Vol. 15—1961 - NorthEastern Weed Science Society

PRELIMINARY INVESTIGATIONSaP' A GEmmJATIONANDGRO!frHINHIBITOR·
PRODUCED BYYELLOl~ FOXTAIL(SEI'ARIAGLAUCA BEAUV.)l
.
H. C. Yokum, H. W. Jutras, and R· • A. Peters
2
(L.)
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Many workers have shown that species of higher plarits produce chemical
substances which are toxic or inhibitory to other s];)9oie6. Bennett and Bonner (2)
have shown that guayul,e excretes trans-cinnamic acid which is toxio to seedlings
of the same soecies. LeTourneau and Heggeness (6) concluded that a germina- .
tion an~ growth inhibitor in leafy spurge foliage is a basic nitrogen compound.
Bonner (3) mentions that a toxic substance extracted from Encelia leaves
was iden\ified as 3-acetyl-6~etho~benzaldehyde after reorystallization
from ether. Barton and Solt {I} state that toxic substances generally belong
to these groups: essential oils, alkaloids, glucosidea, or ammonia from
nitrogenous compounds.
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As a oart of the Regional NE-42 Cooperative vleed Control 'Proj.ect 3, this
study was begun to determine the possible occurrence of a germination and
growth inhibitor in Setaria I!lauca. a prevalent grassy weed. The experimental .
evidenoe indicateri that foxtail produces a germination and growth inhibitor (s) It
Further studies were made to characterize the inhibitor.
METHODSANDRESULTS
The ~ffect of Fax:tail Extraction on Germination and Root Growth
The yellow foxtaU used in this study was either collected from the
Agronomy Researoh Farm or grown in the greenhouse. The plants were dried in
a forced air drier at 60-6,oC for 24 hours and ground to pass a 40-~esh screen
in a v-riley mill. Extractions of dry plants was accomplished by adding five
grams of the ground material to 100 ml., of distilled water. This mixture
was autoolaved for 10 minutes at 15 pounds pressure (260 oF) and then filtered
on a Buckner funnel. Four ml., aliquots of the filtrate ",rere transferred to
cotton st oooered test tubes and autoclaved for 10 minutes at 15 pounds pressure
(2600F).
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1 Contribution "from the Storrs (Conn.) Agricultural Experiment Station,
Storrs, Conn. . .
2 Research Assistant, Graduate Assistant, and Associate Agronomist, reSP8ctAvely,
Storrs (Conn.)
3 'If.TeedLife Cycles, Soill.ficroorganisms and Light as 'Factors in the Control
of Heeds in the Northea.st.