10 BULLETIN 1412, U. S. DEPARTMENT OF AGRICULTURE 
grades is the same in all markets and in all producing sections of 
the United States. " U. S. No. 1 " lettuce means the same in New 
York State as in Florida and the same in New Orleans as in Boston. 
Dealers may rely upon receiving good merchantable lettuce if the 
lot conforms to the specifications of the IT. S. No. 1 grade, without 
regard to the point of origin. It is questionable if it is profitable 
in the long run to ship lettuce lower in quality than U. S. grade No. 
1, except in years of abnormally short crops or poor quality. Con- 
sistent adherence to high standards builds good will and creates 
confidence. 
There are no recognized grades for leaf lettuce. The market 
requirements are for well-trimmed plants showing no broken or 
bruised leaves or other defects. The plants should be neatly ar- 
ranged in the basket or other container, and the package should be 
well filled. 
CULLING OUT DEFECTIVE STOCK 
Successful growers and shippers habitually exercise care in grad- 
ing and packing, discarding all heads showing serious defects or 
injuries. It is cheaper to cull out defective stock in the field or 
packing shed than to have it dumped upon arrival at the market 
after the expenses of labor, packages, freight, etc., have been in- 
curred. Furthermore, a few poor heads in a package of otherwise 
good lettuce detract materially from its appearance and market 
value. 
Immature, leafy heads seldom bring good returns. Heads showing 
severe decay, seed stems, or other serious defects never should be 
packed. Decay is especially injurious, and in its early stages the 
utmost diligence is required to prevent it from finding its way into 
the package. Slimy soft rot is progressive, and is easily communi- 
cable to other heads; if affected stock is packed with sound heads 
great loss may result in storage and in transit. It often accompanies 
or follows tipburn. 
Detection of external indications of tipburn is sometimes difficult 
or even impossible. It is characterized by a brown or black discolora- 
tion of the edges of the inner leaves. Stock known to be affected is 
frequently bitter and is discounted severely on the markets. 
TRIMMING 
The removal of a few outer leaves from each head makes it appear 
neat, and will usually eliminate any surface blemishes that may be 
present, but close trimming is objectionable. (See fig. 6.) Outer 
or wrapper leaves serve as a protection to the head, and the trade 
prefers to have four to six of these outer leaves retained, provided 
they are clean and free from defects. The amount of trimming is 
usually determined by the degree of bottom rot or other defects that 
occur on the stem or outer leaves, the head being trimmed down 
until the base is clean. If it is necessary to take off all the wrapper 
leaves to clean up the head, it is often discarded entirely when pack- 
ing. On the other hand, if the head is free from defects when har- 
vested only the coarser, lower leaves are removed. 
Considerable quantities of head lettuce whose outer leaves have 
become damaged in transit or in handling through mechanical injury, 
