Vol. 15—1961 - NorthEastern Weed Science Society

180.
Post-HillChemiGal Wee4 Contr~~ in Potatoes with Granular Formu­
. . lations ...:.hy Arthur Hawkins ./ 1 . '
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Comparis~ns were made of several granular formulations of chemicals
applied on the day of final cultivation in a field of Katahdin
potatoes where a heavY crabgrass population was expected and
occurred later. ..
Materials and Methods
Granular materials lis~ed in Table 1 were applied on July 1,1960
within three hours after the final cultivation to Katahdin potatoes.
A cyclone seeder 2 1 was used to apply Alanap and Falone on plots 4
rows x 100 feet. The other materials were broadcast from a paper
bag by hand on plots 3 rows wide and 24 feet long. Three or four
row checks were left to either side of each treatment. No provision
was.made to brush granules off plants. The soil was moist at the
time of application, 1" :frain had ocuurred the two previous evenings..
On the 'evening o.f>July 1, there was 1.3" of rain: 2i"
occurred on JUly 14; 1.4 u fell on July 27.
Results
and Discussi')n
.< •
Effect of Materials on Potatoes - Considerable damage to potato
leaves and stalks occurred from DNBPgranules which remained on the
pl~nts. Seve);'e'damage occurred to the base of some stalks where
gr~ntiles had accumulated at the soil line.
Leaves of potatoes treated with Alanap showed 2-4-D type injury within-a
few days after treatment. Potatoes on falone treated plots
showed the same type of injury but to a lesser degree, see Table 1.
Leaf absorption had occurred since granules were not brushed off the
foliage. At another location where granules of Falone were not brushed
off some leaf injury·-was noted within two days after application,
no rainfall having occurred. This sYmptom persisted into early
August probably as a result of the leaching rains.
Randox T injtiry~noted shortly after treatment, became 'increasingly
severe by August 1, and,persisted throughout the season. Esteron
caused severe injury •.
~!fe£t on Weedi - A high. population of crabgrass occurred where not
controlled and grew rapi~y late in August and early September. Weed
control was rated early in the season and on Sept. 15, see Table 1.
Falone at 4 lbs. per acre gave good control of grass; it was also
superior to Alanap at another location. Randox, Zytron and Vegedex
gave very promising results especially at the higher rates at this and
a~ anot.her location. Dalapon gave good controll
.
Yie~ds were obtained only on plots of those treatments which did not
seribusly injure potat~es and where sprayer wheels had not passed.
The yields Bre for only a few treatments and on only single plots.
1/ Agronomist and Extension Potato Spec.,Univ. of Conn~,Storrs,Conn.
21George O'Brien
and P.W. Bohne, Naugatuck Chem. Co., cooperating.