128 DISEASES OF GLASSHOUSE PLANTS 
has previously been described as the cause of a very 
similar disease of the sweet-pea. 
So far little is known concerning the geographical 
distribution of the disease, but it is very common on 
tomatoes grown under glass in this country and in the 
Channel Islands. 
In many cases the disease is not of a very serious 
nature. By most nurserymen it is regarded rather as a 
nuisance than as a disaster, for, with care, a moderate 
crop of fruit can be obtained from plants which have been 
attacked. At times, however, the disease may be so 
prevalent as to ruin the whole crop. Sometimes, during 
the first years of a nursery, plants have shown a con- 
siderable amount of disease, but this has gradually 
diminished until only a small percentage of the plants 
has been attacked in the later years. Conversely, cases 
are known where “ stripe”’ has appeared and gradually 
increased after some ten or twelve years, during which 
time no sign of the disease has been observed. 
The disease may appear in the seed-boxes, producing 
rapid destruction of the young plants and compelling 
fresh sowings to be made; it is not uncommon to find 
the first symptoms of the disease while the plants are 
still in the small pots (sixties), or again after these have 
been planted out in the houses for a fortnight or so. 
Usually, however, the disease first appears about May, 
when the earliest fruit is ready for picking, but frequently 
no signs appear until the tops are allowed to develop, 
when these often become badly attacked. 
- There is a distinct connexion between soft and 
rapid growth and the incidence of disease; plants 
growing rapidly in the early stages are more liable to 
“ stripe’ than others of a hardier nature. In one case 
observed at Cheshunt the plants were so badly attacked 
that it seemed impossible for the crop to recover. The 
conditions were then altered so as to induce a slower 
rate of growth, with the result that the plants completely 
“orew out” of the “striped” condition, showed per- 
