Hayes and Garber - Cucurbit Breeding

MODE OF REPRODUCTION IN RELATION TO BREEDING 41
hybrid plants were obtained and from the M. sativa seed about
7.5 per cent. A part of the difference in the results is doubtless
due to the fact that the plants produce a smaller number of
flowers and are procumbent to prostrate in habit. To find the
amount of cross-pollination that normally occurs in alfalfa, one
might average the above results and multiply the result by two.
This gives in the neighborhood of 50 per cent, of natural crossing
which is only indicative of the probable amount.
Grasses. Some studies with grasses have been reported by
Frandsen (1917). Results obtained are given in the following
table. Some sterility is indicated by comparing the results of
self-fertilization with those of cross-fertilization and natural
pollination. Poa fertilis and Bromus arvensis appear self-fertile.
Considerable self -sterility is indicated in orchard grass, timothy,
and fescue.
TABLE III.
POLLINATION OF GRASSES