azel" and
"filbert" but there is no dispute about the effect of this infection on
members of genus Corylus imported from Europe. Although there is wide
variety in appearance and quality within each of the species, especially
among the European filberts, and although filberts may resemble hazels
sufficiently to confuse even a horticulturist, the action of this fungus
is so specific that it divides Corylus definitely into two species.
Corylus Americana and Corylus cornuta, through long association, have
become comparatively immune to its effects and quickly wall off infected
areas while filbert plants are soon killed by contact with it. Hybrids
between filberts and hazels will usually be found to retain some of the
resistance of the hazel parent.

The ideal nut of genus Corylus should combine qualities of both hazels
and filberts. Such a hybrid should have the bushy characteristics of the
American hazel with its blight-resisting properties and its ability to
reproduce itself by stolons or sucker-growth. It should bear fruit
having the size, general shape, cracking qualities and good flavor of
the filbert as popularly known. The hybrids I am growing at my farm,
which I call "hazilberts" and which are discussed later, seem to fulfill
these requirements. The plants may be grown as bushes or small trees.
They are blight-resistant and their nuts are like filberts in
appearance. Three varieties of these hazilberts have ivory-colored
kernels which are practically free of pellicle or fibre. They have a
good flavor.

A comparison of the ripening habits and the effect of frost on the
various members of the genus Corylus growing in my nursery in the fall
of 1940, is shown by these extracts taken from daily records of the work
done there. It should be noted that the summer season that year was
rainy and not as hot as usual, so that most nuts ripened two to three
weeks later than they normally do.

"September 7 and 8: Wild hazels ripe and picked at this time.
(Their kernels showed no shrinkage by October 25.)

September 14 and 15: I picked ripe nuts from hazilbert No. 5 which
seems to be the first to ripen. Also picked half of the European
filberts. (There was slight shrinkage in the kernels of the latter
a few weeks later showing that they could have stayed on the trees
another week to advantage.)

All of the nuts of a Jones hybrid, which is a cross between Rush
and some European var