Organic Controls of the Ambrosia Beetle  

The Polyphagous shot hole borer (PSHB)-Ambrosia Beetle and a fungus (Fusarium sp.) are what we are dealing with here.

The long term prevention is to get the Brix level of the tree to it's maximum .Keeping in mind that the higher the Brix level, the Higher the Mineral, higher Carbohydrates. The over all protective ingredient is the high Carbohydrates which will keep the Beetle from succeeding in this process. The fungus will not grow if the mineral levels and carbohydrate levels are high enough. It is important to use natural sources of these minerals and not to attempt to be a chemist and supply it directly as this will lead up over use and it will kill the tree!

When checking for Brix level use the leaves and or flowers of the tree. Measure the Brix level of the tree and not of the fruit or juice!

Here are some Organic Controls that can be applied to the tree to kill the Beetle and to prevent the fungus from growing. These will kill the beetle on contact.

Caffeine

Caffeine can be applied in several ways. If you only have a few trees, you can use this method: Place 3 tree vents around base of tree apprx 3 feet out from trunk. A tree vent is what i call it but it is really either a clay drain pipe 4 inches wide or a simple pvp pipe 4 inches wide and 18 inches long. Put a grate on top. Place a drip line around the truck so that you can place a 1 gallon per hour drip head on top of the vent. Inside the vent place the following mixture:

1 part tobacco

1 part compost

1 part rock dust

1 part organic tree fertilizer

1 part microbes 

mix well and place approx. 1 lb in each vent. replace every 6 months. This mixture will not only kill any pests attacking the tree but will also act as a preventative.

Garlic

1 part garlic can be added to the above mix to really make it effective esp if you think it has the beetle already. Garlic can also be planted at base of the tree for control. This will also destroy the fungus on contact.

OrangeTKO

This is an organic product that will kill the beetle and destroy the fungus on contact. You can make a mixture by adding 1 part Mineral oil and 1 part OTKO. Use straight. Should be painted onto the areas that show the small hole bored. Should be done once a month as needed.

Here are some foliar applications that will raise the Brix levels of your trees:

Compost tea

Rock Dust tea

A good microbial spray like Superseaweed, Nitron A-35, or Agrigro. Google em.

All of the above will slowly raise the Brix levels of any plant. Best done during late spring or early summer. Compost tea will also provide a sort of inoculation against most fungus.

Never spray with a chemical fertilizer. Sure it will raise the Brix temporarily but then it will drop lower then before!

There are many excellent organic fertilizers available which also have all the needed micros.

To avoid stressing out the tree, regularly apply rock dust, compost and mulch. Avoid over watering.

Happy growing Organically of course1

Any questions? Email me andy@invisiblegardener.com response next article

 Andy Lopez

Invisible Gardener