Subject: Electrolyzed water, current research in Crop Protection journal

From: Steve Diver <[email-masked]>
Date: Wed, 23 Jul 2003 13:36:47 -0500

A while back electrolyzed water was posted to SANET
as a technology used in Japan for use as a disinfectant around
food and medical facilities and for plant pathogenic disease
control in agriculture. The postings from Keishi Matsumura
and Hugh Lovel were especially interesting.

Since organic farmers have limited product options to control
insect and disease pests, the appearance of electrolyzed
water technology to control foliar diseases seems noteworthy.

The paper below is the first I've seen based on research
into electrolyzed water in the U.S.

Researchers at University of Georgia evalutated acidic
electrolyzed oxidizing water (EO) for any phyotoxic effects
on bedding plants, thus achieving some assurance that
greenhouse growers can at least use the technology
without burning plant leaves.

The equipment, the Hoshizaki ROX-20TA water generator, was
obtained from Hoshizaki America, located in Peachtree City,
Georgia

Here is the citation and abstract, with a couple of interesting
excerpts that explain the technology in a nutshell. In addition,
I have selected references which point to relevant research on
EO water as a disinfectant and disease control method.

Regards,

Steve Diver
NCAT / ATTRA

=============================================

Evaluation of acidic electrolyzed water for phytotoxic symptoms
on foliage and flowers of bedding plants
Crop Protection
Volume 22, Issue 1 , February 2003, Pages 73-77
J. W. Buck, M. W. van Iersel, R. D. Oetting and Y.C. Hung
doi:10.1016/S0261-2194(02)00113-8

Abstract:

Acidic electrolyzed oxidizing (EO) water quickly kills a variety of fungi
and shows promise as a broad-spectrum contact fungicide for control
of foliar diseases of greenhouse-grown ornamentals. One requirement
for use in the greenhouse is that EO water will not cause excessive
phytotoxic symptoms on a wide variety of species. In one experiment,
two applications of EO water did not damage 15 species of bedding
plants. In a second experiment, EO water applied as a foliar spray three
times per week for 4 7 weeks did not produce any visible
phytoxicity on seven of the 12 species tested. Small, white spots
were observed on flowers of geranium (Pelargonium x hortorum),
impatiens (Impatiens walleriana), and vinca (Catharanthus roseus).
Slight necrosis was observed on some leaf edges of petunia
(Petunia x hybrida), and snapdragon (Antirrhinum majus).
EO water generated from magnesium chloride produced more
phytotoxicity than EO water generated by potassium chloride
or sodium chloride. Phytotoxicity ratings of greater than
3 (0 10 scale) were not observed on any of the species tested.
EO water caused slight damage to some plant species but,
in general, appears to be safe to use as a foliar spray on
a wide variety of bedding plants grown under greenhouse
conditions.

Author Keywords: Alternative control; Disease;
Disinfectant; Ornamentals

Excerpts:

"Acidic electrolyzed oxidizing (EO) water has recently gained
attention from the food industry as a non-thermal method for
sanitation (Kim et al., 2000a). EO water is generated by
electrolysis of a dilute solution of sodium chloride in an
electrolysis chamber where anode and cathode electrodes are
separated by a non-selective membrane ( Kim et al., 2000b).
Water collected from the anode (EO water) has unique properties
such as high oxidation reduction potential, low pH, presence
of hypochlorous acid, and strong bactericidal ( Kim et al.,
2000a; Venkitanarayanan et al., 1999a) and fungicidal
( Buck et al., 2002) activity. This activity could facilitate
the use of EO water as a contact fungicide on aerial plant
surfaces."

"EO water reduced lesion development by Botrytis cinerea on geranium
leaf disks (Buck et al., 2002) and eliminated powdery mildew on
gerbera daisy (Gerbera jamesonii) when sprayed three times a week
in preliminary trials (Buck et al., unpublished). Application of
EO water to peach fruit delayed disease development of brown rot
by the fungus Monilinia fructicola (Al-Haq et al., 2001). The
water has been demonstrated to sanitize food preparation surfaces
and hospital equipment ( Kim et al., 2000a; Venkitanarayanan
and Venkitanarayanan) and therefore could be a safe alternative
to fungicides. However, EO water contains free-chlorine, which
can be phytotoxic to plants and damage plant tissue
( Grech and Rijkenberg, 1992; Schubert et al., 1995)."

Selected References

Al-Haq et al (2001). M.I. Al-Haq, Y. Seo, S. Oshita and Y.
Kawagoe, Fungicidal effectiveness of electrolyzed oxidizing water
on postharvest brown rot of peach. HortSci. 36 (2001), p. 1310.

Buck et al (2002). J.W. Buck, M.W. van Iersel, R. Oetting and
Y.-C. Hung , In vitro fungicidal activity of acidic electrolyzed
oxidizing water. Plant Dis. 86 (2002), pp. 278 281.

Grech and Rijkenberg (1992). N.M. Grech and F.H.J. Rijkenberg,
Injection of electrolytically generated chlorine into citrus
microirrigation systems for the control of certain waterborne
root pathogens. Plant Dis. 76 (1992), pp. 457 461.

Kim et al (2000a). C. Kim, Y.-C. Hung and R.E. Brackett ,
Efficacy of electrolyzed oxidizing (EO) and chemically modified
water on different types of foodborne pathogens. Int. J. Food
Microbiol. 61 (2000), pp. 199 207.

Kim et al (2000b). C. Kim, Y.-C. Hung and R.E. Brackett ,
Rules of oxidation reduction potential in electrolyzed oxidizing
and chemically modified water for the inactivation of food-related
pathogens. J. Food Prot. 63 (2000), pp. 19 24.

Venkitanarayanan et al (1999a). K.S. Venkitanarayanan, G.O.
Ezeike, Y.-C. Hung and M.P. Doyle , Efficacy of electrolyzed
oxidizing water for inactivating Escherichia coli O157:H7,
Salmonella enteritidis, and Listeria monocytogenes. Appl.
Environ. Microbiol. 65 (1999), pp. 4276 4279.

Venkitanarayanan et al (1999b). K.S. Venkitanarayanan, G.O. Ezeike,
Y.-C. Hung and M.P. Doyle , Inactivation of E. coli O157:H7 and
Listeria monocytogenes on plastic kitchen cutting boards by
electrolyzed oxidizing water. J. Food Prot. 62 (1999), pp. 857 860.
=============================================
=============================================

********************************************************

To unsubscribe from SANET-MG:
1- Visit http://lists.sare.org/archives/sanet-mg.html and unsubscribe by typing in your e-mail address or;
2- Send a message to <[email-masked]> from the address subscribed to the list. Type "unsubscribe sanet-mg" in the body of the message.

Visit the SANET-MG archives at: http://lists.sare.org/archives/sanet-mg.html