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 (PL 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 washing 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 



