CONTROL OF BOLL WEEVIL IN" MISSISSIPPI DELTA. 



35 



Row records of the weevil and square collections were made in this 

 test in the same manner as that already described for the Hecla 

 experiment. These are tabulated in Tables 28 and 29. The row 

 totals are averaged by blocks in much the same manner as in the 

 Hecla test. Of course, in this case unpicked cotton adjoined only two 

 of the blocks. These were the outside blocks of plats 2 and 4. From 

 Table 28 it is seen that the outside block of plat 4 averaged slightly 

 higher in weevils collected than the remainder of the plat, but that 

 the outside block of plat 2 averaged less than the middle block of the 

 same plat. From Table 29 it is seen that the square collections 

 presented exactly reversed conditions. From these square collections 

 it would seem that the outside block of plat 2 was more highly 

 infested than the inside, while the rows 1 to 6 of plat 4 yielded a 

 higher average than any of the remainder of the plat. These results 

 are rather contradictory, but at any rate they seem to indicate that 

 if the unpicked cotton had any effect on the picked plats it was com- 

 paratively slight and should have been largely eliminated by the 

 buffer system employed. 



WEEVIL INFESTATION. 



The infestation of the various plats of this series was followed 

 throughout the season in the same manner as in the Hecla test. The 

 general rule for determining this record was an examination of 100 

 squares in each end and the middle of each plat. The records 

 secured are shown in Table 30. 



Table 30. — Weevil infestation, Eureka plantation, Tallulah, La., 1916, Test No. 1. 



Date of examination. 



Infestation. 



Plat 2. 



Plat 3. 



Plat 4. 



Plats 

 1 and 5; 

 average 

 of both 

 cheeks. 



June 12 



June 19 



June 26 



July 3 



July 10 



July 17 



July 24.. 



Aug. 1 



Aug. 8 



Aug. 14 



■Weighted average 



Per cent. 



7.3 



5.3 



8.7 



9.2 



12.3 



42.2 



81.8 



76.3 



91. Q, 



96.2 



Per cent. 

 10.7 

 13.3 

 7.3 

 5.7 

 12.7 

 35.0 

 46.5 

 78.2 

 92.8 

 96.3 



Per cent. 



6.7 



8.0 



7.0 



4.3 



9.8 



40.7 



57.8 



81.7 



80.5 



97.0 



Per 



cent. 

 8.0 

 11.2 

 10.7 

 9.0 

 12.2 

 44.8 

 67.7 

 81.8 

 85.2 

 96.2 



50.6 



5.2 



3.7 



From these figures it is seen that starting with a practically equal 

 infestation these three treated plats and the two checks varied back 

 and forth somewhat, but never showed any significant regularity in 

 the difference between the various individual plats. In fact, the 



