Fig. 33. A nursery tree with a good root system.Fig. 33.A nursery tree with a good root system.
Figure 34 shows two pecan trees at two years. The one on the right was carefully lifted so as to preserve as much as possible of the taproot, while the one on the left had the taproot cut when it was transplanted at one year. In the latter, six smallroots from four and one-half to eight inches in length had grown out to replace the taproot, these doubtless having supplied the tree with as much nourishment as would have been given by its single taproot. Furthermore, without doubt, one of these roots would have grown so as to replace the taproot.
The advice has been given to cut the taproots back to five or six inches, but under general average climatic conditions throughout the pecan region anyone who follows this advice will have reason to regret it. Our experience in transplanting pecan trees has been such as to indicate the necessity of having a well-branched, well-developed root system, and a taproot, when present, should be left at least as long as indicated above.
Fig. 34. a. Taproot cut at 1 yr. b. Taproot not cut.Fig. 34.a. Taproot cut at 1 yr. b. Taproot not cut.
A long taproot is objectionable on account of the additional cost and labor entailed in digging holes of sufficient depth for planting. To shorten the length of the taproot, Mr. E. E. Risien, of San Saba, Tex., has patented a method which has given satisfactory results. The nuts from which the stocks are grown are planted over strips of mosquito netting, the netting being some distance below the level of the nuts. When the taproots have penetrated to the netting, their growth is stopped, and the lateral roots develop better in consequence.
While, in preparing a crop of pecan nuts for market, such extreme care need not be exercised as in handling a crop of peaches, plums or oranges, still there are a number of details which require careful attention to secure the best results. Careful attention to these few points is quite as necessary as in handling any other fruit crop, though it might appear otherwise.
Time to Gather.As a rule the bulk of the nut crop must be disposed of before Thanksgiving, and there is in consequence a strong disposition to gather the crop anyway, whether ready or not. Much might be said on both sides of the question, but in general it must be granted that gathering the crop while still somewhat immature, and beating the trees to cause the nuts to drop, cannot be commended.
When the great majority of nut husks are open, the crop of the tree is ready to be harvested. It will not do to wait until every burr is open (some varieties never open, but such are extremely undesirable), for it will usually be found that by far the most of those which do not open, on trees which open their burrs uniformly, are faulty, and it will not pay to wait forthem. Neither should such be left on the tree, but the whole tree should be stripped at the time already indicated. It will be necessary to use light bamboo poles to remove the nuts with closed burrs.
Picking.The nuts must either be picked by hand or knocked off the trees onto the ground with sticks. From whatever standpoint we may regard the gathering of the crops, in orchards of good varieties, the best plan for the removal of the nuts is to take them off, in so far as possible, by hand. Men should climb the trees and collect the nuts in sacks. Men provided with sacks can, with the help of a good extension ladder, reach the most of the nuts on ordinary trees, up to forty or fifty feet in height. A good man will pick one hundred pounds of the shelled nuts in a day, at a cost of one dollar—or one cent per pound.
Fig. 35. After the Harvest.Fig. 35.After the Harvest.
In gathering the crop, the product of each individual tree, in the case of heavy-bearing seedlings, or of eachgroup of trees of a single variety of grafted trees, should be kept in a single pile or lot. It will not do to mix nuts of different sizes, shapes and colors, if the best price is to be hoped for.
Curing.As soon as removed from the trees the nuts should be carried to the curing house. This house should be absolutely rat-proof. Here they are to be picked from the hulls, the unopened burrs being placed apart by themselves. If they open later, well and good; some good nuts may be found among them, but usually they are inferior and should be kept strictly apart from the other portion of the crop. The cost of removing a hundred pounds of nuts from the hulls is about fifty cents.
As soon as the nuts have been separated from the hulls, they should be spread out in shallow trays for curing. These trays should be two and one-half or three feet wide and four or five inches deep. The bottoms are best covered with wire netting with meshes about one-half inch square. They may be arranged around the walls of the curing room, one tier above another. The room should be provided with good ventilation so as to give a free circulation of air. In the trays the nuts may be placed two or three layers deep; if placed too deep there is danger of their moulding. They should be turned over from time to time, and, under average conditions, two weeks will be sufficient to cure them thoroughly.
Grading.Before packing for market, the nuts should be carefully graded. Too much attention cannot be given to this detail. Rigid grading pays—it pays handsomely, and the more abundant the supply, the better it pays.
It will not do to mix together nuts of all sizes, shapes, and colors—some small, some large, some pointed, some blunt, some dark, some light, some streaked, and then expect to get the full value of the crop. It cannot be done with a good grade of pecans.
Perhaps in no kind of fruit which is placed on the market can a more nearly absolutely uniform grade be made (see Frontispiece). The variety should be the basis of the grade. In gathering the crop, each variety should be put by itself as it is gathered. In most varieties the size is quite uniform, and little else need be done; but if there is any considerable variation in size, the small ones should be removed from the first grade of nuts.
Polishing and staining should not be done. It is always best to let each variety retain its own individual marks and characteristics. These are a part of the market quality of the variety and should, by all means, be retained. Mixed lots of seedling nuts may be polished to render them more uniform, but the staining is an abomination, though some people would rather have it, not knowing, perhaps, what a pecan looks like without it.
