BUD VAKIATION JlSf THE LISBON LEMON. 5 



The original plat included 113 trees. Later additional trees which 

 represented important strains were added to this number in order to 

 secure as complete informatioji as possible concerning variability 

 within the variety. 



METHODS OF KEEPING PERFORMANCE RECORDS. 



The same general methods of keeping performance records as those 

 governing the work with the Eureka lemon were followed in the studies 

 of variations in the Lisbon variety. These methods involve consid- 

 erably more detailed observation than is usually considered necessary 

 in commercial orchard practices. A method which has been adopted 

 for commercial lemon-tree record keeping is described in Farmers' 

 Bulletin 794, entitled "Citrus-Fruit Improvement: How to Secure 

 and Use Tree-Performance Records." 



Each of the trees in the performance-record plat was given an 

 individual-tree number which consisted of three parts: (1) The 

 number of the block in which the tree occurred; (2) the number of 

 the row in the block, counting from some fixed point; and (3) the 

 number of the tree in the row. This number was painted in a ver- 

 tical position on the tree trunk. The fruits from each tree were 

 picked at monthly intervals. The size of the fruit to be picked was 

 determined by means of metal rings similar to those used by the 

 regular picking crew in the orchard. While the size of the rings 

 varied at different seasons of the year, no change was ever made 

 during any one picking, so that the crops from, the individual trees 

 each month were comparable with each other. The fruit from each 

 tree was kept separate, and the lemons after picking were assorted 

 into three grades, namely. Green, Tree-Ripe, and Culls. The Green 

 grade was made up of the valuable commercial fruits and included 

 both dark and light green lemons; the Tree-Ripe grade was made up 

 of mature or prematurely ripened fruits, which usually were of 

 small size and thin rinds; and the fruits of the Cull grade were fre- 

 quently extremely coarse or malformed. In addition, all lemons 

 which dropped to the ground between picking periods were included 

 in the Cull grade. The number and weights of the lemons in each 

 grade were secured, and all variable fruits were sorted out and classi- 

 fied. One lemon of each grade was taken from the crop of each tree 

 at each picking and the number of seeds counted. In the event that 

 any samples of fruits of any grade were missing, so that the seeds could 

 not be counted, a note of this fact was made in the field form by using 

 the words ''No count." 



All the data obtained in the field were recorded in special field note 

 forms. As soon as practicable after each picking these data were 

 transferred to forms which provided for a maximum of twelve pickings, 

 or the monthly pickings for one year. When the complete record for 



