and spread the word among your colleagues, clientele and community members to share their feedback – so we can work together to craft a definition that is relevant and useful for all.

Regenerative agriculture was a major theme of this year’s EcoFarm Conference, held Jan. 17-20 in Pacific Grove. 

On 1/26/2024 at 5:09 PM, steven100 said:

 

 

OFF!^® Bug Control I is a concentrate that, when attached to a hose and sprayed around a backyard perimeter, will protect an area up to 16,000 sq. ft. OFF!^® Bug Control I will kill 110+ insects outside the home on outdoor surfaces for up to 8 weeks. It works to kill and repel insects on trees, shrubs, vegetables, and ornamentals.

 

https://off.com/en/product/backyard/bug-control-i

 

Homemade Insecticidal Soap Recipe

The simplest insecticidal soap is nothing more than a 2% soap solution. To make this at home, you will need:

• Sprayer: Any clean spray bottle or garden sprayer will work fine for spraying insecticidal soap. Make sure the sprayer or bottle hasn’t been used for herbicides.
• Pure Soap: Use a pure liquid soap, such as Castile, or all-natural soap. The active ingredient in insecticidal soap comes from the fatty acids in animal fat or vegetable oil, so it’s important to use the real thing. Don’t use detergents (which aren’t actually soaps), dish soaps, or any products with degreasers, skin moisturizers, or synthetic chemicals. Dr. Bronner’s Pure Castile Soap is usually pretty easy to find in stores, or check your local natural-foods store for other options.
• Pure Water: Tap water is fine for making insecticidal soap. If you have hard water, you may want to use bottled water to prevent soap scum from building up on your plants.

To make homemade 2% insecticidal soap, mix together:

• 5 tablespoons soap to 1 gallon of water

OR

• 1 heavy tablespoon soap to 1 quart of water

Other ingredients that can be added to homemade insecticidal soap

Homemade Insecticidal Soap Recipe Variations

Like any other home remedy, there are as many variations on this recipe as there are gardeners! You can also try:

• Diluted Solution: If the spray causes damage or burns your plant foliage, cut the amount of soap in half and try a 1% solution. This is the concentration usually found in commercial sprays. The lighter solution might be less effective but is gentler on plants.
• Cooking Oil: To help the solution stick a little longer, add two tablespoons of light cooking oil (such as corn, canola, olive, or safflower) per gallon of water to the mix.
• Vinegar: To make a spray that also targets powdery mildew, add a teaspoon of cider vinegar per gallon of water to the mix.
• Garlic or Pepper: To help repel chewing insects, add a teaspoon of ground red pepper and/or garlic per gallon of water to the mix.
• Bar Soap: For a less-exact recipe, drop a bar of pure soap (such as organic bar soap or Ivory) into a gallon of water and leave it overnight. Remove the bar and shake well before spraying.

Here's some excepts from a course on Plant Health Care from learntrees.com with some interesting statements on PHC and Integrated Pest Management:

Integrated pest management is an environmentally sensitive approach to controlling pests that does not rely totally on pesticides. IPM depends on frequent monitoring of plants and pests so that control strategies are used only when and where needed. IPM is a decision-making process that assesses pest status and determines logical and environmentally sound management tactics. A variety of control methods--cultural, mechanical, biological, and chemical may be employed.

Furthermore, IPM takes a holistic approach to pest control encompassing pests, and diseases rather than singling out only one pest-plant problem. By understanding the use of IPM as part of Plant Health Care, we can ensure the long-term survivability of our trees and the health of our environment.

If we approach IPM as part of a responsible PHC program this means practitioners should choose the least toxic, narrow-spectrum control option necessary to meet the objective. This helps to avoid pest resistance and secondary pest outbreaks.

These control options may include biorational control products – Insecticidal soaps, horticultural oils, botanicals, insect growth regulators (IGRs), microbial-based products, and microbial agents.

This also means that we must incorporate sound cultural practices as the basis of our PHC program.

If we promote total plant health, we avoid many problems (preventative medicine). Cultural and environmental problems are minimized, and healthy plants are better able to withstand insect or disease damage.

While often the most successful approach, prevention strategies are sometimes insufficient for managing pest populations and plant injury at tolerable levels. When monitoring reveals that an action threshold has been exceeded, control is often necessary.

Eradication, or complete elimination, of a pest is often unrealistic and is rarely a goal in IPM unless dealing with highly noxious, introduced pests.

Suppression is the most common insect pest control goal in plant health care, intending to reduce the pest population to tolerable levels.

Monitoring is a program of regular inspections to make observations and collect information to aid in making decisions about the management of pests and disorders.

