Part 3
"Where it is not possible to work all of the ground between nut trees, cultivation should begin with a three or four foot circle around each tree, annually increasing this space with the growth of the branches. Cultivation, with attention to humus and fertility, are necessary to proper tree growth and nut production. Sod culture will never do."
Mr. Burgart's method has the advantage not only of guarding the trees from excessive winter injury but at the same time adds an almost immediately available source of humus and nutrients to the soil for spring growth. If followed, it should greatly reduce the number of reports of winter injury, failure to start, and of weak growth afterward.
Excessive summer heat is not so great a problem in most portions of the northern states. The highest expected temperatures range, in our reports, from 86° to 110°; mostly from 90° to 100°. The highest known are reported to be all the way from 95° to 120°, but mostly from 100° to 110°. A method of guarding against heat damage will be found in a communication from Mr. H. F. Stoke, of Roanoke, Va., which appears later in this report.
Drouth and hot, dry winds are more dangerous enemies than either cold or heat. It is somewhat ominous that, out of eighty-three reports, forty-two, originating all the way from Maine to Oregon and from Canada to Tennessee, report the occurrence today of frequent drouths, while forty report hot, dry winds. Surely the need for tree planting is immediate and urgent. Mulching, and the protection of recently planted trees by wrapping their trunks, are preventives of some damage, but can not stand up forever against the longer and longer periods of drouth now being reported, during which the water table is gradually being lowered beyond the reach of tree roots.
The length of the frost-free season has an important bearing upon the production of nuts after the trees are matured. This is true in the south as well as in the north. One of the most frequently reported causes of loss of nut production in southern sections is an early spring, inducing growth of buds and blossoms, followed by a frost. No protection seems to have been found against this damage except by use of heavy smudges. Large orchardists protect themselves, but planters of small groves rarely do so. This explains the autumn scramble, reported by many members, in search of early fallen nuts. We should continue our search for trees which produce nuts of early maturity. Thus far the search has not been too successful among most species, but some progress has been made and the future is more encouraging in this respect than it was a decade or two ago. Some early maturing nuts have been found and pollen from the trees is being used for cross-pollination with better known nut producers. In the northern states, dates of the latest spring frosts range from April 1 to June 1, with the average around May 15. The earliest fall frosts come from Sept. 5 to Oct. 15, with the average about Sept. 15 to 20. Where the frosts fall much outside these limits--too late in the spring or too early in the fall--protective measures will help but will not always prevent damage.
_Soil Conditions._ There is a slight preponderance of clay soils over loam among the returns from planters. Loams and sandy loams are tied for second place. A smaller number report that these top soils lie shallow over hard-pan or rock. Fewer still report a soil underlaid with sand or gravel.
By far the best growth for most kinds of nut trees, as well as the best production of nuts, is to be found where trees are planted in deep loam. Next come the trees in clay loam; then come trees in sandy loam and in clay over sand or gravel. Numerous complaints of poor growth come from members who have trees set in a soil which is shallow over rock or hard-pan. Some of the hazels and butternuts are reported as able, for a time at least, to establish themselves in such soils, but their fight for survival seems precarious and is apparently short-lived. Black walnuts, particularly, require deep, rich soils into which their long taproots can easily penetrate. This is one of the few nut tree facts so definitely established that there can no longer be any doubt about it. The reports show that the planting of black walnuts in any but good deep soil should be discouraged. It leads only to disappointment and often to loss of interest.
A somewhat sandy soil, particularly if loamy, seems adapted to the planting of chestnuts and to such trees as do well on ground that will successfully grow peach trees. If such soil is found upon a hillside or hill top, so much the better. All such soils, of course, require more attention to fertility maintenance, for they leach out more quickly than soils with more of a clay constituent.
Do any of the nut tree species prefer an acid to an alkaline soil? This is a question our questionnaire does not answer. Thirty correspondents say their trees are set in a lime soil, fourteen in an alkaline soil (which may or may not, in the commonly accepted usage of that term, have lime as a source of alkalinity). Sixty-one report an acid soil. Only eight of this group report the use of lime, two the use of bone meal, and one of wood ash as acid correctives. Unfortunately, we did not ask definitely about the reaction of trees to the use or non-use of lime. Puzzled by this comparative neglect of lime as a corrective on acid soils, we asked Mr. H. F. Stoke, of Roanoke, Va., a very accurate and acute observer, who had reported plantings in both kinds of soils, what his experience had been. Also we asked Miss Mildred Jones, whose experience with nut trees is second to none, the same question. Their replies follow:
Mr. Stoke says: "In response to your inquiry, 'What nut trees, if any, do best in acid soils?' I should reply that the chestnut leads the list, followed closely by the mockernut hickory.