Shipping Packages.The package should be strong and light, and should afford ample protection to the product. We have known pecans to be shipped by mail, freight or express, in bags, and losses have occurred. Barrels for larger shipments, and wooden boxes for smaller ones are best, and afford the necessary protection. Gift packages, holding ten or twenty pounds or even more, should be made of half inch stuff at least, with ends three-quarters or one inch thick. Grocery boxes may be cut up, planed off, and madeover. In all cases the packages should be neat and clean, and in perfect keeping with the contents. The name and address of the grower, the name of the variety, and the number of pounds should be neatly stamped on the outside.
Marketing.As it is at present, so will it be for many years to come, strictly first-class pecans will be handled almost entirely by or through a private trade. We know of several growers who dispose of their crops of several thousand pounds annually to private customers who have learned the value of good nuts. So greatly has the demand increased that in no single instance is anyone of these men able to supply the demand of the natural outgrowth of his own work, and orders are usually booked a year or more in advance. This is the ideal method of handling the crop, and the one method which enables the grower to secure the best price for his product.
In building up such a private trade, advertising must be resorted to, either through the newspapers, magazines and other channels, or by distributing samples of nuts. "Once a customer, always a customer" should be the motto for the grower to hold in mind, and every effort should be made and every precaution taken tosee that the nuts, from year to year, are absolutely uniform in size, shape, and quality. Do not send a customer one size, shape, or quality one year, at a certain price, and the next year vary it. Such treatment will tend to make customers dissatisfied, and the grower may lose them entirely. This point cannot be too strongly emphasized.
Strictly first-class nuts may be disposed of to advantage to the first-class grocery or fruit trade in the largercities. In cities of any considerable size, there will always be found a grocer or fruiter who is willing to take a first-class article at a price considerably above the usual market price of ordinary nuts. The writer once submitted samples of nuts of medium, but uniform size and good quality, to a grocery firm in New York. They replied that they would take nuts like the samples at twelve and a half to fifteen cents a pound in carload lots, when the common run of pecans could be purchased at four or five cents per pound.
As the output of high-grade pecans is increased, they may be disposed of through the usual nut trade channels—the commission men. The bulk of the product in the country to-day is handled by commission men, either being purchased direct or sold on consignment. If sold for cash in the home market, well and good, but if sold on consignment, choose one reliable commission house in each city in which the product is to be marketed—never two in the same city—and ship to it right along.
Storing.During the cold weather following the gathering of the crop, little or no change takes place in the flavor of the kernels. During the heat of summer, however, they deteriorate. The natural amount of moisture in them is reduced, the air enters, oxidation takes place and the flavor becomes rancid.
These changes can be prevented if the nuts are kept in cold storage, say at a temperature of from thirty-five to forty degrees. When nuts are kept in the house, they should be stored in the coolest possible place, in sealed jars or tight boxes.
The fungous diseases attacking the pecan have not been thoroughly investigated. They have not, however, become so numerous or common as to cause serious damage except in a few instances. The true fungous diseases are usually propagated and disseminated by means of spores, and the most effectual method of control usually consists in spraying with Bordeaux mixture or some other fungicide. For all fungous diseases of the pecan which may be controlled by spraying no substance will give better results than Bordeaux mixture, and directions for preparing it are given at the end of this chapter. Paris green, at the rate of four ounces to each fifty gallons of liquid, may be added to the mixture for the destruction of biting insects. For effectual work in spraying large trees, a platform should be erected on the wagon-bed to make it possible to reach the tops with the spray.
Pecan Leaf Blight(Cercospora Halstedii): This disease of pecan leaves causes them to turn brown, wither up and drop prematurely. At first, small brown spots are noted. These become larger, and at length the whole leaf is destroyed. When attacked by this disease the tree makes no progress. An examination of the discolored areas, under a microscope, shows the presence of tuft-like growths of spores upon short conidiophores. As they become matured the spores are scattered by the rain or wind and so the disease is spread. It probably lives over from one season to another on the diseased leaves.The most effective remedy is to spray thoroughly three times with Bordeaux mixture. The first application should be given just when the young leaves are expanding, followed by two others at intervals of two or three weeks. The fallen leaves should, if feasible, be gathered and burned.Pecan Scab (Fusicladium effusum): This disease attacks the fruit, leaves and twigs. The husks of the diseased nuts become covered with dark spots or specks. They become hardened and crack open in places. As a result of the attack, growth is stopped, the fruit does not fill out and mature, but drops prematurely or, in some cases, remains attached to the trees long after the leaves have fallen. Round, black spots form on the leaves when attacked by the fungous. These become dead and brown and in most cases the whole leaf is destroyed. When attacked, the trees are usually so badly injured that they make little progress. Not all varieties are subject to the disease in the same degree and some appear to be entirely exempt.
Pecan Leaf Blight(Cercospora Halstedii): This disease of pecan leaves causes them to turn brown, wither up and drop prematurely. At first, small brown spots are noted. These become larger, and at length the whole leaf is destroyed. When attacked by this disease the tree makes no progress. An examination of the discolored areas, under a microscope, shows the presence of tuft-like growths of spores upon short conidiophores. As they become matured the spores are scattered by the rain or wind and so the disease is spread. It probably lives over from one season to another on the diseased leaves.
