BUD VARIATIOiSr IN THE EUREKA LEMON. O 



few blossoms or fruits. The fruits wen; usuaJly ridged, rougli in 

 texture, ^vith very thick peel and very little juice (PL II), in strik- 

 ing contrast with the smooth, ver}' juicy, and thin-skinned (PI. I) 

 lemons borne by most of the trees. The unproductive trees were 

 usually much larger than the productive ones, and the foliage was 

 characteristically more dense and abundant. For these reasons they 

 were commonly called shade trees. 



The difTerencos in tree and fruit cnaracteristics of the two types 

 of trees were so distinct and marked that typical trees of each strain 

 could be determined at a glance and from a considerable distance. 



A careful individual-tree census of the 16,000 lemon trees in this 

 orchard was made during June and July, 1911. As a result, 2,200 

 trees, or 14 per cent, were found to have typical characteristics of the 

 Shade-Tree strain. Furthermore, the systematic study of the trees 

 revealed the presence of other undesirable strains not noticed at first. 



In order to throw some light, if possible, upon the large proportion 

 of unproductive trees in this orchard, an individual-tree census was 

 made of the parent orchard from which the buds had been procured. 

 It was found that in the parent orchard only 5 per cent of the total 

 number of trees were of the Shade-Tree strain. The explanation of 

 this condition was found to be that the bud cutters found it easier 

 to secure bud wood from the vigorous vegetative shade trees than from 

 the less vigorous growing productive trees. There were many more 

 vegetative branches, then commonly used for propagation, in the 

 shade trees than in the productive trees. Consequently, without 

 careful individual-tree selection based on performance records, the 

 bud cutters naturally secured more bud wood from the shade trees 

 than from the productive trees. 



Characteristic differences in the trees of the several strains of the 

 Eureka lemon variety were found to exist not only as shoA\Ti by the 

 habit of growth, the amount and the commercial quality of the 

 fruits, the densit}^' and other characteristics of the foliage, but also 

 in the season of production of the fruits, the number and size of thorns, 

 the number, size, and shape of the seeds contained in the fruits, the 

 structure of the flowers, and the variability of the fruits. 



Tree-census studies in many Eureka lemon orchards have revealed 

 the fact that the variety is made up of a number of diverse strains 

 arising from the propagation of striking bud variations. This con- 

 dition of variability is imj^ortant commercially, from the fact that 

 the production of some of the strains is small and of very inferior 

 quality, wliile other strains bear their crops during the late fall or 

 very early spring when low lemon prices are the rule, making the crops 

 of inferior value. 



