The wood of the almond is very hard and strong, enabling the tree to bear
the weight of heavy crops where pruning has been given proper attention
during the formative period of the young tree. As with other fruit trees,
the almond is subject to heart-rot and care should always be exercised
to prevent the checking and cracking of large wounds and consequent
infection with decay organisms. The hardness of the wood makes it the
finest kind of fuel, and when old orchards are being dug up the returns
from the sale of wood often more than pay for the expense of digging and
cutting up the trees and burning the brush.
The nuts are of two general classes—sweet and bitter almonds. The former
is primarily the almond of commerce, though the latter is used largely
in the manufacture of almond oil and almond flavoring, as well as in
the manufacture of prussic acid. The bitter almond is also used largely
in nurseries as a rootstock upon which to bud the almond and some other
fruits.
For a long time there has been considerable evidence to show that some
varieties are always self-sterile while a few are sometimes self-fertile.
Work done in 1916 and 1917 by Tufts[1] shows that practically all
varieties are self-sterile and that some of the self-sterile varieties
are also inter-sterile. In these tests the principal commercial varieties
were used. Blossoms of each variety were pollenized with pollen from
its own blossoms and from each of the others. Checks were for natural
pollination with each variety. The important results of this work are
briefly summarized as follows:
The Nonpareil and I.X.L. are inter-sterile, although both are
inter-fertile with the Ne Plus Ultra.
The Languedoc and Texas are inter-sterile.
The I.X.L. and Peerless are practically inter-sterile.
The California has proved the best pollenizer thus far tested, for all
varieties that bloom near it.
The Drake is inter-fertile with the Nonpareil, I.X.L., Ne Plus Ultra,
Peerless and Jordan, the only ones tested.
The I.X.L. is inter-fertile with the Drake, Jordan, California,
Languedoc, Ne Plus Ultra and Texas.
The Ne Plus Ultra is inter-fertile with the California, Drake, I.X.L.,
Languedoc and Nonpareil.