36 REPORT OF THE AGRICULTURAL RESEARCH INSTITUTE 



to be efficient surface cultivation in the hot weather com- 

 bined with drainage in the monsoon. The hot weather 

 cultivation, for which suitable implements have been 

 introduced into Bihar, enables the crop to obtain an ample 

 air supply and also leads to the destruction of weeds and 

 to a great saving in the cost of production. Surface 

 drainage on the Pusa system, by preventing the flow of 

 surplus rain water over the indigo fields, assists in main- 

 taining the essential air supply to the roots and nodules 

 and so tends to increase the growth and to prevent wilt. 

 The adoption of these methods on the Dholi estate for the 

 1914 crop led to a record yield both of finished indigo and 

 of seeth. 



The discovery of the nature of the wilt disease also led 

 to a method of growing the seed of Java indigo which is 

 rapidly being taken up all over Bihar. Formerly, the old 

 indigo crop was kept over the cold weather and seed was 

 collected from these plants. This placed the planters at 

 the mercy of the season as, in many cases, the crop became 

 so weak from wilt that it produced only a small quantity 

 of poor seed. At the same time, very large areas had to 

 be set aside for seed which became very foul with weeds. 

 The new method makes the planter independent of the 

 season and leads to the certain production of well-grown 

 seed from a comparatively small area which can easily be 

 kept in a clean condition. For seed, Java indigo must be 

 sown in early August in high-lying, well-drained fields 

 which are in good condition. The plants must be well- 

 cultivated and properly spaced so that they grow rapidly 

 and come into flower towards the end of October. At this 

 period, the weather is warm and dry, bees are abundant and 

 all the conditions for pollination are present. This method 

 was adopted on the Dholi estate for the 1915 harvest when 



a very fine crop of seed of over eleven maunds to the acre 

 was obtained. The land was afterwards kept through the 

 hot weather and yielded crops of leaf in the ordinary way. 



The provision of a better cover crop for Java indigo 

 has enabled several estates in Bihar to reduce the cost of 



