2 BULLETIN 1205, IT. S. DEPARTMENT OF AGRICULTURE. 
RESULTS OF EXPERIMENTS AT FORT VALLEY, GA., IN 1921. 
The 1921 post-harvest experiments were conducted in an 8-year-old 
Elbert a orchard. The trees had made fairly good growth, which was 
uniform over the entire orchard, except at one end, where the soil 
was not so fertile. This orchard was at least 300 yards from the 
nearest wooded area, and there were no particularly good hiber- 
nating quarters near by for the beetles, except on one side, where the 
weeds and brush had been allowed to grow along a railroad right-of- 
way. The curculio proved to be very abundant in this orchard and 
along with secondary brown-rot infections had made unmerchantable 
a large part of the fruit crop, which was harvested a few weeks 
before these experiments began. As many as 46 curculios were 
found on a single tree, and the average number per tree in the entire 
orchard was high. 
The orchard of nearly 1,500 trees was divided into three blocks as 
nearly equal in size as practicable. Plat 1 contained 504 trees and 
received two dust applications. Plat 2 also contained 504 trees and 
received one dust application. Plat 3 contained 479 trees and was 
left untreated throughout the experiment as a check. Fifty trees 
were tagged in different parts of each plat, and these were jarred 
regularly every other morning, to obtain data on the abundance of 
the curculios on the several plats. Twenty of these trees were 
selected in the center of each plat, and three blocks of 10 trees each 
around the sides. (See fig. 1.) In the entire orchard, therefore, 
there were 150 record trees, 80 of which were jarred one morning 
and 70 the next, throughout the course of the experiment. Jarring 
operations began at sun-up each morning, in order to complete the 
work before the beetles became active. 
JARRING BEFORE DUSTING. 
All of the record trees in each plat were jarred twice before any 
dust was applied, in order to ascertain the degree of the infest at ion 
on each plat at the beginning of the experiment. (PL I, figs. 1 and 2.) 
Table 1 gives the number of beetles collected from the several plats 
before dusting: 
Table L. - Vvmber of curculios collected before dusting^ 1921. 
Date 
Plat. 
Date. 
I'lal. 
l 
2 
3 
1 
? 
3 
Aug. 8 
Beetles. 
Beetles. 
Beetles. 
214 
A ML'. 11 
Beetles. 
L86 
Beetles. 
311 
Beetles. 
L64 
286 
Total 
Average per tree 
Aug. 10 
321 
3.50 
597 
:.. 97 
.">35 
:,. 35 
The number of beetles collected from the 150 record trees in four 
days was 1,482. The infestation was somewhat lighter on plat 1 
than on the other two plats. This was perhaps due to the fad that 
the trees in plat 1 were smaller than the others, and the further fact 
that the foliage was not so good, because the soil was less fertile in 
thai part of the orchard. The average number of hectics per tree 
in each plat before dusting was found to be as follows: Plat 1,3.5 
beetles; plat 2, 5.97 beetles; plat 3, 5.35 beetles. 
