SCIENCE AND INDUSTRY. 
Tur Propiems or tHE Wortp’s Wuuar Suppty mn rrs Revarron 
to AUSTRALIA, 
The problem of the world’s wheat supply is of absorbing interest to 
Australians, as there are yet millions of acres with a 10 to 20 inch 
rainfall still-untouched by the plough, which in all probability will, at 
some future time, be one of the granaries of the world. » Australia’s 
output of wheat is increasing. In 1901, it was a little over 484 million 
bushels; in 1916 it increased to over 179% million bushels. This increase, 
though mainly due to the increasing area put under wheat, is also partly 
due to growing of selected varieties suitable to the soil and climate, and 
to the adoption of better methods of cultivation and better cropping 
rotations. 
Not the least cause of this marked improvement of the yields is due 
to the efforts of the plant breeder in giving to the growers, as.a result 
of keen selection, prolific varieties suitable to the environment. 
By patient work and study, he crosses and re-crosses seedlings, 
implants in some of the progeny the qualities needed for a particular 
soil and climate, and of these, prolificacy, a quality depending on a 
complexity of conditions, must stand in the forefront; and where diseases 
are likely to occur, he must produce varieties that can resist their 
attacks, especially those resistant to rust. 
Wuears DesrraABLe FOR THE MoRE Arip Disrricrs. 
As the wheat-growing areas extend to the dry belts.of only a 10-in. 
rainfall, drought resistance and rapid maturity must be inherent quali- 
ties of the varieties grown. . Fortunately, the rainfall of these areas 
occurs during winter and spring; whereas in some of the other new 
countries, the rainfall occurs in the summer, making it apparently 
impossible to grow wheat successfully. Still, the limitations of the work 
of the plant-breeder have not yet been reached, and it may yet be 
possible to develop wheat so highly resistant to rust that wheat may be 
profitably grown in them. The plant-breeder, by crossing different 
varieties, breaks the types, and introduces new types in- the progeny. 
The crossing of wheats is a simple operation that can be done by a 
‘child. The great work in wheat breeding is to so arrange the pedigree 
that the qualities desired may be implanted in the individual plants of 
the progeny, and that they will remain fixed, or reproduce themselves 
in future generations. 
SELECTION VARIETIES. 
Keen selection is essential; in fact, during the earlier history of 
wheat improvement, it was by patient selection that many valuable 
varieties came into use. This obtains to-day; but the work of the 
plant-breeder in giving to the world new types has made it possible to 
select varieties suitable to almost every country; and from among these’ 
varieties, strains much better and more suitable may, with patient 
selection, be evolved. The first consideration, however, is to grow the 
variety suitable to the climate, otherwise it would likely take a half 
century to evolve a variety that will give profitable returns. By 
crossing, the object is attained in much less time; even then it takes 
some years to select from the variety strains within it that are the most 
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