20 SOME ASPECTS OF THE INDIGO INDUSTRY IN BIHAR 
III. THe DEGENERATION OF JAVA INDIGO IN BIHAR. 
It has been shown above that wilt during the monsoon phase in Bihat 
is due to the destruction of the fine roots and nodules at a time when regeneration 
is difficult on account of poor soil aeration. This, however, does not explain 
why the crop gradually became susceptible to wilt and why the soil aeration 
factor should destroy the crop in say 1914. and should have had little or no 
effect twelve years earlier. As is well known, the earlier consignments of 
selected seed obtained from the estates of the Dutch planters in Java gave 
excellent results. The plants grew well and gave at least three cuts of leaf, 
followed by high yields of seed. On several estates, the crop behaved as a 
true perennial and gave cuts of leaf during the second monsoon. Slowly the 
size, vigour and seed producing power of the crop fell off and wilt made its 
appearance in the late rains in increasing amounts. By 1914, the area had 
decreased to 15,000 bighas. The progressive degeneration of the indigo crop 
has been found to be due to a gradual change in the gametic constitution of 
the crop which has been in progress since Java indigo was first introduced 
into Bihar. The evidence on which this conclusion is based has been arrived 
at from an investigation of the methods of pollination and fertilization of the 
indigo plant, a botanical examination of Natal indigo from which the Java 
plant was originally developed, a detailed study of the various indigos now 
grown in Java and of the constitution of the crop as cultivated in Bihar. 
Pollination and fertilization. 
All the species of indigo we have examined at Pusa, including Natal 
indigo and the various kinds now growing in Java, rarely set seed under net. 
The floral mechanism is of the ordinary explosive type designed to ensure 
crossing. Fertilization in Bihar is almost entirely brought about by insect 
visitors, the chief agents being two common Indian bees (Apis florea and 
Halictus gutturosus). Even in a single generation from self-fertilized seed 
there is a marked falling off in the size and vigour of the offspring so that both 
self-sterility and natural cross-fertilization have to be considered in any 
improvement by selection. 
Natal indigo. 
Java indigo was originally introduced into Java from Natal, where it was 
found growing in the wild state. Java indigo, as grown by the Dutch planters, 
is, however, quite a different plant from the wild indigo of Natal, and is said 
to have arisen by crossing between Natal indigo and one of the species formerly 
cultivated in Java. In 1913, through the good offices of the Hon’ble Mr. F. B, 
