Black Walnut 20 3 24 2 0 39
Persian Walnut 15 2 13 1 0 15
Chinese Chestnut 35 6 32 7 3 37
Pignut Hickory 19 0 22 0 3 16
Shellbark Hickory 9 0 8 0 0 13
Shagbark Hickory 27 0 25 0 2 28
Pecan 21 0 23 0 0 15
Pawpaw 102 0 140 0 20 85
D. kaki 6 2 5 3 0 10
D. lotus 20 11 18 7 0 30
D. Virginia 16 0 20 0 0 14
showed the least tendency to produce tap-rooted seedlings. Typical branched or fibrous-rooted seedlings grown in vermiculite are illustrated in Figure 1.
[Illustration: Fig. 1. Seedlings grown in vermiculite medium. Left, Juglans regia; right, Castanea mollissima.]
Summary
The chief difficulty encountered in transplanting several nut tree and other commonly tap-rooted seedlings is thought to be due to the lack of a branched root system. The methods and results of a fairly simple technique of inducing fibrous roots, that of growing seedlings in vermiculite, have been presented.
FOOTNOTES:
[Footnote 21: First Assistant in Plant Breeding, University of Illinois,
Department of Horticulture.]
[Footnote 22: Formerly Half-time Assistant in Plant Breeding, University of Illinois, Department of Horticulture.]
Eastern Black Walnut Survey, 1951
H. F. STOKE, Roanoke, Va.