40 DISEASES OF GLASSHOUSE PLANTS 
fungi, and it will thus be apparent that waterlogged 
conditions, although they may persist only for a short 
time, have a deleterious effect upon plants and reduce 
their resistance to disease. 
The appearance of plants grown under waterlogged 
soil conditions is admirably illustrated by an experiment 
conducted with tomatoes. A metal trough ten feet long, 
two feet wide, and two feet deep was placed on the 
ground and one end tilted up to rest on a support a 
foot high, as in Fig. 1. A perforated wooden board was 
BER EAE a a dione to-etiorgsia br the fomato. 
placed in the trough, resting on the bottom of the tilted 
end, laid parallel to the ground, and supported on bricks 
at the other end. The space between the board and the 
trough bottom was filled with water and a siphon with 
tap was fitted at the deeper end. Nine inches of compost 
was placed on top of the board, and six tomato plants 
(Kondine Red) were planted at equal distances. 
The soil was well watered, and after a time the level of 
the water was adjusted to the level of the board by 
means of the siphon, and was kept at this level throughout 
the experiment. The plants were numbered for purposes 
of description, No. 1 being at the low end of the trough 
and No. 6 at the tilted end. Within five days plant 
No. 1 began to show signs of ill health. The lower leaves 
turned yellow and withered and the plant showed no 
new growth. The yellowing and the withering of the 
leaves continued up the stem until in 17 days the plant 
was dead. Plant No. 2 developed similar symptoms in 
14 days and was dead in 43 days. In 31 days No. 3 
began to show signs of yellowing and lost the five bottom 
