HOWARD AND HOWARD 5 
exhibited all stages from healthy to wilted foliage. Counts were made on 
February 17th, 1919, with the following results (Table ITI). 
Taste III. 
Effect of cutting back indigo in the cold weather. 
a 
No. of row > ee ee Badly wilted Partly wilted Normal 
1 205 31 72 102 
2 176 50 ye AG 79 
3 os 136 46 36 54 — 
4 124 35 30 5 
ToTaL Si 641 162 185 294 
Thus more than half the plants cut back developed wilt.!. A number of 
root washings were made and in all cases wilt was found to be associated with 
the practical absence of root regeneration. These plants were kept under 
observation till April, by which time a remarkable change had taken place. The 
rise in the soil temperature in March and the improvement in the aeration of 
the soil caused the wilted plants to recover ; root regeneration took place and 
the growth became normal. 
Perhaps the most interesting case of the artificial production of wilt took 
place during the rains of last year. At the beginning of the monsoon of 1918, 
Java indigo was grown in two sets of lysimeters. These were air-tight cemented 
tanks 1/1000 of an acre in area, four feet high, built about the ground level 
and provided with drainage openings which could be closed at will. In 
one set, alluvial soil obtained from the Kalianpur farm near Cawnpore 
was used, in the other set, light Pusa soil was employed. Kalianpur soil 
is exceedingly rich in available phosphate (0°318 per cent) while Pusa 
soil, when analysed by Dyer’s method, gives very low figures for available 
1 The plants which developed wilt were those which had their laterals near the surface, 
the deeper-rooted plants produced normal growth. Thus the monsoon results are reversed 
during the cold weather. The explanation is simple. In the cold weather, the factor which 
checks root regeneration is low soil temperature. This affects surface-rooted plants much more 
than deep-rooted types, 
