Thinning of the Winesap. 19 
bloom or after the peaches have set. That after the peaches have 
leached some size they will stand a lower temperature for a short 
period of time. Peach trees well loaded with buds which show 
slight traces of pink, have often escaped with a good crop with a 
minimum temperature of 22 degrees. Fruit buds of apple and pear 
open far enough to show the flower tips, are seriously injured by 
temperatures lower than 20 degrees. When they are far enough 
advanced to show the color at the tips, they are generally only 
slightly injured by temperatures as low as 25 degrees. When in 
bloom and after the fruit is set, they will seldom stand temperatures 
lower than 28 degrees. Cherries, apricots, and most of the plums, 
will require about the same protection as peaches. Native plums in 
bloom or with fruit set will often stand a temperature of 25 degrees. 
It will be seen from the foregoing that the danger point in 
temperature varies for the different fruit sections and for the dif¬ 
ferent kinds of fruit. It may also vary in the same locality for 
different years and several years’ observations will be necessary in 
order to get full data on all the conditions that have to do with re¬ 
sistance of freezing temperatures. 
Careful study of the weather conditions should be made when 
orchard heaters are used. Some money can be made in the saving 
of fuel by starting and putting out the fires at the proper time. Oil 
heaters when fired can be put out and relighted instantly, while coal 
is very hard to relight. A good plan is to commence lighting the 
heaters when a temperature of 30 degrees is reached. If the tem¬ 
perature can be kept at 29 degrees or above, as a rule, there will be 
little damage done to the bloom or set fruit. The writer has seen, 
with systematic handling of the heaters, a temperature of around 21 
outside raised to 29 degrees in the orchard. It is thought there is no 
harm done to the trees in the spring from a small amount of oil 
spilled in the orchard, nor from the gases, soot, etc., which come 
from the coal and oil. 