Monitoring is critical to the success of an IPM effort.

When monitoring indicates that pests require attention, PHC employs an IPM approach to manage them.

The primary keys to successful IPM are familiarity with pests' life cycles, correct diagnosis, and monitoring. Monitoring is crucial, but you must also have the correct identity, behavior, and life cycle information. One has to know, for example, when to begin the monitoring process, and to do this, you have to know the pests' complete profile.

So, when do we take action? There are various criteria used to answer this question and determine our action threshold. If the pest is life-threatening to the plant, mere presence may dictate management action. However, mere presence does not always dictate the action. Plant phenological stage can also influence injury tolerance and impact pest control decisions. Phenology is the relationship between recurring biological events and weather changes.

Pest managers often use an economic threshold - population level at which serious damage or yield losses occur, to signal that action must be taken. 

The aesthetic threshold is the damage level that is unacceptable to the viewer, even though plant health may not be at stake. Unfortunately, ignorance about the pest and the plant's ability to withstand some damage often results in unnecessary pesticide applications.

There are four general methods to manage insect, disease, and weed problems.

Cultural Control

Biological Control

Mechanical Control

Chemical Control

Several of these tactics may be carried on concurrently or implemented at different times to achieve a truly integrated management approach.

1. Sanitation, cleanliness.  If you don't feed them they will not come. 

2. Chaindrite Crack and Crevice aerosol for spot spraying of problem areas. Cypermethrin and Bifenthrin with about a month residual effectiveness. Least toxic but use PPEs and avoid food and pet exposure. 

On 1/21/2024 at 4:52 PM, djayz said:

I was/am/was/am striving to grow organically, but sometimes (rightly or wrongly) I feel it's futile here. Despite using organic methods, sprays, etc. once or twice a year I get these infestations and it seems like the organic approach isn't harsh enough to solve the problem. That's why, once or twice a year, I feel like I have no other choice but to turn to the stronger chemical pesticides. 

The time and effort I have put into, and am still putting into, growing fruit and vegetables simply can't be in vain. 

Perhaps it is taking me longer to build up a beneficial growing environment, soil fertility, etc. than I had expected. 

As always, thank you for your feedback. It's very helpful. 

I sympathize, it takes awhile to gain confidence in shelving the harsh chemicals and trusting the biologicals and integrated pest management. But it does work if you can get it right. The key is not one product or practice, but a comprehensive preventive management plan.

I have found that plant pest and disease resistance can be achieved faster than I thought with preventive management, primarily good water management (not too much or too little) and soil fertility building. Not just 'fertilization' for growth response, but building "high nutrient density" in soil and plants, as taught by the Soil Food Web School and modern Regenerative Agriculture models, reduction vs oxidation practices as taught by Dr Olivier Husson and featured by Matt Powers, The Permaculture Student. Avoid high salts, high NPK chemical fertilizers, they definitely set up the wrong kind of chemistry which becomes a pest magnet. Cover crop with mixed species (Dr Christine Jones), or plant mixed diversified beds as in the Grow Biointensive method (How to Grow More Vegetables... John Jeavons), mulch, never allow bare ground around your plantings. 

Recognize that the beneficial soil biology, as well as a protective microbiome on the leaf and stem surfaces, are important natural plant protection processes and barriers for pests and pathogens. Cultivate this and don't destroy this biology as best possible. As well as building soil organic matter content or cover cropping, inoculate your soil with compost, compost tea or extract, worm castings or the effluent, and spray the foliage and stems with it too. 

There are always some aggressive pests or disease that can get started no matter how good your management, but that is best handled by knowing local issues and anticipating seasonal infestations and infections, and by daily or at least weekly inspections and early intervention. Like right now, as the weather warms up and the spring growing season kicks in, you can expect to see moths and butterflies flying around looking for inviting habitat to lay their eggs, which hatch into hungry larvae/caterpillars. If you know this is coming, you can get ahead of it. Inspect daily for egg masses or first instar caterpillars, especially the underside of leaves. Mechanical control is an important and effective IPM method; Hand picking off of caterpillars, rubbing off mealy bugs with a rag or cotton glove, or using a water blast can achieve a practical level of control without any environmental contamination.

If necessary, use your botanicals with the right timing, you don't wait for the caterpillars to start feeding heavily and then try to knock them down, but you anticipate this and apply your rosemary, lemon grass and/or clove botanical, or Aza concentrate (neem seed oil extract of azadirachtin) weekly as a preventive repellent. Or if you are away from your garden and it gets ahead of you a little, then you can still do early intervention before the losses mount. Wood vinegar, pyrethrins (harder to find here) are potent organic program compatible knock down insecticides with minimal residual environmental contamination. 

