Citrus Root Stocks 
W. E. Evans, Leesburg 
Citrus trees for planting are usually 
budded on sour orange, rough lemon and 
other seedling stocks. The problem of 
selecting the best stock is of great impor¬ 
tance, for in case an unsuitable stock is 
used the value of the grove may be perma¬ 
nently impaired. Sweet orange seedling 
stocks were formerly used very extensive¬ 
ly, but as they have been found very sus¬ 
ceptible to foot-rot they are now seldom 
used. 
The sour orange, a hardy species of 
citrus, which is frequently found growing 
wild in Florida forests, is the leading stock 
in Florida as well as in California and 
most of the citrus growing regions of the 
world. It is vigorous and resistant, if not 
altogether immune, to foot-rot, and the 
trees produce thin-skinned fruit of fine 
quality which holds on the branches late 
in the season. In Florida sour orange 
seedlings are the favorite seedlings for the 
hammocks and flatwoods soil as well as 
the best grade pine land. Most growers 
prefer sour orange stock wherever soil 
conditions permit its use. 
On light, dry, sandy soils in Southern 
Florida where sour orange stock lacks 
thrift, rough lemon stock, a vigorous 
growing species of citrus related to the 
common lemon of commerce, is used. 
Trees on rough lemon stock make a very 
vigorous growth and on very light soils 
are easier to care for and require less fer¬ 
tilizer than trees on sour orange roots. 
Rough lemon stocks are tender and not 
sufficiently hardy for Gulf state sections 
and colder parts of southern and central 
Florida. Under favorable conditions 
trees on rough lemon stock usually are 
vigorous and productive but it is claimed 
by many growers that the life of such 
trees is shorter than on some other stocks. 
The fruit produced by trees on rough 
lemon stock, while often good in dessert 
quality, is inferior to that grown on sour 
orange, and it cannot be held on the tree 
so late in the season. The Parson variety 
of orange is seldom successfully grown on 
rough lemon stock. 
Grapefruit seedlings have been used as 
stocks to a limited extent in southern 
Florida. They are too tender for the cold¬ 
er sections of the State. This stock is 
more vigorous in growth than the sour 
orange, but less vigorous than the rough 
lemon. It is best adapted to moist soils 
well supplied with humus, as grapefruit 
seedlings are less hardy and less resistant 
to disease than sour orange. 
Mr. Frank W. Savage, plant breeder at 
Government Test Grounds at Eustis, 
Florida, prefers the grapefruit stock to all 
others, if soil conditions are at all suit- 