The most effective remedy is to spray thoroughly three times with Bordeaux mixture. The first application should be given just when the young leaves are expanding, followed by two others at intervals of two or three weeks. The fallen leaves should, if feasible, be gathered and burned.
Pecan Scab (Fusicladium effusum): This disease attacks the fruit, leaves and twigs. The husks of the diseased nuts become covered with dark spots or specks. They become hardened and crack open in places. As a result of the attack, growth is stopped, the fruit does not fill out and mature, but drops prematurely or, in some cases, remains attached to the trees long after the leaves have fallen. Round, black spots form on the leaves when attacked by the fungous. These become dead and brown and in most cases the whole leaf is destroyed. When attacked, the trees are usually so badly injured that they make little progress. Not all varieties are subject to the disease in the same degree and some appear to be entirely exempt.
Photo by H. A. Gossard. Fig. 36. Spraying Pecan Trees.Photo by H. A. Gossard.Fig. 36.Spraying Pecan Trees.
Those varieties which are not attacked should be given preference in propagating work. The disease may be furthercontrolled by spraying with Bordeaux mixture, as directed under leaf-blight.Pecan Rosette:[L]"The earliest symptoms are a peculiar crimping of the leaves at the ends of the branches. These leaves are smaller with crimped margin, and when held to the light show light green or yellow streaks between the veins. The leaf tissue in these light-colored areas is thin and undeveloped and often breaks away leaving angular holes in the leaves. A tree usually shows the disease over the whole top at once, though sometimes only a single branch is affected at first. As the disease progresses, the foliage assumes a bunched appearance, due to the formation of tufts of leaves at the ends of the branches. This characteristic has led us to use the term "Rosette" as a name for the malady."The next stage of the disease which is observed the second year or later, is a dying-back of the branches from the tips. This is followed by the development of numerous small, lateral branches from adventitious buds. These are short, producing thick clusters of small, unhealthy leaves, sometimes reduced to mere skeletons, so that the rosetted appearance of the tree is intensified. This goes on from year to year. The growth of the tree is checked and these abnormal branches are formed only to die back each year. Trees in the earliest stages of rosette have been observed to have light crops of nuts, but, when badly diseased, are barren and unsightly or worse. Rosette has been found in all ages, from nursery stock to trees forty feet high."The cause of the disease remains a mystery. No fungous or other parasite can be detected in the earliest stages. The appearance of the trees leads us to infer that the trouble is internal, due to some derangement of the nutritive or assimilative functions of the plant, but we are unable to correlate this with any corresponding external conditions. That is to say, that so many cases have been observed on fertile soil, when cultivation, drainage and plant food had all been provided, that it is impossible to conclude that thedisease could be due to starvation or to the lack of any single element in the soil, nor can it be due to over-feeding, since it occurs in light soils and in neglected orchards."It seems probable that it will be classed by the plant pathologist with peach rosette, peach yellows, and related diseases, the causes of which still remain unknown after years of investigation. The indications are that it is contagious, though a complete demonstration of this point remains to be made; at any rate, it must be regarded with concern until more knowledge is available."The best recommendation that can be made in regard to pecans affected by this disease is to dig them up and burn them.Bordeaux Mixture.Copper sulphate,5 pounds.Lime (unslacked),5 pounds.Water,50 gallons.Dissolve the copper sulphate in two gallons of water, place it in barrel No. 1 and add water to make twenty-five gallons. Slack the lime, reduce it to a very thin paste, place it in barrel No. 2 and add water to make twenty-five gallons. To mix the solutions of lime and copper sulphate, dip a bucketful from each barrel, and pour together into the barrel of the spray pump.The two mixtures should flow together as they are poured into the barrel.This is one of the secrets of making a first-class mixture. The best arrangement is to have the barrels, Nos. 1 and 2, elevated, and use a piece of rubber hose to run the liquids into the pump barrel.If a large amount of spraying is to be done, a somewhat different policy should be pursued. Too much time would be taken up in preparing the ingredients in small quantities. Instead, large amounts of copper sulphate should be dissolved and large quantities of lime slacked beforehand. This may be done as follows:In a fifty-gallon barrel place about forty gallons of water. Put one hundred pounds of copper sulphate in a sack and suspend it in the water. As soon as dissolved, fill up to the fifty-gallon mark. When well stirred, each gallon willcontain two pounds of copper sulphate. Each time some of the solution is dipped out, the height of the remaining portion should be marked on the inside of the barrel. Before taking more of the solution out of the barrel, any amount of water lost by evaporation should be made good by filling up to the mark last made.As soon as procured the lime should be slacked, placed in a barrel and kept covered with an inch or two of water. In this way it can be kept indefinitely.To prepare Bordeaux mixture from these stock solutions, dip out two and a half gallons of the copper sulphate solution, place it in barrel No. 1 and dilute to twenty-five gallons. From the slacked lime take fifteen pounds, or thereabouts, to allow for the water it contains, reduce to a thin paste, place it in barrel No. 2 and add water to make twenty-five gallons. Pour the contents of barrels Nos. 1 and 2 together, as already directed.Tests: If free copper be present, severe injury may be done to the foliage or other tender parts of the plants. Sufficient lime should be added to neutralize it.Dip out a small quantity in a porcelain saucer or shallow bowl, and holding it on a level with the mouth, blow the breath gently into it. If a thin pellicle forms on the surface, more lime must be added. Add and test until it does not form. An excess of lime will not hurt.Another test is to dip the blade of a clean knife into the mixture. If a thin film of copper forms on it after holding it there a minute or so, more lime must be added.Use good materials and prepare the mixtures thoroughly.In making up the various mixtures, never use iron vessels, but use glass, wood or crockery receptacles instead.Strain all mixtures thoroughly into the spray pump to prevent clogging of the pump or nozzles.Spray thoroughly and in good season.Be in time.Do not use mixtures which have been leftover and allowed to stand for some time.
