SONG News Spring 1988 no. 32

1987 Year End Report For The SONG Project: Nut Tree Crops For Ontario

In the fall of 1985, the Ontario Government initiated a new farm program entitled Ontario Crop Introduction and Expansion Program. The Society of Ontario Nut Growers (SONG) is now ending its second year in the program and offers this report, submitted by the nine participants in the project at nine different sites. The objectives of the project are:

  1. To determine the commercial potential of the sweet chestnut cultivar "Layeroka".
  2. To grow, identify and evaluate outstanding sweet chestnut, Persian walnut, filbert (hazel), heartnut and pine nut trees.
  3. To determine experimentally, the influences of certain factors on such things as growth rates, nut production, and disease susceptibility.

Site #1 R. Douglas Campbell, R.R.#1, Niagara-on-the-Lake ON L0S 1J0
Experiments concerning the productivity of chestnuts and heartnuts and the effects of various nutrients and extra irrigation water were continued in 1987. Likewise, further explorations were made to determine new sources of chestnut and heartnut germplasm and to relate the growth/productivity characteristics to those of previous sources.

Heartnuts
The productivity of the existing heartnuts were as follows:
CW3 2850lbs/acre
CW1 2700lbs/acre
These production rates are for nuts in the shell dried to room conditions.

Again as last year, it was noticed that a considerable period in the months of May/June required extra irrigation water to promote maximum thriftiness of trees. Also, heartnuts respond well to addition of nutrients as observed in leaf colour, prolificacy of flowering, pollination efficiency, and subsequent nut size.

The belief that heartnuts can be a substantial nut industry in Ontario is further sustained. The attractive factors are: annual and prolific production, insect and disease resistance, and rampant growth characteristics of the trees.

Chestnuts
It was an extremely good year for chestnuts. Chestnut size and productivity factors both were high. These performances, no doubt, were related to careful cultural practices relating to water and nutrient availability. Productivity levels achieved were as follows for selected individual trees:
Mahogany 3400 lb./acre
Layeroka Sdlg #1 3350 lb./acre
Layeroka Sdlg #2 3125 lb./acre
Johnston Sdlg #1 3525 lb./acre
It should be mentioned that these selected trees are all performing in very high density circumstances and therefore the stress levels for nutrients and water is somewhat greater than is the case in a more conventional planting.

Nursery Developments
A large number of seeds were planted for further observation of numerous seedlings of both chestnut and heartnut as well as other species of nuts which are likely candidates for commercial production in Ontario. A notable achievement so far has been the attainment of chestnut types which give growth rates of up to 50 percent faster than seed stocks brought in from other locations. This underlines the considerable benefits of sequential selection of improved types from generation to generation of seedling productions.

Site #2 L.H. Cruttenden, R.R.#1, Lucan ON NOM 2JO
Mr. Cruttenden has approximately 5 acres of land on his Lucan property devoted to the culture of sweet chestnuts and Persian walnuts. The following is his 1987 report.

Chinese Chestnuts
As mentioned in the 1986 report, the Chinese chestnuts did not do at all well on the clay loam soil, which comprised the greater part of the orchard (3.3 acres out of 3.9 acres planted) and it had therefore been decided to transplant the surviving trees on the heavier soil to sandy soil next to the 0.6 acres that was established on light soil and doing well.

Accordingly, in the spring of 1987 (April 16), 30 grafted Chinese chestnuts were transplanted from clay loam on the 21.03 acres of sandy soil. Due to the size of the trees this had to be done by means of a mechanical spade transplanter mounted on a truck for this purpose. These trees were planted in 40 foot rows, 40 feet apart with the idea of interplanting seedling trees in 1988 in between each 40 foot row to act as pollinators. This transplanting appears to have been successful, and the trees produced good green foliage compared to the very chlorotic appearance of the previous summer, a condition that could not be corrected the previous summer with fertilizer and trace element folier sprays. Three of the transplanted trees failed to respond to the more favourable soil initially, but after digging in liberal amounts of peat and manure, in addition to heavy watering, they too produced good green foliage. New growth, however, was minimal (about 6") and no doubt it will take a little while longer before we see improvement in growth. The roots still have to make their way out of the bolus of clay loam with which they were transplanted to a greater degree, and proliferate further into the sandy loam which they prefer.

