24 



BULLETIIsr 821, U. S. DEPARTMENT OE AGRICULTURE. 



district at $190.04 per acre. The initial expense of tlie heating 

 equipment and the cost of maintenance would be much greater at 

 the present time (1920) than in 1913. However, the minimum 

 temperatures experienced in California lemon sections during the 

 last few years show that there is an ever-present danger of frost injury 

 to lemon orchards unless they are safeguarded by an efficient system 

 of heating. From the data presented in this bulletin and from 

 cooperative information secured from lemon growers in different 

 sections, it would appear that the installation of an orchard-heating 

 equipment would be justified not in the saving of one season's crop 

 but because of the frequency with which seasons of low tempera- 

 tures occur. 



Table XIX. — Initial investment for heating equipment and expense per acre for the 

 season of 1912-13 on a ranch of 186 acres at Corona, Calif., on which some of the inves- 

 tigational heated plats were located. 



Itemization. 



Per acre. 



By items. 



Total. 



Initial tavestment: 



S50. 17 



7.07 



17.49 



7.50 



3.89 



5.17 

 12.54 

 2.16 

 5.00 

 57.96 

 21.09 





Oil tank. 





Pipe for oil distribution system 



I $83. 12 







Labor, installing tank, pipe line, etc .' 





Cost of maintenance and operation for the season of 1912-13: 





25 per cent depreciation on heaters 





6 per cent depreciation on other equipment 





TTaTidlinP', painting, and filling hpatprs fp.'stimntfid) 





Oil consumed T. T 





T/abor in lighting and refilling hpn.tprs 









Orand total (if chargpd to any onp year),. 





190. 04 









Table XX. — Total estimated production by grades from plat 6, an acre of Lisbon lemon 

 trees, for each picking during the calendar year 1914. 



[The data in this plat were computed from, the individual-tree records of ten Lisbon lemon trees. This 

 plat was heated during the winter of 1913 and was selected for comparison with plat 8. in an orchard of 

 Lisbon lemon trees which was not heated during that period. The data from plat 8 for the calendar 

 year 1911 are shown in Table XXI.] 



Classification. 



Date of picking. 



Jan. 3. 



Peb. 14. 



Mar. 23. 



May 4. 



Junes. 



July 15. 



Number of fruits: 



Green grade 



30,260 

 730 



52, 120 

 7,210 



32, 580 

 2,210 



22,380 

 5,090 



8,640 

 2,360 



5,930 



Tree- Ripe grade 



1,790 





Total merchantable fruit 



30, 990 



59,330 



34, 790 



27, 470 



11,000 



7,720 







Cull grade 



320 



1,270 



1,660 



1,290 



340 



960 







Total 



31,310 



60,600 



36, 450 



28,760 



11,340 



8,680 





Weight of fruits: 



Green grade 



Lbs. oz. 



7,782 8 

 174 6 



Lbs. oz. 

 14,098 2 

 1,841 14 



Lbs. oz. 



8,999 6 



536 14 



Lbs. oz. 

 5,993 12 

 1, 206 4 



Lbs. oz. 



2,220 



545 



Lbs. oz. 

 1,440 



Tree-Ripe grade 



379 6 







Total merchantable fruit 



7,956 14 



15,940 



9,536 4 



7,200 



2,765 



1,819 6 







Cull grade 



48 12 



201 4 



267 8 



205 10 



62 8 



158 12 







Total 



8,005 10 



16,141 4 



9,803 12 



7,405 10 



2,827 8 



1, 978 2 







