APPLE-BUD SELECTION: SEEDLINGS FROM SELECTED TREES (Excerpt)
Charles S. Crandall
GROWING SEEDLINGS FROM SEEDS OF FRUITS FROM TREES CHOSEN AS POSSESSING SPECIAL MERIT
This project was begun in 1908 and was considerably extended in 1909. The initial planting in the spring of 1909 was, in large part, a failure from various causes, so that few trees of that group survived and details of the group need not be given here further than to record something of the history of the remaining trees. Better success attended the planting made in the spring of 1910, of the seeds secured in the fall in 1909; this lot in 1915 was represented by more than three thousand living trees. Results under this project are not to be attained until the seedlings are established in fruit production; the little that need be recorded at this time concerns growth only.
SEEDLINGS FROM FRUITS OF 1908
In September, 1908, the Station received Grimes apples from the orchard of Perrine Brothers at Centralia. The fruits, 545 in number, all came from one tree that had an established reputation for productiveness. They were separated into two grades on the basis of size. All fruits having transverse diameters of 65 mm. or more were included in the group designated as "large"; those having transverse diameters of 64 mm. or less fell into the group designated as "small." Average weights and measurements of the two groups were as follows:
|Number of apples||293.00||252.00|
|Average weight of apples (grams)||130.70||106.31|
|Average longitudinal diameter (mm.)||57.00||57.25|
|Average transverse diameter (mm.)||67.00||62.00|
|Total apparently good seeds||2,079.00||1,417.00|
|Average seeds to the fruit||7.09||5.62|
Among the large apples one had six cells; all others had the normal number of five. The seeds were stratified in sand in boxes and buried in earth for the winter. In the spring of 1909 there was unavoidable delay in preparation of ground for reception of the seeds, and when they were taken up and separated from the sand, germination had already begun. Some, presumably the seeds possessing greatest vitality, had progressed so far in germination that they did not survive shifting to nursery; thus a serious loss was incurred at the beginning. Of the seedlings that started growth, many were weak and a large proportion of these did not survive the first season.
The young trees were grown in nursery until they were four years old because no land was available upon which to plant at orchard distances. The number living at planting time in 1911 was 123; when finally planted 15 by 15 feet in orchard, on May 3, 1913, there remained 112 trees. Fourteen trees died later, so that at the end of 1915 there were living 98 trees seven years old.
All the trees were slow in starting growth after being planted in orchard and made but feeble growth that season. There was some improvement the next year and still further improvement in 1915, but the trees still had a stunted appearance which seemed likely, to linger for some time if not permanently. The average height was a little less than six feet with an average spread of four and one-half feet. The last rating as to grade divided the trees as follows: good, 20 percent; fair, 58 percent; poor, 22 percent.
At about the same time that the Grimes apples were received, 452 Jonathan apples, taken from one of the most productive trees in the orchard of Mr. J. C. B. Heaton of New Burnside, Johnson county, were also received. These apples were graded into two size-groups on the same basis used in the division of the Grimes apples. The average weights and measurements were as below:
|Number of apples||374.00||78.00|
|Average weight of apples (grams)||141.46||93.83|
|Average longitudinal diameter (mm.)||60.31||52.26|
|Average transverse diameter (mm.)||70.91||60.59|
|Total apparently good seeds||2,157.00||423.00|
|Average seeds to the fruit||5.77||5.42|
The Jonathan seeds were treated in exactly the same manner as the Grimes, and the seedlings of the two varieties were grown in contiguous rows each year. The Jonathan losses occurring were about equal to those sustained by Grimes; the number of trees remaining was small. In 1910 there were 78; in 1911 this number had fallen to 61, and this was the number planted in orchard 15 by 15 feet on May 3, 1913. Nine weak trees died later, leaving but 52 to represent this variety group. These trees had the same stunted appearance characterizing the Grimes seedlings; they had an average height of five and one-half feet and an average spread of five feet. Rated as to quality, at the same time the Grimes were rated, they classified as good, 27 percent; fair, 56 percent; poor, 17 percent.
