7i 



The Journal of Heredity 



been made from the performance record 

 trees since the beginning of these in- 

 vestigations. The jiick of each tree is 

 sorted into various definite and clear- 

 cut grades, and the number and weight 

 of the fruits in each grade have been 

 carefully determined and recorded. The 

 variable fruits from each tree have Ijeen 

 sorted, classified, and the number and 

 characteristics of each kind recorded. 

 Any notes as to variable limbs, or 

 other interesting facts of tree behavior 

 have been recorded when observed, 

 with the data from each tree, in regular 

 forms printed in field note-books for 

 this purpose. These data are then 

 transferred to annual i^erformance rec- 

 ord forms, arranged for the convenient 

 comi)ilation on one page of all of the 

 picks from a tree during the year. 

 Finally, the annual production data of 

 each tree are transferred to period 

 performance record forms where the 

 simimaries of several years' records 

 can be brought together, and where all 

 available information concerning the 

 individual trees can be collected for 

 study. 



The lemon ]:)erformance record data 

 and observations accumulated in these 

 investigations ha\'e furnished a large 

 amount of interesting material for 

 study. One or more men have been 

 continuously engaged on this subject 

 from the incei)ti()n of these studies until 

 the present time. Additional assistance 

 is now needed in order to secure more 

 extensive and adequate progeny records. 



SOME IMPORTANT STRAINS 



The important strains of the lemon 

 varieties in the ])erformance record 

 Idiots are distinguished by the habit of 

 growlh of the trees; characteristics of 

 the bloom; season and amount of pro- 

 duction of the fruits; size, shape and 

 color of the fruits; texture, thickness 

 and appearance of the rind; amount 

 and quality of the juice, and other tree 

 and fruit characteristics. 



The habits of tree growth of the 

 various strains include the ()i)en, erect, 

 upright, spreading and droojnng, and 

 drooping ]jositi(}ns o{ the branches. 

 The habit of growth is usually corre- 

 lated, in some degree, with the density 



of the foliage and leaf characteristics. 

 For example, the Eureka tree, ha\dng 

 an open habit of growth, usually has a 

 rather sparse amount of foliage, and 

 the leaves are usualh- of medium size 

 and bluntly rounded in shape. The 

 spreading type of Eureka tree, on the 

 other hand, has characteristically dense 

 foliage and the leaves are usually large 

 and sharply pointed. 



One strain of the Eureka lemon, 

 commonly called the shade tree, de- 

 velops a large percentage of abnormal 

 blooms. In these blossoms, the pistils 

 are rudimentary or absent, so that 

 shortly after blooming, these flowers 

 fall on the ground. The trees of this 

 strain produce an unusualh- large quan- 

 tity of flowers, more perhaps, than the 

 trees of any other lemon strain in the 

 performance record plots. The trees 

 of the productive strain of the Lisbon 

 variety yield crops more evenly dis- 

 tributed throughout all seasons of the 

 year than the trees of the dense strain, 

 which bear most of their crop during 

 the spring months. The trees of the 

 productive strain of the Eureka variety 

 have a strong tendency to produce 

 fairly regtilar monthly crops, while the 

 trees of the shade tree strain produce 

 their crops mostly during the fall 

 months. 



VARIED PRODUCTIVITY 



The trees of the productive strain of 

 the Eureka variety have produced 

 annually, on an average, more than 

 five times the quantity of lemons pro- 

 duced by the trees of the shade tree 

 strain, under the same conditions. 

 Similar difTerences in the amount of 

 annual production of other strains of 

 the lemon varieties have been found. 



Inasmuch as lemons are picked green 

 when reaching a certain size, which is 

 measured by slipping an iron ring over 

 the fruit, the variation in sizes of fruits 

 borne by trees of the different strains is 

 not so marked as is the case with 

 oranges or other fruits which are allowed 

 to reach full size on the trees. How- 

 ever, the fruits of some lemon strains 

 reach the size required for jjickiTig more 

 (luickh- than those of other strains. 



There is a marked (v>rrelation in the 