The older Chinese chestnut trees on 0.6 acres suffered from the exceptionally hot dry summer which was experienced. The soil was good and moist until April 16th, but then the hot dry conditions developed. By April 20th, the temperature had risen to a record 28C in a prolonged hot spell. The next rain was a pitiful 0.25" on what was by then very dry soil by May 15th. Rainfall throughout the rest of the summer was as follows:
Month Total in Inches
May 0.65
June 1.63
July 1.34
These low rainfall amounts meant that for nearly all summer, the soil had large cracks that one could push a walking stick into. Combined with temperatures well above average, this meant that conditions were droughty all summer. Consequently, water had to be carried to the trees at intervals all summer. This was a lifesaving effort at best and not nearly enough to allow the trees to grow reasonably. In fact, the top growth on four of the older established grafted Chinese chestnuts on the sandy soil died off very suddenly due to the drought. They then promptly regrew from the rootstock.

Under these extreme conditions, the chestnuts made only minimal growth in 1987. New growth varied from 8" to 20".

The trees produced an abundance of catkins, but most of the fruit that formed did not fill out. Only about one to two percent did fill out to produce decent nuts. This was a little better than the previous year. This was not unexpected, since the trees are still young and the drought did take its toll. Lack of bearing is primarily due to the immaturity of the trees.

A little less than half of the seedling chestnuts produced pollen. This again is an improvement on last year. It was likely also, to some extent, responsible for the number of unfilled nuts.

No diseases or pests were noticed on the chestnuts. The total area planted to chestnuts is now 1.63 acres.

Carpathian Walnuts
As mentioned in the 1986 report, the plan was to replace Chinese chestnuts on the clay loam soil with Carpathian walnuts. This was, indeed, done during 1987 to give a further 3.7 acres of walnuts. The trees were planted 40 feet by 40 feet using both Young's B1 grafted on black walnut and seedlings from a local selection. As far as possible, these were alternated in the row. '' However, there was not enough of the B1 grafts to be able to do this throughout the planting. Growth was variable in this first year, but generally quite satisfactory. These trees did not suffer unduly from the drought as it was easier to supply their lesser need by carting water to them.

Site #3 Niagara-on-the-Lake
Ernest Grimo has 6 acres of Persian walnuts, 3 acres of sweet chestnuts, 1.2 acres of hybrid hazels ' and a newly established heartnut planting of about 0.5 acres. Most of the walnuts are grafted cultivars under test to determine their commercial potential. The chestnuts are largely hand-pollinated seedlings of Layeroka being grown to develop new selections. The hazel hybrids are made up of good parent sources in an effort to develop new cultivars also. The following is the 1987 evaluation.

Hazelnut Orchard (Corylus species)
Since this orchard is designed to test individual trees for cultivar status, little effort has been made to maximize production. Instead, poorer trees have been removed and sites were replanted to test new seedlings. This has resulted in a planting that has a wide age range from one year to fourteen years in location. In 1987, 20 out of 209 trees or 10 percent of the planting was replaced with young seedlings as part of the upgrading program.

After the heavy crop of 1986, a lighter crop in 1987 was not unexpected. The crop on the trees appeared to be down about 25 percent. However, the crop was down about 60 percent, cropping at 198.6 kg or 437 lb. This compares to 487 kg or 1070 lb. in 1986. In the winter of 1987, the trees were pruned after several years of no pruning. An effort was made to remove low lying limbs and to reduce the number of stems to facilitate the harvest. As a result, 20 to 40 percent of the bearing surface was removed from the orchard. This accounts for the more drastic reduction in the crop than would otherwise be.

