KKKKCT ON I'K(»LIFKKATinX (»K FKKTl LIZI N(; SOIL. 17 



paivd witli tli(> boll, which wouhl therefore exhihit a more composite 

 result of uny inMuential conditions uirectiii^j it . 



It is probably true that the increased morlahty in s(juares occur- 

 rini,^ (luriii<; hot <hy wcathcM- is more directly attributable to the 

 absolut(> maxinuim l(Mii|)cratui-e experienced than it is to the slif^litly 

 liiilhci- invnn average temperature ])revailing. The ol)servatiors 

 which have been here recorded refer only to conditions found in 

 squares which have been attacked by the weevil, but before they 

 have fallen to the <;round. After squares have fallen the influence 

 of hot dry weather in lartjely raisinj^ the percentage of nuirtality 

 wherever the squares become directly exposed to the sun is unqufs- 

 tionably a still more imjiortant factor in destroying the immature 

 stages of the weevil. 



EFFECT ON PROLIFERATION OF FERTILIZING THE SOIL. 



In accordance with indications shown by some of the examinations 

 of bolls made in 1903, it was expected that fertilization of ccjtton 

 might i)r()(hice a considerable increase in the percentage of cases in 

 wiiicli })roliferation followed injury by the weevil. A test of this 

 point required a comparison of a considerable number of varieties 

 under similar cultural and soil conditions with check plats unfer- 

 tilized for each variety. Tests of this nature were instituted at the 

 beginning of the season of 1904. Favorable conditions for such 

 oljservations were also furnished by the field experiment at Calvert, 

 Tex., during the season of 1905. Fourteen varieties were there grown 

 upon Brazos bottom lands. Each fertilized plat received an appli- 

 cation of 400 j)()unds of acid ])hosphate j)cr acre. Conditions in all 

 plats were similar with the exception of fertilization. 

 31022— No. 59—06 3 



