104 University of California Publications in Agricultural Sciences [Vol. 1 



Climate includes a large number of factors. The specific 

 climatic factor which is the cause of this variation has recently 

 been the subject of much study and investigation. 



The formation of organic compounds in the plant, such as 

 starch and gluten, is a physiological process. The maximum 

 development of these compounds is necessarily dependent upon 

 favorable conditions. Starch is formed under the influence of 

 sunlight. The formation of nitrogenous compounds requires not 

 only an adequate supply of nitrogen, but also a supply of carbon 

 compounds in the proper form and under the proper conditions. 

 Just what these conditions are is not definitely known. 



In general, investigators have concluded that the large amount 

 of sunshine prevalent in the coast states during the period in 

 which the seed develops works directly in favor of the formation 

 of large amounts of starch. In other words, that the gluten 

 content is low only by reason of the formation of proportionally 

 larger amounts of starch. Were this the case, the exclusion of 

 portions of the sunlight should tend to increase the percentage 

 of gluten. Theoretically the gluten would increase inversely with 

 the amount of sunlight which the plants received. 



In order to determine whether or not sunlight is a prominent 

 factor a series of experiments were planned in which portions 

 of the natural sunlight were excluded from the growing plants. 



Duplicate experiments were conducted during the seasons of 

 1908 and 1909 at the Tulare Sub-station and at the University 

 Farm at Davis. 



Original Seed. — At the Tulare Station in 1908 the originals 

 used Avere as follows : 



No. 864/07 Weissenberg 



No. 879/07 Currell 



No. 892/07 Beloglina 



No. 894/07 Velvet Don (starch grains) 



No. 901/07 Turkey Eed (gluten grains) 



No. 899/07 Yellow Gharnovka (gluten grains) 



At Davis the following varieties were used : 



No. 868/07 Kubanka 



No. 847 Kubanka 



No. 870A Velvet Don (gluten grains) 