As in 1986, to determine bearing performance, the total area of the individual trees was calculated and produced a production rate of 1288 kg/ha or 1150 lb./A. The following selections are the five best trees in our evaluations rated over the last four years (in rank order). Production figures are an average of the last two years: Gellatly #502, 2247 kg/ha; NY 616, 3380 kg/ha; NY 200, 1980 kg/ha; Grimo 184P (a Gellatly seedling), 1865 kg/ha; NY 398, 1588 kg/ha. The two year crop record of the five best rated selections yields a production rate of 4205 kg/ha or 3750 lb/acre.

Our favorite selection, Gellatly #502 has been the most consistent bearer in the orchard. It ripens and drops the nuts clean of husks by mid September, making it an easier selection to handle than the NY selections which ripen almost a full month later. They also tend to stick in the husk. It is our opinion that they would be better suited to warmer climates, though they still perform well at the Niagara-on-the-Lake location. Other selections which show promise include; Grimo 188P, our Myoka x Petoka cross, and Chinoka.

Our orchard has demonstrated that commercial quantities of hazelnuts can be produced in Ontario even through the use of selected seedling sources. We have had good early bearing from seedlings of Manoka, Myoka, Gellatly #502 and Chinoka. Where seedlings prove to be unsatisfactory they can be removed and replaced with layers the best selections or from grafted selections such as Gellatly #502.

The total 1987 crop was sold as seed to nurseries at $2.50 to $3.00 per pound.

Persian Walnut Orchard (Juglans regia)
On a scattered planting of about 5 acres, and over 200 trees, there are two different studies being made. In the first, 60 selections and cultivars have been grafted onto black walnut rootstocks. These trees will be fruited and evaluated over the long term to determine the best cultivars. The number of replications vary from one to ten or more for each cultivar. In the second, there are about 50 seedlings which are also being evaluated for cultivar status. In this planting, the poorest trees are removed annually and replaced by new seedlings.

The crop was lighter this year than last year but the nut quality was generally good. A few trees had very light crops including the selection called Young's B#1. Young's B#4, another excellent selection, produced a light crop of poorly filled nuts this year for the first time. These have been two of our most outstanding selections for several years. Overall, the crop was down about 50 percent from last year. Metcalfe and Hansen, on the other hand, produced their usual heavy crop of nuts. Colby was down by more than half of its previous year. This can be accounted for, in part, because it was heavily cropped for scion wood in the spring of 1987. Since most of our trees are annually cropped for scion wood, production records are only indicators at best.

Table 1 summarizes the evaluation data for 1987. Rate of production is measured in kg/ha. Percent kernel is an indication of the amount of kernel in relation to the shell. Nuts with thinner shells and better developed kernels tend to have higher percentages. Ideal percentages lie somewhere between 50 to 60 percent kernel. Annual overall ratings are based on bearing quantity as well as a number of other considerations. These include: percent kernel, nut size, cracking quality, kernel filling and plumpness, kernel colour, and flavour. Table 1: (Ratings 1 high, 5 low)
Selectionkg/ha% Kernel198519861987
Young's B1-50%123
Metcalfe823058%221
Colby211046%212
Hansen957052%222
Korn-51%322
Young's M3-50%312
Greenhaven146043%222
Young's B4--214
62Z Hansen Sdg383052%-22

Metcalfe has been our heaviest and most consistent bearer over the years, while Hansen has had the most uniform kernel quality. Hansen, in some years, will have poorly formed shells which do not seal. It appears to be less hardy than others in some ways and so is not recommended for general commercial planting. The Young selections have had a poor year in 1987. However, they have qualities, including nut size, kernel quality and tree vigour that keep them established with the outstanding selections.

