232 
Journal of Agricultural Research 
Vol. XXIII, No. 4 
survive even lower temperatures. The evergreen nature of the tree 
also recommends it for home gardens or lawn planting. Judicious 
pruning or pinching back of long shoots will assist in giving the tree a 
fairly compact habit in place of its natural upright form. 
The Thomasville citrangequat makes an excellent marmalade without 
the admixture of any other citrous fruits. The mildly pungent peel and 
the pleasantly flavored acid juice combine to give the marmalade an 
unusually good flavor, rivaling the best Dundee marmalade. 
RESISTANCE TO DISEASE 
The advent of Citrus-canker in the Gulf Coast States made it necessary 
to test any new Citrus varieties and hybrids with reference to their sus¬ 
ceptibility to that disease before they could be recommended for culture. 
As is well known, the kumquat is the most canker-resistant of all 
citrous fruits, its resistance amounting to practical immunity under 
field conditions. In this new hybrid, the Thomasville citrangequat, the 
kumquat parent has seemingly transmitted its remarkable canker resis¬ 
tance unimpaired, notwithstanding the fact that one parent of the 
citrangequat, the citrange, is decidedly susceptible to canker. 
Several plants of the Thomasville citrangequat have been inoculated 
and continuously exposed to Citrus-canker for a period of four years 
without any canker having been developed except from needle punctures, 
from which canker failed to spread. 5 
It is highly important that only canker-resistant citrous fruits be propa¬ 
gated in the Gulf Coast States west of Florida, as a measure of insurance 
against a serious reinfection. From this viewpoint, the citrangequat 
becomes of great importance to this region, to meet the need for home¬ 
grown acid citrous fruits. 
While somewhat affected by Citrus scab, the quality of the fruit is not 
greatly impaired thereby, and if planted away from scab-susceptible 
varieties it is probable that scab would not be at all serious on the citrange¬ 
quat, 
POSSIBLE USE OF CITRANGEQUATS AS A STOCK FOR SATSUMA ORANGES 
The extraordinary vigor of growth, great hardiness, and extreme 
canker resistance shown by this hybrid suggested at once its possible 
value as a stock, especially for use in the Gulf Coast States west of Florida. 
In this region almost the only stock used for Satsuma and other Citrus 
varieties is the trifoliate orange, a very hardy, deciduous tree, closely 
related to the true species of Citrus. It is extremely thorny and is used 
extensively as a hedge plant, the fruits from these hedges providing an 
abundance of seeds to use in growing nursery stock. Unfortunately, the 
trifoliate orange is very susceptible to Citrus-canker. One necessary step 
in the eradication of canker is the complete elimination of these trifoliate 
orange hedges. The presence of large numbers of trifoliate seedlings in 
Citrus nurseries is also a menace in the event of a reappearance of Citrus- 
canker. / 
When considering the possible use of the citrangequat as a stock, the 
small number of seeds produced seemed an almost unsurmountable 
* PELTIER, George L ,. susceptibility and resistance to citrus-canker op the wild RELATIVES, 
citrus fruits, and hybrids of the genus citrus. In Jour. Agr. Research, v. 14, no. 9, p. 350. 1918. 
