ially suited to the needs
of the walnut grower. The nuts from many of these grafted varieties fall
considerably short of the commercial standard for high-grade walnuts.
Some of the heaviest-bearing sorts, such as the Chase, Prolific and El
Monte, produce nuts that cannot be sold in the very best grade of the
commercial product. On the other hand, the Placentia, which produces one
of the most nearly ideal commercial nuts, is not a heavy-producing
variety, especially in the northern walnut sections, and is quite as
susceptible to walnut blight as the average seedling tree. Again, the
Eureka variety, which seems to successfully avoid the walnut blight
during many seasons by its lateness in coming into bloom, is a very
moderately yielding variety in the southern sections. The above
examples are only a few of many that might be cited to show the
short-comings of most of the varieties of walnuts now being propagated.

The wide range of climatic and soil conditions makes the eventual
propagation of quite a large number of varieties inevitable. While the
coast regions are bathed in fog nearly every morning during the growing
season, the inland valleys experience an extremely dry climate with high
maximum temperatures. Walnuts are being grown at the present time on
soil types varying from the extremes of sand to heavy clay loams. Many
of the future varieties must be especially adapted to some one of these
particular environments if they are to stand the test of time.

Many of the present seedling groves are of uncertain origin and
represent greatly varying values. No doubt some of these groves are the
progeny of especially selected trees known to have considerable merit.
On the other hand, it is very apparent that many of them are the result
of a great demand for seedling trees when the industry was in its
infancy twenty or thirty years ago. At that time without doubt, great
quantities of walnuts were planted without due regard for their
parentage. Again, there is a wide range of variability among the
individual trees of any grove, as variations in type of tree, blooming
season, character of foliage, resistance to disease, productivity and
character of the nuts.

_Type of Tree_

The tree types vary from the upright, sturdy individual to the more or
less spreading, weeping types which droop nearly to the ground under the
burden of the crop. The upright, vigorous growing type is well
exemplified in the Eureka. On the other h