i66 



Yearbook^ of Agriculture 1949 



enough to be cultivated mechanically. 

 In southern nurseries, machines can 

 be used 2 to 3 weeks after germination. 

 In northern nurseries, where initial 

 growth is slower, machine weeding is 

 supplemented by hand weeding the 

 first year and, for some species, the sec- 

 ond and third year. Transplants some- 

 times are hoed or cultivated to remove 

 the greater part of the weeds, and the 

 rest of the weeding is done by hand. 



Drill-sown hardwoods are cultivated 

 with ordinary farm-tractor cultivators 

 in about the same manner as farm row 

 crops. Cultivating tools should not go 

 deeper than 2 inches. Timeliness is im- 

 portant to keep weeds from interfering 

 with normal development of the trees. 



In areas of high summer rainfall and 

 longer growing season, the weeding job 

 is greater than in drier areas or colder 

 climates. Normally, about one-half 

 man-day to 1,000 trees is necessary in 

 the South and about half that in north- 

 ern sections. 



Recent developments indicate that 

 costs of weeding conifers can be re- 

 duced appreciably by the use of a pe- 

 troleum product known as Stoddard's 

 Solvent, or mineral spirits. When ap- 

 plied under certain temperature and 

 soil-moisture conditions, conifers are 

 unaffected, but most of the weeds and 

 grasses are killed. This promises to re- 

 duce weeding costs, particularly in the 

 South, to about 5 or 10 cents per thou- 

 sand trees. Other chemicals such as 

 2,4-D and ammonium sulfamate are 

 being used to some extent. 



Some species need shade during the 

 first year. Tolerant trees, such as the 

 spruce, hemlock, balsam fir, and white- 

 cedar require 50 percent cover. In 

 some localities where growth is slow, 

 shade is necessary for 2 and sometimes 

 3 years. Other species, such as white 

 pine and Douglas-fir, can be grown in 

 some localities without shade but re- 

 quire it in others. Generally, hard- 

 woods are grown without shade except 

 for a small amount during the germi- 

 nation period. Sugar maple must be 

 kept under shade during the first year. 

 Care must be exercised in using shade 



because of the tendency of all species 

 to develop large, succulent tops sus- 

 ceptible to frost damage or other in- 

 jury. Winter mulches of straw, pine 

 needles, or seed-free hay are needed 

 in nurseries where frost heaving is 

 serious, particularly on shallow-rooted 

 seedlings and transplants. Where frost 

 heaving occurs throughout the winter, 

 mulch is applied in the late fall before 

 snowfall. If confined to the spring 

 period, it is applied after the snow has 

 melted. 



LIFTING,, GRADING, AND PACKING of 

 trees for shipment to planting sites is 

 commonly termed "stock distribution." 

 In the Deep South the work may start 

 around December 1 and end in late 

 February. Northward, spring planting 

 begins in February and continues to 

 April, interrupted only by inclement 

 weather. Farther north, spring plant- 

 ing may not begin until late April and 

 extend to mid-May or later. Fall plant- 

 ing starts in October and continues 

 until frost or snow. 



Most deciduous stock is dug during 

 the fall months, counted, graded, and 

 held in storage or in heeling-in beds 

 until planted. 



It is essential to have a current in- 

 ventory of trees in the nursery accord- 

 ing to species and age classes. It is 

 obtained by counting a series of ran- 

 dom samples. The intensity of the 

 sampling varies from 0.5 percent for 

 beds with uniform density and size to 

 5 percent for those with high variabil- 

 ity. The average density is obtained 

 from the random samples and is used 

 in computing the total number on 

 hand. A smaller number of samples is 

 dug and graded ; from them is obtained 

 the cull percentage, which is used as a 

 factor in computing the total number 

 of plantable trees. The sampling unit 

 is either 6 inches or 1 foot wide, ex- 

 tending across the bed. Deciduous trees 

 in rows are inventoried by a series of 

 1-foot random samples, amounting to 

 0.5 to 1 percent of the total stand. 



Care must be taken to get accurate 

 inventory data. The samples must be 



