Diseases of Cereals : Rust and Take-all in Wheat. 711 



to be looked after but there is plenty of scope for testing those 

 imported from other lands. Many of our pastures require to be 

 renewed, and the question arises as to the best grasses to stock theni 

 with. 



There are some which withstand the drought and could be used 

 as summer fodder, and others which thrive through the winter 

 months in spite of the cold. It is only by actual trial under different 

 conditions that these facts can be determined, and so small test plots 

 consisting of about 100 varieties have been established at Leongatha 

 and at Rutherglen. The seed of some of our best native grasses, 

 such as Wallaby grass and Kangaroo grass, have been saved, and it 

 may be possible by a process of selection to improve them. Then 

 the United States Depai'tment of Agriculture has a Division devoted 

 solely to investigation in grasses and forage plants, and they have 

 kindly supplied a large number from different portions of that great 

 continent in the hope that some of them may supply a want with us. 



Inoculation with Nitrogen Bacteria. 



I now wish to draw your attention to an important discovery 

 which has recently been made, and like so many other investigations 

 pursued in the laboratory, without at first being appreciated, is being- 

 turned to practical account for the benefit of the producer. On the 

 roots of leguminous plants grown under proper conditions, such as 

 peas and beans, clovers, lucerne, and our native wattles, there are 

 always to be seen little nodules or tubercles in great^er or less 

 quantity, and it is now known that these are formed by the remark- 

 able micro-organisms which we call bacteria. It may seem strange 

 at first sight that what appears to be a diseased condition of the 

 plant should prove of benefit in any way, but as is well-known, there 

 are useful as well as injurious bacteria, and in this instance they form 

 a sort of co-operative concern, in which both partners are benefited. 

 These bacteria which produce the swellings have the wonderful 

 property of fixing the free nitrogen of the air and thus enabling the 

 plant to draw upon the atmosphere for its supplies of nitrogen. Only 

 plants belonging to the pea and bean family have this power, as far 

 as at present known, and it would seem that each variety of plant has 

 its own particular bacterial form. 



Cultures have been made of these organisms, and they can be used 

 to inoculate either the soil or the seed, wherever the soil is too poor to 

 grow legumes or for some reason or another the tubercles are not 

 produced on the roots of the plants. 



The United States Department of Agriculture, recognising the 

 practical importance of providing a supply of this inoculating material 

 in a handy form, have hit upon the happy expedient of using an 

 absorbent such as cotton-wool for soaking up these nitrogen-fixing 

 bacteria and then by allowing them to become dry they can be sent 

 to any part of the world and still retain their active properties. They 

 are done up in neat ])ackages and enclosed in tinfoil, about 4 ins. by 

 2 ins. in size, each of which contains sufficient to inoculate an acre of 



