THE WILT DISRASE OF PIGEON-PEA. 17 
: Date of sowing 
No. of plants. Treatment. andinnealdian. Result. | Remarks. 
17 plants in | Not inoculated (con- | _Sown on 1-11-08, | No deaths up to 
2 pots. trol). 5-3-09. 
About 50|Sown in soil previ- | Sown on 28-3-08. | 
; No death up to| Transplanted to 
plants in 3) ously inoculated | 26-10-08, | garden soil on 
pots. with indigo Neocos- | 1-7-08, the plants 
; mospora. ; having become too 
8 plants in 2) Inoculated with) big for the pots. 
pots. gram Neocosmo- | Sown and inocu- | No deaths up to | hee another experi- 
spora. | lated 1-11-08. 5-3-09. ment pigeon-pea 
was sown in 4 pots 
previously inoculat- 
ed with gram Neo- 
cosmospora. 45 
plants grew and no 
| deaths occurred in 
| 
44 months. 
17 plants in | Not inoculated (con- | Sown on 1-11-08. 
2 pots. trol). 
Attempts to produce pigeon-pea wilt by inoculating with 
ascosporal cultures of Neocosmospora obtained from the roots of 
wilted cotton, indigo and gram failed. 
Summary of experiments with Neocosmospora vasinfecta 
Smith on Pigeon-pea. 
The above experiments (Series V to X), in which attempts were 
made to induce pigeon-pea wilt by imoculating with Neocosmo- 
spora, may now be considered as a whole. Apparently successful 
results were obtained in Series V (one pot out of six moculated), 
Series VII (four plants out of fifty inoculated), and Series VIII 
(seven plants out of several hundred inoculated). 
In each of these cases the experiment was not carried out under 
conditions which precluded the entry of foreign spores. In Series 
V the pots and seed were not sterilised, and it is proved by Series 
VI that the infective material did not arise from the tube with 
which the inoculation was made. Further work, the details of 
which will be found under Series XIV on p. 36 below, showed that 
the soil of this pot contained eventually another fungus which there 
is abundant evidence to prove is the real cause of pigeon-pea wilt. 
Series VII and VIII were field experiments, in which, of course, the 
soil was not sterilised. The four deaths out of the fifty moculated 
2 
