58 



BULLETIISr 815, U. S. DEPARTMENT OF AGRICULTURE. 



Further study of the seasonal variations in production from the 

 east and west sections of the investigational plat is afforded by 

 Table X, in which the total production at each picking period, 

 including the fruits of the Cull grade, is expressed in terms of field 

 pickuig boxes. It is interesting to study this table in the light of 

 the data presented in Tables V and IX, showing the picking dates 

 and the sizes of the picking rings used for fruit of the Green grade 

 throughout the period during which these records were obtained. 

 Such study will show the reasons for the variations stated in Table X, 

 which at first appear to be incorrect. For example, during the 

 first three years there is recorded a very heavy increase in yield from 

 December to January, notwithstanding that Table V shows that the 

 mtervals between those pickings were less than 30 days. In 1916-17 

 there was a decrease in production at that period, although the inter- 

 val between the pickings was 33 days. The explanation is found in 

 Table IX in the use of a ring of a smaller size for the January picking 

 during the first three seasons and the use of a larger sized ring in 

 January, 1917. 



Table X. — Total fruit yields of the lemon trees of the Lisbon variety in the investiga- 

 tional performance-record -plat for each month during the 4-year period from July, 1913, 

 to June, 1917 , inclusive. 



[The yields are expressed in terms of the number of field boxes of fruit. Records on 14 of the trees in the 

 west section of the plat .were begun in July, 1914. Eleven of these trees were of the Bull strain.] 





Number of field boxes of fruit produced. 



Month. 



East section of plat, 106 trees. 



West section of plat, 15 trees. 





1913-14 



1914-15 



1915-16 



1916-17 



1914^15 



1915-16 



1916-17 



July 



61§ 

 32i 

 11 

 46 



43J 

 12J 

 15f 

 481 

 47f 

 79 



179 



206§ 



246 



184 



73i 



66 



26 



22 



57i 

 105f 

 113 ' 

 113f 

 140§ 

 117f 



88i 



59i 



12 



Hi 



27 



21 



63 



45J 

 192 

 235 



2 



6f 



3i 



3 



2J 



9§ 



241 



36 



27i 



25 



34J 



12 



lOJ 



4 





i 



September 



61 

 36 

 19i 

 20 



48 

 28 

 39 

 29J 



2 

 14 



November 



25i 



December 



60 

 200 

 409 

 204 



29J 

 16§ 



February. . . . 



34J 





28 



April. 







186 

 70 



479 

 237 



397 



67i 







25 



35J 







Total 



1,279 



1,594J 



1,1081 



1,111 



253-i 



195 



190 



Heaviest 



February . 

 September 



March 



August — 



April 



November 



March 



September 



January... 

 July 



January. . . 

 October... 



February. 



Lightest 



August. 



Similarly, Table X shows a decrease in yield from February to 

 March, 1914, with a picking interval of 36 days, and practically no 

 change in the production for that period in 1916, with a picking inter- 

 val of 30 days, while there was an increase in the crops for that month 

 in 1915 and 1917, with picking intervals of 21 and 33 days, respec- 

 tively. Table IX shows that a change was made in March, 1914, and 