The division of the apples of these two varieties into size-groups, at the time the seeds were collected, was made with the intention of testing the relative vigor of seedlings from seeds of large fruits as compared with those from seeds of small fruits. At the same time record was made of the number and distribution in cells of the seeds of each apple in an effort to determine whether or not there is a definite relation between seed production and size of fruit. The seedlings of these 1908 groups, however, were so few in number that the division between those from large fruits and those from small was abandoned, and further records, to be maintained until the seedlings are established in fruit production, consider them only as variety groups. The seed-production record was combined with other like records since obtained, and the whole is treated in a separate publication (Bulletin 203).
SEEDLINGS FROM FRUITS OF 1909
Seedlings from seeds collected in 1909, numbered, in 1915, above three thousand and represented six varieties. Such results as the project may yield when the fruiting characteristics have been determined will be derived mainly from these groups, and it therefore seems best to record the history of the trees in some detail.
All apples used in 1909 were supplied by Mr. J. C. B. Heaton from his orchards at New Burnside in Johnson county. They were barreled and shipped to the Station late in October. When received they were at once placed in storage, where they remained until the work of weighing and measuring them and extracting the seeds could be undertaken. Six varieties were represented, each by apples from a single tree that had been selected because of exceptional fruiting qualities.
Removal of seeds was begun November 9 and continued intermittently until finished November 29. The fruits of. each variety were separated into two size-groups. The division point between large and small apples was fixed at 65 mm. as the minimum transverse diameter for large apples of Arkansas Black, Ben Davis, and Minkler, and at 58 mm. as the minimum transverse diameter for large apples of Rhenish May, Winesap, and Smith Cider. The groups of large fruits thus very closely correspond with the No. 1 grade for the classes to which the varieties belong. Each fruit, was weighed. calipered for longitudinal and transverse diameters, then cut transversely for determination of the number and distribution of the seeds. As each lot was completed the seeds were sorted for the removal of those which had been accidentally injured by the knife in opening the fruit, of which had been partially eaten by codling-moth larvae, or otherwise subjected to apparent injury. This process reduced the total of seeds by about 11 percent and left only those that, so far as could be judged by appearance, were capable of germination. Each lot of seeds was then stratified in sand in bulb pans and buried in earth.
Comparison of size-groups is not very satisfactory because of the wide differences in numbers of apples. In the aggregate of all varieties the large fruits were 2.8 times as many as the small and contained 3.22 times as many seeds. With each variety the averages of seeds to the fruit were larger for large fruits than for small. Bringing the groups of large apples together, Rhenish May led in number of seeds to the fruit with an average of 11.76; Minkler was the least productive, as shown by the average of 4.22 seeds. Assembling the groups of small apples, Winesap had the highest average, 8.91 seeds to each fruit, and here also Minkler had the lowest, 2.91 seeds to each fruit. Discarding size-groups and considering the aggregate of fruits for each variety, Rhenish May showed greatest productiveness with an average of 10.83 seeds for each fruit. The other varieties ranked in descending order as follows: Winesap, Smith Cider, Arkansas Black, Ben Davis, and Minkler.
To avoid repetition of the experience of the preceding year, when a considerable portion of the buried seeds germinated before it was possible to plant them, all the seed pans were taken up in February and placed in cold storage at a temperature of 31°F. On March 28, 1910, the seeds were separated from the sand and planted in nursery rows; they were then in excellent condition. It was the intention to determine the percentage of germination in each lot of seeds, but the demands of other projects were such that it was found impossible to do this, hence it is only known that germination was abundant.
