VIII 



PEPPERS 281 



from 5 to 10 or 15 yds. square, and I may say, killed them off 

 outright. As regards the pepper vines, most are attacked at 

 the root, though some are attacked a few feet from the ground, 

 and very soon afterwards the vine dries up, having affected 

 most of the other vines in the neighbourhood. I have tried 

 coal tar mixed with water, and paraffin oil, also mixed with 

 water, all to no purpose, but I have found great benefit from 

 the application of fires lighted in large numbers throughout the 

 affected parts, though a great number of vines get scorched and 

 die afterwards. 



Of this Mr. Massee writes : 



The material sent shows that the pepper fungus can 

 reproduce itself by two different methods. 



1. The most general form, and the only one when the disease 

 spreads from a centre, is by mycelium or spawn, which travels 

 in the soil, spreading from plant to plant and destroying the 

 roots. When such centres of disease are found they should be 

 at once isolated by digging a narrow trench, about 10 in. deep, 

 round the diseased patch, thus preventing the outward spread 

 of the mycelium, which cannot pass the trench. As there is 

 no cure for the plants when the roots are attacked, it would 

 be best to remove and burn all plants within the affected area, 

 otherwise the diseased plants will form a centre of infection by 

 another method. 



2. If the stem of a plant that has been diseased at the root 

 for some time is examined, very minute black lumps, just visible 

 to the naked eye, will be seen scattered over the surface, and in 

 addition small velvety black patches are also very frequently 

 present. 



These are two distinct fruiting conditions belonging to the 

 fungus, each of which produces myriads of conidia or very 

 minute reproductive bodies which are dispersed by wind and 

 inoculate other plants. By this method the plants become 

 diseased above ground, while the roots remain healthy. 



Nothing short of prompt destruction by burning of all plants 

 showing such black lumps or velvety patches can prevent the 

 disease by diffusion of conidia. As conidia are dispersed 

 mostly by very low currents of air, screens of branches might 

 with advantage be erected between the plantation and the 

 affected forest region. 



The benefit derived from the fires is explained by the fact 

 that each fire forms a vortex, through which a certain volume 

 of spore-laden air passes and is purified. 



Where the root form of the disease has shown itself, it 



