ovide sufficient pollen for
pollination purposes. There must also be very little killing of the wood
or the crop will be reduced in proportion to the amount of wood that is
winter injured. Several years observations in the Station filbert
orchard at Geneva have shown a great variation in hardiness of filbert
varieties. With some varieties the catkins are severely injured each
winter, with others, very little injury occurs. Because of this great
variation in hardiness we must accumulate as much data as possible
concerning the ability of varieties to withstand our winters, especially
the mild winters, before we are in a position to make definite variety
recommendations.

Last winter, 1932-33 was especially hard on filberts, in fact, much more
winter injury was experienced than at any time since the Station orchard
was set in 1925. It was a good season to separate the hardy and tender
sorts. Throughout the winter the weather was exceptionally mild and
favorable for that type of winter injury due to early growth activity.
In a normally cold winter catkin killing as a rule is not very serious,
except on a few tender varieties. Although catkin killing was so serious
at Geneva, S. H. Graham of Ithaca, who is growing a number of varieties
on an exposed location where winters are more severe than at Geneva,
reports that his trees suffered less catkin injury than at any time
since he has been growing them. Catkin killing does not seem to be due
to extreme cold during the winter and rarely are the catkins injured
before late February or early March. Injury may be severe even though
the temperatures are not lower than the catkins are thought to endure
when in bloom. Apparently the injury may be due to the cumulative effect
of dessication throughout the winter months, this effect becoming
apparent shortly before the catkins bloom. Catkins forced into bloom
prior to late February bloom normally and without apparent injury.

The data on winter injury of catkins is being accumulated for two
purposes. First, it is being used as a basis for recommending varieties
as pollinators; and second, it is being used in selecting parents for
breeding hardy varieties.

The amount of winter killed catkins is determined by observation during
the blooming season in late March. All catkins that fail to open, or
open weakly and shed no pollen, are considered winter killed and the
proportion that are killed is expressed in per cent.

Based on the amo