32 



BULLETIN 1320, U. S. DEPARTMENT OF AGRICULTURE 



Weevil damage to mature bolls was a minor factor as compared with 

 damage from anthracnose, boll-rot, and bollworms. 



RATE OF SEEDLING GROWTH INCREASED BY LATER PLANTING 



In order to compare the rate of plant development in the four 

 plantings, records of the formation of nodes on the main stalk were 

 obtained from 10 representative plants in each planting. Differences 

 in the growth rate during the seedling stage of these four plantings 

 are shown by the interval between the planting date and the date 

 of appearance of the first square in each planting. 



As shown by the data in Table 19, the period from the date of 

 planting to the appearance of the first square on the April 5 planting 

 was 51 days, as compared with 44 days for the planting of April 16, 

 40 days for that of April 25, and 38 days for that of May 4. The 

 latter planting reached the fruiting stage of development in 13 days 

 less time than the planting made on April 5. 



Table 19. — Rate of nodal growth during the seedling stage of cotton grown in succes- 

 sive plantings at Charleston on jour different dates 



Date planted, 1923 



Number of days- 



Average date of appearance of first fruiting 

 branch 



Apr. 5_ 

 Apr. 16 

 Apr. 25 

 May 4. 



May 26 

 May 30 

 June 4_. 

 June 11. 



] As these records were made from the planting date rather than from the date of germination, a deduction 

 of about five or six days is necessary in comparing these figures with those that were obtained in Texas. 

 (See Table 3.) 



The April 5 planting required an average of 6.37 days for the 

 development of each of the first eight nodes, as compared with 4.75 

 days per node for the May 4 planting, a difference in growth rate of 

 1.62 days. Higher air temperatures and warmer soil conditions dur- 

 ing the seedling stage of growth are probably the factors causing this 

 increased rate of growth in the later plantings. The cotton plant is 

 very sensitive to low temperatures, and if the young seedlings are 

 exposed to periods of cold weather their growth may be so checked 

 that they may not readily resume normal growth when conditions 

 again become favorable. 



PLANT GROWTH DURING THE FRUITING PERIOD 



Records of plant growth during the fruiting period indicate that 

 the accelerated development of the internodes of late-planted cotton 

 is practically confined to the seedling stage. The average date of 

 appearance of the first and twelfth fruiting branches on 10 plants of 

 each planting and the average interval between the appearance of 

 successive fruiting branches are presented in Table 20. The number 

 of days required by each planting for the development of the first 

 11 fruiting branches was as follows: April 5 planting, 31 days; April 

 16, 27 days; April 25, 29 days; and Mav 4, 28 days. 



