32 
Colorado Experiment Station 
in this respect. But the southern strains are not adapted to our 
climatic conditions. They are not sufficiently hardy. 
2. Seed selection for prolific seed' yield improves the ability of 
the selected stocks to produce seed yields. But the improvement is 
not sufficient to solve the problem. 
3. The amount of moisture for alfalfa seed production should 
be regulated to such an amount that a minimum amount of forage 
growth results and still have water enough to fill and mature the 
seed. This virtually amounts to what might be called a medium 
quantity. 
4. Pasturing off the first growth late in the spring has apparently 
stimulated good seed yields. Good seed yields seem to be coupled 
with such an arrangement of the irrigation system as to regulate 
the amount of water and hold it close to a minimum requirement. 
Apparently this is best done by having small irrigation furrows 
about every thirty inches and thus irrigate by the furrow method. 
5. A thin stand of plants is necessary for the best seed pro- 
duction results. A uniform stand is essential. A plant to every one 
or two square feet is about right if the stand is uniform. 
6. There are serious objections to growing alfalfa in rows. The 
most serious objection is the difficulty in handling the crop with 
machinery. 
7. There is very little evidence that bees are essential to alfalfa 
seed yields. 
8. Dry climatic conditions with high temperatures seem to be 
among the most essential requirements for successful alfalfa seed 
production. 
9. The effect of fertilizers or nutritive substances on alfalfa seed 
production has not been investigated. There are indications which 
point to soil nitrates in excessive quantities as a serious cause of 
poor seed yields in many irrigated regions. 