Sweet Chestnut Orchard (Castanea mollissima)
The chestnut planting consists of about 250 trees on nearly one hectare of land. Most are planted on 4.7 m spacings, though more recently some had to be planted at 1 m distances in rows to conserve space. About 90 percent of the planting is made up of hand pollinated crosses using the cultivar "Layeroka" as the seed parent. Though some of this planting is thirteen years old, most of the trees are under five years old. As the planting grew, trees that cropped poorly or produced small sized nuts were eliminated from the orchard over the year. The only large trees that remain are grafted selections on test or seedlings that have some promise.

The chestnut trees are rated on a similar five point scale as is used for the other nuts. They are evaluated on: crop size, nut size (number of nuts per kilogram), flavour, shell colour and pellicle quality.

Nut production continues to be erratic. Most of the under four year old trees have few or no nuts. On the other hand, the larger trees had reasonable crops of nuts. The best performer in our planting for the second year in a row is Grimo 142Q, a ten year old Layeroka seedling planted in 1978. The 1987 crop totalled 5.3 kg with a calculated production rate of 1760 kg/ha. This compares to the 1986 crop of 8.6 kg yielding 4729 kg/ha. The nuts were uniformly large, attractive and fine flavoured. The nuts dropped freely from the husks in mainly two drops a few days apart, making them relatively easy to handle.

Our other good performers include Layeroka, producing 2466 kg/ha, Campbell #1, at 3100 kg/ha and Campbell #2, at 1500 kg/ha. It can be noted that even though all of our best selections are down an average of about 50 percent in production over 1986, there is still a commercial sized crop. However, in these three selections the nuts were more difficult to harvest. About one quarter of the nuts came down stuck in the husks. These had to be physically removed. Nut size and quality were excellent this year in all of the above selections.

Heartnut Orchard
The heartnut orchard of 35 trees was newly established in the spring of 1987 on about 0.4 ha. Most were two year field grown grafts on two year old black walnut rootstocks. Eight were fresh spring grafts on two year old rootstocks. One tree died during the summer. The field grown grafts averaged about 25 cm of growth, while the fresh grafts produced about 10 cm.

Fourteen cultivars or selections are represented in the planting. They will be evaluated for nut production and nut quality characteristics.

Site #4 Cornelius Keeren, P.O. Box 7280, Oakville ON L6J 6L6
Twenty-one acres of a 40 acre chestnut planting established in 1986 and 1987 is included in this project. Involved are a one acre planting of grafted Layeroka chestnuts (100 trees) and 1500 Layeroka seedlings planted on 15 acres. These seedlings will be evaluatedjor cultivar status when they begin to bear.

1987 was a very dry growing season. As a result, the herbicide used for weed control around the trees was not activated and again this year the weed control was not sufficient. Timely spraying prevented leafhopper damage this year.

As it is an impossible task to remove the burrs from 4000 trees, the trees were allowed to bear. Although the 1986 grafted trees had an average of 25 burrs per tree, only 10 percent of the trees had nuts, making the total harvest about the same as the one of 1986 (10 kg).

Since we noted that many of the grafted Layeroka trees planted in 1986 had not survived the winter, we decided to give a final mortality rate after a two year period, 1988 for the 1986 planting and 1989 for the 1987 planting. The average growth of the 1986 planting was as follows:
Layeroka grafted trees 12.1cm
Layeroka seedlings 28.5 cm

Site #5 Charles Rhora, R.R.#1, Wainfleet ON LOS 1VO
Charles Rhora has approximately 17 acres devoted to the project and deals with Chinese chestnuts, Corylus species, Persian walnut, and the nut pines.

Chinese Chestnut Orchard
This orchard is planted on a sandy loam type soil with average drainage. It consists of approximately two acres with about 350 trees. The trees are mostly seedlings selected from named varieties. There are a few grafted Layeroka also. The average age of the trees are now about four years. Approximately 40 percent of these trees produced some crop this year and as with seedlings, the nut size and quantity varies. As this was an unusually dry summer at my location there were many nuts that were not filled. Probably, if they were properly irrigated, more nuts would have filled better. The trees with the very small nuts will be culled out and replaced with new seedlings. There was a crop of approximately one half bushel of good nuts.