During the first season the seedlings made that same slow, weak growth that appears to be characteristic of all apple seedlings grown on the black soil of this locality. About midsummer, at the time of hand-weeding the nursery, many weak seedlings were taken out to make more room for the better ones. In the fall of 1910 all were taken up for winter storage and again planted in nursery in the spring of 1911. This was repeated in the fall of 1911 and again in 1912. The aggregate of seedlings taken up for storage in the fall of 1911 was 5,648. In the fall of 1912 they numbered 5,315. In May, 1913, the seedlings, being then three years old, were permanently planted in orchard, 15 by 15 feet. The number thus planted was 4,988; of these, 4,568 were planted on the Station farm at the University and 420, 35 of each size-group of each variety, were sent to the Station farm at Olney in Richland county.
The losses indicated by the differences in the aggregates here given were mainly due to the death of seedlings that from the beginning had exhibited very low vitality. Many of these weak seedlings existed thru the second year in nursery and some thru the third year without making any appreciable growth. It is not to be understood that all weak seedlings had been eliminated at the time of planting in orchard. Some that were set out were but little more promising than many that had died, but were given their chance to overcome the weakness, if possible. Most of these weak trees did not improve; many died the first year in orchard, and others have since succumbed.
TABLE 23.—MEASUREMENTS OF FRUITS AND ENUMERATION OF SEEDS FROM FRUITS OF 1909
|Average diam. (mm.)||No. of
A few words are here necessary in explanation of the loss of a large number of trees during the first two seasons in orchard. The planting in the spring of 1913 was divided between two areas. In one forty-acre tract which was largely occupied by trees grown under other projects but which still had some unused space, there were planted 1,205 seedlings of three varieties as follows: Arkansas Black from seeds from large fruits, 108, from small fruits, 50; Ben Davis from large fruits, 392, from small fruits, 7; Smith Cider from large fruits, 328, from small fruits, 320. The trees were planted May 7 to 9. The soil here was well cultivated and in excellent condition for planting.
At the opening of spring in 1914, 159 trees, or 13 percent, had died. It was the small, weak trees that died, largely from inherent lack of vitality, but in part because of the extremely dry conditions that prevailed thruout the season. The second enumeration, made in the fall of 1915, two seasons after the first enumeration, showed an additional loss of only twenty-five trees, or a little more than 2 percent of the original planting. This small loss indicated that the weak trees had been eliminated. There remained at this time 1,021 trees: 352 classed as good, 429 as fair, and 240 as poor. These trees appeared to be established and most of them should reach maturity, produce fruit, and fulfil the purpose for which they were grown. They are by no means an even lot, but exhibit great diversity in growth habit and in vigor.
Seedlings of the remaining varieties, Rhenish May, Minkler, and Winesap, together with a few trees of Arkansas Black remaining after filling the area referred to above were planted May 15 to 22 on another forty-acre tract that at this time became available. This tract had been used for farm crops and had been neglected. It was not in satisfactory condition for the reception of trees, but the season was so far advanced that further delay was out of the question; the trees were planted as quickly as possible and much labor was expended in an effort to improve the unfortunate surroundings. No rain fell following planting and extreme drouth prevailed thruout the season. Three times at short intervals during July and August water was hauled in tanks and applied to the trees, but little benefit was derived from this treatment.
No enumeration of the trees was made until the spring of 1914, when the aggregate loss was ascertained to be 1,339 trees, or 40 percent of the number planted. The largest losses fell on Rhenish May, in which variety they amounted to 55 percent, while with Winesap the loss was only 21 percent. Of the 3,363 trees planted in the spring of 1913, there remained 2,024 in the spring of 1914. Some of these were shifted in the process of filling gaps and consolidating rows. From the time of enumeration in 1914 to the end of 1915 there was an additional loss of 175 trees, making the total loss 1,514 trees, or 45 percent of the number planted. Most trees made satisfactory growth in 1915, and, when the difficulties thru which they had lived are considered, the unfavorable conditions at time of planting and two summers of extreme drouth, it would seem that they had proved their resistant qualities and were safely on the way to full development and fruit production.
