Just as the farmer is advised as to the most suitable varieties of wheat for his district, so experiments are conducted to ascertain the most useful quantity of manure, and full particulars made available in the agricultural gazettes or journals which are published in the different States, as well as being made available in bulletin form. The question of manuring is a very important one to the wheatgrower, as it influences the yield greatly in most of the principal areas, if not all. As Australian wheat soils possess abundance of nitrogen and sufficient potash, but are mostly deficient in phosphoric acid, the manure chiefly used on the wheatfields is superphosphates. There are some localities where further experiment is required to definitely ascertain the most suitable fertiliser, but in the main superphosphate is the requirement, and practically the only manure used. This has been the course proved most satisfactory by practical experience in wheatgrowing, and careful experiment also with nitrogenous, pathonic, and phosphate manures, singly and combined. Superphosphate has proved superior to bonedust or basic slag; sulphate of potash has not increased the yield, while nitrogenous fertilisers, such as dried blood or sulphate of ammonia, have proved either useless or harmful. In New South Wales the quantity of superphosphate usually used is 56 lbs. per acre, and the same quantity is generally applied in Victoria, but in South Australia the dressings are much heavier, running from 1 cwt. to 2 cwts. per acre. In New South Wales experiments carried out clearly prove that larger quantities, say, 84-112 lbs. to the acre, do not result in bigger yields being obtained, while the still heavier quantities, 1-1/2 to 2 cwt., have actually resulted in poorer yields.
In Victoria about 56 lbs. of superphosphate to the acre is also the usual thing, but the amount used averages probably from 56 to 84 lbs.; the drier districts require less, and the wetter districts more, than these amounts. Remarkable results are obtained from such small dressings as 30 lbs. of superphosphate.
In South Australia heavier dressings of superphosphate are used than in the other States. Wheatgrowing in South Australia was, in fact, revolutionised and changed into a most profitable business through the introduction and general practice of using this artificial fertiliser.
With Australian Stripper Harvesters Wheat is Harvested, Threshed and put into the Bag for 8 to 10 cents per bushel.
Commercial fertilisers are analysed by the Departments of Agriculture, and official lists are published showing their content.
The Australian wheatgrower is practically not troubled with wheat diseases. Thirty years ago rust was a trouble, but the breeding of rust-resistant varieties of wheat has effectually overcome that drawback, and rust is seldom, if ever, heard of now. In addition, wheatgrowing is now carried on in districts where the conditions are seldom favourable to rust, which is only liable to cause serious loss when there is hot, moist weather late in the spring. This weather is very rarely experienced in the Australian wheat belt, and certainly little has been heard of rust for many years.
Smut is the only other important parasitic disease, but as the practice of "pickling" seed before sowing is extending, this trouble has practically disappeared. Bunt or stinking smut is so called because it has an objectionable smell, which makes its presence known in the grain and deteriorates its value. As stated, it can be readily prevented by treating the seed. Smut belongs to a low form of plant life, and the plant is produced from a seed, which in its turn matures and produces other seed, which are microscopic and are known as spores. These spores are found when matured in masses occupying the place of the wheat kernels, and these masses are called bunt-balls. The chief and almost only cause of smut is sowing wheat seed which has healthy smut spores attached to it. By destroying the vitality of these spores the grain crop will be clean.
The most common solutions for pickling wheat seed are bluestone (copper sulphate) 1-1/2 lb. to 10 gallons of water, and formalin 1 lb. to 45 gallons of water. Bunt balls are lighter than wheat, and float in water, so if the wheat to be treated is poured slowly into the pickle, and in such a way that the bunt balls will not be carried down by the grain, they will float on top, and can be skimmed off and destroyed. The details of pickling vary on different farms, but a common method is to place the wheat about 2 bushels at a time in loosely-tied butts or bags, and then by means of a lever it is lowered into the solution for two or three minutes, when it is raised on to a sloping trough, where the superfluous solution can drain back into the cask. Another method is to place the seed wheat, either loose or in bags, in elevated casks or troughs made out of hollow logs, and pour the bluestone solution over it. After it has remained on the wheat the necessary time it is run off into another cask or trough placed in a lower position. After the seed has been treated it requires some time drying before it can be sown through the drill. All that is necessary is to place the butts where they can drain freely, and the seed will be ready to sow after a few hours.
The fullest particulars as to the best way of combating this disease or any minor trouble is always obtainable from the Departments of Agriculture in the various States.