Persian Walnut Orchard
This orchard has about 3000 seedling trees in a hedgerow planting with 20 feet between rows and about three feet between trees in the row. The seed was all home grown from superior selections from Canada, the United States, Europe and China. As these trees average in age from two to five years, they have not produced any crop to date. They have proven to be winter hardy and are late enough in vegetation to not be harmed by late frosts in the spring. They occupy about five acres.

Hazelnut Orchard
This orchard consists of approximately 3000 seedlings, again selected from named cultivars and others that had shown promise in their bearing. They range in age from one to six years, and their shape varies from bush to tree form. Those in the four to six year range have borne nuts and some have shown to be quite promising. Others, although quite productive, will be eliminated due to lateness of ripening or not falling free from their husks. The ones culled out will be replaced with other seedlings.

Heartnut Orchard
This planting consists of approximately 2500 seedlings with an average age of three years. They occupy approximately 2.5 acres and are planted in a hedgerow twenty feet between rows. Seedlings were grown from selected named cultivars that produce the heart shape of nut more frequently from seed. As of this date, they have not borne any crop but have adapted well.

Nut Pine Orchard
In the spring of 1987, an orchard of Jeffery pines were set out consisting of approximately 150 trees on three quarters of an acre of land. In 1988, a further 200 trees will be set out to complete this orchard. All of the seedlings were selected from trees that had withstood temperatures to -30°F and were home grown. Unfortunately, about 25 percent were lost due to the extended dry spell of last summer. These were watered but due to a busy schedule, they were not watered as frequently as they needed.

Korean Pine
A planned orchard of Korean pine trees did not materialize as planned this year. They will remain in the nursery until the spring of 1988. They were treated with the proper inoculum and put on approximately eight to ten inches of growth. There are about 150 seedlings that originated in Siberia. To date they have shown no injury. Seedlings are easier to grow than grafted trees when grown with the proper inoculum. Most nut pines require this treatment to promote growth and later when producing nuts.

In summary, Charles Rhora believes that the above mentioned species have the potential for commercial production at his location, as well as many other locations across Ontario. This should be pursued as quickly as possible.

Site #6 Joseph Triola, Line 2, Niagara-on-the-Lake ON LOS 1JO
Joseph Triola has 38 remaining American x Sativa castanea hybrid seedlings at two locations in their second year. At the Line 6 location, there is a total of 17 trees. There has been very poor growth except for two or three which have reached a height of one foot. Poor response may be due to the clay soil at this site.

At the Line 2 location, there are 21 plants. They are all between two to three feet in height, except for two that do not appear to be as hardy. It may be that they are too close to the septic tile system. One plant at this site died after turning yellow. One plant had burrs but they did not fill.

Site #7 Paul A. Bennett, R.R.#4, Paisley ON NOG 2ND
Paul Bennett has as his primary objective to find cold hardy filberts which will produce good quality nuts in a clay loam soil of the Paisley ON area.

A nursery of approximately 6000 filbert seedlings was established in the spring of 1984 and 1985. The site was a level, well drained area of clay loam. Seed selections were chosen for their hardiness and/or nut quality. Forty, two year old New York Hybrid seedlings (from Ernie Grimo's nursery) were planted in the spring of 1984, and thirty-five WHES 301 seedlings (from Doug Campbell) were planted in the spring of 1987.

Observations: A) Growth rate of trees started from seed on site:
Parent Source SeedlingsAvg. size after
3 summers
Comments
Grimo 192G (Manoka Sdg)28"Best growth next to Gellatly 502
Petoka (Gellatly)30"
Laroka (Gellatly)25"
New York 10432"
New York 11034"
Grimo 202K35"
Grimo 206M34"
Grimo 208N25"
Gellatly 50238"Consistently tall and healthy.
New York "Unknown"36"
John Gordon Largest27"
Grimo 202D (Gordon Sdg)35"
Grimo 206C (Gordon Sdg)36"
Grimo 32 N (Unknown Par.)34"

No fertilizer was used on this planting, but they were mulched with black plastic covered with wood chips. Of all the above seedlings, the Gellatly 502L had the most consistent growth rate and the best general health, followed by the Grimo 192G. The rest varied more in growth rate.