"Throughout its native habitat the heaviest stands of the native chestnuts are to be found on acid soils over granitic and sandstone formations, rather than on limestone ridges. The best stands are on granite ridges, partly due, no doubt, to the poverty of sandstone soils.
"The mockernut hickory occurs about anywhere on the poor, acid, clay soils of the south, its vigor depending on fertility. Shagbark does not occur on the acid (granitic) Blue Ridge mountains, but is found on the limestone Alleghanies running parallel only a few miles away. I have never seen a shagbark hickory between Roanoke and the coast, more than 200 miles away, but it occurs freely to within two or three miles on the west. The difference is not in elevation or rainfall, but in the soil.
"On the other hand, black walnut occurs on both acid and limestone soils, but seems to prefer the latter. Part of its preference may be due to the generally greater fertility and better drainage to be found in limestone soil. Persian walnut, I believe, when on its own roots, is more or less allergic to acid soil. Wild hazels grow here on both limestone and granite soils.
"Frankly, I believe the matter of soil acidity, as such, is rather over-emphasized. There are other factors entering into the problem that are of as great or greater importance. I doubt if there was actually any really alkaline soil, in its native state, in the humid region lying east of the Mississippi River. In the glaciated region lying to the north, the soil seems to have been more nearly neutral (pH 7). Such was the case in Iowa and in Minnesota where I homesteaded many years ago.
"Throughout the south the soil averages much more acid, even much limestone soil being greatly benefitted by liming. North or south, soil acidity is greatly affected by drainage and by the resulting native vegetation.
"Peat or muck soils are notably acid; also they are notably deficient in potash. The addition of wood ashes greatly benefits such soils in two ways. On the other hand, the addition of wood ashes to a soil already alkaline might be harmful even though in need of potash.
"In the last several years I have been making some soil experiments that I may write up when I am sure I know what I am talking about. In general, I may say I should prefer a soil slightly on the acid side for any and all tree and farm crops if I had an eye to future fertility. Lime breaks down vegetable matter and makes its constituent plant foods quickly available, but prevents a build-up of humus in the soil. The effect is very pronounced in times of drought, the alkaline soil crops drying up much more quickly than do those on acid soil. On the other hand, such soil elements as phosphorus seem to require the lime as a flux to prevent the phosphates from becoming fixed and unavailable to crops.
"In regard to peat moss, it is undoubtedly acid, but it is beneficial in its water-holding properties and in the comparatively slow release of its nutritive elements. Lime added to the peat will break it down rapidly and make it more available as a fertilizer, but until the decomposition reaches a certain point; its effect is to impoverish rather than to enrich the mixture. This seeming paradox can perhaps best be explained by some experiments I have been making with sawdust. A number of plots were prepared and given various treatments, including mixing one surface-inch of sawdust with the soil, and wheat was sown on the area.
"Wheat sown on the test plot without any treatment or fertilizer was normal for the poor clay soil on which the experiments were made. Where sawdust, only, was added, the wheat came up but sickened and produced no filled heads. The same was true where lime was added to the sawdust. Where heavy applications of nitrate of soda were added to the sawdust treated plots, both with and without lime, the 'sickness' disappeared and wheat was matured.
"My analysis of this, coupled with experiments in composting, leads to the following conclusion: During the period of decomposition of the sawdust (hastened, no doubt, by the lime), the bacteria of decomposition fed so heavily on the nitrates in the soil that the plants were starved. When the material had reached the condition of humus, the bacterial activity decreased to the point where fertility was restored.
"The above analysis accounts for the fact that coarse vegetable material, injures crops, when plowed under, for the current season. Fresh succulent material decays so quickly that it becomes almost immediately available, releasing its constituent plant food.
"With proper conditions of moisture and aeration, sawdust, when mixed with quickly decaying material like kitchen garbage, can be reduced to an excellent, usable humus in three summer months. In fact, it is then better material than if permitted to lie out in the weather for fifteen years.
"There is another factor I think important in tree growth, especially where summers are hot, and that is soil temperature.
"For any of our nut trees I should say that an acidity test of pH 6 to 7 would be entirely satisfactory. If the soil is infertile, some form of humus should be worked in at the time of planting. If much such material is used, some lime may be added. Better yet, wood ashes and bone meal will furnish potash, phosphorus, and the lime necessary to correct acidity and maintain the phosphorus in an available condition. Add to this, proper drainage and cool soil achieved by, first, cultivation, and later by heavy mulching, artificial shading, or shrubby undergrowth extended outside the root area, and your tree should 'go to town.' When the tree is large enough to shade its own root area it will take care of its own soil refrigeration. Nature knew what she was about when she planted trees in forests. Trees require warm heads (sunshine) and cool feet (shade), just the opposite from us humans."
