GROWING ALFALFA SEED. 459 
expense. However, as there is such great variation in the value 
of different plants, this procedure may be justified at least until 
strains of known high value for the conditions at hand have been 
selected and propagated for use on a field scale. 
Row-sown alfalfa fields that have not been properly thinned 
will not give maximum seed yields on account of the various in- 
jurious effects of crowding, which have already been discussed. 
If it is impracticable to reduce the stand by hoeing or by use 
of the ordinary harrow it may be done by cross-disking with a 
disk harrow. The disks should be so adjusted as to cut out the 
proper number of plants, which will depend, of course, upon their 
original thickness in the rows. 
The Right Crop to Leave for Seed.—Experiments at Stockton, 
Kan., show clearly that at that place no crop later than the second 
will yield returns that will be at all satisfactory. Retarded 
growth during the dry part of the summer defers ripening until 
so late in the season that cold nights prevent the maturing of the 
seed. On the other hand, if the first spring growth is devoted to 
seed production the flowers are likely to become overmature be- 
fore the best season for seed development arrives. Frequently 
also, largely on account of the variation in location of the zero 
point of growth in the different individuals composing uny strain, 
the first spring growth matures very unevenly. 
For these reasons it is recommended, especially for the Great 
Plains and the cooler parts of the intermountain area, that the 
first growth of the second and subsequent years be clipped so 
early that the time of seed setting will fall in midsummer or 
slightly later, when favorable conditions are likely to obtain. 
The problem as to what crop should be left for seed under the 
varying conditions of different areas has not yet been fully 
worked out. It may be well for seed growers to try by simple ex- 
periments along this line to get definite information on this 
point. One row may be given an early clipping and then left to 
go to seed; another a later clipping, while still another may be 
Jeft for seed after the first crop has been cut for hay, and so on. 
The temperature and moisture requirements will largely deter- 
mine the best practice in this regard, but the necessary presence 
of suitable insects must: not be overlooked. 
Harvesting the Seed Crop—The harvesting of alfalfa seed 
grown in cultivated rows does not differ materially from that in 
broadcasted fields. With the rows 3 feet apart a mowing ma- 
chine with a 6-foot cutter bar is necessary if two rows are to be 
cut in each swath. This arrangement does away with the neces- 
sity of having an extra man to remove the newly cut bunches 
from the path of the mower at the next round. A mower with a 
