ACALA COTTON IN CALIFORNIA 9 
more or less mixture was likely to occur, since an appreciable amount 
of cross-pollination is carried on by insects. 
Still another agency of varietal mixture is present in the South- 
west, when more than one kind of cotton is grown in the same com- 
munity. On account of the mild winters the cotton roots and stalks 
frequently live through from one season to another, and ratoon plants 
grown from the old stumps of the year before are often present in 
the fields. Any seed cotton from the previous year's crop that has 
fallen on the ground constitutes another source of danger, since it is 
likely to germinate when the field is irrigated the next spring. 
When different varieties are grown in successive years, mixture from 
ratoon and volunteer plants of the year before would be very detri- 
mental and would probably exceed the mixture caused by cross- 
pollination from neighboring fields. 
With the cotton acreage about equally divided among three 
varieties, and Acala sometimes planted on land that had grown 
other varieties the year before, it was apparent that the Acala seed 
from the crop of 1921 would be of several degrees of purity. 
CLASSIFICATION OF ACALA SEED IN 1921 
An account of the various degrees of mixture to which the different 
Acala fields had been exposed, it was decided to segregate the seed 
produced into several classes or grades. Grade 1 consisted of seed 
from the rogued date-garden seed increased by three special growers. 
Their fields had not been in cotton the previous year, were isolated 
from the fields of other varieties, and were rogued during the sum- 
mer. This seed was to be used for planting in the Coachella Valley 
in 1922. The other grades of seed were all grown from unrogued 
seed purchased in the San Joaquin Valley and were to be offered for 
sale outside of the Coachella Valley. Grade 2 consisted of seed from 
clean fields; that is, fields not in cotton the previous year and 
isolated by a quarter of a mile from all other varieties. Grade 3 
consisted of seed from fields that were clean but had not been isolated 
from other varieties. Grade 4 was seed from fields that were neither 
clean nor isolated. 
The cooperation of the county horticultural commissioner was 
obtained, and the local horticultural inspector, H. G. Bloom, in- 
spected the Acala fields during the summer for the purpose of 
determining to which grade seed produced by the various growers 
should be assigned. The horticultural inspector's decision was final 
in case of a difference of opinion, 
GINNING IN 1921 
* 
Since the public gin constitutes the greatest cause of seed mixture 
and consequent varietal deterioration, it was necessary for the asso- 
ciation to protect its seed from mixture during the ginning process. 
Experiments have shown that more than 25 per cent mixture may 
result in seed of the first bale that follows a different kind of cotton, 
and that it will contain seed of the second, third, and fourth bales 
ahead if the seed is allowed to go through the screw conveyor. 3 
3 Ballard. W. W., and Doyle, C. B. Cottonseed mixing increased by modern gin equip- 
ment. U. S. Dept. Agr. Circ. 205, 12 pp., illus. 1922. 
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