FROST PROTECTION IN LEMON ORCHARDS. 



19 



Munerg 

 r/ruirs 



effect of even a small number of heaters in an orchard, but also 

 presents strikingly the value of efTicient heating in orchards, as the 

 number of merchantable fruits produced during the 

 year 1913 in the adequately heated orchard is much 

 greater than that produced in the partially heated one. 

 Table XV shows the percentages of fruits by 

 grades for each picking during the calendar year 

 1913 in the nonheated plat 1, an acre of Lisbon lemon 

 trees, as compared with the heated plat 4. The 

 percentages of frozen and merchantable fruits in 

 these plats are shown graphically in figure 9. A 

 study of this diagram shows that in the heated plat the 

 percentage of merchantable lemons during February 



was 76, 

 while 

 in the 

 n o n - 

 heated 

 plat 

 the 



- .-nn ., 



a c . .A Hr. A a c . 



^nll ■/,^ilnr r 



Fig. 8. — Diagram showing the number of frozen and merchantable fruits produced on plat 3, 

 a nonheated acre of Eureka lemon trees, plat 5, a partially heated acre of Eureka lemon 

 trees, and plat 7, an efficiently heated acreof Eureka lemon trees. The figures here shown 

 are taken from Tables VII, IX, and XI, respectively, which give^the estimated production 

 by grades for each month's picking for these plats during the calendar year 1913. 



per- 

 cent - 

 age of 



merchantable fruits was zero. At no time during the calendar year 

 did the curve of merchantable fruits in the heated plat fall below 

 the curve of the same class of fruits in the nonheated one. Cor- 

 respondingly, the curve of the frozen lemons shows a relatively 

 higher percentage during all the pickings up to October in the non- 

 heated orchard, as compared with a low percentage of this class of 

 fruits in the heated one. 



Table XV. — Percentages of fruits by grades produced in the nonheated acre of Lisbon 

 lemon trees, plat 1, as compared with the heated acre, plat 4, during the calendar year 

 1913. 



[These percentages are computed from the total number of lemons produced by these plats as shown in 



Tables V and VIII.] 



Grade and condition. 



Date of picking. 



Feb. 14. 



Apr. 7. 



May 14. 



June 24. 



Aug. 11. 



Sept. 12. 



Oct. 26. 



Dec. 12. 



Green grade: 



Not heated 



Heated 





 43.35 





 32.81 





 76.16 





 



100 

 23.84 



12.77 

 60.08 



5.66 

 19.26 



18.43 

 79.34 



1.54 

 8.03 



80.04 

 12.63 



28.67 

 67.24 



3.67 

 18.10 



32.34 

 85.34 



3.67 

 9.72 



63.99 

 4.94 



42.35 

 68.80 



21.57 

 26.20 



63.92 

 95.0 



14.57 

 2.65 



21.57 

 2.35 



31.76 

 35.22 



37.65 

 66.81 



69.41 

 92.03 



27.06 



7.45 



3.56 

 .52 



15.46 

 29.83 



. 55. 67 

 64.64 



71.13 

 94.47 



11.34 

 4.42 



17.53 

 1.11 



44.0 

 54.28 



24.0 

 25.0 



68.0 

 79.28 



32.0 

 20.72 





 



95.28 

 99.30 



Tree-Ripe grade : 



Not heated 



Heated 



.41 

 .70 



Merchantable fruit: 



Not heated 



Heated 



95.69 

 100 



Cull grade: 



Not heated 



Heated 



4.31 

 



Frozen grade: 



Not heated 



Heated. . . . 





 