Those varieties which are not attacked should be given preference in propagating work. The disease may be furthercontrolled by spraying with Bordeaux mixture, as directed under leaf-blight.
Pecan Rosette:[L]"The earliest symptoms are a peculiar crimping of the leaves at the ends of the branches. These leaves are smaller with crimped margin, and when held to the light show light green or yellow streaks between the veins. The leaf tissue in these light-colored areas is thin and undeveloped and often breaks away leaving angular holes in the leaves. A tree usually shows the disease over the whole top at once, though sometimes only a single branch is affected at first. As the disease progresses, the foliage assumes a bunched appearance, due to the formation of tufts of leaves at the ends of the branches. This characteristic has led us to use the term "Rosette" as a name for the malady.
"The next stage of the disease which is observed the second year or later, is a dying-back of the branches from the tips. This is followed by the development of numerous small, lateral branches from adventitious buds. These are short, producing thick clusters of small, unhealthy leaves, sometimes reduced to mere skeletons, so that the rosetted appearance of the tree is intensified. This goes on from year to year. The growth of the tree is checked and these abnormal branches are formed only to die back each year. Trees in the earliest stages of rosette have been observed to have light crops of nuts, but, when badly diseased, are barren and unsightly or worse. Rosette has been found in all ages, from nursery stock to trees forty feet high.
"The cause of the disease remains a mystery. No fungous or other parasite can be detected in the earliest stages. The appearance of the trees leads us to infer that the trouble is internal, due to some derangement of the nutritive or assimilative functions of the plant, but we are unable to correlate this with any corresponding external conditions. That is to say, that so many cases have been observed on fertile soil, when cultivation, drainage and plant food had all been provided, that it is impossible to conclude that thedisease could be due to starvation or to the lack of any single element in the soil, nor can it be due to over-feeding, since it occurs in light soils and in neglected orchards.
"It seems probable that it will be classed by the plant pathologist with peach rosette, peach yellows, and related diseases, the causes of which still remain unknown after years of investigation. The indications are that it is contagious, though a complete demonstration of this point remains to be made; at any rate, it must be regarded with concern until more knowledge is available."
The best recommendation that can be made in regard to pecans affected by this disease is to dig them up and burn them.
Bordeaux Mixture.Copper sulphate,5 pounds.Lime (unslacked),5 pounds.Water,50 gallons.
Dissolve the copper sulphate in two gallons of water, place it in barrel No. 1 and add water to make twenty-five gallons. Slack the lime, reduce it to a very thin paste, place it in barrel No. 2 and add water to make twenty-five gallons. To mix the solutions of lime and copper sulphate, dip a bucketful from each barrel, and pour together into the barrel of the spray pump.The two mixtures should flow together as they are poured into the barrel.This is one of the secrets of making a first-class mixture. The best arrangement is to have the barrels, Nos. 1 and 2, elevated, and use a piece of rubber hose to run the liquids into the pump barrel.
If a large amount of spraying is to be done, a somewhat different policy should be pursued. Too much time would be taken up in preparing the ingredients in small quantities. Instead, large amounts of copper sulphate should be dissolved and large quantities of lime slacked beforehand. This may be done as follows:
In a fifty-gallon barrel place about forty gallons of water. Put one hundred pounds of copper sulphate in a sack and suspend it in the water. As soon as dissolved, fill up to the fifty-gallon mark. When well stirred, each gallon willcontain two pounds of copper sulphate. Each time some of the solution is dipped out, the height of the remaining portion should be marked on the inside of the barrel. Before taking more of the solution out of the barrel, any amount of water lost by evaporation should be made good by filling up to the mark last made.
As soon as procured the lime should be slacked, placed in a barrel and kept covered with an inch or two of water. In this way it can be kept indefinitely.
To prepare Bordeaux mixture from these stock solutions, dip out two and a half gallons of the copper sulphate solution, place it in barrel No. 1 and dilute to twenty-five gallons. From the slacked lime take fifteen pounds, or thereabouts, to allow for the water it contains, reduce to a thin paste, place it in barrel No. 2 and add water to make twenty-five gallons. Pour the contents of barrels Nos. 1 and 2 together, as already directed.
Tests: If free copper be present, severe injury may be done to the foliage or other tender parts of the plants. Sufficient lime should be added to neutralize it.
Dip out a small quantity in a porcelain saucer or shallow bowl, and holding it on a level with the mouth, blow the breath gently into it. If a thin pellicle forms on the surface, more lime must be added. Add and test until it does not form. An excess of lime will not hurt.
