CUSTOM GINNING IN COTTON-SEED DETERIORATION. 7 
SIGNIFICANCE OF THE RESULTS OBTAINED. 
Previous publications * of the Department of Agriculture have de- 
scribed methods of selecting cotton and ways of maintaining through 
community action the supply of pure seed. While there are already 
many individuals who recognize the value of pure seed and are much 
concerned about maintaining a permanent supply, it is likely that 
the movement for better cotton will develop very rapidly in the next 
few years. That careful methods of selection must be supplemented 
by careful ginning methods if the movement is to succeed is made 
clear by the results here discussed. Farmers must take steps to 
minimize mixing at custom gins if they are to maintain the purity of 
their improved varieties and in this way prevent deterioration. 
It has been shown that no less than 14 to 16 per cent, and probably 
much more, of the seed delivered to a patron at custom gins as ordi- 
narily operated is seed of the variety ginned just previous to the 
arrival of his cotton. The results at Greenville indicate also that 
some seeds from the second bale preceding are likely to appear in the 
seed delivered to the patron. This means that if different varieties 
are being ginned consecutively a patron will receive in the seed de- 
livered to him at the gin an admixture of at least three varieties* 
It is apparent that if such seed is planted opportunity is afforded for 
a vast amount of cross-fertilization in the field, and deterioration 
begins. During the next ginning process one or more other varieties 
may be added to the mixture and still further opportunity for crossing 
is afforded. Thus, a farmer may start out with an improved variety 
and in a few years find that his crop ceases to show marks of improve- 
ment and more nearly represents a composite stock of many varieties. 
Deterioration has developed so far that the bolls are small, the yield 
is light, the plants are not storm-proof, and the fiber produced is of 
poor quality and brings only low prices. 
WAYS OF MINIMIZING THE AMOUNT OF MIXING. 
It should be possible for interested patrons to establish some 
understanding with the ginner whereby he will cooperate in taking 
precautions aimed at minimizing the amount of mixing likely to 
occur. The precautions which appear most practicable and which 
even now are exercised in some localities involve the following steps: 
The patron should accompany to the gin the lot of seed cotton from which he expects 
to save seed for planting, and he should aid the ginner in seeing that everything pos- 
sible is done to prevent mixing. 
He should see that the flues, feeders, and cleaners are cleaned as thoroughly as their 
construction will permit before he allows his seed cotton to enter them. 
The roll should be dropped from the roil box and the box should be thoroughly 
cleaned. The dropping of the roll is an operation with which all ginners are familiar. 
^Cook, O. F. Cotton selection on the farm by the characters of the stalks, leaves, and bolls. U. S. 
Dept. Agr., Bur. Plant Indus. Circ. 66, 23 p., 1910. 
Cotton improvement on a community basis. U. S. Dept. Agr. Yearbook, 1911, p. 397-410. 1911. 
