The European Union has banned tebuconazole as of 2018. http://digitaljournal.com/article/265134 ---------------------------------- Apparently the reason for the ban is: "Due to the potential for endocrine disrupting effects, tebuconazole was assessed by the Swedish Chemicals Agency [3] as being potentially removed from the market by EU regulation 1107/2009.[4]" http://en.wikipedia.org/wiki/Tebuconazole --------------------------- Journal: Toxicol Appl Pharmacol. 2012 Feb 17. [Epub ahead of print] Title: The fungicide mancozeb induces toxic effects on mammalian granulosa cells. Authors: Paro R, Tiboni GM, Buccione R, Rossi G, Cellini V, Canipari R, Cecconi S. Authors affiliation: Department of Health Sciences, University of L'Aquila, Via Vetoio, L'Aquila, Italy. Abstract: "The ethylene-bis-dithiocarbamate mancozeb is a widely used fungicide with low reported toxicity in mammals. In mice, mancozeb induces embryo apoptosis, affects oocyte meiotic spindle morphology and impairs fertilization rate even when used at very low concentrations. We evaluated the toxic effects of mancozeb on the mouse and human ovarian somatic granulosa cells. We examined the parameters such as cell morphology, induction of apoptosis, and p53 expression levels. Mouse granulosa cells exposed to mancozeb underwent a time- and dose-dependent modification of their morphology, and acquired the ability to migrate but not to proliferate. The expression level of p53, in terms of mRNA and protein content, decreased significantly in comparison with unexposed cells, but no change in apoptosis was recorded. Toxic effects could be attributed, at least in part, to the presence of ethylenthiourea (ETU), the main mancozeb catabolite, which was found in culture medium. Human granulosa cells also showed dose-dependent morphological changes and reduced p53 expression levels after exposure to mancozeb. Altogether, these results indicate that mancozeb affects the somatic cells of the mammalian ovarian follicles by inducing a premalignant-like status, and that such damage occurs to the same extent in both mouse and human GC. These results further substantiate the concept that mancozeb should be regarded as a reproductive toxicant." H. Kuska comment: Are there any medical Doctors in the house? Here is a link that might be useful: New Mancozeb research

There seem to be a lot of chemists on this thread, so hopefully one of you can check my thinking here: Peracetic acid is created in large amounts by mixing concentrated H202 with concentrated acetic acid. But in the final dilution, there should be an equilibrium between the three compounds (H202, acetic acid, peracetic acid), in which peracetic acid is only present in small concentrations. However, peracetic acid reacts very rapidly, and the equilibrium provides a constant source of it as it is used up, making it effective even though it's only barely present. If this is case, shouldn't dilute vinegar and dilute hydrogen peroxide provide an almost identical product, if used immediately? The addition of a compatible surfactant, which seems to include common spreader-stickers and SLS, would bring it even closer. As far as I'm aware, acetic acid doesn't have any significant signaling effects on plants. Conveniently, salicylic acid is compatible with hydrogen peroxide - it's used as an aromatic stabilizer in cleaning formulas. I've long used hydrogen peroxide as a foliar "disinfectant" for ectoparasitic fungi and some bacterial diseases. It works - the main downside is the frequency of application, which is reflected in some of the studies linked above. Even full strength drugstore peroxide, 3%, doesn't seem to harm most plants as long as a small amount of spreader-sticker or surfactant is included to keep the drops from collecting/concentrated in small areas. It's pretty much equivalent to dilute bleach in this application, but without the hazards of applying sodium and chloride ions to leaves. I can't see the full paper linked in the original post - for those who have read it, how big was the difference between the treated and control? Often flat effectiveness is reported even when the actual effect size is very small.

Moril: I appreciate your raising question about how much nitrogen tree bark robs compared to others. There's this government website http://www.fpl.fs.fed.us/documnts/fplrn/fplrn091.pdf which makes a big issue out of tree bark and nitrogen deficiency by suggesting addition of 25 ammonia, or 80 lb. of urea, or 100 lbs. of ammonium nitrate or ammonium sulfate. On the other hand, there's this Colorado University Extension that says tree bark doesn't rob the soil that much nitrogen, since it's a very slow decomposition. Then there's another University Extension that recommends stable owners to add nitrogen to their horse manure mixed with hay, so that they can get rid of their manure easier to the farmers. My take: Horse manure on hay breaks down faster that big chunk of tree bark, so nitrogen deficiency is more of an urgent issue with aged horse manure. My main concern with tree bark is NOT the nitrogen issue (I have to supplement NO MATTER what with my poor-nitrogen alkaline clay). My concern is the fungus issue. Check out this website from Pen. State University: http://www.personal.psu.edu/users/d/d/ddd2/ The above links is about artillery fungus on decayed wood bark that gets on white cars parked nearby. That's the same concern that the British paper wrote about tree bark mulch contributing to blackspot in roses. I take www.greenharvest.com recommendations of using number choice 1) oat straw and 2) pine park with a grain of salt: I used pine bark in the past with my 15 roses and had the worst blackspot, despite chemical spray. This website makes a good point about potassium deficiency as making the rose more prone to blackspot.

Hi Kitty: I'm glad to hear that you get great result in using charcoal pieces to enrich your soil. I found the table of chemical composition for woodash versus limestone, thanks to Kimmsr in the Soil Forum. Here's an excerpt from the link below: http://hubcap.clemson.edu/~blpprt/bestwoodash.html Table 1. Range in elemental composition of industrial wood ash samples and ground limestone. Wood Ash ******** Limestone Conc. in % Calcium 15 ******** 31 Potassium 2.6 ******* 0.13 Aluminum 1.6 ******* 0.25 Magnesium 1.0 ******* 5.1 Iron 0.84 ******** 0.29 Phosphorus 0.53 ***** 0.06 Manganese 0.41 ******* 0.05 Sodium 0.19 ****** 0.07 Nitrogen 0.15 ******* 0.01 Microelements Concentration in mg/kg Wood Ash ****** Limestone Arsenic 6 Boron 123 Cadmium 3 ***** 0.7 Chromium 57 ***** 6.0 Copper 70 ***** 10 Lead 65 ***** 55 Mercury 1.9 Molybdenum 19 Nickel 20 **** 20 Selenium 0.9 Zinc 233 **** 113 Other Chemical Properties CaCO3 Equivalent 43% (woodash) 100% for limestone pH woodash is 10.4 versus pH of limestone is 9.9 Woodash is high in calcium, potassium, zinc, chromium, and all trace elements . Woodash also contains 123 mg/kg of Boron, which is vital for plant growth. Boron is less available in alkaline clay. My soil in Chicagoland is dolomitic/limestone alkaline clay. Woodash has 70 mg/kg of copper, a fungicide in Bordeux mixture. It has 233 mg/kg of zinc (compared to 113 in limestone) a fungicide fraction in Mancozeb spray. It has boron, another fungicide for dry rot. It has 65 mg of lead, compared to 55 mg of lead in limestone, also a fungicide. Finally woodash has 57 mg of chromium, another fungicide, here's a quote: "In the past, chromium was also used in cooling towers as a rust and corrosion inhibitor and as a fungicide. " http://corrosion-doctors.org/Elements-Toxic/Chromium.htm Here is a link that might be useful: Clemson.edu on wood ash This post was edited by Strawberryhill on Wed, Jan 15, 14 at 19:44