72 Rusts (CH. 
from yellow rust and known as Girka. Little Joss is 
immune from rust and has a rather higher cropping 
power than the high yielding parent Square Head’s 
Master. This increase of yield in the Little Joss over 
Square Head’s Master is probably accounted for by 
the rust preventing the latter from yielding as high as 
it would do if it were not rusted. Little Joss is immune 
only to yellow rust. 
It is to crossings of this kind that we look for 
assistance in helping to prevent the rust fungi from 
taking their yearly toll from our cereal crops. 
Beet root Rust. The rust which attacks mangolds, 
beetroot, and sugar beet does not belong to the same 
genus as cereal rusts. It is known as Uromyces betae. 
It also occurs on wild beet. 
The three stages are found on the same plant and 
it differs from Puccinia in that the teleutospores or 
winter spores are single-celled. 
In spring the yellow aecidium cups may be found 
on the leaves. In summer the brown patches of 
uredospores are present and in autumn these change 
to a dark brown colour caused by the teleutospores. 
This disease is most prevalent in crops manured with 
too much nitrogen and not enough potash as is well 
shown on the mangold field at the Rothamsted Experi- 
mental Station. Diseased leaves should be collected 
and destroyed. 
Pea Rust is caused by Uromyces pisi. The aecidio- 
spore stage occurs on a wild spurge. 
Bean Rust is caused by Uromyces fabae. 
