Effect of ethylene dichloride emulsion on peach trees


Material Information

Effect of ethylene dichloride emulsion on peach trees
Physical Description:
Snapp, Oliver I
United States -- Bureau of Entomology and Plant Quarantine
U.S. Department of Agriculture, Bureau of Entomology and Plant Quarantine ( Washington, D.C )
Publication Date:

Record Information

Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 030285492
oclc - 779489752
System ID:

Full Text

November 1941


By Oliver I. Snapp,
Division of Fruit Insect Investigations

Following the announcement of the ethylene dichloride treatment
for peach borer control, a large number of growers in many parts of the
country have adopted this new method and have used it very successfully
for the control of the peach borer. Literally hundreds of thousands of
peach trees have been treated, and for the most part no damage has occurred.
During 1940, however, the death of considerable numbers of trees and serious
injury to others which occurred in the Middle Appalachian region was attrib-
uted to the use of ethylene dichloride. A careful investigation of the situ-
ation revealed the fact that much of the reported injury was actually caused
by winter conditions. In many cases there was just as much injury in or-
chards not receiving the ethylene dichloride treatment as there was in similar
orchards nearby which had received the chemical. In a very few cases, how-
ever, the emulsion was used at excessive strengths or in other ways not in
accordance with recommendations, and in such cases some of the injury re-
ported was undoubtedly caused by the chemical.

As a result of these reports further investigations are being carried
on by State and Federal workers to determine the conditions under which
injury is most likely to occur. This work is still in progress, and final
conclusions have not yet been reached. However, a brief statement on the
present trend of the results can be made. It appears that the danger of
injury is least in light sandy soils. Experimental treatments with the pure,
undiluted ethylene dichloride caused little or no injury to young and bear-
ing trees in light sandy soils during the season of 1940-41. The narrowest
margin has been found in certain rather heavy types of soils, and there may
be very exceptional types of soil in which the usual treatment may cause
injury. Considerable injury has also developed from the application of doses
in excess of those recommended, to trees in water-logged soil in late fall
at low temperatures. Whether the water-soaked condition of the soil, the
low temperature, or the two together were responsible has not been deter-



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h investigation has emphasized further the need for strict ad-
here e o 3he directions for preparing and applying the material. Before
... applied, special care should be taken to fill with soil any
cracs -o the trunk or close to it. The emulsion should be diluted
e irc ted, and the quantities applied should not be greatly in
c o recommended. The e.ulsion should be a very stable one and
r tly' stirred with a paddle before any is taken out. This
t o the stock emulsion and to the diluted mixture, The material
poured directly on the trunk, but should as far as possible be
appliedJ ;o the soil close to it.