-6 
Similar use of a dust • r 'ing only 2 percent of a com- 
mixture of di- and tri-methyl naphthalenes) on an 
outside row in the same cucumber planting apparently caused no inj\ 
to the- plants. Is of marketable Palmetto cucumbers, a recent, 
developed mildew-resistant var e reduced by 64 percent and 
se of the S.C. 5 breeding 1 63 percent. The purified, but not 
Impregnated, 3 -percent DDT dust caused slight chlorosis in some S.C. 5 
:its and moderate chlorosis in some Palmetto plants I third appli- 
I his inji. ,e less apparent as the plants grew, and there 
was no significant effect on yields. The 5-percent methoxychlor dust 
caused slight chlorosis in a few plants of each variety, but did not 
significantly affect the yields. 
One percent gamma BHC dusts, prepared from concentrates of 
approximately 95-percent gamma content, caused no visible plant inji: : 
and did not significantly affect yields in either year. The commercial 
product used in 1948 had little odor when diluted to a 1 -percent gamma 
dust; that used in 1949 had a slight odor. In 1948 plants of the Marketer 
variety getting the 1 -percent gamma dust gave slightly higher yields 
than untreated plants; the reverse was true of the S.C. 5 breeding line. 
1 he yields of dusted plants of both S.C. 5 and Palmetto cucumbers tended 
to be lower than those of plants not recei the gamma BHC dust in the 
spring of 1949, but the differences are not statistically significa . 
i.me was used when it became available in the fall of 1949. 
CONTROL EXPERIMENTS 
Thirteen field -pl( nts desig: • : • Lop a program for 
the control of the pickleworm and assoi I insecl - on the fall 
crop of cucumbers were conducted each year from 1948 through 1951. 
Tw<» c conducted on squash, one each in 1950 and li' 
1 ich m t was used on four to s. 
Id plots cons plants. The rows 
, av 1/20* 
in which ' ere ii T feet '. , . The dusts w 
in th< J as in tin 
(two or- thre< trips per row) w ■ ■ 
I 
i tely v. 
. _ g 
pp] ic<i, bul d hen th< 
i) D gall< 
the 
am 
applied at th< 
