TOMATO LEAF MOLD 



19 



Table 6.--Temperature and Relative Humidity in Greenhouse Planted 



TO Tomatoes 



(Readings on rainy day in April. 1929: outride relative humidity, 100 percent) 



Air Relative 



Temperature Humidity 



°F. Percent 



Hour 



Position of Hygrometer 



In corner near plants 



At fan 



In corner near ground 



At fan 



Between rows near ground 



At foliage 



At fan 



Between rows 8 inches from ground 



At fan 



At foliage 



At fan 



In draft halfway between fan and ground 



Between rows 8 inches from ground 



At foliage 



At fan 



This is substantiated further by another set of readings (Table 7) obtained 

 during rainy weather and when the greenhouse atmosphere was stirred by ventila- 

 tion rather than by the motions of an electric fan. As the readings reveal, the 

 influence of ventilation during wet weather conditions outside on the relative 

 humidity inside is quite insignificant in the absence of heat. Under these condi- 

 tions, the air at the leaf surface is saturated with moisture. 



Table 7.-Temper.\ture and Relative Humidity in Greenhouse Planted 



TO Tomatoes 



(Readings in moi?t. cloudy weather) 



Ventilation 



Hour 



All ventilators and 



doors open 4:00 p.m. 68 88 66 100 



All ventilators open . 2:00 p.m. 62 100 61 100 

 All ventilators and 



doors open 8:00 p.m. 64 94 63 100 



Top ventilators open 9:00 a.m. 62 100 61 100 



Top ventilators open 2:00 p.m. 71 88 70 100 



