Nilsson: Plant-Breeding in Sweden 



293 



Gradually, as we obtained a large 

 enough collection of new and well- 

 known lines, characteristic and stable, 

 each one with a superior quality of 

 practical worth, it was natural for us to 

 seek to obtain still more valuable com- 

 binations among these qualities by 

 hybridization experiments, well planned 

 and systematically executed. That is, 

 accordingly, what we have had in 

 hand since the commencement of 

 this century. 



hybridizing important. 



Since the researches of Mendel, so 

 fundamental for the study of hybridi- 

 zation in general, have again become 

 accessible, this sort of work has been 

 much increased at Svalof. It is es- 

 pecially by the widelj^-known studies on 

 oats and wheat of Dr. Nilsson-Ehle that 

 remarkable contributions have been 

 furnished by actual investigation of the 

 phenomena of this category. The new 

 light thrown by them on the problems 

 of heredity and variation has a really 

 great influence on improvement. The 

 new laws which teach us to think of 

 the different characters of the plants as 

 behaving like autonomous unities from 

 the very beginning, are also important 

 in our work. 



It is incontestable that these dis- 

 coveries still further increase the possi- 

 bility of progress. It appears that, 

 particularly in Sweden, it will finally 

 be possible for us to create by this 

 means an agricultural material adapted 

 to the most northern latitudes, which 

 will add to general good qualities 

 a greater cold-resistance or earlier 

 maturity. 



However, the application of this 

 method in a widespread way at Svalof 

 shows that the combination and break- 

 ing-up of qualities, ordinarily very com- 

 plicated in products of hybridization, 

 makes very illusory the hope of reaching 

 resiilts based solely on theoretical calcu- 

 lations. That is an inconvenience which 

 we must endure, however, since hybridi- 

 zation offers so many chances, even if 

 they are vague, which we could not 

 otherwise obtain. 



In any case, hybridization as we 

 practice it at Svalof with our varieties 



already fixed, must be considered only 

 as a supplement of our original method 

 of selection in pure lines, and not at all 

 as replacing it. Every hybridization 

 experiment demands as starting point a 

 pure and constant material with well- 

 known qualities — consequently, that is 

 what we must first produce. Besides, 

 the final evolution of the process of 

 hybridization depends on the continual 

 creation of new material superior to that 

 which preceded it. To produce these 

 two types of indispensable material, we 

 must continue to employ our method of 

 selection, which is the best and most 

 efficacious for the discovery of the most 

 precious and most constant components 

 in the old, mixed varieties. In addition, 

 selection in the extremely variable 

 products of hybridization is practiced 

 indiscriminately with the older style of 

 selection in our work at Svalof. 



Although the Institute of Svalof has 

 already given, and probably will still 

 give, as rich contributions to Mendelism 

 as any of its contemporaries, it must 

 never be forgotten that its main work, 

 its specialty, will always be the hunt for 

 novelties by its own, original method, 

 which must never be set aside in favor 

 of the other work of improvement fol- 

 lowing this. Furthermore, for a large 

 and important part of the material 

 treated, such as the forage plants and 

 root crops, the time for hybridization 

 will only arrive in the distant futiire. 



growth of the work. 



The crops dealt with at Svalof have 

 been fall and spring wheat, rye, barley 

 and oats and also, since 1889, peas and 

 vetch. Oats were, however, not given 

 intensive study until after the adoption 

 of the new method in 1893 and rye only 

 in 1900. The original program in- 

 cluded other crops, but these have had 

 to wait until larger subsidies are avail- 

 able. It was not until 1905, when the 

 government made an allowance of 

 $7,000, that we were able to take up the 

 improvement of forage crops, clover and 

 potatoes. The root crops have not yet 

 received any keen attention, although 

 they will be given it as soon as the 

 financial reorganization, of which I have 

 already spoken, is completed. It is true 



