476 



Journal of Agricultural Research 



Vol. VI, No. 13 



Table I . — Sumviary of the climatic conditions at Garden City, Kans. ,for IQI4 and igi^ — 



Continued 



Period (inclusive). 



1915- 



July — Continued. 



II to 15 



16 to 20 



2 1 to 2 5 



25to3i 



August : 



I to 5 



6 to 10 



II to IS 



16 to 20 



2 1 to 2 5 



25 to 31 



September: 



I to 5 



6 to 10 



II to IS 



16 to 20 



2 1 to 2 s 



25 to 30 



Air temperature (°F). 



Average of — 



72 

 74 

 75 



69 

 70 

 72 

 61 

 70 

 63 



68 

 69 



71 

 69 

 66 

 56 



Maxt- Mini- 

 mums, naums. 



97 

 84 



85 



74 



83 

 80 



83 

 80 

 81 



77 



83 

 81 



84 

 82 

 76 

 67 



Maxi- 

 mum. 



67 

 62 

 61 

 64 



56 

 60 

 61 

 61 

 60 

 50 



55 

 56 

 60 



55 

 58 



lOI 



96 



91 



90 



90 



94 

 86 



85 



87 

 91 

 97 

 87 

 84 

 78 



Mini- 

 mum. 



64 

 56 

 56 

 62 



51 

 56 

 59 

 57 

 57 

 40 



51 



54 

 53 

 39 

 50 

 44 



Precipi- 

 tation. 



Inches. 

 O. 06 



•15 

 •13 

 .24 



.90 



5- II 

 . 10 



• 03 

 .46 



.82 



Evapora- 

 tion. 



Trace. 



. 20 



I. 00 



•25 



Inches. 



1-743 

 1.407 



1-397 

 1.528 



1. 012 

 .860 



•927 



.790 



1.018 



1-313 



1.424 

 I. 029 



-983 



I. 072 



.864 



•66s 



Wind 

 velocity 

 per hour. 



Miles. 

 6.7 

 7.0 



5-5 

 6.8 



7-4 

 6.3 

 7-2 



5-2 



18.2 



4-4 



The holes in the lids were made water-tight by using a mixture of 

 approximately 16 parts by weight of beeswax to i part of Venetian 

 turpentine. Under ordinary conditions the young seedlings of the corn 

 and sorghum can readily penetrate this wax. After the plants had 

 emerged through the wax, it was replaced by a mixture containing a 

 much smaller amount of Venetian turpentine, in order to secure a seal 

 that would remain firm around the plants during the hot summer weather. 

 The lids of the cans were given a heavy coat of white paint and were 

 then covered with a layer of burlap in order to protect them from ex- 

 cessive heat. The water lost by the plants was replaced every 48 hours 

 by the method used by Briggs and Shantz * in their extensive work on 

 the water requirement of plants. 



It was thought advisable to determine the water requirement based on 

 the dry weight of both the aerial portions and the roots of the plants. 

 The water requirement was obtained in this manner for Pride of Saline 

 corn, Blackhull kafir, Dwarf milo, and Dwarf Blackhull kafii. The 

 method used in the isolation of the root systems of these plants has been 

 previously reported by the writer int his Journal.^ 



1 Briggs, L. J., and Shantz, H. L. The water requirement of plants. I. Investigations in the Great 

 Plains in 1910 and 1911. U. S. Dept. Agr. Bur. Plant Indus. Bui. 284, 49 p., 2 fig., 11 pi. 1913. 



The water requirement of plants. II. A review of the literature. U.S. Dept. Agr. Bur. 



Plant Indus. Bui. 285, 96 p., 5 fig. 1913. 



The relative water requirement of plants. In Jour. Agr. Research, v. •?, no. i, p. 1-64, 



ifig., pi. 1-7. 1914- 



2 Miller, E. C. A comparative study of the root systems and leaf areas of corn and the sorghums. In 

 Jour. Agr. Research, v. 6, no. 9, p. 311-332. 1916. 