Mr. Stoke's letter recalls a very ancient Arabian proverb connected with the date palm. "The date palm tree must have his head in hell and his feet in water." We are indebted both to Mr. Stoke and to the Arab scientists for many things.
Miss Mildred Jones' reply, fortunately, goes into other and equally important phases of the same subject. She says: "Anyone who is going to lime and fertilize nut trees should take at least a five year period for his work, using lime and fertilizer each year, and not dump it all in one year, then wait for results. He should study the return on a five year basis. One year is too short a term. Weather conditions can upset a program to the extent that both lime and fertilizer may not have their effect until the following year. Let those who really want to know, make graphs of growth in young trees and of nut production from older trees, in pounds, for five years, as against five of the same years during which trees similarly situated received no fertilizer or lime.
"I shouldn't be at all surprised if those who state in reports to you that they have an acid soil, merely have a top acid soil. They may be growing their trees in basic limestone soils. Walnut trees grow in this environment very well, because they are found growing wild in woods where laurel and other types of plants loving an acid condition grow. This is true here in our county, but these soils are not seriously acid. They grow good garden crops.
"Ground, or pulverized, limestone is the safest type of lime to apply to trees or crops, in my estimation. Some of it is ground so fine that it looks like hydrated lime and is used for medicinal purposes. I am inclined to think that any reports you received that noted injury from the use of lime may have been due to the use of burned lime (calcium oxide) which is caustic when wet. This type of lime may be used in winter, but during the growing season, or too close to the growing season, may injure trees. I believe such injury depends entirely upon weather conditions, but it is a good thing to be on the safe side and use a lime which will not have the hot reaction that burned lime has.
"Your reports will serve an excellent purpose if they lead to getting a yearly record by planters on bearing and tree growth of their varieties. Few people know enough to go into the matter of soils and treatments intelligently. One can hardly blame them. It is a baffling subject. An unbalance in one element will lock up another element until one has quite a time unlocking them again. It seems that a conservative middle course is about the best to advise."
Upon reflection, it seems likely that if our questionnaire had asked specifically about the use of lime, many more reports would have been received of its use.
In response to an inquiry as to how weed competition near young trees is controlled, the replies are encouraging. Forty-seven practiced mulching; forty-five, mowing; thirty-four, occasional cultivation; twenty, regular cultivation, and a few others, slag or cinders around the trees. As is evident, some used several of the above methods. A few used none and suffered losses. Their honesty is admired, and their experience, disappointing as it is, is useful information.
As to fertilizing, forty-three reported the use of manure in some form as the principal material; twenty-eight used nitrogenous fertilizer; twenty-one, a complete fertilizer. Other materials were, in order, lime, compost, bone meal, ammonium sulphate, wood ash, tankage. One used a mixture of muck and manure and got results in excellent growth where the use of muck alone produced unsatisfactory growth. Several reported injury from too much fertilizer or from too late an application. Tree growth was thus pushed on into late fall; the trees were too sappy to stand the winter freezes and suffered from winter killing. The same result was reported from "over-cultivation." In this connection, we refer back to the letter from Mr. H. P. Burgart, of Michigan, whose suggestions on cultivation and fertilizing are well worth careful study and practice by all who have had this trouble. It is possible that some planters, especially those whose trees are set on hillsides, where erosion is a robber of fertility, would modify Mr. Burgart's practice of turning under the green crop in the spring. They might prefer, as indeed might others who would like to see their green manure nearer the top of the soil, to disk in the green crop rather than bury it deeply with mouldboard plows. They would of course follow it up with repeated diskings until the time came for sowing another cover crop. This is, however, entirely in line with Mr. Burgart's recommendations.
Pursuing this subject to its conclusion, we next asked: "_When young trees failed to grow with you, what percentage of these failures was due to_ ..." (various causes enumerated below)? The question was misunderstood. Many evidently gave percentages of all trees planted. Others, correctly, gave percentages merely of the trees which failed to grow. As nearly as could be arrived at, about 30 percent of losses were among trees that failed even to start; 40 percent failed from weak growth the first year or two; 10 percent from failure to maintain later growth; 16 percent were winter killed, and 3 or 4 percent died from rodent or similar (mole, gopher, deer, bear) injury. It is evident that by far the greatest losses were suffered within the first two years--not less than seventy percent. Probably more. It would seem that two years of intensive care should not be too burdensome a stint for a reward which lasts a lifetime.
Rodent and similar injuries were no doubt kept low because of extra protective care. Hardware cloth (galvanized wire 1/4" mesh, 24" high, preferred) around each tree proved the most common and effective preventive. Following this, in order of use, were: wrapping the trunks (including wrappings of tar paper); mounding with earth or ashes; poison bait, dogs and cats, clean cultivation; resinous paint; spray (with Purdue formula mentioned); and, finally, hogs, against mice.
