FIELD CROPS. 637 



and other qualities. . . . The selection of large-yielding individual wheat plants is 

 important as a means of securing strong plants to l)e tested in centgener trials to 

 determine their power of producing plants with large average yield. . . . Exten- 

 sive trials of new and old wheats show conclusively that wheats must be specially 

 bred for each of several conditions in Minnesota, as well as for each of the sev- 

 eral adjoining States. . . . By inspection the choice of 5 per cent of the best- 

 appearing j)lants nearly always includes the plant which gives the largest weight 

 and -superior graile of grain. . . . Records on the rust resistance of 100 progeny of 

 each of numerous parent plants made in percentages promise to aid materially in 

 finding blood lines which resist rust within the standard variety and among the 

 plants of the new hybrid. . . . Wheat hybrids should be grown in quantity during 

 the first 3 to 5 years that variation may have its full opportunity ; then the selection 

 of superior plants should be from among large numbers, as from among several 

 thousand in the nursery plats." 



The results of crossing and hybridizing further show an increase in variation in 

 numerous characteristics, such as the yield, percentage of protein, etc., and the work 

 as followed out promises to give good results in breeding for strong chaff to prevent 

 easy shelling. Natural crosses have been found to occur, but the percentage is very 

 small. In the work of making a strain or variety of wheat from a single or from 

 several mother plants it has been the experience that numerous strains, each from a 

 single mother plant, and grown for 8 years in field-test plats, have continued to 

 average as much superior to the parent variety as at first, and have so far shown no 

 signs of deterioration. The best of several tried methods of handling the spike in 

 cross-pollinating wheat is described as follows: "Remove the smaller upper and 

 lower spikelets and the smaller floi'ets on the central spikelets, leaving 10 to 20 of the 

 best. Emasculate these early, about the time the first tinge of yellow appears in the 

 anthers. Cover the spike with tissue paper. Twenty-four to forty-eight hours later, 

 when the florets on neighboring spikes of similar age are opening, bring pollen from 

 the plant chosen for the male parent and, removing the covering, apply pollen to 

 each floret." 



The fertilizer requirements of cultivated plants and the relation of the 

 composition of the plants to the chemical composition of the soil, E. God- 

 LEWSKi (Ztec/iv-. Landw. Versuclisiv. Ocstevr., 4 {1901), No. 4, PP- 479-536). — This is a 

 report on a series of experiments begun by Czarnomski, extending over a period of 

 several years. The experiments were conducted with wheat, rye, potatoes, and 

 barley in plats 1 acre in size, 6 plats being devoted to each croj). The results of 

 analyses of the soil and the plants produced under different conditions of soil fer- 

 tility are given and discussed at some length. 



Although a 25 per cent solution of sulphuric acid dissolved about equal quantities 

 of potash and phosphoric acid out of the soil, the application of potash fertilizers 

 was very effective, while fertilizers furnishing phosphoric acid were almost without 

 effect. Rye ami barley showed a greater requirement of nitrogen and phosphoric 

 acid than potatoes, but this latter crop needed more potash than the cereals. When 

 potash is lacking in the soil, the life of the stems and foliage of the potato is much 

 shorter than when the soil supply of potash is sufficient, and the <lying off of these 

 parts takes place still sooner in the presence of large quantities of assimilable nitro- 

 gen and phosphoric acid. The application of nitrogen and phosphoric acid when 

 the supply of assimilable ])otash was insufficient was not only ineffective but in 

 some cases reduced the yield and injured the quality of the potatoes. The use of 

 potassium sulphate in potato fertilizer applied in the spring had a good effect on the 

 quality. It wa,s found that the surplus of assimilable phosphoric acid in the soil 

 sometimes reduces the yield. Rye seemed to require more potash than barley. An 

 insutticient supply of potash retarded tiie develoj)ment of the stems of the barley 

 plant, and under these conditions nitrogen fertilization tends to cause lodging. The 



