International Society of Arboriculture

         "The Legend of The Texas Bluebonnet"  -  The Devils' Cigar


Global Forests -
Little Known or Interesting Factoids About Trees and Tree Physiology

Contact:  Cell: 830.257.8871
                     Jim Rediker - Nurseryman -  Arborist  - TDA Certified
e mail:



Our Services and All We Do


Photo Gallery

Very Special Trees 
My Tree Live Oak Tree

My Tree
The following letters are also posted on the web site of The Vista Verde Community Association, Vista Verde CA. 

E-Mail Letter From: Dr. Cindy Russell, M.D. October 16, 2007

Dear Amanda and Woods/Vista Verde neighbors:

FYI. Just want to alert you to the potential dangers of Pentra-Bark (used with Agri-Fos) prior to the mass spraying which will soon occur for sudden oak death in our neighborhood (early Nov) Beware! Please take precautions! ! References at the end.

Pentra-Bark is comprised mostly of alkyphenol ethoxylates (APE's) which are a family of "inert" surfactants used in pesticides to increase the amount of spray solution that remains on the surface. It makes the solution sticky. It is widely used in pesticides. These chemicals are related to and breakdown into nonylphenol ethoxylates. Nonyl phenol is classified by the EPA as an "inert of toxicologic concern". Nony phenol is also an "inert" ingredient in many pesticides and is not listed as it is considered "proprietary" . It is not "Non Toxic".

Adverse effects of Nonyl phenol which is in the mix of APE's and is the breakdown product of alkyl phenol ethoxylates:

1) It is acutely toxic to humans- Exposure may cause respiratory problems-wheezing, coughing, headache, nausea. Skin exposure causes irritation.

2) It is acutely toxic to a wide variety of animals: bees, spiders, fish, molluscs. Canadian study of forest application of nonyl phenol alone showed 4 fold increase in mortality of honey bees and 4 fold increase in mortality of spiders (our outdoor pest control service). The Canadian study also showed that the nonyl phenol "inert" ingredient was more toxic to fish than the pesticide used to kill spuce budworm.

3) It bioaccumulates in aquatic organisms.

4) Causes breast cancer cells to proliferate. Although it is not known to be carcinogenic it is an endocrine disruptor- mimics estrogen and has been shown to stimulate the growth of breast cancer cells. Well documented in literature and in great book "Our Stolen Future" by Colburn, Meyers, Vom Saal. Recent environmental health research focusing on these and other endocrine disruptors we are commonly exposed to.

5) Causes reproductive problems in laboratory animals.

6) Has been shown to persist in soil for up to a year. Although breakdown rates vary with climate most breaks down in 1-2 months.

Thanks for your consideration. Use carefully and sparingly if you do use it. Use protective gear- gloves/ masks/ protective clothing as I am sure you have been advised. Some references below.

Cindy Russell, M.D.


1) Our Stolen Future- Colburn. Meyers, Vom Saal-- Easy, informative
detective read about the wildlife studies leading up to the discovery
of endocrine disruptors in our environment.

2) White,R. et al. 1994 Environmentally persistent alkylphenolic
compounds are estrogenic. Endocrinology. 135(1);175-182

3) Ahel,M 1994. Behavior of alkylphenol polyethoxylate surfactants in
the aquatic environment: Ocurren ce and transformation in sewage
treatment. Water Research 28(5):1131-1142

4) Bicknell, R. 1995. Oestrogenic activity of an environmentally
persistent alkylphenol in the reproductive tract but not in the brain
of rodents. J. Steroid Biochem. Molec. Biol. 54(1/2):7-9.

5) Naylor,C.G. et al 1992 Alkylphenol ethoxylates in the environment.
J. Amer. Oil Chem. Soc. 69(7);695-703

6) Sundaram,K.M. et al 1980. Residues of nonyl phenol in spruce
foliage, forest soil, stream water and sediment after its aerial
application. J Environ. Sci. Health, B 15(4):403-419.

7) Northwest Coalition for Alternatives to Pesticides. Journal of
Pesticide Reform- Spring 1996. Vol.16. No 1. www.PESTICIDE. org

 From Dr. Matteo Garbelotto, Forest Pathologist and Mycologist, UC Berkeley October 20, 2007:

The assumption (in Dr. Cindy Russell's email ) is that massive spraying will occur, which is not the case.  Treatments are focused on individual trees and the bark applications are not broadcasted but basically carefully applied on individual trees.

Fueling a car is a lot more dangerous than an appropriate application of Pentrabark from an environmental perspective.  Because the product sticks on the target surface, it is extremely difficult for it to get into the environment.

The email I was sent takes the treatments out of context, however we will dedicate an equal amount of time to injections that do not require Pentrabark.

I hope this helps.

MY WORD  Jim Rediker 

First read  Dr. Cindy Russell's letter again..... she might be like someone you know in your area, that cares about you, your friends and YOUR NEIGHBORHOOD.

Agri-Fos and Pertra-Bark are listed as pesticides and carry the CAUTION statement on the respective labels.

My personal observation is just this; The Intent of Dr. Russell's letter is to alert her friends and neighbors regarding the potential risk hazards and potential toxicity of Pentra-Bark; using pesticides and just as important to take all the necessary precautions when making the applications to protect oneself and the environment. Typically in the fall and spring, spraying the trunk applications gets into full swing throughout their neighborhood. I would interpret her statement regarding massive spraying, just as there are a lot of people, homeowners and commercial applicators in the neighborhood, spraying a lot of individual trees trunks and not spraying the surroundings of every home or some type of aerial spraying covering the entire neighborhood. It was a responsible warning and let face it, it is human nature to take short cuts and rightly so, ignore to read all the label caution statements or heed to take proper steps to protect ourselves.

