exity of the score? The actual
amount of kernels recovered reflects both the size of nuts and the yield
of kernels. Plumpness of the kernels is reflected in the total weight of
kernels and does not need to be considered separately.
The important elements in a score were considered to be:
1) The crackability of the nuts of the variety. This is measured by the
weight of kernels obtained in the first crack.
2) The yield of the variety. This is measured in the total weight of
kernels.
3) The marketability of the product. This can be measured by the number
of pieces in the sample. In general, the smaller the number and the
larger the size of the pieces the better the marketability.
With this general background in mind, many samples were tested and the
results published in the 1945 report[1]. In order to secure the data
needed the kernels of the individual nuts in the samples were weighed
separately.
NOTE: All samples were cracked with the (John W.) Hershey nut
cracker.
Some of the conclusions drawn from these tests were as follows:
1) Using kernel weights only gives a rapid and accurate test of
differences between varieties.
2) Ten nuts are adequate for a single sample.
3) The location of the tree with reference to climate and soil is
probably the most important single factor influencing kernel yield. No
evidence was obtained, however, to indicate that the varieties ranked
significantly different at different locations.
4) If reasonable care is used in cracking the differences due to
different operators tend to be non-significant.
The statistical proof that a ten-nut sample is adequate and that
differences between operators are not significant are two findings that
are important in setting up a schedule.
During the past year further testing has been done, in which scores were
computed from ten-nut samples.[A] The samples had preliminary cool, dry
storage to assure comparable moisture content. Enough nuts were cracked
in each sample to secure ten that were well filled. Empty nuts were
recorded. The following data were kept for each sample:
1) The weight of the kernels recovered in first crack in grams.
2) The total weight of the kernels in grams.
3) The number of quarters and number of halves recovered.
Scores were computed as 1) the weight of the first crack in grams plus
2) half of the total weight of the kernels recovered in grams plus 3)
the number of quarters divided by four and, 4)
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