CKKKAI. KXI'KlilMKN'TS IN MARYLAND AKI» \M;<;I XIA. 7 



is available. If a variety fails to give evidence of superior merit or 

 adaptability after repeated trials in nursery rows, it is usually dis- 

 carded, although sometimes it is retained for some character that may 

 be of value for breeding purposes. 



Many hundreds of varieties and strains from various sources have 

 been tested in the nursery. These have included importations from 

 many foreign countries, new and untried sorts, and numerous local 

 varieties. After several trials in nursery rows most of them have 

 failed to warrant more extensive tests. Only a small proportion has 

 been grown in the plats. 



The plat tests at College Park have included 107 varieties and 

 strains of winter wheat, 13 of winter oats, 12 of winter barley, and 

 several each of winter spelt and emmer. At Arlington Farm they 

 have included 43 varieties and strains of winter wheat, 19 of winter 

 oats, 56 of winter barley, 12 of winter rye, and 6 of winter spelt and 

 emmer. A rate-of-seeding test with wheat has also been conducted 

 at Arlington. With some of these cereals the varietal trials have not 

 been of sufficient duration to be conclusive. With others some very 

 reliable results have been obtained. In general, those varieties that 

 were discarded, more especially those that were grown only two or 

 three years, were mixtures of some of the varieties already in the 

 tests or were decidedly inferior in some character or characters. 



During the period of crop growth, rather complete notes are taken 

 on the different varieties. The date of seeding, rate of seeding, date 

 of emergence, and stand usually constitute the data recorded in the 

 autumn. In the spring the winter survival (estimated) , dates of head- 

 ing, ripening, and harvesting, the percentage of smut and rust infec- 

 tion and of lodging, and the average height of plants are recorded. 

 At harvest time samples of the heads and of the whole plants are taken 

 and stored for reference and study. 



A small separator, especially designed for the purpose, is used in 

 thrashing. The total weight of the crop is obtained just before 

 thrashing, and the weight of the thrashed grain immediately there- 

 after. After thrashing, the grain is fanned and the weight per bushel 

 determined. The yield per acre in bushels is figured at the standard 

 weight per bushel for each crop. 



CONDITIONS OF THE PLAT EXPERIMENTS. 



DIMENSIONS. 



At College Park the varietal tests have been conducted almost 

 exclusively on twentieth-acre plats (10£ feet by 208 feet). They lie 

 in series running north and south, with 18-inch alleys between the 

 plats in the series. The roadways dividing the series (or fields, as 

 they are called at the Maryland station) are 16£ feet in width. 