B) The forty-three year old mixed New York Hybrid seedlings transplanted in 1984 fared as follows: one died; of the remainder, the maximum growth was 58 inches; minimum growth was four inches, and average growth was 26 inches.

Thirty-five of the living trees grew from single or dual stems, rather thinly foliated trees, into thick multi-stemmed bushes. Four trees remain relatively thinly foliated. The percentage of trees which produced catkins was:
0% in 1984
12% in 1985
25% in 1986
90% in 1987
Twenty nuts were produced in 1987, only two of these contained kernels.

Fertilization of these trees was:
1984-none
1985 - cup of 7-7-7 per tree, applied in early June
1986 - cup of 7-7-7 per tree, applied in April and June
1987 - cup of 7-7-7 per tree, applied in April and June

C) The thirty-five WHES 301 seedlings appear to have wintered well as of January 31 of this year, but no other meaningful observations can be made at this time.

D) All seedlings which have been transplanted from the seeds planted in 1984 have large, dense root systems. Those trees transplanted into lighter soils appear to have had little or no setback due to the transplanting, and in most cases had substantial growth even in the summer immediately following being transplanted.

Secondary Objective: To find cold hardy heartnuts, walnuts and pecans which will thrive in clay loam soil.

A small planting of Persian walnuts, Bates heartnuts, Calendar heartnuts, Brock heartnuts, and northern pecans was established in April, 1984.

Observations:
A) The Persian walnuts, which had an average height of 38 inches in April 1984 now have an average height of 51 inches. Maximum growth was 32 inches, minimum was zero inches. All the walnuts sustained winter injury every year and had the leaves killed off by late frosts at least once each spring.

B) The heartnuts in general seemed to be less prone to winter damage than the Persian walnuts, but generally fared poorer due to late frost damage. Growth rates:
Bates -Average 28", max. 55", min. 1"
Brock - Average 11"
Calendar -Average 21", max. 38", min. 9"

C) The pecans had minimal winter damage and little frost damage, due to their habit of sprouting leaves late in the spring. Growth rate averaged 20", max. 25", min. 15".

D) Fertilization was at the same rate as the forty filbert trees planted in 1984, as described earlier.

Site #8-Glenn D. Sandham, B.Sc.(Ag), R.R.#3, Collingwood ON L9Y3Z2
Glenn Sandham has established a five acre orchard of nut trees in the spring of 1987 in the Tillsonburg area. His main objectives will be to test some of the better grafted cultivars and to make selections from his own seedlings in an effort to determine the best selections for his area.

0.48 ha of Chestnuts, 0.42 ha of Persian walnuts, 0.24 ha of heartnuts, and 0.24 ha of hickories were planted in rows 6m x 6m. Planted throughout this seedling planting were grafted trees of known origin and presumably of superior quality. Every fourth tree in each row, planted in a scattered pattern were grafted trees. This scattered pattern will help to compare the seedlings with themselves and with the grafted cultivars. The grafted trees will be used as a standard when comparing the seedlings to them. The nuts, and therefore the trees, will be evaluated on crop size, nut size, cracking quality, kernel colour, percent fill, and flavour. Initially, other factors such as growth rate, hardiness and dieback will be used to eliminate poor performing seedlings.

The 1987 growing season in the Tillsonburg area was very hot and dry. The initial soil preparation was ahead of schedule which led to very good planting conditions. Expecting little growth in this, the first year, it became a struggle to keep the leaves from burning up in the hot weather. In the fall, all but about ten trees looked in very good condition.

