CONTROL OF BOLL WEEVIL IN MISSISSIPPI DELTA. 23 



Table 20. — Row records of weevils collected with bag-and-hoop, Hecla plantation experi- 

 ment, Mound, La., 1916. 





Weevils collected. 



Row No. 



June 16. 



June 22. 



June 29. 



July 10. 



July 17. 



Row 



total. 



Average 

 per row 

 m 5-row 

 blocks. 1 



Average 

 per row of 



outside 

 and inside 



blocks. 



1 



8 

 5 

 8 

 9 

 9 



10 

 6 

 8 

 6 



25 

 8 

 6 



14 

 3 

 4 

 9 

 8 

 2 



13 

 4 



11 

 9 



7 

 7 



12 



14 



16 



6 



1 



8 



2 



11 



14 



5 



6 



14 



2 



5 



10 

 9 

 11 

 6 

 7 

 5 



4 

 4 

 2 



18 

 5 



14 

 7 

 6 



10 

 8 

 5 

 5 

 3 



14 

 8 



12 

 

 2 

 9 

 4 

 9 



11 



8 

 5 



14 

 8 

 5 

 5 

 6 



13 

 7 



11 

 5 



12 

 7 

 5 

 8 

 6 

 3 

 5 

 7 

 6 

 3 



10 



17 

 7 



11 

 8 

 6 

 8 



13 



10 

 8 

 8 

 4 

 8 

 4 

 6 

 7 

 7 

 9 

 3 

 9 

 3 

 5 

 2 



44 

 28 

 47 

 57 

 41 

 43 

 33 

 45 

 33 

 63 

 36 

 36 

 34 

 42 

 29 

 39 

 30 

 21 

 49 

 23 

 35 

 37 



43.3 



42.0 

 36.0 



32.5 





2 





3 





4 



43.3 















O 





9 





10 





11 





19 



> 39.0 



13 





14 





15 





16 





17 





is 





19 





20 



32.5 



2] 





22 









1 Outside blocks each consist of 6 rows. 



The weevil collection records are shown in Table 20. Owing to 

 the variations produced by the individual efficiency of the pickers, it 

 does not seem advisable to compare the various rows at a single 

 picking, but this factor should be more or less averaged out in the 

 five pickings, and to reduce this error further the rows have been 

 averaged together in blocks. It will be noted that the first average 

 of this type divides the plat into four blocks, the outside blocks 

 consisting of six rows each and the two inside blocks consisting of 

 five rows each. From this grouping it is seen that rows 1 to 6 

 averaged 43.3 weevils per row, while rows 7 to 11 averaged 42; 

 rows 12 to 16 averaged 36 and rows 17 to 22 averaged 32.5. Thus 

 it is seen that there is a more or less regular decrease in the infesta- 

 tion of the picked plat as the distance from the check plat is increased. 

 However, the highest record for any single row was row 10, which 

 was very nearly in the center of the plat. These figures would seem 

 to indicate that picking cotton beyond the ends of the picked plat 

 and to the north of it prevented the plat from receiving an infestation 

 of weevils from those sides. It is also seen that there was apparently 

 some migration of weevils from the check plat into the south side of 

 the picked plat. However, this was not of grave importance and is 

 probably largely counteracted by the later omission of rows 1 to 4 as 

 butlers. 



