Vol. 15—1961 - NorthEastern Weed Science Society

320.
growing season in the 1957-59 study, fall treatments were not included in
the 1959~60 experiment.
The experimental design of the treatments applied was a 3 x 6 splitplot
factorial as fo,Hows:
~1hole plots---Cultural treatments
A - Plow
B - Fallow '
C- .~ cultivation
r.' Split plots---bhemical treatments'
1 - Atrazine
2 - Stmazine
3 - /.mitrol-1
4 - Penac
5 - Dalapon
6 - No herbicide
All possible combinations of the treatments were replicated four times,
makings total of 12 plots •.
. The herbicides Were all applied on May 16, 1959 at the rate of eight
Ibs. per acre in 30 gallons of water. All plots except those which were to
receive no cultural treatment were plowed on June 2, 1959. The plots to be
fallowed were disked or harrowed with a spring-tooth harrow frequently during
the growing season to prevent growth and photosythesis.
" Samplesofquackgraas rhizomes were taken periodically for laboratory
analysis according to the folloWing schedule:
June IS, 1959
Auaust 5, 1959
·September 10, 1959
November 10,1959
Hay 10, 1960
A steel cylinder having an area of one square foot was used to obtain
the samples •. An area in each plot which had not been previously sampled
W4S selected at random and all weeds and topgrowth of quackgrass was removed.
The cylinder having sides constructed of 3/8 inch thick steel and 12 inches
high, with a one inch steel plate top, was placed over this area and pounded
into the soil to a depth sufficient to obtain all rhizomes. After all soil
and foreign material were removed, the clean rhizomes from each plo'twer,e .
placed in a paper bag and dried in a forced"'alr oven at 70· C. After drying.
the rhizomes were weighed, ground and stored in airtight bottles until
analysis' was to be made. They were then redried, mixed thoroughly and
analyzed for carbohydrate content.
The procedure used in the quantitative determinations of carbohydrate
was the same as preViously reported for the 1957·59 experiment ( 1 ).
which was bas&d!on a colored compound formed by the interaction of~f!ucto~e
and resorcinol.