juh- 15. 1919 Relation between the Flowers and Fruits of the Lemon 1 63 



a large plantation, receiving regular orchard treatment during the time 

 obser\^ations were being made, and exposed to the vicissitudes which 

 beset the commercial orchards. The effects of winter cold and of sum- 

 mer heat are plainl\' \'isible at places in the records, yet there is no reason 

 to expect that the average lemon tree may escape the vicissitudes which 

 befell these. The figures showing the proportion of buds which develop 

 into mature fruit were based only upon observations made early enough 

 to allow fruit to mature before the close of the observations. 



Several definite stages in the development of fruit have been recog- 

 nized in making this study. They are as follows: (i) the plump bud 

 just ready to open; (2) the flower; (3) the first stage of the fruit at which 

 the corolla has fallen but the style is still attached, designated for con- 

 venience "style attached"; (4) the young fruit having a diameter of 

 % inch and having lost the apical portion of the style; (5) the fruit 

 having a diameter of 2% inches, ready to pick. 



The individual histories of a random sample of lemon buds were 

 followed from stage to stage to see what proportion survived and to 

 locate, approximately, the time of heavy mortalities. A sample of 

 4,440 buds which appeared during the observation period was chosen. 

 Their developmental history is shown in Table VIII. 



Tabi,E VIII. — Ratio of lemon buds to fruits -which reached various stages 



Stage ol developiQent. 



Number 

 observed. 



Buds ready to open. . . 



Styles attached 



Fruit X inch diameter 



4,440 

 2,308 

 964 



Fruit mature 294 



100. 00 



51.98 



21. 71 



6.62 



These figures sho^v that there is a large mortality between the young 

 buds and the mature fruit, and that the mortality seems to increase 

 with the age of the fruit. It should be stated, however, that losses 

 were comparatively small after the fruit had reached a diameter of 

 I inch. There is no reason, however, to regard the losses of fruit on 

 these trees as abnormally high, since the crops produced on these trees 

 were above the average for this district. 



The effect of seasonal conditions upon the survival of young fruits 

 seemed worthy of study in determining the ratio between buds and 

 fruit. Since the time at which the fruit sets is the time at which it 

 begins to grow, calculations were begun with the stage designated 

 "style attached." Data were available for 2,453 fruits of this size 

 which had the chance of developing into mature fruit during the time 

 observations were made. Records were taken of the numbers of fruits 

 reaching this stage in each month and of the numbers which matured 

 from each of the several samples of "style attached" fruits. 