Another test is to dip the blade of a clean knife into the mixture. If a thin film of copper forms on it after holding it there a minute or so, more lime must be added.
Use good materials and prepare the mixtures thoroughly.
In making up the various mixtures, never use iron vessels, but use glass, wood or crockery receptacles instead.
Strain all mixtures thoroughly into the spray pump to prevent clogging of the pump or nozzles.
Spray thoroughly and in good season.Be in time.
Do not use mixtures which have been leftover and allowed to stand for some time.
FOOTNOTES:[L]Orton, W. A., proceedings second annual convention National Nut Growers' Association, 1903, p. 82. 1904.
[L]Orton, W. A., proceedings second annual convention National Nut Growers' Association, 1903, p. 82. 1904.
[L]Orton, W. A., proceedings second annual convention National Nut Growers' Association, 1903, p. 82. 1904.
Some time ago the statement was occasionally made that the pecan had no known enemies. This, to thinking and observing persons, was too good to be true, and fortunately the words, "no known," were inserted, for later investigations, particularly on the part of Profs. Gossard and Herrick, have revealed the fact that the pecan, in common with all other fruit trees, is subject to the attacks of insect and other enemies. But the outlook is hopeful, for we know of the abandonment of no fruit industry because of the attacks of insect pests, and the pecan industry is in no wise in danger of being abandoned because of their inroads.
If an insect is to be successfully controlled, the grower must know something of its life-history, and particularly of its feeding-habits. Careful observation of the insect, while at its work of destruction, will frequently give a clue to the method of control. Many insects, like the caterpillars of the pecan, bud-moth and case-worm, obtain their food by biting off pieces of the leaves or other parts of the tree and swallowing the solid particles. On the other hand, a number of insects, such as the scales and plant-lice, obtain their food by thrusting their small, bristle-like sucking tubes into the tissues of the leaves and sucking out the juices contained in the cells.
Plate VIII.Plate VIII.The Pecan Bud Moth (Proteopteryx deludana).1. Winter stage on bud, enlarged. 2. Tube made in leaf. 3. Work of bud destruction. 4. Caterpillar, enlarged about twice. 5. Cocoon, enlarged. 6. Chrysalis, reduced. 7. Moth, enlarged. 8. Moth, about natural size.
It is quite obvious that these two classes of insects cannot be controlled or destroyed in the same way. Those which eat solid particles of food may, in most cases, be destroyed by applying some poisonous substance, such as arsenate of lead or Paris green, to the food which they eat. But those which obtain their food by sucking cannot be killed in this way. They can be destroyed, however, by spraying over their bodies some substance, such as kerosene emulsion, which will penetrate their bodies and so kill them. Or, they may be killed by suffocating them with a gas or by stopping up their breathing pores with some powdered substance, such as pyrethrum. Some insecticides, such as resin wash, act both as a caustic application and a suffocating covering.
For convenience in referring to insects which attack the pecan, we have grouped them as follows: (1) Insects attacking buds and leaves; (2) Insects attacking the trunk and branches; (3) Insects attacking the fruit.
Insects Attacking Buds and Leaves.The Bud Worms: At least two species of caterpillars are known by this name. The moth of one has been called the bud-moth. The caterpillar of the other has been called the case-worm. Prof. Gossard writes, that he unexpectedly found adult moths ofProteopteryx deludana, November 28th, 1905, and therefore believes, from this observation and other circumstantial evidence, that he was "mixed" regarding the autumn life-history of these insects, as set forth in Bulletin 79 of the Florida Experiment Station. He furnishes the following paragraph as a summary of what he can say of the bud worms:"The Bud Moth,Proteopteryx deludana, is a serious pest, especially in young orchards. Sometimes, in such orchards, even when large, scarcely a tree can be found during the month of May that does not contain one or severalnests. The caterpillars are usually found singly, each with one side of a leaf folded over it and fastened to form a tube, or sometimes two leaves are fastened together with silken bonds and the caterpillar feeds between them. As fast as the leaves it has attached become brown and die, it draws fresh leaves to the dead ones and fastens them there, thus gradually making a very conspicuous nest. The caterpillar is full grown during the last of May and the first of June when they transform into moths. Their pupæ cases are formed of silk and excrement, smoothly lined with silk and snugly hidden away in a nest of leaves. In about two weeks from the time of pupation, the moths appear. Early specimens have sometimes been hatched from buds, only partially expanded. They are small, about five-sixteenths of an inch in length and five-eighths of an inch across the expanded wings. In general color they are grayish, streaked and dotted with blackish-brown. A characteristic habit is to alight and rest on the tree trunk, head downward. The moths have again been observed in November, suggesting that there are two broods a year. Thorough, persistent spraying with arsenate of lead or Paris green, in April and May, ought to control this species."
