AND COLLEGE, PUSA, FOR 1914-15. 35 



mendations to be placed before the planting community. 

 A study of the so-called wilt disease, which has been 

 responsible for the great diminution of area under Java 

 indigo in Bihar in recent years, led to the realization of 

 the important part played by the root nodules in the 

 general economy of the plant and also in the production 

 of indican. This in turn made it possible to perceive 

 the factors on which the yield of indigo depends and to 

 work out improved methods of production both of indigo 

 and of indigo seed. 



Indigo wilt was found to be the last phase in a star- 

 vation process which always takes place in this crop when 

 the work of the root nodules is seriously interrupted. Wilt 

 may be produced in two quite different ways. In the first 

 place, when indigo has been subjected to long continued 

 wet weather, resulting in a waterlogged condition of the 

 ground and in an insufficient supply of air for the roots 

 and nodules, the plants cease to thrive, growth slows down 

 and the characteristic unhealthy foliage associated with 

 wilt is produced. Such plants die slowly without setting 

 seed and when the wilted condition has been reached are 

 found to have lost most of their nodules and feeding roots. 

 In the second place, wilt is produced in healthy plants 

 growing in soil where there is plenty of air and moisture, 

 when the nodules are suddenly deprived of their food 

 supply. If rapidly growing Java indigo, sown in August 

 for seed, is cut down to the ground in October, most of the 

 plants die and only a few make fresh growth. In the 

 majority of cases, this new growth is wilted and such plants 

 maintain themselves during the cold weather with the 

 greatest difficulty. Examination of the roots, soon after 

 the cutting back, shows that the nodules are in a moribund 

 condition. These results enabled improved methods of 

 cultivation and of seed-growing to be devised, which were 

 immediately tried and found successful on the indigo 

 estates themselves. 



The secret of success in the cultivation and manage- 

 ment of both Java and Sumatrana indigo has been found 



d2 



