NURSERY PRACTICE ON THE NATIONAL FORESTS. 61 
surface, western yellow-pine stock is now being produced in Arizona, 
which succeeds when planted even under the arid conditions obtain- 
ing in that country during the spring of the year. This success is 
a good criterion of the stock's merit, particularly as very poor results 
had previously been obtained from field planting with the ordinary 
run of stock without pronounced lateral roots developed near the 
surface. Little or no watering for the purpose of hardening the 
trees to the conditions which obtain in the field has not yet, in Forest 
Service operations, produced more successful stock for field planting 
than well-watered stock. At the Bessey Nursery, in fact, much 
better results have been secured in field planting with stock which 
was watered in accordance with the regular nursery operations than 
with that which was not watered at all. 
Any of the methods of watering applicable for seed beds may be 
used, but sprinkling by hand with a hose is expensive and scarcely 
practicable. Irrigation or the use of garden sprinklers is almost 
essential. Because of the large size of the transplants, irrigation is 
much more feasible than in seed beds, and because of its rapidity it 
is a method which should always be given consideration. At the 
Bessey Nursery, where flooding is practiced, the transplant area is 
watered in sections. Areas of one or more beds are banked up with 
soil around the edge, and water is then conveyed to them from the 
4-inch main pipe line through large canvas irrigating hose. When 
one section becomes flooded the hose is moved to the next one. One 
acre can be covered in six hours. At the Savenac Nursery, where 
ditch irrigation is used, the water is controlled, as in agricultural 
projects, by a system of headgates and by temporary mud dams for 
diverting it from one ditch to another (PI. XXI). On steep grades 
some wooden troughs, with small holes bored through at intervals to 
allow the water to escape to the ditches, are employed. It is claimed 
that one man can water 3 acres per day. Ditch irrigation is prac- 
ticed also at the Fort Bayard Nursery. There a system of galvanized- 
iron troughs to carry the main body of water is being tried. Oppo- 
site each ditch in the transplant area these troughs have openings 
the size of which can be regulated by means of a sliding cap. The 
amount of water turned into each ditch can be controlled easily and 
absolutely. 
A single watering by any method should be thorough enough to 
soak the soil to a depth of about a foot. Experience indicates that it 
may ordinarily be conducted at any time of the day without injury 
to the plants, except at the Pilgrim Creek Nursery, where sprinkling 
is practiced, and where it seems to be necessary to water bigtree 
(Sequoia w ashing toniana) in the evening rather than in the morning. 
Shading. — Shading is almost wholy unnecessary in transplant beds, 
except in a few cases ; and because of the expense involved, if for no 
