EXPERIMETSTTS IN WHEAT BREEDING. 55 



IV. fi. Making better varieties by improving each of two stocks by selection I's. 

 first hybridizing the two varieties, and then selecting. 

 (Recent results irom incrosses and outcrosses lead to the belief that 

 hybridizing is of paramount importance to supply the best stocks for the 

 more laborious work of selection.) 

 IV. S. Time required to reduce hybrid types to good yield, then to uniformitj^ of 

 type. 

 (Hybrid wheats vary as to the length of time variation continues under 

 rigid nursery selection, but generally they are reduced to a type in a few 

 generations, this being accomplished with little special effort while select- 

 ing for superior yield and other qualities. ) 

 IV. 10. Study of best methods of planting field-crop nursery. 



(Important modifications of the plan of breeding annually result from 

 these experiments. ) 

 IV. 12. Comparison of yield of crop from large-yielding plants with crop from 

 poor-yielding plants. 

 (The selection of large-yielding individual wheat plants is important as 

 a means of sectiring strong plants to be tested in centgener trials to deter- 

 mine their power of producing plants with large average yield.) 

 IV. 15. Does crossing and hybridizing increase variation':' 



(Many results show this very plainly in numerous characteristics, both 

 those of botanical interest and of economic value, as yield, percentage of 

 protein, etc.) 

 IV. 17. Method of breeding for strong chaff, which prevents easy shelling. 



(By means of hybridizing and centgeuer-plot selection, good results are 

 promised. ) 

 IV. 32. Breeding wheats for special soils. 



(Extensive trials of new and old wheats show conclusively that wheats 

 must be especially bred for each of several conditions in Minnesota, as well 

 as for each of the several adjoining States.) 

 IV. 23. Effect of changing seed wheat from one locality to another. 



(The change in the new crop of seed is marked: sometimes for the bet- 

 ter, often for the worse. General facts for practice are not yet available. ) 

 IV. 27. Methods of seeking the best plants in the centgener or in the large nur- 

 sery plot of stock seed. 

 (By inspection, the choice of 3 per cent of the best-appearing plants 

 nearly always includes the plant which gives the largest weight and supe- 

 rior grade of grain. ) 

 IV. 28. Does environment modify the individual, and are acquired characters 



transmitted':' 

 IV. 29. How much do wlieats cross in nature? 



(Natural crosses do occasionally occur; percentage of such has not yet 

 been determined, but it is very small. ) 

 IV. 30. Methods to use in breeding for rust resistance. 



( Records on the rust resistance of 100 progeny of each of numerous par- 

 ent ijlants, made in percentages, promise to aid materially in finding blood 

 lines which resist rust within the standard variety and among the i)lants 

 of the new hybrid. ) 

 IV. 3"). Vigor of parents rs. the vigor of progeny of different degrees of relation- 

 ship. 

 IV. 36. Should plants adjoining blank hills be thrown out in nursery selection and 

 in scientific nursery studies of variation, etc.":' 

 (One or two blank hills have so little t-ffect on the yield of adjoining 

 plants, where the hills are 4 by 4 inches apart, that in selection to form 



