Analyses of the data to determine the percentage of the score that was derived from each component showed that crackability as measured by the weight of the kernels recovered in first crack gave an average of 54% of the score with a range of 49 to 58 for the different samples; yield, as measured by total weight of kernels divided by two, 31% with range of 27 to 34%; marketability measured by number of quarters divided by four 14% with range of 10 to 22% and number of halves divided by two 1%. The percentage of the score derived from the number of halves was so small as to be negligible. It seemed better, therefore, to base the score on only three elements, namely, the weight of the first crack, the total yield of kernels and the number of quarters recovered from the sample.
On this basis the problem becomes that of deciding the weights that should be given to these three components. The score as set up emphasizes the crackability of the variety much more than its marketability. This seems logical because the value of a variety is in large part dependent upon the ease of recovery of the kernels on first cracking. Several different combinations of the weighting of these three components were considered and it was decided that the most logical was to weight the elements as follows: 1) The weight of first crack in grams. 2) The total weight of the kernels divided by two and 3) the number of quarters recovered divided by 2. If there are halves, each half would count as two quarters.
Table I. Average scores from 18 black walnut samples cracked by three operators and computed by two scoring systems.
| Variety | Source | Year | Scoring | Systems[3] |
|---|---|---|---|---|
| I | II | |||
| points | points | |||
| Thomas | Maryland | '46 | 83.9 | 93.1 |
| Snyder | Ithaca, N. Y. (A) | '46 | 81.8 | 89.2 |
| Ohio | Maryland | '46 | 79.5 | 88.9 |
| Thomas | Ithaca, N. Y. (A) | '46 | 76.4 | 85.5 |
| Norris | Tennessee | '45 | 76.1 | 83.9 |
| Stambaugh | Ithaca, N. Y. (A) | '46 | 75.9 | 81.0 |
| Stambaugh | Ithaca, N. Y. (A) | '46 | 74.0 | 83.2 |
| Thomas | Tennessee | '45 | 71.5 | 79.6 |
| Thomas | Ithaca, N. Y. (B) | '46 | 65.7 | 74.6 |
| Cornell | Ithaca, N. Y. (C) | '46 | 59.3 | 67.6 |
| Stabler | Maryland | '45 | 56.9 | 64.5 |
| Cresco | Ithaca, N. Y. (A) | '46 | 55.8 | 65.2 |
| Seedling No. 1 | Geneva, N. Y. | '46 | 52.7 | 62.2 |
| Seedling No. 3 | Geneva, N. Y. | '46 | 50.6 | 59.0 |
| Brown | Ohio | '45 | 49.7 | 59.4 |
| Stabler | Tennessee | '45 | 47.5 | 51.4 |
| Seedling No. 2 | Geneva, N. Y. | '46 | 44.4 | 52.2 |
| Huen | Iowa | '46 | 37.4 | 44.9 |
| Least significant difference (5%) | 6.3 | 6.6 | ||
Calculating the percentage of each component in the total score on this basis gives crackability 48%, yield 27%, marketability 25%. This schedule gives relatively more weight to marketability as against the other two components. The average scores of 18 samples cracked by three operators and calculated on both the above described schedules are given in table I.
The table shows that the rank of the different samples was not changed materially by using only the three components, except in a few cases in which there were an appreciable number of halves. The Stabler has many one-lobed nuts which increase the number of halves recovered. It is to be noted that with both schedules the least significant difference at the 5% level is about 6 score points.
Table II gives the score calculated by schedule II for five samples, each cracked by six operators. The difference between operators is not significant but the difference between varieties is highly significant.
Table II. Scores from five samples of black walnuts each cracked by six operators according to scoring schedule II.
| Operators | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Variety | Location | Year | 1 | 2 | 3 | 4 | 5 | 6 | Average |
| Snyder | Ithaca, N. Y. | '46 | 89.2 | 87.3 | 78.9 | 94.4 | 87.5 | 91.5 | 86.5 |
| Thomas | Ithaca, N. Y. (A) | '46 | 83.5 | 79.2 | 83.1 | 78.0 | 84.2 | 83.8 | 83.6 |
| Thomas | Ithaca, N. Y. (B) | '46 | 73.1 | 67.4 | 73.4 | 74.1 | 69.6 | 83.8 | 73.6 |
| Cresco | Ithaca, N. Y. | '46 | 66.0 | 69.2 | 63.1 | 67.2 | 68.5 | 60.2 | 65.7 |
| Brown | Ohio | '45 | 62.5 | 51.0 | 65.4 | 60.4 | 48.1 | 64.8 | 58.7 |
| Average | 74.9 | 70.8 | 72.8 | 72.8 | 71.6 | 78.8 | 73.6 | ||
| Least significant difference (5%) for variety averages | 6.2 | ||||||||
A third scoring system, involving 1) weight of kernels in grams for the first crack, plus 2) total weight of kernels, 3) all divided by the number of marketable pieces (as counted following sifting on a ¼" round hole screen) was tried, and the resulting ranking of the varieties was very similar to that obtained with systems I and II. The results from this system appeared to be the most precise, but it was not considered as generally acceptable as system II, since the latter would be easier to record and calculate.