FROST PROTECTION IN LEMON ORCHARDS. 
11 
pickings were not all made on the same day. This condition was due 
to the fact that each plat was of necessity picked in turn, and the care- 
ful examination of every fruit for possible frost injury required con- 
siderable time. The number of pickings for the plats is not the same 
in all cases, for the reason that in some of the nonheated plats the 
great proportion of the fruit on the trees at the time of the freeze 
was removed at the first picking in 1913, while in some of the heated 
plats as many as eight pickings were made during the year. 
Table V shows the estimated production by grades for an acre of 
Lisbon lemon trees (plat 1) during February, April, May, June, Au- 
gust, September, October, and December, 1913. These figures are 
calculated from the actual individual-tree performance records of five 
selected trees in the plat. This orchard was nonheated during the 
winter of 1912-13 and was selected for comparison with plat 4, which 
is in a Lisbon lemon orchard that was heated during that period. 
Table V. — Total estimated production by grades from plat 1, an acre of Lisbon lemon 
trees, for each picking during the calendar year 1913. 
[The data in this plat were computed from the individual-tree records of five Lisbon lemon trees. This 
plat was not heated during the winter of 1912-13 and was selected for comparison with plat 4 in an 
orchard of I^isbon lemon trees whiclj was heated dvning that period. The data from plat 4 are presented 
in Table VIII.] 
Classification. 
Date of picking. 
Total 
for year. 
Feb. 14. 
Apr. 7. 
May 14. 
June 24. 
Aug. 11. 
Sept. 12 
Oct. 26. 
Dec. 12. 
Number of fruits: 
Green grade 
Tree-Ripe grade 


13,300 
5,900 
2,500 
320 
2,160 
1,100 
540 
640 
300 
1,080 
1,100 
600 
9,280 
40 
29,180 
9,680 
Total merchantable 
fruit . . 

19,200 
2,820 
3,260 
1,180 
1,380 
1,700 
9,320 
38 860 

183, 140 
1,600 
83,360 
320 
5,580 
740 
1,100 
460 
60 
220 
340 
800 

420 

4 560 
Frozen grade 
273,580 
Total 
183, 140 
104, 160 
8,720 
5,100 
1,700 
1,940 
2, 500 
9,740 
317,000 
Weight of fruits: 
Green grade 
Lbs. oz. 


Lbs. oz. 
3,506 4 
1,268 12 
Lbs. oz. 
660 
73 12 
Lbs.oz. 
488 12 
207 8 
Lbs. oz. 
125 
111 4 
Lbs. oz. 
60 
145 
Lbs. oz. 
282 8 
87 8 
Lbs. oz. 
2,511 4 
10 
Lbs. oz. 
7,633 12 
Tree-Ripe grade 
1,903 12 
Total merchantable 
fruit 

4,775 
733 12 
696 4 
236 4 
205 
370 
2,521 4 
9,537 8 
Cull grade 

17,952 8 
275 
10,633 12 
60 
733 12 
91 4 
101 4 
51 4 
12 8 
28 12 
46 4 
80 

65 

651 4 
Frozen grade 
29 480 
Total 
17,952 8 
15,683 12 
1,527 8 
888 12 
300 
280 
450 
2,586 4 
39,668 12 
A study of the figures shown in Table V shows that at the first 
picking, on February 14, immediately following the freeze, all of 
the fruits were frozen. In April the estimated number of sound 
fruits was 19,200, as compared with 83,360 frozen fruits. In May 
there were 2,820 sound lemons and 5,580 frozen ones. In June there 
were 3,260 merchantable fruits, while the frozen fruits had dropped 
to 1,100. In succeeding pickings the relative proportion of sound 
fruits to frozen ones is more marked, with a gradual increase in the 