The Bud Worms: At least two species of caterpillars are known by this name. The moth of one has been called the bud-moth. The caterpillar of the other has been called the case-worm. Prof. Gossard writes, that he unexpectedly found adult moths ofProteopteryx deludana, November 28th, 1905, and therefore believes, from this observation and other circumstantial evidence, that he was "mixed" regarding the autumn life-history of these insects, as set forth in Bulletin 79 of the Florida Experiment Station. He furnishes the following paragraph as a summary of what he can say of the bud worms:
"The Bud Moth,Proteopteryx deludana, is a serious pest, especially in young orchards. Sometimes, in such orchards, even when large, scarcely a tree can be found during the month of May that does not contain one or severalnests. The caterpillars are usually found singly, each with one side of a leaf folded over it and fastened to form a tube, or sometimes two leaves are fastened together with silken bonds and the caterpillar feeds between them. As fast as the leaves it has attached become brown and die, it draws fresh leaves to the dead ones and fastens them there, thus gradually making a very conspicuous nest. The caterpillar is full grown during the last of May and the first of June when they transform into moths. Their pupæ cases are formed of silk and excrement, smoothly lined with silk and snugly hidden away in a nest of leaves. In about two weeks from the time of pupation, the moths appear. Early specimens have sometimes been hatched from buds, only partially expanded. They are small, about five-sixteenths of an inch in length and five-eighths of an inch across the expanded wings. In general color they are grayish, streaked and dotted with blackish-brown. A characteristic habit is to alight and rest on the tree trunk, head downward. The moths have again been observed in November, suggesting that there are two broods a year. Thorough, persistent spraying with arsenate of lead or Paris green, in April and May, ought to control this species."
The Case Worm(Acrobasis nebulella): This insect, often found associated with the bud moth, probably does more damage than any other pecan insect. The caterpillars are about five-eighths of an inch in length, a dirty brownish-green in color, and live in silk-lined cases or tubes attached to the petioles of the leaves. From these they protrude themselves to feed. Frequently a pair of leaflets are tied together (Plate IX, Fig. 6), and between these the caterpillars live and feed upon the tips of the protecting leaflets. Opening buds, partially developed and full-grown leaves alike are destroyed. Earlier in the season, characteristic nests of partially eaten leaves, petioles and excrement are formed by several caterpillars tying the mass together with silk. In this nest they live and develop. The caterpillars pupate within their silken tubes, and the small gray moths (five-eighths to three-fourths of an inch in length) emerge about two weeks after pupation, chiefly in June. The small, hibernating "cocoons" found on and around the buds in winter and the tortuous tubes observed on the leaves in summer and fall, which have been referred to (Proteopteryx deludana), probably belong to this species. At least, caterpillars one-fourth grown and contained in cocoons apparently not essentially different from the smaller ones, contain worms having the characteristic appearance of the grownacrobasis. Spraying with arsenicals in April, May and June should destroy this pest. Spraying in late July and August would also promise results of value.
Plate IX.Plate IX.The Case Worm.1. Supposed winter stage. 2. Caterpillar, enlarged. 3-4. Moth, nearly natural size. 5. Cases. 6. Work on leaves.
The Catotocalas(Catocala piatrixandC. viduata): The caterpillars of these insects are frequently found during April, May and June feeding upon the leaves of the pecan. They are ravenous feeders, and if present in sufficient numbers, considerable damage is done. The caterpillars are from two to two and a half or three inches in length when fully extended, gray and striped, leathery in appearance, very closely resembling the back of the tree upon which they rest when not feeding. Having attained its full growth as a caterpillar, it ties together two or three leaves with strands of silk, thus making a loose cocoon within which it pupates. The pupa is dark brown, covered with a whitish or bluish-white bloom. In about one month the moths emerge. They are large in size, the body being one to one and one-fourth inches long and the expanded wings two and one-half to three inches across. When at rest they are dull gray in color, more or less marked with irregular waving lines. The hind or under-wings are strikingly different from the fore-wings. In C. piatrix they are deep orange-yellow marked from side to side with two black bands. The hind-wings of C. viduata are dark brown and edged with a narrow white band.
The caterpillars may be destroyed by spraying with some one of the arsenical poisons, or they may be removed by hand and destroyed. Prof. Gossard recommends the tying of a piece of burlap around the trees. Beneath this the caterpillars hide during the night and they may then be destroyed.
Plate X.Plate X.A Pecan Catocala. (C. Piatrix.)Caterpillar, Cocoon, Chrysalis, and Moths about one-half natural size.
The Fall Web-Worm(Hyphantria cunea): The caterpillars of this insect begin work early in spring, shortly after the leaves are full grown. They work in colonies, and the leaves on which they feed are enclosed in a web, which is extended as the caterpillars grow or as they require additional leaves to feed upon. When full grown the caterpillars measure about one inch in length and are covered with hairs both long and short. The matured caterpillars leave the webs and crawl down the trees to hunt for places beneath the bark, under sticks, weeds and trash in which to pupate. A light, flimsy cocoon, composed of silk and the hairs of the larva, is made. From this, in due time, a beautiful moth, an inch or an inch and a quarter across the wings, emerges. The wings are pure white or white spotted with black or brownish-black. The eggs are laid in masses of four or five hundred on the leaves. These hatch in about ten days, and the colonies of young caterpillars begin their work of destruction. There are two broods in the South each summer; the first appearing in May and June, the second in August and September. The fall brood hybernates in the pupa state.