Don't panic at the first sign of insect activity. If you have built reasonably good soil fertility the moths may fly around but not be attracted and not lay their eggs  and feed on your plants. One or two grasshoppers may start to feed a little but not be attracted and not call in their swarm of buddies. Some insects seek habitat on your plants but do not feed there. Try to identify and know what you are dealing with so that you don't over-react and can manage appropriately and use biorational methods and materials.  Don

On 1/7/2024 at 6:10 AM, djayz said:

Am away for a few days but my missus has just sent me these photos.

 

The fruit was taken from my Spanish Lisbon lemon tree, which I sprayed with abamectin 2 weeks ago and again last week with wood vinegar. 

 

What are these little red fellas called? Anybody know? 

 

 

I thought you were striving for organic management.  The approach you indicate is contrary to a biological program. Be advised, Abamectin as well as obviously being ineffective, is a harsh chemical pesticide, detering or killing off beneficials (pest predators and parasites, birds, weaver ants, mini-wasps, beneficial bacteria and fungi). It's also a "translaminar" (penetrating systemic) chemical that can penetrate the skin and contaminate your fruit.  A better approach might be to cultivate the micro-biome on plant and fruit tissue surfaces, and to build a favorable environment for beneficials, build soil fertility and natural resistance to pests and diseases. 

On 12/20/2023 at 10:43 PM, Steve910 said:

We've found some land we are looking at which is around 4-6 rai, next door there is a rubber farm around 4 rai which is very well kept. Opposite there is a large mango farm much larger size in rai.

If you have a rubber/mango farm or live near one, are there any considerations you should make before deciding to live next to these types of farms?

Thank you very much.

Conventional/chemical mango orchard management will possibly involve repeated foliar pesticide spraying during mango fruit fly infestation season,unless they are bagging the fruit. Your property could be subject to pesticide spray drift, if that's a concern for you and especially if you are planning on any organic growing for personal use, and/or it could affect organic grower certification if you are going that route. 

Shade from mature orchard trees could affect your bordering property if you are intending to grow veggies, home orchard or field crops.

"Very well kept", what does that mean to you? It could mean heavy herbicide applications for weed control that can leach into ground water or drift into your property and a water pond. Some herbicides (and the surfactants that are mixed with them as adjuvants) can volatilize at over about 26C into a gaseous drift that can pollute nearby water, crops or landscapes.

On 12/26/2023 at 12:49 AM, stupidfarang said:

Hi, am planning on doing a PH test next weekend when we are back in Ranong. The trees are already planted, they cut out the old and replanted, I have no say in what is growen and do not want to upset the family, I will not be sinking much money into the trees and it is not a business I know anything about and my wife has no interest in farming. The wife has been given the 10 rai and we will build a small two bed room house on it which will be rarely used, the family just want her to have a house near the family. I will have a read of the book and see what insights I can gain from it, my plan is minimal looking after the trees as they come with the land, will have someone do all the hard work.

In my opinion a pH test alone is almost worthless, this is a much misunderstood and misused measurement; so you find out he pH is acidic or alkaline, what are you going to do about it?  Conventional soil testing (SLAN system geared to chemical fertilizer inputs) is inappropriate and obsolete in light of the most up-to-date organic land care and regenerative ag science and practices. 

With the questionalble economics of rubber and your non-interest in farming, why put a lot of money into soil testing and Rx amendments?  It takes much more than fertilizer to have a successful plantation, you would need to do a lot of self-study on tree crop management, methods and materials, or maybe decide to just rent or contract out the ag aspect of your land and the rubber production to a neighboring grower. Even intercropping the young rubber plantation with a cash crop will take some farming experience and dedication. 

I had the e-book in my files. Copyright 2014. The author's website is no longer online. 

But the orientation is primarily about nitrogen fixation with legume cover crops. There has been so much more evolved information come out in the last 10 years.

fertilizer_for_free.pdf

On 12/24/2023 at 2:52 AM, stupidfarang said:

I agree about the rubber trees and even palm is being cut down so durian can be planted. Malaysia, Indonesia even China is planting Durian so am sure the price will drop one day. I am in Chumphon which grows a lot of durians, now there are massive warehouses are being built around Sawi and Laung Suan by Chinese and they buy the durian and ship them out. The traditional Thai buyer will be squeezed out. Had looked at pineapple but they take a couple of years to fruit, I want something that will help the soil so am looking at corn so there is a small return until the rubber kicks in, and looking at legumes to help the soil. Am no farmer and I do not want to be one, yet happy to help a wee bit to get the soil in good condition

Mixed species cover cropping. Most beneficial for soil and tree health and least expensive. 

