878 
Journal of Agricultural Research 
Vol. XXXI, No. 9 
DIFFERENTIATION AND DEVELOPMENT OF FRUIT BUDS OF THE PEAR GROWN 
UNDER THE VARIOUS CONDITIONS 
Heavy and Light Pruning Compared 
Up to July 20 buds from the heavily pruned and irrigated pear 
tree were slightly more developed than those from the lightly pruned 
and irrigated pear trees at the university farm (fig. 2). After that, 
however, the slight differences that existed fluctuated from one to the 
other, so that on the average they were uniform in development from 
August 1. As previously stated, these two trees did not show condi¬ 
tions as extreme as would have been desirable. The lightly pruned 
tree blossomed about two days earlier than the other. The blossom¬ 
ing of lightly pruned trees somewhat sooner than heavily pruned 
ones has been noticed in previous years also. 
July 10 July 20 Ku&l MuflO 
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A PI ft ^ 
3 ft ft ft 
ft 
ft I fi 
Hup. to St pi. I Stpl.rs Oct. I 
Ph ft ft W 
Interior Valley . Lightly Rruned . Irrigated 
Interior Valley. Heavily Pruned . Irrigated 
h ft n H 
Interior Valley. Lightly Plruned , NonJrriyated 
ft Y ft 
Coast . Heavily Pruned . Irrigated 
Cooat . Heavily FYvned . Hon-lrrivaled 
ft, ^ ft ft 
Coast . Lightly Pruned . Mon-Irrigated 
P ft 
Sierra Foothills.Lightly Pruned . Irrigated 
$ (ft) \%J) 
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w 
Seasonal Development 
of Bartlett Pear 
Fruit Buds in 1922-23 
as Influenced by the 
Conditions Indicated 
Fig. 2.—Outline drawings of longitudinal sections through Bartlett-pear fruit buds, showing the average 
stages of development on the various dates and under the various conditions 
Although lightly and heavily pruned nonirrigated trees were 
observed in Sonoma County, the two trees did not grow near each 
other or on similar soil. However, when the comparison (fig. 2) was 
made between the two trees, it was found that the lightly pruned 
tree as compared with the heavily pruned one was in a more advanced 
stage of development when first examined (July 11) and kept slightly 
in the lead until August 21. At this date and afterwards the develop¬ 
ment was approximately the same under the two conditions. 
Irrigation and Nonirrigation Compared 
On the university farm the fruit buds from the nonirrigated pear 
tree were farther advanced than those from the irrigated tree on July 
7 and 20 (fig. 2). After the latter date, however, slightly the reverse 
