tor in the
selection of varieties, growers should keep accurate yield records for
each variety. Where pests are a factor in reducing final yield, a crop
estimate should be made early in the season.

~Varieties~--Mr. Stoke considers Bedford, Broadview and Lancaster best
under his conditions. Mr. Becker's choice is McDermid but he thinks
Crath No. 1 a potential commercial variety. Mr. Oakes likes Crath No. 1
and Ill. No. 3. Mr. Etter lists Burtner and Alleman as his best
varieties. Mr. Fateley especially favors one tree because of nut and
bearing qualities. Other growers have not as yet evaluated their
varieties.

~Hardiness~--Only several growers in the colder regions felt that lack of
winter hardiness was a serious limiting factor with their varieties.
Those with winter temperatures ranging from 10 to 23 degrees below zero
report little damage. Spring frosts are serious to many, especially in
the southern states.

~Pests~--Several insects causing damage to Persian walnut were reported.
The butternut curculio was most frequently mentioned. Others included
leaf hoppers, tent caterpillars, and husk maggots. Few effective control
measures have been developed. Squirrels are an ever present threat to
nut crops in some localities, as are blackbirds.

~Cultural Practices~--Most growers apply varying amounts of fertilizer or
manure to their trees in some form or other. Few mulch their trees. All
do some pruning, mainly of a corrective nature.

~Pollination~--Most growers agree that usually, but not always, pistillate
flowers are produced several years before the occurrence of catkins.
Generally, Persian varieties do not adequately pollinate themselves but
exceptions are reported. The problem is one of variable dichogamy. Some
varieties shed pollen before pistillate flowers are receptive; others
shed pollen when pistillate flowers are no longer receptive. This
unfortunate situation probably explains the low yields experienced by
some growers. Mr. Stoke lists the flowering dates of 13 varieties in the
1942 NNGA Annual Report which clearly illustrates dichogamy in Persian
walnut.

Some varieties are considered sufficiently self-pollinating to produce
at least light crops. However, this may be influenced by weather
conditions. During an unusually warm spring catkins develop more rapidly
than terminal growth containing the pistillate flowers. Mr. Stoke
reports that ~Bedford~ produces both flowers simultaneously and that
~Caes