area, located in a north-facing cove, was 



regenerated by a complete clearcutting. All 

 trees and brush larger than 1.5 inches (3.8 cm) 

 dbh were cut. The original stand contained a few 

 northern red oak trees but -no black walnut. 



Northern red oak and black walnut seedlings 

 were plaj|ted in^the spring of 1964. The field 

 layout coMsisted'of four square blocks, 105.6 feet 

 (32.19 m) on a side. Two of the blocks were on a 

 noticeably better site. Each block contained 32 

 red oak seedlings and 32 black walnut seedlings, 

 planted alternately in a checkerboard fashion, 

 13.2 feet (4.02 m) apart. The average height of 

 all 256 seedlings at the time of planting was 1.2 

 feet (0.37 m) ± 1.6 percent. 



Planting stock. — Red oak seedlings were 

 selected from 1-year nursery-run stock. The 

 black walnut seedlings were H-O surplus stock^ 

 from a walnut progeny study. The black walnut 

 seedlings planted on the two blocks with lower 

 site were from a selected parent tree located in 

 Indiana, and the walnut seedlings on the two 

 blocks with higher site came from a selected 

 parent tree in Ohio. Results of other outplant- 

 ings using these seed sources (Funk 1972) in- 

 dicated that the progeny from the Indiana tree 

 grew better than the progeny from the Ohio 

 parent tree; the 9-year height growth averaged 

 13.5 feet (4.11 m) and 9.5 (2.90 m), respectively. 



Cultural treatment. — Each seedling received 

 one of three treatments: 



Mulch: brush was cut from a 3-foot (0.91-m) 

 radius around the seedlings, and a 

 mulch of building paper was applied. 



Rake: brush was cut from a 3-foot radius 

 around the seedling, the soil was culti- 

 vated in an 18-inch (45.7-cm) radius, 

 and herbicide spray was applied from 

 18 inches out to a 3-foot radius. 



Spray: brush was cut from a 3-foot radius 

 around the seedling and stubs were 

 sprayed with herbicide. 



On check seedlings, no cultural treatments 

 were applied. 



Treatments were assigned randomly to 

 seedlings within the limits of a Latin square 

 design. The rake and spray treatments were 

 repeated four successive springs from 1964 to 

 1967. The mulch treatment was made in the 



^Some of the walnut seedlings planted on the two blocks 

 with lower site may have been 1 + 1 stock. Records are not 

 clear on this point. 



spring of 1964 and repeated in 1966, using black 

 polyethelene plastic instead of the paper mulch. 

 Total heights were recorded for each tree in the 

 summers after treatment. Both total height and 

 dbh were recorded in August 1976, thirteen 

 growing seasons after planting. 



-Naitural reproduction competing with the 

 planted seedlings included fast-growing species 

 such as yellow-poplar, aspen, and cherry. 

 Shrubs such as hazelnut, dogwood, sassafras, 

 and serviceberry were prevalent. Other species, 

 some of which were fast-growing sprouts with 

 established root systems, included chestnut oak, 

 red maple, and black oak. 



Natural Disturbances 



A drought in 1964 and a periodical cicada 

 attack in 1965 were the two major natural dis- 

 turbances during the experiment. The drought 

 caused some damage, but the cicada attack 

 caused damage to 60 percent of the red oak 

 seedlings and 25 percent of the black walnut 

 seedlings. 



Since many of the leaders had been damaged 

 by cicadas or had died back and sprouted, it was 

 decided in the spring of 1966 to try cutting back 

 some of the stems to the ground line and letting 

 the new sprouts take over (coppicing). Forty- 

 five damaged red oak seedlings, 10 uninjured 

 red oak seedlings, and 24 uninjured black 

 walnut seedlings were cut back. None of the 

 damaged walnut seedlings were cut back. Those 

 seedlings selected for coppicing had the least 

 height growth. It was hoped that the new 

 sprouts would grow faster and straighter than 

 the original stems. 



Results 



The most recent height and dbh measure- 

 ments recorded in 1976 were used in the 

 analysis. Results indicated that site quality was 

 a major factor affecting the establishment of 

 the black walnut seedlings. Survival and 

 average height were therefore determined for 

 each species x site x treatment category (table 

 1). Planned statistical analyses were not per- 

 formed because there were not enough surviving 

 trees in some of the categories. 



Suppression was the major cause of mortali- 

 ty. The drought and cicada attack undoubtedly 

 increased the number of suppressed seedlings. 



2 



