"Growth of corn roots under low-input and conventional systems," by
Eric Pallant and several colleagues appears in the latest issue of the
"Journal of Alternative Agriculture." (Vol. 12, No. 4). It documents that
corn root systems develop more fully under sus. ag systems, compared to
conventional systems. As a result, corn yields tend to be higher on
average, especially during years when there is some drought or nutient
stress. The reason -- fuller root systems are more efficient in extracting
from the soil whatever moisture/nutrients are available. Moreover, the team
found some of the differences between systems to be surprisingly
significant, e.g. root density under low-input/animal systems on July 6 were
5.51 (cm root/cubic cm soil), compared to 2.99 in the conventional corn/corn
system.
A second useful article appears in "Plant Disease," the journal of
the American Phtyopathological Society. There is a press release on it
dated 2/17/98 from APS, "Phase Out Planned for One of Top Five U.S.
Pesticides, Plant Doctors Respond" --
http://www.scisoc.org/opae/media/methyl.htm
An Abobe Acrobat version of the full article is free and prints very
nicely. It is entitled "Agriculture, Methyl Bromide, and the Ozone Hole:
Can We Fill the Gaps", by Dr. Jean Beagle Ristaino, Dept. Plant Path, UNC
and Mr. William Thomas, U.S. EPA, appears in the "Plant Disease" (Vol. 81,
No. 9, pages 964-977) -- http://www.scisoc.org/feature/2-98_mb/top.html
Click on "DOWNLOAD..."
full article on left margin.
The press release says the methyl bromide phase out "...leaves the
ag industry in a
transitional situation, looking for alternatives." In response, plant
pathologists are "working hard...the phase out of m.b. has stimulated a
great deal of creative research..." The release lists 6 categories of
"promising
tactics."
The full article is an excellent, up to date summary of the
mechanism of ozone depletion, the history of the issue, m.b. use, trade
issues, etc. Some of the direct comments on the key question -- are
there/will there be alternatives? -- follow.
"...it is clear from most research to date that a single alternative
fumigant will not be found..."
"Use of a diversity of approaches of management practices that
include less dependence on single-chemical strategies and greater use of
biological and cultural management strategies could enhance grower options."
"Clearly, some cost-effective alternative soil fumigants will be
available by the 2001 phaseout date (Table 3). The best long-term solution
for strawberry producers will be the development of resistant varieties,
crop rotations, planting of pathogen-free planting materials, and judicious
use of low-risk pesticides."
[Good discussion of the impact of m.b. on soil microbial
communities, beneficial nematodes, disease suppressive soils, etc]
"A number of creative, ecologically based approaches to disease and
pest management have emerged from the debate over m.b. use that may not have
been developed without the impending loss of this compound." [Ditto, OPs, IMHO]
The APS m.b. article is the APSNet feature of the month, and can be
downloaded for free for the time being.
chuck
Charles Benbrook 208-263-5236 (voice)
Benbrook Consulting Services 208-263-7342 (fax)
5085 Upper Pack River Road benbrook@hillnet.com [e-mail]
Sandpoint, Idaho 83864 http://www.pmac.net
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