8 
BULLETIN 270, U. 8. DEPARTMENT OF AGRICULTURE. 
TasBLeE 1V.—Summary of mean, maximum, and minimum temperatures at the Williston 
substation, by months, for the growing season, 1909 to 1914, inclusive. 
[Data (in °F.) from the records of the Biophysical Laboratory of the Bureau of Plant Industry.] 
Apr. May. June. July. 
ES Oeee Sea- 
ee Maxi-| Mini Maxi-) Mi feiss ENE lat N Ste 
axi ini- axi-)| Mini-| Maxi-| Mini-|,, Maxi-| Mini-|/mean. 
Mean mum.|mum. Mean. mum..mum |Mean. mum.|mum. weet num. mum 
: L ff ee ees a 
NGOs ea cee 35 62 9 51 86 20 61 91 40) 67 94 47 54 
MOTOR ee ao See eeaers 50 92 i2 51 81 25 67 | 105 32 68 | 104 43 59 
LOU Se Oe eee 42 89 12 56 90 15 68 100 43 65 99 38 58 
1 0) Bea ier cae neta inate 45 68 19 54 85 31 64 99 32 65 90 38 57 
11s Be ee -47 89 19 52 95 22 67 95 41 67 93 | ~40 58 
O14) 2 o> eee ae 48 79 10 54 86 20 62 92 39 73 | 100 44 | 59 
Average....... Oe een ec Be ice eee 65¢\o alee 68 aie | 58 
| 
EXPERIMENTAL METHODS. 
In all the varietal tests at Williston the primary objects have been 
to determine the relative yielding powers of the varieties and to 
increase the yield and quality through the selection of standard 
varieties or the importation of new ones. 
The work has been conducted along the two lines usual on experi- — 
ment farms: (1) Testing in field plats under conditions that conform. 
as closely as possible to farm practices, and (2) testing in nursery 
rows, where a very much larger number of varieties or races can be | 
grown more economically than is possible in large plats. 
The work of testing and improving cereals has included both spring 
and winter varieties, but the greater part of the work has been with 
spring cereals 
PLAT EXPERIMENTS. 
DIMENSIONS OF PLATS. . 
The field tests were conducted on plats approximately one-twen- 
tieth of an acre in area. The plats have varied slightly each year in 
size and shape, but all plats were uniform in size for each year. The 
approximate dimensions have been 8 feet wide (the width of the drill 
used) and 272} feet long, but in some years they were longer and nar- 
rower and in other years they were shorter, making an area slightly 
more or less than one-twentieth of an acre. The alleys between the 
plats have been 18 inches wide. A general view of the plats is 
shown in figure 4 
TREATMENT OF PLATS. 
In 1908, the first year during which the Williston substation was 
operated, all of the field plats were located on old ground that had 
borne oats the previous year. The following two years, 1909 and 
1910, the varietal plats were located on new ground and were there- 
fore in a different location each year. In each case, the virgin soul 
Prey o- y 
