Choanephora cucurbitarum, (B. and Rav.) Thaxter, 
on Chillies (Capsicum spp.). 
BY 
JEHANGIR FARDUNJI DASTUR, M.Sc., 
Supernumerary Mycologist , Pus a, India. 
With Plate XIX. 
I N 1917 considerable damage was for the first time observed in chilli 
plants at Pusa and other chilli-growing tracts, north of the Ganges 
(India), by a new disease, caused by a species of Choanephora. In previous 
years it had not been found to be parasitic on this host, though it had been 
seen on fading flowers and dead twigs. In 1917 conditions of high humidity 
were generally prevalent in the last week of September and in the first week 
of October, when the plants had commenced to flower, and these conditions 
are believed to be correlated with the epidemic caused by this faculative 
parasite. It was first found on a few plants on September 30th, and was 
present in the fields till about the end of November. It was most virulent 
in about the second week of October. In 1918 careful search was made 
for this disease in Pusa and in the neighbouring villages, but not a single 
case was found. This maybe due to the abnormally dry weather conditions 
prevalent in September and October. 
The general appearance of the infected crop in the early stage of attack 
is not much unlike another disease, which does great damage in Behar, and 
which is caused by Vermicular ia capsici , Syd., an account of which will 
be published later. There is the same drooping of the topmost tender parts 
of the plants and the dying back of the branches. But on a closer exami- 
nation the effects of the Choanephora disease are very characteristic. The 
diseased parts show a distinct wet rot and are soon covered by a luxuriant 
crop of shining silvery conidiophores, without any trace of external vegeta- 
tive mycelium. Unlike Vermicularia capsici , Choanephora attacks the 
leaves as well as stems ; it does not produce on the infected stem the chalk- 
white areas, delimited by a black border, so characteristic of V. capsici. 
The first evidence of the attack is generally when the flowers have 
opened ; the infection starts from the flowers, as a rule, and sometimes also 
through the flower-buds. The flower first turns brown and then black, and 
[Annals of Botany, Vol. XXXI V. No. CXXXV. July, igao.] 