The caterpillars may be destroyed on small trees by removing the webs and killing the larvæ. On large trees a torch of some sort may be used to burn the web and the caterpillars within it. They may be also held in check by applying a spray of Paris green or arsenate of lead at the time the broods are feeding.
The Pecan Caterpillar(Datana interrigma): A buff-colored moth, having a body about one-half inch long and a wing expanse of one and three-fourths inches, with four transverse brown stripes on the front wings, lays its greenish or white eggs in clusters of five to twelve hundred on the underside of the lower leaves of the pecan trees. These eggs hatch in less than a week, and the colonies of young caterpillars at first feed upon the undersides of the leaves. They cast their skins four times, each time increasing in size and changing their color somewhat. The last moult, and sometimes the last two, take place on the trunk of the tree, and the clusters of discarded skins frequently remain for several months afterwards. After thelast moult they ascend the trees, remain feeding for a short while, then go down to the ground to pupate. When disturbed, the larvæ raise both ends of their bodies from the twigs or leaves, on which they rest. They are easily recognized by this habit. When full grown they are one and one-half to one and three-quarters of an inch in length, covered with dirty white hair, and marked with two conspicuous longitudinal white lines, one on each side of the body. There are two broods, the last one hibernating in the ground in the pupa state.
The leaves on which the eggs are laid may be gathered and destroyed, or the colonies of young caterpillars may be gathered and burned. Later, they may be burned off with a torch, killed when clustered on the trunk during the last moult, or poisoned with an arsenical spray.
The Twig Girdler(Oneideres cingulatusandO. texana): These two insects frequently do considerable damage to pecan trees in late summer by cutting off the smaller branches. Branches from one-fourth to three-fourths of an inch are usually the ones attacked. The insect is a beetle, and the two species closely resemble each other. They are dark gray in color, one half to five-eighths inch in length, with antennæ longer than the body and provided with stout, powerful mandibles. The female insect cuts the branch by working round and round it until it is almost entirely severed. She then lays a number of eggs in it, usually one or two being placed near each bud. A small cut is made and the egg is inserted between the bark and the wood, and the opening is then sealed up with a gummy substance. As the insect moves along the twig a series of transverse cuts are made in the bark. The twigs usually drop to the ground. The eggs hatch as soon as the weather becomes sufficiently warm in spring, and the larvæ feed in the twigs, making tunnels through them as they grow. Later, they pupate within the tunnels and emerge during August and September as fully developed insects, having spent one year in their growth from egg to mature insect.It is believed that in some cases the life cycle lasts two years.
The best and most effective treatment is to gather and burn all the twigs which have been cut from the trees. This should be done, preferably late in autumn after the leaves have fallen, as there is greater certainty of getting all the severed twigs than if left until a later date.
The Oak Pruner(Elaphidion villosum): Sometimes[M]pecan twigs, when smartly bent, will snap off with a clean, square cut across the branches, as if they were hollow-glass tubes, breaking at cracked or weakened places. An examination of such a broken stem shows "that its woody part, with the exception of a few fibers and the bark, has been cut across as if with a saw by a soft, yellowish-white grub, which can often be found in a burrow in the severed part. Since the uncut bark is the chief support left for the branch, any stiff wind or even its own weight will break it off as soon as it has become deadened. * * * * * *
"The adult is a longicorn beetle, of slender, cylindrical form, over one-half inch in length and about one-eighth of an inch in width. It is of a dull, black color, tinged with brown on the wing covers, especially toward their tips. The underside of the body and legs are chestnut colored. Over all parts of the body can be found short, grayish hairs. Some small, gray spots on the wing-covers and a whitish dot on each side of the thorax are formed by dense collections of gray hairs at these points. Coarse, round punctures are thickly sprinkled over the upper surface of the thorax and wing-covers."The larva, when grown, is about three-fifths of an inch long, tapering backwards from the neck. The body is divided by deep grooves into twelve rings or segments. There are three pairs of feet. The color is yellowish-white, the front of the head being blackish. Probably, about midsummer, with a possible variation of two mouths in each direction from this date, the parent beetle deposits her eggs, preferably on a small twig of the preceding year's growth. Upon hatching, the young larva commences toeat the tender wood just beneath the bark, and later enters the center of the twig and works toward its base. In this manner it works its way into the main limb, which may be of considerable size, and feeds within it for a period of about three years. The burrow thus becomes several inches in length, in many cases. Just before transforming to pupæ some, but not all, of the larvæ, cut the wood for the purpose of dropping the branches, as before described. Limbs in which the immature larvæ are working often break off with ragged end when bent with the hand."* * * Pick up and burn all fallen branches. Similar attention should be given nearby oak and hickory limbs, which have fallen."
"The adult is a longicorn beetle, of slender, cylindrical form, over one-half inch in length and about one-eighth of an inch in width. It is of a dull, black color, tinged with brown on the wing covers, especially toward their tips. The underside of the body and legs are chestnut colored. Over all parts of the body can be found short, grayish hairs. Some small, gray spots on the wing-covers and a whitish dot on each side of the thorax are formed by dense collections of gray hairs at these points. Coarse, round punctures are thickly sprinkled over the upper surface of the thorax and wing-covers.
