Apr. 8, i9i8 Effect of Meteorological Factors 07i Sorghums 147 



SUMMARY 



(i) Sorghum is semitropical in its adaptations and does not thrive in 

 regions of low temperatures. 



(2) Sunshine is probably an important factor of growth; witness the 

 difference of growth at Chula Vista, Cal., and Puyallup, Wash., where 

 the mean temperatures and the total positive heat units available are 

 but little different. 



(3) The "physiological constant" for the ripening phase of sorghums 

 according to Linsser's law of growth is about 0.53. 



(4) Extremely high temperatures during the period of flowering and 

 fruiting result in a decreased yield of seed. 



(5) The date of planting should be so arranged that germination and 

 early growth of the plants will take place during the period of high 

 temperatures and the flowering and fruiting when more moderate tem- 

 peratures prevail. 



(6) Adverse weather conditions affect such supposedly stable charac- 

 ters as the number of leaves per plant, as well as the volume of growth, 



LITERATURE CITED 

 (i) Abbe, Cleveland. 



1905. A FIRST REPORT ON THE RELATION BETWEEN CUMATES AND CROPS. U. S 



Dept. Agr. Weather Bur. Bui. 36, 386 p. Catalogue of periodicals and 

 authors referred to, p. 365-375. 



(2) Balls, W. L. 



1908. TEMPERATURE AND GROWTH. In Ann. Bot., V. 22, no. 88, p. 557-591, 

 illus. 



(3) BosE, J. C. 



1906. PLANT RESPONSE AS A MEANS OP PHYSIOLOGICAL INVESTIGATION. 781 



p., 277 fig. London, New York, Bombay. 



(4) EWART, A. J. 



1896. ON ASSiMiLATORY INHIBITION IN PLANTS. In Jour. Linn. Soc. [London] 

 Bot., V. 31, no. 217, p. 364-461. 



(5) Sachs, Julius. 



i860. PHYSIOLOGISCHE UNTER SUCHUNGENUBER DIE ABHANGIGKElT DER KEIMUNG 



VON DER TEMPERATUR. In Jahrb. Wiss. Bot., Bd. 2, p. 338-377, illus. 

 (6) 



1874. UEBER DEN EINFLUSS DER LUPTTEMPERATUR UND DES TAGELICHTS AUP 

 DIE STUNDLICHEN UND TAGLICHEN AENDERUNGEN DES LANGENWACH- 



STHUMS (streckung) DER iNTERNODiEN. In Alb. Bot. Inst. Wiirz- 

 burg, Bd. 1, p. 99-192, 7 pi. (fold.). 



(7) Smith, A. M. 



1906. ON THE APPLICATION OP THE THEORY OP LIMITING FACTORS TO MEASURE- 

 MENTS AND OBSERVATIONS OP GROWTH IN CEYLON. In Ann. Roy. 

 Bot. Gard. Peradeniya, v. 3, pt. 2, p. 303-374, pi. 22-25. List of litera- 

 ture, p. 372-374- 



(8) Vines, S. H. 



1886. LECTURES ON THE PHYSIOLOGY OF PLANTS. 710 p., 76 fig. Cambridge 

 [Eng.]. 



