HARVESTING FOR SEED
The first cutting should not be used for seed for three reasons: First, if that cutting is delayed until the seed has ripened, the second and third cuttings will be very light, and in the extreme northern alfalfa territory there may not be even a second. A stronger reason is that at the time of the first cutting, favorable weather is likely to be much less certain and rains will interfere with the stacking of the seed crop, which, to insure its best value, must be put in the stack or mow without wetting. Another is that the seed pods at that season are not usually so well filled and the proportion of fertile seeds is less because the bees and other insects have not so early in the season had time and opportunity to aid in the pollenation.
Cutting should be done when the greater proportion of the seeds are hard, but not sufficiently ripe to shell. At this stage a majority of the pods are turned a dark-brown color and the seeds are fully developed. Frequently the cutting can be raked into windrows after two hours if the weather is drying, and in two or three hours more put into cocks and let stand for twenty-four to forty-eight hours, as the weather may justify. It should, however, be well cured and thoroughly dry when put in the stack, or there is danger of heating, and stack-heating seriously injures the vitality of the seed. It is not uncommon, if extremely ripe, to leave the cutting in the swath only an hour or a half-hour, then stack, and let stand for autumn or later threshing. If allowed to stand in the stack for about thirty days, the entire mass goes through a sweating and curing process which makes the threshing easier, while less of the seed is left in the straw than would be if it had not stack-cured. In western Kansas many seed raisers cut their seed crop with a self-binder, put the sheaves in shocks the same day and thresh in about ten days, or put it into a stack to await a convenient threshing time. They claim to secure 20 per cent more of the seed in this way than if they cut with the ordinary mower. Others cut with a mower having a dropper attachment which leaves the alfalfa in small bunches at the will of the driver, in the center of the swath, and these are “straddled” by the team and the wheels of the mower in the subsequent rounds. These bunches are left for two or three days and then stacked. There is little, if any, danger from mold or spontaneous combustion in stacks of alfalfa cut for seed, but there is danger of the seed heating in the stack if stacked when damp. If bright, clean seed is expected, the stacks must be well topped with slough grass, or covered with tarpaulins or boards, or given other protection. It is better still to put the alfalfa intended for seed into a barn.
One Kansas farmer in the western part of the state reports that he used a self-binding harvester, shocked the sheaves like those of grain, let them stand ten days and then put in a mow, with no bad results.