ATMOSPHERIC TEMPERATURE. 61 



overhead less heavily than would be necessary in 

 the case of trees forced under more favourable con- 

 ditions as regards light and sunshine. 



ATMOSPHERIC TEMPERATURE. 



The trees should be started with a minimum 

 night temperature of from 40 to 45, according as 

 the weather is cold or mild, and 50 to 55 in the 

 daytime with fire-heat, rising 10 or 15 higher with 

 sun-heat. These temperatures are meant to be 

 observed in houses closed about the first week in 

 December. Houses closed a month later may be 

 safely given 2 or 3 more of heat all round to 

 start with. When the trees are in flower the 

 temperatures should range from 45 to 50 at night, 

 and from 55 to 60 with fire-heat by day, rising 

 from 70 to 75 with sun-heat, fresh air being 

 admitted to the house meanwhile. When the fruit 

 is set, a rise of 5 in the temperature all round 

 should be observed in the house until the fruit 

 has stoned. From this important and interesting 

 stage of growth until the fruit approaches maturity, 

 the temperature should range from 65 to 70 at 

 night, 70 to 75 by day with fire-heat, 80 to 85 

 with sun-heat, air being .given at 80, increasing 

 and decreasing the quantity given according to the 

 rise and fall of the thermometer until closing-time 



