20 
BULLETIN 1483, U. S. DEPARTMENT OF AGRICULTURE 
are in an inherently unstable condition, as is the case with the limbs 
and progeny trees of the Flattened and Long strains described above. 
CORRUGATED STRAIN 
The Corrugated strain variation of the Valencia orange was the 
first striking bud variation which was found in the bud-selection 
studies of this variety. The rough, coarse, and corrugated appear- 
ance of the fruits makes this variation very conspicuous after its 
characteristics have once been identified. A study of the block of 
Valencia trees in which the first variations of the Corrugated strain 
were discovered revealed the fact that about 12 per cent of the trees 
were of this strain. Subsequent individual-tree studies in other 
Valencia orchards showed the presence of a considerable proportion 
of trees of the Corrugated strain and of normal trees producing limb 
variations bearing typical corrugated fruits, wholly or in part, the 
Pig. 10. — Fruits of the Fluted strain of the Valencia orange. These were produced by 
progeny tree No. 10-35, as listed in Table 8, which was propagated from a similar limb 
variation Riverside, Calif., January, 1926. (About four : fifths natural size) 
number in some instances being as much as 25 per cent of the total 
number of trees. 
The trees of the Corrugated strain have a drooping habit of growth, 
and the leaves are larger and more sharply pointed than those pro- 
duced by trees of the Valencia strain. As a rule, the trees of the 
Corrugated strain are considerably less productive than trees of the 
Valencia strain. 
The typical fruits are usually large and oblong or cylindrical in 
shape, very rough in texture, and with thick, greenish, corrugated 
rinds. The rag is tough, the juice scant in quantity and of poor 
flavor. The fruits do not mature as early as the fruits borne by trees 
of the Valencia strain. They are usually discarded during picking 
or grading as not being worth shipment, on account of their inferior 
appearance and quality. 
There is a marked tendency for trees of the Corrugated strain to 
produce both normal Valencia oranges and fruits typical of the 
strain. This condition is also true of limb variations of the Corru- 
