THE CONTROL OF TOMATO LEAF-SPOT 7 
One of the greatest objections to the use of southern-grown tomato 
plants is the danger of introducing serious diseases. This 
has already happened in Indiana. For the past eight years the 
tomato-wilt fungus has been carried into the fields of this State 
through the use of large numbers of uninspected southern-grown 
tomato plants. These small infestation spots will gradually spread 
until they become a serious factor in tomato production. Root-knot 
is another disease often carried on tomato seedlings shipped from 
the South. In 1923 the State entomologist of Indiana found nema- 
todes (the cause of root-knot) on some southern-grown tomato 
plants and tried to inspect all subsequent shipments coming into 
the State. During the remainder of the season he condemned ap- 
proximately 2,385 cases of tomato plants on account of root-knot. 
Some of these showed only a scattered infestation throughout the 
crates, but others were severely affected. The shipment of infected 
seedlings even for this one year would have been sufficient to cause 
a widespread distribution of the root-knot nematode in the State if 
the plants had not been condemned and destroyed. There are sev- 
eral other fruit and stem parasites of the tomato that may be 
carried into northern fields in the same manner. 
The production of southern-grown plants by the companies using 
them is a safer practice than to buy them in the open market. With- 
out some such direct connection between user and grower that will 
insure a supply of plants of the proper age, size, variety, and condi- 
tion, the use of southern-grown plants in the North is attended with 
much danger. 
Owing to the danger of introducing serious tomato diseases, the 
use of southern-grown tomato plants can be recommended only when 
they are properly grown on clean land and when every possible pre- 
caution is taken to keep them free from disease. The plants should 
be grown from high-grade seed of the varieties and strains best 
adapted to the conditions and uses of the locality in which the crop 
is to be grown. The plants themselves should be large, stocky, well 
rooted, and fairly well hardened at the time of shipment. In lifting 
the plants care should be taken to retain their roots, and they should 
be so packed that they will carry to destination in good condition. 
With these assurances and precautions, great possibilities are doubt- 
less afforded by the use of southern-grown tomato plants. The 
northern tomato grower, however, ma} 7 gain little financially or 
otherwise from the use of these plants as compared with those grown 
locally in hotbeds and coldframes. 
PREVENTION OF OVERWINTERING 
The marked effect of soil on the overwintering of Septoria sug- 
gests the possibility of preventing leaf-spot epidemics by thoroughly 
ploAving under all dead tomato vines and other Septoria-infested 
material in the fall to prevent the fungus from living over winter. 
Some field experiments were made to test the effect of this practice. 
Four isolated plats which lay at some distance from other tomato 
fields and which had never been cropped with tomatoes or at least 
not for many years were selected for this purpose. Two of these 
were on high land and two on low parts of the farm. On one high 
and one low plat tomato stems and leaves infected by Septoria were 