See The Regenerative Agriculture discussion on this forum. 

There is a former member on this forum (2009 -2010 maybe) a permaculture advocate, who wrote a book that I think was available as an e-book "Fertilizer For Free",  about cover cropping. I can't remember his name. I'll look for it.

But the following videos from Dr Christine Jones  (Australian soil microbiologist) are the most up to date with modern science and practices in my opinion.

cover cropping orchards and vineyards

https://youtu.be/PJs8GU1cG30?si=aKmMgXp1oCSDH112

why change

https://youtu.be/SYRpFqUlK78?si=iUJnvKVDJtGt5boK

On 12/18/2023 at 3:56 AM, sidjameson said:

Yes yes, I expected ridicule.

 

This

 

Off to China, where “levels of outdoor air pollution…are among the highest in the world.” By day one, those getting broccoli sprouts were able to get rid of 60 percent more benzene from their bodies. “The key finding…was the observed rapid and highly durable elevation of the detoxification of… a known human carcinogen

 

https://nutritionfacts.org/blog/combating-air-pollution-effects-with-food/#:~:text=Written By Michael Greger M.D. FACLM • July 21%2C 2020&text=Outdoor air pollution may be,%2C stroke%2C and respiratory infection.

 

Its a pity that this topic has been moved to farming forum. I wanted the widest readership because this could potentially save lives.

Keyword "Growing" = Farming or Plants/Pets forum.  Try "Health Benefits of ..." or something like that next time. 

In any case, we all would like a quick fix, a single 'superfood' that makes health and immunity from harm a simple matter.  But in fact achieving health comes from a comprehensive wellness program with many factors to consider. Even the linked article, even though focused on broccoli sprouts as a superfood, points out that public policy and genetics are also important factors in the defense against pollution. Personally I don't like broccoli, but I have some other cruciferous foods and 'superfoods' that I consume, home grown organic high-nutrient-density fruits and veggies, spirulina, moringa, wheat grass, matcha green tea, cloves, and a lesser known 'superfood' - fulvic acid (https://www.manalifelab.com/wu-jin-san), as well as an omnivore diet with minimal added sugar, no maltodextrin, low carbohydrate diet, has helped me maintain health into old-age, along with exercise and qigong, hiking, mtbiking and outdoor work. 

I apply the same 'wellness', preventive approach to the work I do with plants, crops, and landscape turf and ornamentals. No one product or practice fits all, but what works is a comprehensive program considering the growing conditions, soil and water management, species selection for the right plant - right place, integrated and compatible plantings, appropriate irrigation, minimal tillage, mulching, shading of soil surface, cover cropping where possbile, Integrated Pest Management, biologicals for soil and plant health and avoidance of detrimental products and practices like high NPK chemical fertilizers and pesticides as much as possible.  

On 10/7/2014 at 4:32 AM, WtFugarwe said:

I have always considered EM to be pop science. Microbes require oxygen and EM is anerobic. I take about 4 kilos of finished plant based compost in cheesecloth, suspend in a 32 gallon plastic trash can,fil it with water., then suspend the hose of an aquarium pump for aeration i the water. I add molasses to feed the microbes and they reproduce in multiples.

In my opinion this statement is flawed and gives a wrong impression, confusing EM (effective microorganisms) with AACT (actively aerated compost tea) .  

Both of which are cultured for the "microbes" content, but with different combinations of organisms for different purposes. All EM is not created equal, as with compost, compost extract and compost tea.  Both EM and compost derivatives have aerobic and anerobic components. 

Dr Elaine Ingham's Soil Food Web School has the compost/AACT cultivation down to a science with microscope analysis of exactly which organisms are present in the mix and which are desireable or not for soil and plant health. There are many formulas that have come out of this general approach, with bacterial dominant and fungal dominant microbe mixes cultured for specific purposes. 

Dr Higa's original EM formula is what the concept of EM and many EM formula's are based on, and which is primarily a "bio-digester" used for sewage and manure decomp and odor control, to accelerate crop residue and turf thatch decomp, pond water algae control, and other purposes. 

4 minutes ago, ozimoron said:

 

I'm totally on board with using natural methods for anthracnose control. I do think it's probably for smaller orchards up to about 10 acres but more than that might, as you suggest, be a losing battle, especially in humid areas. Like all tree diseases, close mono cropping makes pest and disease control difficult 

Well said! Yes, mono-cropping has its advantages of course, and in fact is considered a necessity for large commercial orchards. But it comes with potential horendous problems. 

