62 BULLETIN" 813, U. S. DEPARTMENT OF AGRICULTURE. 
The notes that follow regarding some of the methods of recording 
and compiling the data presented in Table VIII may assist the 
reader to understand and interpret it. 
The continuity of the records on this plat was badly disturbed by 
the severe freeze in the early part of January, 1913. It will be noted 
in Table VIII that no pickings were made from February to No- 
vember, 1913. In summarizing the records it has been considered 
that all the trees were affected to practically the same degree, and the 
crops recorded during this experiment have been credited as the 
production for the 6-year period. This procedure necessarily results 
in a decreased average annual yield as an index of the performance 
of the individual trees. However, this is not a serious matter, 
inasmuch as these studies are based primarily upon the relative 
character and behavior of the various strains, and their differences 
are as apparent during periods of unfavorable conditions as at times 
when production is normal. 
Spaces left blank in these records indicate that no fruit was picked 
at that time. The absence of fruit of any special grade or of seeds 
at any time when a picking was made is indicated by zero. 
The fruits of the Cull grade were not recorded separately until 
February, 1912. Previous to that time they had been included with 
those of the Tree-Ripe grade, and it is not possible to separate them. 
In endeavoring to make pickings every month, unavoidable delays 
were sometimes occasioned by unfavorable conditions of climate, by 
interfering periods of irrigation, or from other causes. In this way 
it sometimes happened that the interval between pickings was con- 
siderably prolonged beyond the 30-day schedule time. Because of 
the longer time required to secure the records at seasons when the 
crop was increasing in amount it was necessary to begin the picking a 
few days in advance of the corresponding date in the previous month. 
Unfavorable weather conditions during the winter season often 
delayed the progress of the work from a day to a week at a time so 
that during that period it was usually necessary to keep at the record 
work continuously in order to forestall unforseen delays and inter- 
ruptions. The ideal way to obtain data such as these would be to 
determine the number of days required to make the records at the 
season when the crops were lightest, then to have a sufficient number 
of trained men available so that the work could be begun on the cor- 
responding date each month and completed in the same minimum 
number of days, regardless of the weather or other unfavorable con- 
ditions. However, this ideal is impossible of attainment under 
practical conditions. 
Table IX records the first and last dates of each period for picking 
lemons on the Eureka study plat. As already stated, no records 
were made from February to November, 1913, on account of the 
