That year was a very poor one in which to make these tests, for during all of July and August we had continuous rainy and cloudy weather and by the first of September all of the leaves had turned yellow and dropped.
Most of the trees had a big crop of walnuts which were gathered about October 10th, the nuts from each tree being kept separate. After they were cracked the kernels were weighed and graded and believe it or not, the tree that received lime only had the best grade of kernels, and second best were one that received lime and potash and another lime, nitrogen and potash. The tree that received mulch and potash also had a very good grade of kernels.
In 1943 the same tests were repeated. This was again a poor year for we had very little rain during all of August and September just when the trees needed it most. The tree that received nothing had the best quality of kernels and again all the trees that received potash had good kernels.
In 1941 I grew two acres of tobacco and the following spring the stalks were cut in one-inch pieces and put on about twenty-five trees. The first year I could not see that it did any good but this past summer all the kernels from these trees were just perfect. It surely is a pleasure to crack walnuts when at least 98% of the kernels are perfect.
Lime and Fertilizers for Our Black Walnut Trees
By Seward Berhow, Iowa
In 1941-1942-1943 black walnut crops from trees growing in timberland in competition with other trees were nearly a total failure. The nuts were fair in number but not filled, the kernels badly shriveled, tough, lacking greatly in flavor and discolored. Some of these black walnut trees have been bearing for 50 years. Are they through, due to having used up all the soil fertility?
Wild or native black walnut trees, growing on good soil and not crowded have done better. It looks to me as if it is time our experiment stations, particularly those having black walnut trees on or near their grounds should start studying the cultural requirements of nut trees in the way of lime and fertilizer for better nuts. I have experimented by applying lime and fertilizer to a few bearing trees with very good results. But we need to know the proper amounts to be used for all sizes of trees from the transplants to the bearing trees of different sizes. Such investigations can best be conducted by our experiment stations.
There is a very substantial increased demand for grafted nut trees each year. This is evidence that we should make a study of our nut tree culture and care.