"The larva, when grown, is about three-fifths of an inch long, tapering backwards from the neck. The body is divided by deep grooves into twelve rings or segments. There are three pairs of feet. The color is yellowish-white, the front of the head being blackish. Probably, about midsummer, with a possible variation of two mouths in each direction from this date, the parent beetle deposits her eggs, preferably on a small twig of the preceding year's growth. Upon hatching, the young larva commences toeat the tender wood just beneath the bark, and later enters the center of the twig and works toward its base. In this manner it works its way into the main limb, which may be of considerable size, and feeds within it for a period of about three years. The burrow thus becomes several inches in length, in many cases. Just before transforming to pupæ some, but not all, of the larvæ, cut the wood for the purpose of dropping the branches, as before described. Limbs in which the immature larvæ are working often break off with ragged end when bent with the hand.
"* * * Pick up and burn all fallen branches. Similar attention should be given nearby oak and hickory limbs, which have fallen."
The Pecan Tree Borer(Sesia scitula): The moth of this insect is clear-winged and closely resembles the moth of the peach tree borer. Little is known of its life-history.
"It[N]is probable that the eggs are deposited by the female moth on the bark of a tree near a fresh wound. For example, near newly set buds. The eggs hatch and the larvæ bore into the bark, and there live for a time, eating out the soft inner-bark and tender wood. It is certain that the borers live in these situations the over winter and change to pupæ in the spring, from which the moths emerge in April. The moths I reared appeared April 3rd, 4th and 6th. The pupæ are in cocoons, just under the bark. The cocoons are made from excrement and bits of bark that have been fastened together with silk similar to the cocoons of the peach tree borer. Whether these moths, that emerge in the spring, lay eggs and produce a brood in the summer, that in turn develops a fall brood of larvæ, I am unable to say."
"The[O]young borer is apt to gain entrance to the sapwood through some wound in the bark, such as a graft-union, and here it feeds, sometimes completely girdling the sapwood above and below the wound. It is said to prefer to attack buds that have been budded on old, large trees. As a general rule the burrows ascend the tree in a spiral about the trunk, so complete girdling is unusual, butgrowth sometime ceases above the groove, new limbs being shot out from below."
The only satisfactory means of controlling this pest is to go carefully over the tree and dig out the borers. The trees should be examined from time to time in order to keep them free from borers.
The Pecan Weevil(Balantinus caryae): In some localities considerable damage has been caused by the pecan weevil. The insect is a small, brownish-black snout beetle, somewhat less than one-half inch in length. The proboscis or snout is slender and as long as the body. With this proboscis the beetle bores a very small hole through the husk and shell of the immature pecan to the kernel, and at the bottom deposits an egg. This egg hatches into a larva, which feeds upon the kernel of the nut. In autumn the larvæ, when full grown, bore holes through the shells of the pecan and enter the ground in which they pass the winter. The next season they emerge from the earth as fully-matured insects, and about the month of August deposit their eggs in the nuts.
After the harvesting of the crop the hogs should be allowed to feed under trees in which the weevil is present, so as to devour any infested nuts which may have been left on the ground. Poultry may also be of assistance in destroying the insects after they have entered the ground to pupate. It is probable that the larvæ in the nuts may be destroyed by fumigating with carbon bi-sulphide. The nuts should be placed in a tight box, and one-half pound for each five hundred cubic feet of space used, allowing them to remain for forty-eight hours.
The Hickory Shuck Worm(Grapholitha caryana): Sometimes pecan nuts are attacked, as they approach maturity, by a small, white caterpillar, which mines its way through the shucks of the nuts. This caterpillar is the hickory shuck worm, the larva of a small moth.
But little is known of its life-history, and until more is known of its habits, the best advice that can be given is to gather and destroy the infested nuts by burning them.
FOOTNOTES:[M]Gossard.[N]Hedrick. (See index of literature).[O]Gossard. (See index of literature).
[M]Gossard.
[M]Gossard.
[N]Hedrick. (See index of literature).
[N]Hedrick. (See index of literature).
[O]Gossard. (See index of literature).
[O]Gossard. (See index of literature).
Pecan nuts are used in a variety of ways. Not so very long since they were used almost entirely for dessert purposes, now they are largely used in making pastries and confections of different kinds. Based on these uses, new industries for supplying the kernels have been developed. The kernels are now put on the market in glass jars of different kinds and sizes, usually retailing at from 50 cents to 75 cents per pound. This is perhaps the most convenient form in which to buy them, but unfortunately, they are too frequently old and rancid. When stock is carried through the heat of summer in the ordinary jar, this is invariably the case, and some new method of packing them must be introduced if this way of disposing of the product is to increase in favor, as it should. Certain experiments now under way give promise that the kernels can be kept fresh and free from rancidity indefinitely.
For the present, at least, the only certain way of procuring good, fresh pecan kernels is to procure fresh nuts—those which have been kept over in cold-storage are good—and crack them at the time when they are needed. For the household, an ordinary pair of nut-crackers will answer, but they should be of a particulartype. The jaws should be formed with sharp-cutting edges.
In the accompanying illustration, four kinds of nut-crackers are shown. The two at the right are reversible. The best pair is represented at the extreme left of the engraving. The bars are square, the grooves in them are curved inward leaving the teeth sharp and pointed out flush with the edge.