12 BULLETIN 815, U. S. DEPARTMENT OF AGRICULTURE. 
PRESENTATION OF DATA. 
The diagrams and tables presented herewith in summarizing the 
studies on the Lisbon lemon variety have been prepared from indi- 
vidual-tree performance records of 128 trees located in a 100-acre 
orchard near Corona, Calif., which was planted in 1893. Only a few 
crops of winter barley had been grown on the property prior to that 
time. Records were begun on 113 of these trees in July, 1913. Two 
months later, one of the trees adjoining this block was found to be of 
the Sporting strain, and it was included in the record plat. Because 
of the small crops borne by the tree at that season, its record for that 
year has been summarized as though the 12 months were represented. 
An additional block of 14 trees, among them being several represent- 
atives of the Bull strain, was added to the plat in July, 1914. 
The orchard where these trees were located was protected by 
orchard heaters from the frosts of the winter of 1912-13, and very 
little injury occurred to the trees or fruit. The excessive number 
of fruits of the Cull grade recorded in October, 1913, and to some 
extent in December, were put in that grade because they showed 
slight injury from the frosts of the previous winter. Performance 
records were secured on the Lisbon plat continuously from the time 
of its establishment until June, 1917, inclusive, a 4-year period for 
the 114 trees first selected and a 3-year period for the remaining 
14 trees. Seven trees of the Open stram near the center of the origi- 
nal plat became badly diseased in 1915 and were given a severe 
pruning and other treatment to restore them to normal production. 
On this account these trees have been omitted in summarizing the 
records presented herewith. 
Included in the 121 trees for which records are presented are repre- 
sentatives of the five Lisbon strains, as follows: Lisbon, 22; Open, 
77; Bull, 11; Dense Unproductive, 8; and Sporting, 3. © 
The average annual crop of each of the 121 trees in the investiga- 
tional plat of Lisbon lemons is shown in Table I, which also shows 
the percentage (by weight) of green fruits produced, the percentage 
(by number) of variable fruits, and the average number of seeds per 
fruit for each of the trees. The trees are listed in this table in the 
order of their average annual production by weight. The trees of 
the Bull strain are large and vigorous growing and produce heavy 
crops, but their fruit is coarse, thick skinned, and much less desirable 
than that borne by the trees of the Lisbon strain. The trees of the 
Sporting strain may bear heavy or light crops, but because of the 
variable character of the fruit those trees are very undesirable, from 
the standpoint of both the producer and the propagator. It is inter- 
esting to note that Table I shows that 18 of the 22 trees of the Lisbon 
strain occurring in this plat averaged heavier crops than any other 
trees except some of those of the Bull and Sporting strains. 
