PLANT BREEDING IN SWEDEN 123 



rust from Kottevete (Cone Wheat), a sort which very likely is a product of a 

 spontaneous crossing between land wheat and Squarehead wheat, and from Grena» 

 dier Wheat high specific yielding power, stiff straw, relatively early maturity and 

 relatively good kernel quality. In the same way Fylgia Wheat has inherited 

 high yielding power, relatively good resistance against yellow rust and relatively 

 early maturity from Smaahvede (Small Wheat), a Danish improved sort, and 

 from Extra Squarehead II relatively good winter=hardiness and relatively early 

 maturity. Both are intended for southern Sweden and Iron Wheat for Skane 

 especially. The importance of its high yield can easily be understood when one 

 hears that about half of the wheat, produced in Sweden, comes from this province. 

 None of the sorts mentioned in the summary, however, have all qualities to the 

 highest degree and therefore the workers hope, by continued crosses to be able to 

 produce still better combinations. Besides with the sorts mentioned at the bottom 

 of the summary. Dr. Akerman is now also working with crosses, which he 

 himself has made. 



Systematic crossing has also been sucessfully used when improving other 

 selfsfertilizing crops and has given rise to several valuable sorts even if it has 

 not been able, from above mentioned reasons, to show such fine results as with 

 winter wheat. 



I will be brief when speaking about the other plants, rye, field roots and 

 forage plants etc., mentioned in the beginning. To force typical crosssfertilizers to 

 self-fertilization, year after year, can by degrees result in a weakening of the 

 progeny. This seems for instance often to be the case with timothy, according 

 to WiTTE who has also shown a greatly different power of self-fertilization in 

 different strains of this grass. They vary from almost self^sterile strains to such 

 with a very high degree of self»fertilization. HeribertsNilsson at the plant 

 breeding institution of Weibullsholm, about which more will be mentioned later 

 on, has found the same fact to be true with rye. 



The pedigree method, however, is also used when improving cross=fertilizers, 

 but naturally with necessary care and combined with mass selection. When im« 

 proving these crops systematic crossing is also used. The methods of the work 

 must of course vary in each case according to the plant and the chief object of 

 the breeding. In order to avoid spontaneous undesired cross*fertilization different 

 isolating methods are used. 



The work with the plants in question has also made considerable progress. 

 Three sorts of rye have hitherto become of practical use, two especially for south* 

 ern and one for middle Sweden, and all superior to the sorts before cultivated. 

 Rye is, in view of the extension of the cultivated areal, next to oats the most 

 important cereal in Sweden and for bread uncomparably more important than 

 wheat. The former occupies about Vh times as large an areal as the latter. It 

 is easy to understand what an increase of the yield of rye per hektare would mean 

 for the nourishment of the people. 



Even of several of the chief grasses have been produced strains, improved in 

 different respects, with higher yielding power than those hitherto cultivated and 

 guaranteeing a more even and a more uniform development of the mixed plants 

 of the artificial meadows, a necessary condition for a good quality of the hay. 