Anti-rodent treatments which proved injurious to trees were reported to be; tar paper wrappings; coal tar washes; close-set creosoted posts; oil sprays; "any paint"; any chemical to smear on trunks; rooting cement. For those who are located in regions where deer are a source of injury, Mr. J. U. Gellatly, of West Bank, B. C., reports the successful use of an old and heroic Russian formula. Spray or paint all branches with manure water, using hog or human offal. Deer will stay away. Naturally.
Next come answers to some personal questions as to experiences from which the reader may glean a wide variety of suggestions. The first of these questions is:
"_What is your ONE greatest source of success?_" The answers seem to show many royal roads, each of which was the one road for someone. The answers: Mulching young trees; watering care; planting seeds; planting one-year seedlings; wrapping-with paper; 50% moist peat mixed with earth in transplanting; manure; sod in bottom of planting hole and use of nitrogen later; setting trees at bottom of slopes; clean cultivation until August then sowing rye, soy beans or cow peas as cover crops to turn under in spring; topworking hickories; grafting in cool, moist spring weather; pigs in orchard; chickens in orchard; planting 12-14-foot trees severely cut back, burlap wrapped, heavily mulched.
It seems a pity that limitations of space do not permit the telling of the various stories connected with the above glimpses of successful solutions. Each represents a little or a big success story connected with an individual problem. It is sufficient, perhaps, to know that someone somewhere found that each was the answer to his own difficulties.
The next question brings out the reverse side of the planters' work: "_What is your chief source of failure?_" The answer most often given was the honest one, lack of attention. We can all convict ourselves here, either involuntarily or otherwise. Especially during this period of warfare, when so many have been taken away from their plantings and have been unable to get help, there is no question but that our trees have suffered. The next in frequency is "unsuitable soil." Following this come: lack of water; poor planting; planting too big a tree; spring planting of nut trees; buying 5 to 7 year-old trees; climate; transplanting failures; grafting; grafting in dry, hot, springs; top-working old trees; stink bugs on filberts (nuts); lack of drainage; forcing with nitrogenous fertilizer; fertilizing young trees too much; birds breaking off top growth. It had been the intention to confine this question to young trees, but it was not so phrased, so we shall let the answers stand as they are. It is a bit ironical that some found their chief source of failure exactly where others had made their best success. The explanation must lie in differences in technique, in soil or in some other local condition. Skill, knowledge, and persistence must always play a great part in any success.
We next asked, "_What have been your chief difficulties with established, bearing trees?_" The difficulties here shift from matters of soil, rodent protection and the like to other types; caterpillars, neglect, winter injury, limited crops, failure of nuts to fill, disappointing quality of nuts, bag and tent worms, blight, "blight" due to drought, too early leaf fall, insects in early spring, trees drowned out in flooded bottom lands. It is probable that this last disaster happened to younger trees.
As to the species of trees chiefly damaged by these causes, black walnut comes first (possibly because more of these trees have been planted), then hickories, Persian walnuts, chestnuts (blight), heartnuts, pecans, filberts, butternuts, and finally butternuts in the south areas from fungus troubles.
Trees reported to have been least damaged were, first, butternuts, then hazels and filberts, black walnuts, hickories, Manchurian walnuts, Jap. walnuts, heartnuts, chestnuts, pecans, Persian walnuts.
In response to the specific question, "_What insects damaged the trees?_", we found that walnut caterpillars were more common than any others, followed closely by web or "tent" worms. The Japanese beetle is a close second and is broadening its entrenched positions steadily. Others are flat-headed apple borers, lace-wing fly, aphis, leaf hoppers. To this list two reporters added sapsuckers among the insects. These birds would almost girdle some of the branches with punctures.
Insect damage was reported as serious by eight reporters, as slight or occasional by six, and of yearly occurrence by nearly all. Others reported damage as serious if not controlled.
"_What do you do to control the insects?_" was then asked. Most of the answers referred to clustering types of insects and involved removal of the clusters by burning, by cutting off the infested twigs, or by scraping off the clusters from the trunks in the early morning or late evening. Others sprayed with lead arsenate, "sprayed in late summer with lead arsenate", sprayed with nicotine sulphate for aphis and lice. Other methods mentioned were early cultivation, shaking the tree with a pole early and often, and chickens in the grove. Some of these means are adapted manifestly, to small plantings and others to larger groves. None mentioned the attracting of birds by plantings of trees or shrubs that bear berries or small seeds. When trees are tall enough to be beyond reach of poles or sprays, the birds become more essential as insect destroyers.