Hayes and Garber - Cucurbit Breeding

BREEDING OF VEGETABLES 253
"By following the proper methods any skillful cabbage grower
who has Fusarium sick soil may either undertake with reasonable
confidence to develop a resistant strain of his own, or having
secured one of these resistant strains he can maintain its resistance
and produce his own seed."
ASPARAGUS
Asparagus (Asparagus officinalis)
is dioecious in habit of flowering
altho hermaphrodite plants have been discovered (Norton,
1911-1912). With this vegetable, cross-pollination is usually
necessary for seed production.
Rust-Resistant Asparagus. The fungus, Puccinia asparagi,
has occasioned a great deal of alarm among commercial asparagus
growers, particularly those of the eastern United States. This
rust differs from that occurring on the small grains in that all
stages of the rust occur on the asparagus plant. At the invitation
of Massachusetts growers, the United States Department of
Agriculture in cooperation with the Massachusetts Agricultural
Experiment Station undertook to produce a resistant variety.
Norton (1911-1912, 1913) has reported on this investigation.
Because of the dioecious habit of asparagus it was necessary to
select two kinds of plants male and female. Selections were
based on rust resistance, i.e., only plants which showed a high
degree of resistance were chosen. In 1909 the first test of the
transmission of relative rust resistance was made. Twelve lots
saved from as many plants showing various degrees of rust resistance
were planted in duplicate in short rows. After the
young shoots appeared they were dusted several times with fresh
uredospores. Later in the season observations were made on
the degree of infection. The results are given in Table LXV
(Norton, 1913).
Table LXV shows clearly that rust resistance is inherited.
Various artificial crosses were made between forms showing rust
resistance. The progeny of some of these crosses proved highly
resistant and in some cases were more resistant than the parents.
By this method several strains of asparagus with a high degree of
resistance have been produced. In the production of a new form
a male plant obtained in 1910 from a lot of New American of unknown
origin proved of marked ability in transmitting vigor and
rust resistance to the progeny. The female plants known as
Mary and Martha were selected from the variety Reading