COMMUNITY PRODUCTION OF EGYPTIAN COTTON. 21 
work was done early in July, soon after blossoming began, in order 
to take out the inferior plants before their pollen should contaminate 
those left in the field. Of the cotton grown from seed produced by 
fields which were rogued in 1914, about 100 acres were roguecl during 
the summer of 1915, somewhat less than 1 per cent of the plants 
being removed. 
The association undertakes to have the seed from the rogued fields 
ginned under such conditions as to avoid mixing with other seed and 
also to have the seed sacked and tagged as it comes from the gins, 
in order to prevent mixture while it is held in storage. The rogued 
seed is placed by the association in the hands of careful farmers hav- 
ing good land sufficiently remote from other cotton to prevent crossing. 
The fields planted under these conditions are inspected during the 
summer, and the product of those which are properly grown and 
are otherwise satisfactory is ginned separately, in order to furnish 
seed for general planting the second year after the roguing is done. 
Thus, the seed used for general planting in 1916 will be derived 
from the fields which were rogued in 1914, and that which is used 
for general planting in 1917 will be derived from the fields rogued 
in 1915. It is believed that the seed from inspected fields can be 
sold for planting at a price very little above current oil-mill prices, 
thus removing the temptation to plant vm selected seed because it is 
cheaper. 
If the growers' association follows year after year the plan thus 
outlined it is to be expected that deterioration, if it occurs, will be 
so gradual that there will be time for the substitution of a pure 
strain selected and multiplied at the plant-breeding station. 
AGRICULTURAL RELATIONSHIPS OF THE CROP. 
The outstanding agricultural feature of cotton production in Ari- 
zona is the value of the crop in the farm rotation. Alfalfa, which 
occupies more than half the irrigated land in the Salt River Valley, 
is the basis of the agriculture of that locality ; but the alfalfa fields 
after a few years become so badly infested with Bermuda grass and 
other weeds that their value is greatly impaired. It has been found 
that these old alfalfa fields, when thoroughly broken up and worked 
into good tilth, yield large crops of cotton. At the same time the 
intertillage of the cotton crop while the plants are young and the 
complete shading of the ground later in the summer effectually rid 
the land of weeds. One or two well-tilled crops of cotton following 
alfalfa will leave the land clean and in excellent condition for re- 
seeding with alfalfa or for growing other crops. Because of its 
renovating value in the farm rotation, cotton is a valuable crop for 
the Salt River Valley, quite aside from the cash returns it brings. 
