44 SCIENTIFIC REPORTS OF THE AGRICULTURAL RESEARCH 



surface is reduced and the young roots and nodules lose 

 their freshness and become discoloured and unhealthy. 

 The above-ground portion ceases to grow normally and the 

 young branches are frequently attacked by Psylla. Similar 

 results have been obtained in the August sown seed crop 

 when the indigo has been sown in land foul with weeds 

 which have been turned under a few weeks previous to 

 sowing. 



The effect of complete or partial cutting back on the 

 root system of rapidly-growing Java indigo has yielded 

 some interesting results. In the cultivation of indigo 

 in Bihar it is the universal practice to cut the indigo back 

 completely in June and to leave the stumps for a second 

 crop. The time taken in forming new shoots varies with 

 the season. In very wet weather, sprouting is delayed and 

 the process is distinctly favoured by a break in the rains. 

 It has frequently been observed at Pusa that if a few leaves 

 are left at the first cut, the new growth is much more rapid. 

 This year, the effect of complete cutting back and of hard 

 pruning on the root system was examined. It was found 

 that complete cutting back, while the plant is in active 

 growth, kills the fine roots and nodules and that a new 

 absorbing system has to be produced before new shoots 

 form. This naturally takes time. Heavy pruning, on the 

 other hand, leads to far less damage to the roots and 

 nodules, which at once explains the rapidity with which 

 such plants form new growth. This fact may easily prove 

 of considerable practical advantage to the indigo industry, 

 If the crop could be grown in double lines with interculture, 

 it could be heavily pruned at the first cut and the^second 

 crop could be advanced by several weeks. A new system of 

 growing Java indigo, based on these results, has been 

 worked out at Pusa. The crop is sown in September (after 

 a clean fallow) in double lines with a space between for 

 mechanical interculture to keep down weeds and to aerate 

 the soil. The lines are pruned as early as possible after 

 the rains break and the second cut is taken as soon as 

 possible afterwards. Whether it will be better to be 



