10 BULLETIN 1169, U. S. DEPARTMENT OF AGRICULTURE. 
RESULTS FROM WINTER AND SPRING TREATMENTS. 
To obtain information on the results that may be expected to 
follow the application of paradichlorobenzine to peach trees in the 
late fall or spring for the control of the peach borer, an experiment 
was conducted on 6-year-old trees during the fall of 1921 and the 
spring of 1922. This experiment also furnished additional data on 
the results from not uncovering the tree base after applying the 
chemical. 
Kighty trees were used in this experiment and 1l-ounce doses were 
applied in all tests. Ten of the trees were treated October 24, which 
was about two weeks after the usual time. These trees were not 
examined or the soil disturbed until May 5, 1922. Ten other trees 
were treated on November 9, which was about four weeks later than 
the time for best results. Ten others were treated on November 23, 
which was about six weeks late, and 10 others on December 6, which 
was eight weeks later than the date recommended for best results. 
None of these trees was examined nor was the soil around them dis- 
turbed until May 5, 1922. Ten untreated trees were examined on 
May 6, as a check on this experiment. 
For the spring test l-ounce doses were applied April 3, 1922, to 
twenty-five 6-year-old trees which had not been treated the previous 
fall. By this date the daily soil temperature in Georgia was averaging 
over 60° F. at a depth of 3 inches. These trees were all examined on 
May 13, 1922, or about six weeks after the material was applied. Five 
untreated trees used as a check on this experiment were also examined 
on May 13. 
Table 7 gives the summary of results on the effect of late fall and 
spring treatments of 1-ounce doses of paradichlorobenzene on peach- 
borer larve. 
TaBLe 7.—Summary of results of late fall and spring 1-ounce dose treatments of para- 
dichlorobenzene on peach-borer larve in 6-year-old Redbird peach trees, Fort Valley, 
Ga., 1921-22. 
Number and condition of larve. Per cent larvee. 
Dead. Stupefied Active. 
d |Z d |Z d | 
Num- - fe) we) w=) 
Date | Dateex-|p.... Ele Bie B = 
Aah applied. | amined. Exposed to gas. 3 | & & 3 5 & F Eb & 
elalts|/Elal's|}Blalta 
Sd eens (ed ae Ol od eons 
8 jag) | 5 gel &| 5 IgE : 
aa © sroup es © |s> oo) oS |} oO ® : 
£1 S be 21S J we eda 
OlH lO 1oJ{e lo |6oO [BIO J A a < 
1921-22. 1922. | 
10.);Oct: -24.| May 5.| Over’ riwinter-| | 2222 0)-22.|_ 3 aot ag ie 2) flo 0 25.0 
(193 days). 
LOW NONe. Sale -sdOs--< 3 Over), Winter jo: -}ec D Neer she cia. | foe IROSSTEEE - 100. 0 0 0 
(177 days) 
1ORVINOF. 23 |... 3002-22 Over winter] 1 D ist & eee ae as ie ees 100. 0 0 0 
(163 days). 
LOUD ees 64). 2.d0l.2 2. Ower ) “winter-He : ofp tah Ae AS Ae oe L*gr) 0 0 100.0 
(150 days). 
PURI MeCK.>. |) May MOMlne case amemee ace cepa? [aoe ot eee ae ae IZ B3t Lib. | 0 0 100. 0 
25 | Apr. 3] May 13 | 40 days......... 7110 t 2 1 0 0 4 1 | 72.4 10.4 T7622 
5 | Check... |... GO Sele ov tcn hos se eh oe ae SS eee <= 1 8} 0 0 100.0 
It is difficult to locate dead borers 150 to 200 days after applying the chemical, on account of decomposi- 
tion; hence the few borers recorded on long exposures above. The checks show the number probably 
dresent when the experiment began. 
