The accompanying record is taken from a report for the Experiment Station in 1949. It should tell you in brief the status of our investigations at present.
Very truly yours,
W. G. BRIERLEY
University of Minnesota
Department of Agriculture
Division of Horticulture
Nature and Extent of Work Done this Year
All black walnut and hickory trees made fairly satisfactory growth in
1948 in spite of deficient rainfall. The "Gideon Seedling Hickories"
(~Carya laciniosa~) planted in 1945 have become established at Waseca,
Rochester, Lakeville, Mound and at the Fruit Breeding Farm.
Attempts to establish nut varieties by top-working on seedling trees again met with poor success. At Waseca 5 of 14 hickory grafts and 4 of 25 black walnut grafts grew. At the Fruit Breeding Farm only 6 of 33 hickory grafts grew. In this case, the poor results were due in large part to use of an asphalt grafting compound which injured the callus tissue at the union. Better than usual success was obtained with black walnuts as 19 of 37 grafts grew.
As in previous seasons, the best temperature for storage of scion wood was 34 to 36 degrees F.
Major Results
The best black walnut varieties for Minnesota are Thomas, Ohio, Stambaugh, Smith and Schwartz. Of these Thomas produces the best nuts, but the tree is somewhat straggly in growth. The Ohio produces large nuts of good quality and is by far the best tree in ornamental value. It also is the hardiest of all varieties tested as it has shown no injury during 16 winters. Of lesser value are Ten Eyck which apparently is not fully hardy, and Mintle in which quality is poor here. Varieties which have not shown sufficient merit to warrant recommendation here are Stabler, Monterey, and Clark. Varieties which have not fruited are Allen, Cochrane, Huber, Kraus and Myers.
Practical Application of Results or Public Benefits