Site#9-G.R. Hambleton, M.B.A., B.A. Sc., P. Eng., R.R.#2, Niagara-on-the-Lake ON LOS 1JO
Mr. Hambleton has studied the Bacterial Blight disease of walnut (Xanthomonas juglandis) in an effort to effect a control for the disease.

Purpose
1) To investigate the possibility that an identifiable minor element in leaf samples from Juglans regia trees that can be linked to the '-} resistance of the trees to bacterial blight.
2) To investigate graft unions as to whether they affect the transmission of some of the minor elements as some grafted trees are more susceptible to the blight than the scion parent tree.

Introduction
The orchard is made up mainly of seedling Juglans regia trees. A few named varieties were budded on Carpathian (strain) walnut rootstocks and also some of the better and so far unnamed seedlings on to Carpathian and also black walnut rootstocks. From year to year there is considerable variation in the susceptibility to the blight even from tree to tree. The odd tree may act in reverse to the general blight levels (i.e. one year little infection on one tree and heavy on another). The next year the reverse could be true. In general, the budded trees appear to be more prone to heavy blight infection than the scion parent (an own rooted selection). Some trees appear to be much more susceptible to the blight than other trees. Curiosity about the interactions taking place here has led to this investigation.

Procedure
Leaf samples (20 in all) were taken from 17 different trees and sent to the Agri-food Laboratories in Guelph for analysis of ten major and minor elements. The five major elements are plotted on Figure 1 (tree sample number against percent of the element). The five minor elements are plotted on Figure 2 (tree sample number against the parts per million of the element).

Samples #2 and #11 had some copper nails hammered through the bark to see if copper content could be raised in the leaves since copper sprays give some control to the blight.

Description and Comments on Trees from Which Leaf Samples Were Taken

Trees numbered 1 x 10 to 3 x 24 are in an area where they normally have been fertilized with 33-0-0 and 0-0-60 fertilizers. None was applied in 1987 due to equipment problems and a lack of time once the repairs were made. Most of the other trees have not been fertilized to any extent. Copper sprays cannot be applied to the nut trees to help control the blight as these trees are interplanted with peach, pear and apple trees. Copper has a harsh effect on most fruit trees. Thus, it was hoped that another means of control was possible.

Results

  1. Copies of the leaf analysis results from Agri-food Laboratories follows. The results are plotted on Figures 1 and 2.
  2. Sample 2 (limb of tree tested as Sample 1) and Sample 11 (limb of tree tested as Sample 10) had Cu nails hammered into the limbs. For most elements, there was very little difference in ppm or percent except for percent calcium and ppm of manganese for samples 10 and 11.
  3. Pulling out one of the copper nails from Sample 2 revealed that the end that was in the hard wood was as shiny as new. In the area of sap flow, it was scaly from reactions with the sap. The rest of the nail that was in the bark and was exposed to the air was oxidized and dark but not corroded.
  4. There was no evidence in the ppm or percent of any element that could establish a correlation with the blight resistance of any of trees.

Conclusions

  1. The natural amount of the various elements picked up by the leaves does not appear to have any effect on the resistance of a tree to Bacterial Blight, since there is no sign of change in ppm or percent of an element when compared to the blight resistance of the trees.
  2. The copper nails did not appear to change the copper content of the leaves to any degree. Perhaps not enough nails were used. They may have been more effective if driven in on an angle to hit the sap bearing area and keep the nail out of the hard wood. To keep them active for a longer period, perhaps a sealant should have been placed over the exposed part of the nail and the surrounding bark. There probably is a toxic limit of copper that can be absorbed by the trees and be contained in the nuts for human consumption.

Overall Conclusions
This report suggests that commercial quantities of sweet chestnuts, hazelnuts, Persian walnuts and heartnuts can be grown in Ontario with little added development. Basic selections and cultivars presently exist that would make these nut crops viable, particularly in the more moderated regions of the Lower Great Lakes.

Provided by SONG. Feel free to copy with a credit.