1 Ava., 1899.] QUEENSLAND AGRICULTURAL JOURNAL. 163 
earing. Itis well to know that itis generally harmless, for many farmers have cut down 
their wheat on the appearance of this rust, thinking that it would eventually destroy 
their crop and make it even worthless for hay, and have thereby lost a good yield of 
wheat. Summer rust (P. graminis) or streaky rust attacks the whole plant, stem, 
stalk, and leaf sheath, and I have even seen it on the ear. It does not usually set in 
until the wheat is well in ear—Mr. Farrer says “changing colour.” It varies in the 
intensity of its destructiveness. With early-sown wheats, quick ripening sorts, and a 
few rust-resistant, it is often com pena SLy narmless. It is not so, however, with the 
late sown wheat; this has no chance whatever. With us wheat that is not out 
of danger in ordinary seasons by the middle of November can be given up. I say 
“ordinary seasons’ because there are some seasons which from the summer being late, or 
very mild, or from some other reason, are specially favourable for the production of the 
cereal, just as on the contrary there are other seasons when the rust a ppears earlier 
than usual, really in the form of an epidemic, and sweeps from one end of the country to 
‘the other. Now, I come to the difficult and perhaps most controversial part of the 
‘subject—what are the remedies for this disease in wheat? Can this destructive 
arasite or fungus on our cereal plants be rendered innocuous, avoided, or destroyed P 
ikon whence does the rust originate? Does it come from some of our Australian 
grasses, plants, or bushes, and on which it is probably perennial? Orisitin the wheat 
or seed itself as what is termed a myco-plasma, only developed as opportunity and con- 
dition offer? In his lecture on the subject Professor Eriksson propounds the latter 
theory or hypothesis, and Mr. Farrer says “ in regard to Professor Eriksson’s hypothesis 
of the existence of a symbiostic myco-plasma in some wheats, facts have come under 
my notice which have the appearance of according with it.” And modestly, as an 
unscientific observer, I have come to the same conclusion. Rust is infectious, yet this - 
infection has its limitations, for of different kinds of wheat growing in rows side by - 
side, although it spreads along a row of the same sort, or perhaps develops spontaneous. 
throughout, yet it may not infect the next row of a different kind of wheat at al i; 
although such row is so close that the ears and leaves may intermingle with 
or touch one another, There are, moreover, other limitations to infection for 
which I beg to refer you to Messrs. Farrer and Eriksson. The fact that 
on land on which a rust crop of the previous year has been burnt, the 
wheat is generally free from rust is not peas against the plasma theory, for 
wheat plants grown on such enriched and purified soil may be of such fibre that the 
rust parasite cannot break through. If we econ Professor Eriksson’s theory it 
follows, I submit, that there may be wheats which are absolutely free from the 
disease, and that there are others more or less clean or what is termed rust-resistant. 
Furthermore, that it should be possible to eliminate the rust from many wheats, or to 
do as Mr. Farrer has been doing for many eats with more or less success, by cross 
breeding, elimination, and selection, to make or create new wheats which are free 
fromrust. There are several wheats which are even now more or less free from rust— 
I mean the streaky rust—viz., Medeah, an Egyptian wheat, which Mr. Molyneux, of 
the South Australian Agricultural Department, informed me has never been known to 
have the rust; Ward’s Prolific—which Mr. Farrer says came to this country from 
Egypt as a stray grain in other wheat—I have known or heard of having the rust, 
though itis a wheat I do not like. Others are the Belatourka, the varieties of the 
Defiance, and Mr. Farrer says the Fife wheats, Sicilian Square Head, and Blount’s 
Lambrig, Budd's Karly have been free so far; and Allora Spring, originally called 
Pugh’s Rust Proof—though itis not a rust-proof wheat, but rather a rust-escaping one— 
has many of the characteristics of a rust-free wheat, viz., it stools sparingly, it has 
narrow, erect leaves, and fills quickly after blooming. If rust is inherent in the seed 
of certain sorts as a myco-plasma, we need not des iutr that ultimately the seed 
may be so treated by some chemical preparation, or otherwise, that the germs 
of the rust will be destroyed. Meanwhile farmers have apparently no other 
course before them but to sow wheats which are named rust-resisting or rust- 
escaping, and tobe guided in their choice of such wheats by the experience 
of practical men, and the advice of professional experts. Now for my probable 
preventive, which I may say I have been experimenting with and trying for the last 
16 years. And although my knowledge and conclusions are incomplete, and I 
can only say that I believe it to be a preventative, but cannot go so far as to say I 
know it to be one, I think the time is opportune for laying it before you. I have been 
led to do so by a paragraph in the Asoen number of the Department's Agricultural 
Journal. In that paragraph a farmer at the Cape says that he sowed 3 bushels of 
2 years’ old seed wheat, and the resulting crop was free from rust whilst a cro 
alongside from 1 year old seed was rusty. He says the crop is 18 inches high nana 
quite green. Unfortunately he does not state the crop’s stage of growth, or whether: 