Not my thing, I prefer 'in the ground' bio-intensive system. But there are good reasons as stated for raised beds for some folks, if you can afford the higher costs for initial construction and soil imports.  Tons of info with an Internet search: "raised bed vegetable gardening for beginners". 

1 hour ago, ozimoron said:

Some species of mango are more susceptible than others. I owned a commercial mango farm in oz for 15 years. I used to spray mancozeb soon after the fruit set and then copper every 2 weeks.

 

https://industry.nt.gov.au/__data/assets/pdf_file/0005/233591/604.pdf

This is of course a viable conventional approach for commercial growers who are not yet on board with modern ecological farming methods and materials and efforts to adopt practices that are more earth and climate friendly. A losing battle maybe, but some of us think its important to try. 

From your countryman Dr Christine Jones, Australian soil microbiologist (https://amazingcarbon.com/)

cover cropping orchards and vineyards

https://youtu.be/PJs8GU1cG30?si=aKmMgXp1oCSDH112

why change

https://youtu.be/SYRpFqUlK78?si=iUJnvKVDJtGt5boK

First recommendations:

1. Review and improve your watering program for during the dry season. Not too much or too little. Drought-stressed trees will be more susceptible to pests and diseases, decline and die-back. 

https://www.fertileearthlandcare.com/watering-trees/

2. Soil fertility. Avoid high NPK chemical fertilizers. Use biologicals, real compost, vermicompost/worm-castings, aged/composted manures, COF (complete organic fertilizer), hydrolized fish fertilizer, and mulch the soil surface throughout the tree root zone (dripline and more).  This may be practical for small home orchards, but larger commercial orchards must consider costs of inputs and more economical alternatives like well managed mixed-species cover cropping. 

Some examples of local Thailand sources for biologicals: 

COF and Vermicompost

https://www.facebook.com/bestgardenstate/

https://maruchubussan.co.th/product/takumi-organic-fertilizer/

https://maruchubussan.co.th/product/fish-amino-organic-fertilizer/

3. Biocontrols  With good watering and soil restoration practices in place, then biological fungicides and botanicals can be used with greater effectiveness. (They are not a stand-alone substitute for chemical fungicides, they don't work in the same way. They must thought of as components in a comprehensive IPM program.)

Bokashi fertilizer.docx

That's a very thorough paper on Mango Athracnose Disease.  Read the entire article and recognize that its never a good idea to reach first for chemical treatments, cypermethrin or bordeaux mixture or any other quick fix dreams. 

In my professional opinion, based on over 50 years as a tree care professional, as my father before me, that its always best, for any pest or disease problem to look first at the growing conditions, soil and water management to determine why that pest or disease is there in the first place and what you are doing or not doing to create the conditions that make those trees susceptible to biotic and/or abiotic disorders. Because healthy plants grown in heathy soil don't get pests or diseases, and that is a well established scientific and practical truth of IPM (Integrated Pest Management) and the Soil-Food-Web, Regenerative Ag movement.  

"The mango trees are all grafted varieties planted by us..."  Recognize that grafted varieties are usually bred for desireable fruit characteristics and often not so much for resistance to disease. This is a critical factor in IPM. 

Chemical fungicides should not be depended on as a stand-alone, or a long term treatment. IPM considers a much wider viewpoint, especially the environmental and cultural factors that contribute to resistance or susceptibility. If you don't improve the growing conditions and management of watering, soil and plant health, then you are fighting a losing battle.  Also, if you are using high salt index, high NPK chemcial fertilizers, are not mulching and/or cover cropping, then the problems will be exacerbated. And if it's not one thing (MAD), it will be another ("There is also a problem with what I believe to be leaf cutting weevils.") 

From the article: "Alternatives to fungicides have been developed in light of rising awareness of the fungicides’ deleterious effects on human health, the presence of fungicide residues in mango fruits, and the contamination of the natural environment that results from their widespread use. Essential oils, botanicals, and oxalic acid treatments have all been shown to be effective alternatives to chemical control, especially in locations where the use of synthetic fungicides is prohibited. Microbial agents and biological control of the MAD have also broadened developmental prospects for establishing environmentally friendly pest management."

If you are still reaching for chemical treatment as the first response to plant problems, then you are way behind the times with modern plant science and environmental, biological awareness and practical treatment modalities. 

Biologicals 101.pdf

   Start with an on-site assessment from an experienced grower/orchard manager to evaluate current status and available water and other resources. I may be able to help myself or with a referral. PM me.

Structural pruning may be one of the first remedial measures to consider. Cover cropping for soil restoration is another.

cover cropping orchards and vineyards

https://youtu.be/PJs8GU1cG30?si=aKmMgXp1oCSDH112