90 The Philippine Journal of Science 1921 
Table 4. — Number of trees affected with mottled leaf on calamondin stocks. 
Table 5. — Number of citrus trees affected with mottled leaf on mandarin 
orange stocks. 
Mandarin orange stock budded with— 
Total 
trees. 
Trees affected with 
mottled leaf. 
1 
Number. 
Per cent. 
Cabuyao 
14 
0 
0.00 
Sour orange 
10 
0 
0.00 
Stock unbudded _ 
84 
0 
0.00 
8 
0 
0.00 
Pummelo __ .. _ 
68 
0 ! 
0.00 
Grapefruit _ ...... ... 
10 
0 
0.00 
Mandarin orange 
138 
2 
1.44 
Sweet orange 
70 
3 
4. 28 
Lemon 
63 
17 
26. 98 
Previous work on this subject has offered little opportunity 
for a comparison between the various citrus species as to their 
susceptibility to mottled leaf ; the above tables will indicate such 
comparative susceptibility in a general way. Although it will 
be impossible to arrange the species in the order of susceptibility 
(from these tables at least), still it can be said that the calamon- 
din and the lime exhibit the mottled leaf symptoms but slightly ; 
and that the tangelo, sweet orange, and mandarin orange varie- 
ties are most commonly affected by mottled leaf. 
The relationship of the stocks to mottled leaf is indicated in 
the foregoing tables by comparison of the figures in the various 
tables for a given species; as, for instance, the sweet orange, 
which is recorded in all of the tables. Thus, the sweet orange 
on pummelo stock developed 191 cases of mottled leaf of a total 
of 223 trees so propagated, or 85.65 per cent of positive cases. 
Sweet orange propagated upon cabuyao stock developed 5 cases 
of mottled leaf from a total of 19 trees budded on cabuyao, or 
26.31 per cent. Sweet orange on sour orange stock developed 
