COTTON IN WEEVIL-CONTROL EXPERIMENTS £7 
cotton illustrates the difficulty of obtaining accurate comparisons of 
productiveness from adjacent plantings of early and late planted 
cotton when complete weevil control is not obtained. 
WEEVIL DAMAGE TO BOLLS 
Records of the extent of weevil injury to bolls in the different 
plantings were made on four dates during the period of boll opening. 
These records were obtained from the same 50-foot sections of rows 
which were used in comparisons of flowering and boll shedding. The 
weevil damage was determined by counting the number of injured 
and uninjured locks in each of the bolls that had opened in the 
intervals between the four dates when the records were made. This 
afforded a means of comparing the extent of the injury to early and 
late bolls of the successive plantings. 
Table 11 gives the number of bolls picked, the number showing 
weevil damage, the total number of locks, and the number and 
ercentage of locks damaged by the weevils. The records from the 
our 50-foot sections of the first three plantings are summarized and 
presented in a single unit corresponding to a 200-foot row. 
TaBLE 11.—Exztent of weevil injury to bolls in successive plantings of cotton at San 
Antonio 
Number Locks damaged by 
Number ; of bolls Total weevus 
Date planted, 1923 a of bolls |damaged | number 
P picked by of locks 
weevils Number | Per cent 
Aug. 14 243 56 1, 061 92 8.7 
pr. 19 Aug. 18 312 57 1, 390 89 6.4 
IC ce SS SoS Sea ee oe a Aug. 30 403 175 1, 733 366 21.1 
Sept. 10 101 72 432 163 Bad 
TRotaliss 2s Bae Fe eee a Mees nh Pd 1, 059 360 4,616 710 15. 4 
Aug. 14 161 52 719 66 9.2 
Aor. 28 Aug. 18 215 52 968 69 ek 
Oe SR ain ee 3 Se Sa oe oer eo Aug. 30 519 249 2, 258 521 pa ik 
Sept. 10 138 105 584 239 40.9 
Oba ae ee ee ee ee se 1, 033 458 4, 529 895 19.8 
Aug. 14 105 25 472 35 7.4 
May 5 Aug. 18 216 31 968 52 5. 4 
ee Slee oe eee, ee Aug. 30 521 313 2, 387 656 27.5 
Sept. 10 198 129 849 35. 2 
PROLA Se so eee eee bee OM a he) ot 1, 040 498 4, 676 1, 042 22.3 
Aug. 30 300 192 1, 410 433 30. 7 
May 12---_------------------------------- Sept. 10 86 69 75 173 46, 1 
SRG bale | 2S. eee ee ee Pa Be DE 386 261 1, 785 606 33.9 
The maturation period of Lone Star bolls in Texas has been shown 
to be about 42 days,‘ so that bolls open before August 18 must have 
developed from flowers appearing prior to July 8. The small amount 
of weevil injury to these early bolls is due to the slight weevil in- 
festation during the first part of the flowering stage of the plants 
and also to the presence of squares. While squares are available 
{ Martin, R. D., W. W. Ballard, and D. M, Simpson. Growth of fruiting parts in cotton plants. In 
Jour. Agr. Research, v. 25, p. 204. 1923. 
20718°—25° 3 
