12 BULLETIN 815, U. S. DEPARTMENT OF AGRICULTUEE. 



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 tim.e 

 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 strain 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. 