All the trees in this planting had a more or less stunted appearance; all were below normal size for trees six years of age. The growth made in 1915, however, gave promise that the stunted appearance would soon be overcome and that control of direction and amount of branch extension by pruning would, within a few years, bring the trees into satisfactory forms.
As the project stood at the close of the year 1915, six years from the planting of the seeds, there were in the two plantations on the University farm, 2,868 trees. Add to these the 365 trees which were living at the time of the last enumeration of the 420 planted at Olney, and the total number of surviving trees becomes 3,233, distributed as follows:
|NUMBER OF TREES IN 1915||From seed
|Arkansas Black||University Farm||85||41|
|Ben Davis||University Farm||365||0|
|Rhenish May||University Farm||587||104|
|Smith Cider||University Farm||279||257|
If the total number of living trees be compared with the total number of seeds planted, it appears that there was one tree for 17.2 seeds planted, or, expressed in percentage, 5.81 percent of the seeds planted persisted as living trees at the end of six years. The proportion of seeds surviving as trees was small and did not fairly represent the possibilities in apple-seedling production. No germination record was made, nor was any record kept of the seedlings destroyed in thinning during the first summer. The seedlings were first enumerated when two years old; at that time the number represented a little more than 10 percent of the seeds planted. The losses in the succeeding four years amounted to 43 percent, chiefly thru unfortunate conditions that were beyond control.
From the standpoint of future work on the project it is perhaps fortunate that the number of seedlings is no larger. To maintain accurate annual growth records, and particularly to diagram land describe the fruits of individuals as they are produced, is not a serious task when no more than one hundred trees are involved, but multiply these by thirty-two and the work is destined to tax the resources of the Department, especially in view of the fact that some thousands of trees grown wider other projects promise demands for attention at the same time.
The six varieties here included showed considerable differences in numbers of seedlings living at the time of the first enumeration, when they were two years old, as contrasted with the numbers of seeds planted, and also in relative resistance as shown by a similar comparison of numbers of trees living in 1915. The groups of seedlings from seeds from large fruits will illustrate this. In 1911 the ratio of seedlings to seeds planted was I to 6 for Arkansas Black and Smith Cider, 1 to 10 for Ben Davis, 1 to 11 for Winesap, 1 to 12 for Rhenish May, and 1 to 25 for Minkler, while the ratio in 1915 was 1 to 8 for Smith Cider, 1 to 12 for Ben Davis, 1 to 15 for Winesap, 1 to 18 for Arkansas Black, 1 to 39 for Rhenish May, and 1 to 48 for Minkler; or, to indicate the losses during the four years by percentages, Ben Davis had the least, 17 percent, followed in order by Smith Cider with 23 percent, Winesap with 24 percent, Minkler with 48 percent, Arkansas Black with 68 percent, and Rhenish May with 69 percent.
Except for the two varieties Smith Cider and Winesap, comparisons between size-groups are unsatisfactory because of disparity of numbers. Two of the small size-groups are entirely eliminated, namely, Ben Davis and Minkler. The small size-group of Ben Davis was represented by only eighty-nine fruits, from which 455 seeds were planted. Only fifty-four seedlings were living at two years of age; 'Only seven were planted in orchard, and these died that same year. The small size-group of Minkler had only twenty-four apples, which yielded 69 seeds; only fifteen weak seedlings survived to be planted in orchard in 1913 and these soon died. The small size-group of Arkansas Black had but thirty-five apples, from which 185 seeds were planted; most of the seeds germinated and seventy-seven trees lived to be planted in orchard in 1913. More seedlings in proportion to the number of seeds planted were produced by the seeds from small apples than by those from large apples. The ratio for the small size-group was I to 2.4, and for the large size-group, 1 to 14.29. Three years later the ratios between living trees and seeds planted were 1 to 4.51 for the small size-group and 1 to 18.16 for the large size-group. These ratios indicate a higher productiveness on the part of seeds from small fruits than is shown by seeds from large fruits. If, however, the percentage of trees lost in the three-year period between planting and the end of 1915 be examined, it is found that for the seedlings from seeds from small fruits the loss was more than twice as great as for those from seeds from large fruits. This indicates less resistance to adverse conditions and presumably a less degree of vitality in the seedlings from small fruits than is possessed by the seedlings from large fruits.
