Black Walnut Nursery Studies
S. B. Chase, Tennessee Valley Authority, Norris, Tennessee
Briefly summarized, here are the results of a series of black walnut nursery studies undertaken in 1940 and 1941 by the Tennessee Valley Authority. The object was to develop nursery practices which would yield the large uniform seedlings most desirable as understocks for grafted or budded trees.
Germination and Stratification
It is known that either fall- or spring-planted walnuts germinate readily if the nuts are viable and if those planted in the spring are properly stratified over winter. To find out just what effect spring and fall planting has on germination and to compare various methods of stratification, three seedlots were given the following treatments on November 28, 1940:
1. Planted in seedbeds 5. Stratified at 65-75° F
2. Stratified outdoors 6. Stored dry at 45-50° F
3. Stratified at 38-40° F 7. Stored dry at 45-50° F
4. Stratified at 45-50° F subsequently soaked in
water prior to planting
Nuts from the three seedlots were kept separate and planted in random plots in three seedbeds. Each treatment was therefore represented nine times with a total of 162 nuts in each treatment.
To determine whether time of outdoor stratification has any effect on germination and emergence, three other seedlots were treated as follows:
1. Planted November 28, 1940 5. Stratified January 30, 1941 2. Stratified November 28, 1940 6. Stratified February 20, 1941 3. Stratified December 19, 1940 7. Stratified March 13, 1941 4. Stratified January 9, 1941
These three seedlots were also planted in three seedbeds with a total of 135 in each treatment.