Once the product is applied to the trees; it then becomes part of the environment and all those trees are part of the habitat of small animals; squirrels, mice, birds, frogs, lizards, bees, spiders, other beneficial insects and microorganisms within those small ecosystem of every back yard. Pesticides which are sprayed can become airborne and eventually end up in soil or water and can percolate through the soil into the groundwater, a major source of our drinking water. The degradation process of pesticides, can sometimes produce more toxic products.

And Dr. Garbelotto's analogy of the gas fill up... well .. that statement tells me that he is very much aware of the Pentra-Bark potential toxicity.... so lets change the subject, brush it off and avoid any scientific explanation, compare oranges to apples and what to heck, lets go for a little ride; all those gas fumes slowly exposes the atmosphere with other pollutants, we so commonly know about, but usually ignore..

There is some good news here, Dr. Matteo Garbelotto is going to dedicate more time to illustrate the injection procedures that does not require the inclusion of Pentra-Bark. Now, that is a good environmental move! 

The contents of Dr. Russell's letter is to alert the reader and bring to their attentions, information about the active ingredient in this products, the potential risks and use of any pesticide, which are well documented and can be found by any search engine on the web. Dr. Russell makes verifiable references as her source material and all these references ready available and verified on the web, as it is public information and well researched and documented by independent research facilities.

With regards to Sudden Oak Death articles describing treatment protocols; the most often mention of ecological risk assessment or product safety; Potassium Phosphite is the one product most often described excluding any mention of Pentra-Bark, that which is applied with Potassium Phosphite. Is there a justifiable reason for this deliberate exclusion !

How safe are phosphites? A potential for exposure exists to nontarget insects, fish, and other wildlife with foliar spray applications. However, test results indicate that the compound is practically nontoxic to birds and freshwater fish, and, at most, slightly toxic to aquatic invertebrates. Low toxicity, the proposed rate of application, and mitigating label language present minimal to nonexistent risk to wildlife.

" Can We Say The Same Thing For Pentra-Bark  .......  and what about all those  'inert"  ingredients?"

Of all the articles I have read in the last year and a half on Sudden Oak Death, I came across this one very obscure caution statement:  Caution:  Potassium Phosphite is relatively benign, but the Pentra-Bark compound it is typically mixed with, can irritate the lungs and the skin as well as cause nausea and head aches. Avoid "over spray" and heed the Manufacturer's Instructions on handling the product and wearing protective equipment. 

Can someone tell me why, Pentra-Bark is usually excluded from these "ECOLOGICAL RISK ASSESSMENT" in all these articles written about Sudden Oak Death? ..... It is a pesticide !!

The eco-risk assessments are usually described in this typical manner for the majority articles on S O D

The new treatment for SOD is a phosphate compound, sold under the brand name of Agri-Fos. This compound can be injected into the tree’s vascular system by a trained professional, or it can be applied topically to the bark of the tree when combined with organosilicate, brand name Pentra-Bark. The treatment is only approved for use on Coast Live Oak, Black Oak, Shreve Oak, Canyon Live Oak and Tanoak. Phosphites have been used for more than ten years on other Phytophora species with numerous commercial agricultural applications. It is considered a low-toxicity chemical and the method of application, the injection and bark spray, are targeted so that the chemical is not dispersed into surrounding areas.

Lets face it: Pesticides should always be treated with CAUTION as indicated on the Manufacturer's Label

 PESTICIDE FACTS and much much more.   

“RATE” (Real Alternatives to Toxins in the Environment) P.O. Box 25188,  Halifax, NS.Canada.  Pesticide Facts - 

Pesticide Action Network of North America -

Corporate Watch

One more thought: Chemical companies produce pesticides and the bi-products are hazardous waste. One would believe that these hazardous by-products should be properly disposed of in a hazardous waste dump. Your Environment, Your Home and Surroundings are just that hazardous waste dump. Hazardous waste is legally recycled back into the pesticides and LABELED “INERT” This is not something you want to put on your garden, or around your home, yet that is where pesticide manufacturers intend to put it, It has got to be dumped somewhere and it is with sanctions and the blessing of state and federal environmental agencies. These finding are documented and supported by the US. Federal Government, private agencies, and other experts.   

NOW LET'S SEE BILL STRINGFELLOW'S  PERSPECTIVE:    Pentra-Bark - Toxicity   Go To Page 2 

I must say I got a much different prespective from his e mail than I would have gotten from a direct personal interview. I could only imagine that the conversation would be very, very loud !

There is a lot of information available on the web regarding PESTICIDES,  use your search engine or visit our Related Links                                                                                                                                                      ,2933,89913,00.html

Disclaimer: This article may contain pesticide recommendations that are subject to change at any time. These recommendations are provided only as a guide. It is always the pesticide applicator’s responsibility, by law, to read and follow all current label directions for the specific pesticide being used. If any information in these recommendations disagrees with the label, the recommendation must be disregarded. No endorsement is intended for products mentioned, nor is criticism meant for products not mentioned. The Writer assumes no liability resulting from the use of these recommendations. The information given herein is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement is implied.


Contact: cell: 830.257.8871
                     Jim Rediker - Nurseryman -  Arborist  - TDA Certified

Home | Company | Services | Information Desk | Products | Info Request | Related Links | Contact
Jim Rediker - Experienced Arborist, TDA Certified - Licensed Nurseryman - TDA Licensed Applicator Consultant
Member: ISA,  Member: Better Business Bureau,  Free Estimates,  Insured & Bonded,  Cell:  830.257.8871
©Copyright 2012 Scenic Hills Nursery.  All Rights Reserved     Disclaimer
Maintained by the CYBERRANCH


Please use our icon to link to this site.