Investigations at Phillipsburg, Kansas. 



59 



water was present. Only 1.96 inches of rain fell during this period (June 10 

 to July 9), and about 20 per cent of this occurred in 9 light showers which had 

 little or no appreciable effect upon water-content. An examination of table 

 13 reveals the scarcity of available moisture, which was entirely exhausted 

 from the surface 6 inches of soil on July 1 and 9, Throughout the period the 

 evaporating power of the air was relatively high, about 24 c. c. daily (table 14). 

 The average daily air-temperature ranged from 64° to 76" F., maximum 

 temperatures of 88° to 99° F. not being unusual. The soil-temperature at 6 

 inches depth varied from 65° to 77° F. (fig. 26). 



June 



€01- 



FiQ. 26. — Average day and average night air-temperatures and average 

 daily soil-temperature (broken line) at Phillipsburg, 1920. 



Barley, Hordeum vulgare. 



On June 10, when the barley roots were first examined, the crop was in good 

 condition and had an average height of about 10 inches. The parent plants 

 had from 4 to 6 leaves each. They frequently had 3 to 5 tillers, and some 

 of these were almost as tall as the original shoot. The stand was fairly even 

 and the plants of uniform height. The roots had a working depth of 2.5 feet, 

 a lateral spread of about 0.5 foot on all sides of the plant, and reached a maxi- 

 mum depth of 4.3 feet. 



A second examination was made on July 9, when the crop was 2.4 feet high 

 and in the dough stage of development. It was badly affected by stem rust, 

 Puccinia graminis tritici, and the grain, when ripe, was light and wrinkled. 

 The root system had a working depth of about 3.3 feet; several roots were 

 traced to a depth of 6 feet and a few even to 6.7 feet. Root habit as regards 

 lateral spread, degree of branching, etc., was nearly identical with barley 

 grown at Lincoln. 



Wheat, Triticum .estivum. 



At the time of the first examination (June 10), the Marquis Spring wheat 

 was about 7 inches in average height and of good, even stand. It had tillered 

 more freely than either of the other cereals, 6 offshoots not being uncommon. 

 Some of the tillers were as tall as the parent plants, and, like them, had 4 or 

 5 leaves each. The crop was not only shorter above ground than the other 

 cereals, but the root system was much more poorly developed. The working 

 depth was only 2.1 feet (compared with 2.5 feet for barley), while practically 

 no roots penetrated beyond the 3.7-foot level. 



On July 9, when again examined, the crop was 2.3 feet in average height. 

 The wheat was badly rusted, and the grain, now beyond the dough stage, was 

 shriveled and Ught when harvested on July 20. The surface-rooting habit 

 was similar to that at Lincoln, the roots having a maximum lateral spread of 

 a foot. The working level now reached 3 feet, while maximum root penetra- 



