256 Journal of Agriculture. [10 April, 1909, 



In connexion witli rust, it is not only necessary to detexmine the 

 amount but also the kind of rust, for there is one species, Puccinia triticina, 

 which is comparatively harmless because it does not pinch and shrivel the 

 grain, and P. graminis, which is ver\- destructive. The latter is the 

 only one requiring to be specially guarded against. 



It was not a particularlv rustv season, vet several of the varieties were 

 badly affected with P. graminis. Bobs and Queen's Jubilee were both 

 bad, while Jade, Fan, Jumbuck, Fife Essex, and Dart's Imperial, were 

 moderately bad, and Federation was moderately rusty. Red Egypt 

 from Vilmorin was the only variety without rust of any kind, and Thew 

 and Upper Cut were both practically free. These and others will l)e 

 further tested during the forthcoming season. 



II. — Testing for Smut-resistance. 



It is well known that different varieties vary considerably in their 

 susceptibility to stinking smut or bunt. Thus Allora Spring, which is most 

 susceptible, has yielded 95 1 pex cent, of bunty plants when the seed was 

 coated with spores, while under the same conditions Minnesota Blue Stem, 

 a strong flour variety, was the least susceptible of ten varieties tested, only 

 producing 12 per cent. But while a small proportion of rust is admis- 

 sible without seriously interfering with the yield or the quality of the grain, 

 a very small percentage of stinking smut is objectionable and it is necessaxy, 

 if treatment of the seed is to be dispensed with, to have a variety or strain 

 which is absolutely free. 



Experiments in the direction of producing a bunt-resisting wheat have 

 been mainly carried out by the late Mr. Farrer and Mr. Pye, and they axe 

 now being continued at the CoWra Experiment Farm, N. S. Wales, by 

 Mr. Sutton. Farrer hit upon the idea of selecting clean plants from the 

 strains of his crosses which showed the smallest percentage of bunt, in 

 order to see if bunt resistance could be increased by a course of systematic 

 selection. He observed that the plants of the variable generation of a 

 cross differed widely in their liability to bunt just as has been observed 

 in the case of rust ; and he came to the conclusion that, if the plants of this 

 generation were exposed to infection, by inoculating the seed from which 

 they were grown, then a large proportion of the plants which might 

 otherwise have produced bunt-liable varieties, would be culled out and a 

 higher average of bunt-resistance would be secured in those retained. And 

 if the next generation was similarly infected, further culling out would 

 be made and a still higher average of bunt-resistance secured in the remain- 

 ing plants. The untimely death of Mr. Farrer in 1906, prevented these 

 experiments being carried to a final issue during his lifetime, but they 

 were continued by his successor, Mr. Sutton, who succeeded in producing 

 varieties which apparently resist bunt ; for he writes as follows in the 

 Agricultural Gazette oi N. S. Wales, for March, 1908: — - 



Florence and Genoa have in our trial plots shown themselves under severe trial 

 to be practically smut-proof, and in consequence seed of them does not require 

 to be bluestoned or treated with any other fungicide for the prevention of smut. 



If this fxeedom from smut could have been substantiated on further 

 trial, it would have been a distinct gain to the farmer, if the 

 varieties were otherwise suitable, although it must be remembered 

 that stinking smut of wheat can be so easily and certainly pre- 

 vented by treatment of the seed, that there is not the same 

 importance attaching to a smut-proof as to a rust-proof wheat. 



This question of immunity to smut is a very important one, and experi- 

 ments to test how far this immunity is hereditary or transmissible and if it is 



