22 BULLETIN" 797, U. S. DEPARTMENT OF AGRICULTURE. 



mostly the 13, 12, 10, 7, and 5 centimeter sieves, those bulbs caught by 

 the 13-centimeter sieve being designated as size 1, those caught by a 12- 

 centimeter sieve as size 2, etc. This gives six sizes, the last being 

 those bulbs passing through the 5-centimeter sieve. Again, with tu- 

 lips we employ another size, designated as " toppers," which are 

 occasionally taken out by a 14-centimeter sieve. This size, however, 

 is seldom used except when it is necessary to keep the larger bulbs of 

 some varieties for propagation at the time the stocks are disposed of. 

 The separation of narcissus bulbs is accomplished by the use of the 

 16, 14, 12, 10, 7, and 5 centimrcter sieves, the first size being the largest 

 bulb. In the sizing of hyacinths the same sieves are used, plus an 

 18-centimeter sieve, which here is designated as size 1. 



ADVANTAGES OF SIZING. 



The sizing just specified, as stated elsewhere, is purely a matter of 

 private concern and does not enter into commerce at all, being 

 merely for the use of the grower. The only object served in this 

 close sizing is to facilitate planting. It enables the grower to dis- 

 tribute plant material evenly over his ground, thus securing the 

 maximum of economy. A grower will have bulbs of several sizes of 

 one variety and, of course, will plant the smaller bulbs more thickly 

 than the larger ones. 



In practice, it is seldom that one variety is separated into as many 

 sizes as have been listed here, but in order to illustrate more fully the 

 use of sizing let us suppose that a variety of narcissus, for instance, 

 has been so separated, that the land is laid off, the first bed opened, 

 raked down, and marked, as described elsewhere. The largest sized 

 bulbs will then be planted 7 to the row across a conventional 3-foot 

 bed; the next size, 9 to the row, and the third size, 11 to the row. 

 These, with us, are all planted singly, uniform distances apart, and 

 set upright. The fourth size, or that caught by a 10-centimeter sieve, 

 will be planted 14 to the row, but in seven clusters of two each, the 

 bulbs in any position they happen to be. The next size will 

 be planted similarly, three in each of seven clusters. The sixth size 

 is again similarly placed in seven clusters of five each. The seventh, 

 or smallest size, is planted 50 to the row, the bulbs being drilled uni- 

 formly along the 3-foot mark. 



CULLING. 



One of the most important operations — in reality a series of 

 operations — in bulb culture is that of getting rid of undesirable 

 plants. Successful bulb culture must be a constant process of selec- 

 tion or the reverse, elimination, for it is only by constant elimination 

 of the undesirables that the stock can be kept up. The large amount 



