Apr. 8, 1918 Effect of Meteorological Factors on Sorghums 141 



ing at Bard, will shorten the growing season 21 days, thus making the 

 normal growing season at Bard 108 days, which is about the same as 

 at Chillicothe, This is assumed as the normal growing season for Bard, 

 since the growth of sorghums planted at this date is more nearly normal 

 than when planted earlier. 



The longer growing season at Bard and Chula Vista seem to have 

 resulted in an increase in height most noticeable at Bard, where the 

 plants averaged 14 inches taller than at Chillicothe. Again, however, 

 we find by consulting Table V that where the sorghums were planted 

 later and the growing season was shortened the height was reduced an 

 average of 8 inches. This would make the average height for Bard 74 

 inches, only 6 inches taller than at Chillicothe. At Chula Vista the 

 average height was 73 inches, which is but little over normal. The 

 average height of 27 inches at Puyallup emphasizes the very inferior 

 growth which the sorghums made under the conditions existing there. 



In diameter of stem the chmatic effect is the reverse of that where 

 height is concerned. The stems were larger and stronger at Chillicothe. 

 than at either Bard or Chula Vista. If we take into consideration the 

 effect of the time of planting at Bard, however, the difference in diameter 

 at Chillicothe and Bard is very slight, only 0.02 inch. 



On the whole Table V shows that a normal growth may be expected 

 at both Chillicothe and Bard if the time of planting at the latter point 

 is properly regulated. At Chula Vista the rather low temperatures 

 lengthened the growing season very markedly and caused the plants to 

 have somewhat slender stems. At Puyallup, where low day tempera- 

 tures were combined with a very decided deficiency in the sunshine and 

 with cool nights the sorghums did not behave normally, and all failed 

 to mature. 



At Puyallup measurements were taken every two weeks on the growth 

 made by the sorghum varieties, and these measurements emphasized 

 the backwardness of the growth. For Sumac sorgo the growth was for 

 the first month, 4 inches; second month, 3 inches; third month, 10 

 inches; and fourth month, 13 inches. Blackhull kafir grew^ in the first 

 month only 4 inches: second month, 4 inches; third month, 12 inches; 

 and fourth month, 12 inches. Dwarf milo, which was the only variety 

 that headed, made a growth of 5 inches the first month; 2 inches the 

 second month ; 1 2 inches the third m.onth ; and 9 inches the fourth month. 

 This low rate of growth indicates a temperature too low to stimulate 

 properly the growing functions of sorghums, or else the deficiency of 

 sunshine had a very decided retarding effect on their growth. The 

 percentage of possible sunshine was only 46 at Puyallup, while it was 

 68 at Chula Vista 



