BEE KEEPING MAY 



INCREASE THE COTTON CROP 



Fertilization of the Cotton Flower Takes Place Soon after Sunrise — 



Twenty-Five to Fifty Pollen Grains Necessary for Each Flower 



— Shedding of Bolls Often Due to Imperfect Fertilization 



Ivowi.AXD M. Mi:adl:, Jhird, Cal? 



Till-: pcrcH-nlage of colton tlowcis 

 iliat develop into mature bolls is 

 j,'enerally low. Even under the 

 most favorable conditions many 

 of the buds do not reach the blooming 

 stage, and many flowers that open fail 

 to set bolls. 



.\ test of twelve I'pland varieties 

 made at Bard. Cal., in 1911, showed 

 that during the first thirty days of 

 tlowering. 44 to 66^0 of the flower 

 buds aborted before opening, and that 

 22 to 52% of the flowers that opened 

 failed to develop into bolls. .\n exami- 

 natitjn of all the nodes on the fruiting 

 branches at which it would have ])een 

 possible for bolls to develop showed 

 that at only 12 to 23% of these nodes 

 were bolls produced. 



In the same series of varieties at 

 San Antonio, Tex., in 1912, 35 to 82'/o 

 of the flowers that opened failed to 

 mature bolls. The shedding at San 

 AiUonio was doubtless due largely to 

 unfavorable climatic conditions, as 

 drought, and. also, to the depredations 

 of the boll weevil. The boll weevil, 

 however, is not present at l>ard, and as 

 iirigation is practiced the lack of water 

 coidd hardly be an important factor. 

 Inadequate pollination was considered 

 as a possible cause of the shedding. 

 when the flowering stage had been 

 reached. 



The cotton flower is a large, cup- 

 shaped blossom; it is borne in an up- 

 right position on the ui)per side of ibe 

 fruiting brancli. Tbe structure and \v- 

 lation of floral ])arts arc shown in 

 [•'ig. Id. The jxillen grains are \ir\ 



' This report was found amonp the papers of 

 same form as proseiUed.— J. H. Konii)t<>n. 



2U 



large aiul have n)oi>t spino>e surfaces, 

 so that they tend to cohere when freed 

 from the anthers and are not carried 

 about by the wind. 



i'I';rioi) of i-i:Kiit,i/..\'noN .siiokt 



The period during which fertiliza- 

 tion is possible lasts only a iitw hours. 

 The flowers open soon after sunrise, 

 commence to wither as the temperature 

 rises in the middle of the day, and close 

 in the evening, when the stigmas are 

 (Irv. The second or third day after 

 blooming the petals, stanu-ns. and pistil 

 separate from the rest of the flower 

 and fall from the ])lant. 



In some Ivpes the relative jx^sition of 

 the stigmas and stamens is favorable, 

 .'ind in others unfavorai)U'. for self- 

 ]>o]lination. This doubtless partially 

 accounts lor the difl'erences between 

 varieties with respect to the percentage 

 of flowers that develop into bolls. 



i.oxi; ST.si'Li-: corrox oi-tkx 

 self-sti;kili; 



Most of the flowers with long stigmas 

 jMojecting above the stamens do not 

 l)econie completely self- fertilized, as 

 the anthers and stigmas arc too widely 

 separated. The (lowers of many of tbe 

 long staple varieties are of this type. 

 ilu' stigmas often exceeding tbe anthers 

 h\- 15 nun. ( See b'ig. 17. ) The bolls re- 

 >-ulling from such flowers have 23 to 

 5()'"o of aborted seeds, and it seems not 

 muTasonable to attribute this abortion 

 in i)art to the lack of perfect pollination. 

 I'lowers with short stigmas iml)i'<lded 

 .iinong the upper stamens are readily 



tlic laU- Rowland M. Moadc in cs-sentiaUv tlic 



