develops first in fruit exposed to the direct sunshine on the south and 
west sides of the trees. Consequently, apples from the exposed south 
er west and top parts of the tree should be examined for water core. If 
water core is not found or if it is present in only a shght degree in fruit 
from these positions on the tree, 1t is improbable that it will be present 
to an injurious extent in fruit from more protected parts of the tree. 
ELAPSED TIME FROM FULL BLOOM TO PICKING 
MATURITY 
Magness et al. (74) and Palmer (16) observed that the number of 
days from full bloom to maturity was rather constant for a given va- 
riety even when grown under widely different climatic and cultural con- 
ditions. Further investigations of the reliability of this factor as a 
means of predicting apple maturity have been conducted in recent 
years (8).4. The results confirm the earlier observation that the num- 
ber of days from full bloom to picking maturity is rather constant over 
a wide range of climatic and cultural conditions and that this con- 
stitutes a more reliable index of maturity than any other single factor 
that has been suggested. Thus, the Delicious variety requires 145 to 
150 days from bloom to reach acceptable picking maturity, and this 
has been found under widely varying climatic, soil, and cultural condi- 
tions of Washington, Oregon, Dhinois, Ohio, Michigan, New York, 
and Maryland. It has not been possible to establish any influence of 
temperatures prevailing during the growing season on the elapsed time 
from bloom to maturity of apples although it may be a factor with 
other fruits. However, there have been some variations in elapsed 
time and certain factors undoubtedly influence this variation. Heavy 
nitrogen fertilization, for example, results in delayed color development 
of fruit and may result in greater scald development unless picking 
is postponed. On the other hand, dropping may be more pronounced 
from heavily fertilized trees than from trees not heavily fertilized. 
Because fruit from nitrogen-fertilized trees is likely to show poorer 
color and to be more susceptible to scald, it is usually desirable to post- 
pone the time of picking such fertilized trees if the fruit is holding well 
enough to permit it, and thus to increase the time interval from full 
bloom to maturity. Similarly, a very light crop of fruit is likely to 
mature earlier than a heavy one. The extent to which these or other 
factors may retard or advance maturity has not been fully established. 
The date of full bloom has been taken as the date when the first 
petals fall. Theoretically the date of full bloom should be the time of 
pollination or fertilization in the blossoms that set the fruit. During 
some seasons warm weather brings out all the blossoms in a very few 
days so that the time of full bloom can be readily established and 1s 
nearly the same for all blossoms. During other seasons, however, a 
_period of warm weather may bring the center or king blossoms into 
full bloom and may be followed by cool weather that will retard the 
opening and pollination of the other blossoms for a week or more. 
Under such circumstances there is likely to be considerable error in 
establishing the date of full bloom applicable to most of the fruit that 
sets. 
4 See footnote 2, p. 2. 
2 9 
602694°—44 
