The spring and summer season of 1933 made an adverse combination in some localities. In the Ohio and Mississippi River Sections, the result was disastrous to a large part of the crop. In those sections, May was an exceedingly rainy month. June was equally hot and dry. It is in May that the blossoming periods of most varieties of walnut occur, also it is then that most of the nursery grafting is performed. Insofar as pollination was concerned, there were probably enough hours of sunshine during the blossoming period for the distribution of pollen to have been adequate and effective. On some of the trees the rains came at just the right time to wash practically all of the pollen to the ground. Had it not been for later pollinating trees either of the same variety, or of other varieties, or even of seedlings in the neighborhood, it is probable that no nuts would have set. However the actual set was about normal, but the heat and drouth which followed resulted in a drop which took the greater part of the crop. A pecan grower in southwestern Indiana, with between 300 and 400 grafted trees now of bearing age, recently reported that in August he was unable to find a single nut in his entire orchard. The result has not been quite as serious with the walnuts. Nevertheless, the crop prospects are reported to be not at all bright.
Nursery grafting in southern Indiana had literally to be performed between showers. Sap flow was excessive and the resulting stand below normal. The heat and drouth which followed killed outright many of the scions which had begun to grow. Thus, in that section the orchardists lost most of their crops and the nurserymen most of their grafts.
Walnut Relationships
In regard to walnut relationships within the genus, continued studies have led to certain conclusions which would appear to bear mentioning. One of these is to the effect that not all so-called "butterjaps" appear to owe their origin to staminate parentage of butternut but that they may be due to chance crosses of either Japanese walnut with Persian or possibly black walnut, or quite as often to reversion to the true Manchurian walnut, Juglans mandschurica.
Hybrids and Intermediate Forms
It is generally known that natural hybridity occurs so frequently between almost any two species of Juglans when growing together and blossoming simultaneously that it is unwise to plant the seed of either if pure types are desired. Intermediate forms, evidently between Persian (English) and black are fairly common throughout the East. The James River and O'Connor hybrids are well known typical examples. Such hybrids are most apt to occur in vicinities of Persian walnut trees. Crosses in which the Persian walnut is the staminate or pollen producing parent may sometimes occur but if so, they have never come to the attention of the writer. Crosses between these two species commonly have the Persian walnut as the pistillate or nut producing parent.
The most commonly seen forms which appear to be due to hybridity are in the case of certain Japanese walnut seedlings in the East. The offspring of these trees frequently takes on much of the character of the American butternut. Nuts of this type have been recognized by this Association and other authorities as "butterjaps." In his Manual of American Trees, Dr. Albert H. Rehder of the Arnold Arboretum, Jamaica Plains, Mass., recognizes crosses between the Japanese walnut and American butternut under the technical name of Juglans bixbyi after the late Willard G. Bixby of the Association by whom the matter was called to his attention. However, it is not certain that nuts definitely known to represent a cross between these two species have yet been brought to notice.
Butterjaps
It has been commonly assumed that nuts of the butternut type, from trees grown from Japanese walnut seed are due to butternut hybridity, but the theory is clearly open to reasonable doubt. Nuts of this identical type are common in the orient where the butternut does not occur and also they sometimes occur in this country on trees grown from imported Japanese walnut seed. The late Luther Burbank wrote the Department of Agriculture in 1899 that in California where he had grown many thousands of seedlings from both imported and California grown seed, he was unable to detect the slightest differences in foliage, yet the trees were apt to produce nuts of any one of three types then known as Juglans sieboldiana, J. cordiformis or J. mandschurica. He wrote that "They all run together and are evidently all from the butternut family."
An authentic case of butterjaps from imported seed was made public during the first annual meeting of the Pennsylvania Nut Growers' Association which was held in Harrisburg on January 11 of this year. Butterjaps were on display during that meeting which had been grown by Mr. Ross Pier Wright of Erie, Pa., from seed which he had imported directly from Japan. His trees are growing in the outskirts of Westfield, Chautauqua County, N. Y., and within a mile of Lake Erie.