Alfalfa Seed Yields 
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A typical plant of the common alfalfa. 
An experiment was conducted to determine to what extent 
alfalfa seed failures were due to bees and other insects. A number 
of alfalfa plants were protected with screen cages before the bloom- 
ing time. These plants were compared in seed yields with similar 
plants which were given the same care except that they were not 
covered with screens. The results were that some of the plants under 
screens set well with seed. Some did not. This was also true of the 
plants not covered. The experiment was repeated two years in 
succession, with practically the same results. That is, there was no 
clear evidence that bees or other insects were essential to alfalfa 
seed production. It is possible, under field conditions, bees may have 
an influence in slightly assisting fertilization of alfalfa bloom. 
However, the covered experiments showed that fertilization could 
take place without the insects and did so take place. 
An experiment was carried on to determine the effect of artificial 
“tripping^’ of flowers. The branches of a number of selected plants 
