56 SCIENTIFIC REPORTS OF THE AGRICULTURAL RESEARCH 



The trials are being repeated as the season of 1918-19 in 

 the Doab was abnormal. The monsoon was a failure at 

 Cawnpore while hot winds during the ripening period 

 lowered the yield of the later kinds very considerably. 



III. Indigo. 



In last year's report, a somewhat detailed account 

 was given of the work in progress on Java indigo. This 

 dealt with a study of the conditions necessary for growth 

 and for seed formation, of the factors of importance in 

 root development and of the principles underlying improve- 

 ment by selection. These investigations are being con- 

 tinued and extended. During the past year, a number of 

 interesting results have been obtained many of which bear 

 on the practical aspects of the industry. 



Indigo wilt. One of the difficulties encountered in the 

 cultivation of Java indigo in Bihar is a condition known 

 as wilt. After the middle of the monsoon, it often happens 

 that the Java plant ceases to thrive, growth slows down, 

 the foliage changes colour and afterwards becomes pro- 

 gressively reduced in amount. This is followed by the 

 gradual death of the plant. Associated with the wilted 

 condition during this period is extensive destruction of the 

 fine roots and nodules. As there appeared to be a connec- 

 tion between the rise of the subsoil water in Bihar (Plate 

 VI) and the development of wilt, a series of lysimeter ex- 

 periments was carried out in 1918 in order to determine 

 whether or not there is any relation between waterlogging 



