68 Summary ok Agricultural Experiments, [april 



that as far as the trials have gone they point strongly to the fact that 

 Chevallier is capable of producing the heaviest yield of grain, but 

 such grain is on some soils, and in dull seasons, not of the best 

 quality. In the Lindsey Division, where these trials were conducted, 

 barleys of the Goldthorpe type generally produced better samples of 

 grain than the Chevallier. 



Barley Growing and Selection (Journal of Irish Dept. of Agric, 

 October, 1908). — Variety tests have been conducted for several years in 

 all the barley-growing districts of Ireland, with the view of ascertain- 

 ing the most suitable variety for different localities. In a very short 

 time, Archer demonstrated, and has since maintained, its superiority 

 in yield on the generality of barley soils. On heavier soils, however, 

 and in wet seasons, Goldthorpe proved its equal at some centres, and 

 its superior at others. Standwell, during the whole period of experi- 

 ment, fell considerably below both Archer and Goldthorpe in yield, 

 while Chevallier, the usual type of barley then in general use, showed 

 a decided inferiority to either of the two types. Both Standwell and 

 Goldthorpe proved to be slightly better malting material than Archer, 

 while this variety and Chevallier were about equal in value. 



The botanical characters of the varieties and various methods of 

 selection for the improvement of seed are discussed. 



Colonial and Foreign Experiments. 



Excretion of Poisonous Substances by the Roots of Plants. 

 (Memoirs of the Department of Agric. in India, 1908, Botanical Series, 

 ii., No. 3.). — These investigations have been carried out by Mr. F. 

 Fletcher, Deputy Director of Agriculture, Bombay Presidency, and 

 were suggested by observations made both in Egypt and India which 

 pointed to the fact that materials injurious to some crops were 

 excreted by the roots of certain other crops. Mr. Fletcher considers 

 that the following conclusions may be drawn from his experiments : — 

 (1) All plants excrete substances which are toxic, both to themselves 

 and to other species; (2) the quantity of toxic material excreted by the 

 different crops varies, when reckoned per unit area of a field sown 

 in the ordinary way; (3) sensibility to the excreted substance varies 

 with the plant; (4) the substance excreted by all crops is apparently 

 identical. The nature of the substance, which may be an alkaloid, is 

 being investigated. The toxic substance appeared to have an injurious 

 effect on adjacent crops according to the extent to which it was distri- 

 buted through the soil, while its effect on subsequent crops grown 

 on the same land would depend on the extent to which the roots 

 came into contact with it, especially by occupying the same layer of 

 soil. 



Preservation of Unfermented Apple Juice. (U.S. Dept. of Agric, 

 Bureau of Chemistry, Bull. No. 118.). — It is stated in this publication 

 that the consumption of fresh fruit juices is increasing in the United 

 States, and that the increase would be more rapid but for the objection 

 to the use of chemical preservatives in products of this kind. Investi- 

 gations have, therefore, been carried out to test the effect of the 

 sterilisation of apple juice, and they appear to show that by this method 

 these juices may be perfectly preserved in small or large quantities. 