In Rhenish May the disparity in numbers between the size-groups was not so great as in Arkansas Black, Ben Davis, and Minkler, but the numbers of fruits, and hence of seeds, were much larger. Here the ratios between seedlings living in 1911 and seeds planted were 1 to 12.17 for seedlings from large fruits and 1 to 6.77 for those from small fruits. Four years later, in 1915, these ratios became 1 to 39 for seedlings from large fruits and 1 to 26.25 for those from small fruits, showing that the small fruits gave a larger number of seedlings in proportion to the number of seeds planted than did the large fruits, but, as with Arkansas Black, the percentage of loss between the first enumeration of seedlings and the end of the season of 1915, in this case four years, was greater for the seedlings from small fruits. With this variety the percentages of loss were much greater than with Arkansas Black, but the difference between loss percentages of the two size-groups was much less, 68.71 percent for seedlings from large fruits and 74.2 percent for those from small fruits. The difference is too small to indicate any clear superiority, in matters of resistance and vitality, of seedlings from fruits of large size over those from small fruits.
With Smith Cider and Winesap, parity of numbers of fruits and of seeds planted renders comparison of size-groups more satisfactory. These varieties, at the time of first enumeration in 1911, gave ratios between number of seedlings and number of seeds planted as follows: for Smith Cider 1 to 6 for seedlings from large fruits, 1 to 5 for seedlings from small fruits; for Winesap 1 to 11 for seedlings from large fruits and 1 to 10 for seedlings from small fruits. At the time of the last enumeration, four years later, the ratios were for Smith Cider 1 to 8 for each of the two groups; for Winesap 1 to 15 for progeny of large fruits, and 1 to 17 for progeny of small fruits. The ratios for Smith Cider showed, for 1911, a slight advantage in productiveness on the part of the small size-group, and equality for the two size-groups at the last count. For Winesap the advantage in productiveness was with the group from small fruits at the time of the first enumeration, but was transferred to the group from large fruits and was somewhat increased at the last enumeration. When percentages of loss for the four-year period between the enumerations considered are examined, the advantage is found to lie with the seedlings from large fruits in both varieties. These percentages are, for seedlings from large fruits, 23 for Smith Cider and 24 for Winesap; for seedlings from small fruits, 37 for Smith Cider and 43 for Winesap.
Bringing together the evidence bearing upon comparison of size-groups, it appears that relative productiveness as exhibited in ratios between numbers of trees living in 1915 and numbers of seeds planted was slightly better for seedlings from large fruits in the varieties having nearly equal numbers of fruits and seeds, and markedly to the advantage of seedlings from small fruits in the varieties in which the small size-groups were represented by too small numbers for satisfactory comparison.
Death of trees during the four-year period from the first enumeration, in the fall of 1911, to the close of the season of 1915, offers a better basis for comparison of the relative resistance to adverse conditions and the possession of sustaining vitality. In each of the four varieties having both size-groups represented, the losses were greater among seedlings from small fruits than among those from large fruits. In the two varieties Arkansas Black and Rhenish May, in which there was disparity of numbers in the groups, the differences between the loss percentages of the groups were small, but in Smith Cider and Winesap, where the numbers approximated equality, the differences were decided.
Combining the records here considered with many observations on the relative vitality of seedlings of the two size groups, as indicated by the character and amount of growth, gives warrant for the conclusion that, in a general way, seedlings from seeds of large fruits are somewhat more resistant to adverse conditions and possess a higher degree of vitality than do seedlings from seeds of small fruits. Differences, however, were not perfectly constant and were often quite small, indicating that further definite records are needed before the question can be regarded as finally answered.