THE ASPARAGUS MINER

(_Agromyza simplex_)

In a recent bulletin from the New York Experiment Station, Prof. F. A.

Sirrine describes a comparatively new and injurious insect on asparagus.

It was discovered on Long Island, and injures the young plants by mining just underneath the outside surface. The habits of this creature are such that there is little chance of applying remedies for its destruction. Cultural and preventive measures seem to be the most practical, and are suggested. The parent insect is a small fly, which deposits its eggs for the first brood early in June, and no doubt much can be done toward keeping the pest under control by not allowing small shoots to grow during the cutting season. Professor Sirrine is of the opinion that where young beds are put out yearly the pest can be kept in check by pulling and burning the old stalks. He points out the fact that the stalk should be pulled in the fall rather than in the spring, as it is difficult to pull them early in the season, and in many cases the dormant stage of the insect is left in the ground.

FOOTNOTES:

[A] Condensed from an official report by J. H. Chittenden of the United States Department of Agriculture.

XV

FUNGUS DISEASES

Asparagus is subject to the attacks of a number of fungi, the most widespread and destructive being the "rust," the cause of which is a fungus described by De Candolle as _Puccinia asparagi_ in the year 1805.

From this it is seen that the rust upon the asparagus has been known to scientists for nearly a hundred years, and it is but reasonable to suppose that more or less of this fungus has existed beyond the history of man.

The first mention of asparagus rust in the United States was by Dr.

Harkness, who claimed to have observed it on the Pacific Coast in 1880, although it is doubtful whether the genuine asparagus rust was ever found there. The first mention of it in the Eastern States was in the fall of 1896, and since then its range has been widening each year. Dr.

Byron D. Halsted, of the New Jersey Experiment Station, was the first to call attention to it, and made it the subject of careful study. The results and conclusions derived from his experiments were published in a special bulletin, and from this the greater part of the following has been condensed.

RECOGNITION OF THE RUST

[Ill.u.s.tration: FIG. 46--ASPARAGUS STEMS AFFECTED WITH RUST]

[Ill.u.s.tration: FIG. 47--PORTION OF RUSTED ASPARAGUS STEMS]

When an asparagus field is badly infested with the rust the general appearance is that of an unusually early maturing of the plants (Fig.

46). Instead of the healthy green color there is a brown hue, as if insects had sapped the plants or frost destroyed their vitality. Rusted plants, when viewed closely, are found to have the skin of the stems lifted, as if blistered, and within the ruptures of the epidermis the color is brown, as shown in Fig. 47. The brown color is due to mult.i.tudes of spores borne upon the tips of fine threads of the fungus, which aggregate at certain points and cause the spots. The threads from which the spores are produced are exceedingly small and grow through the substance of the asparagus stem, taking up nourishment and causing an enfeebled condition of the victim, which results in loss of the green color and the final rustiness of the plant, due to the mult.i.tude of spores formed upon the surface. These spores are carried by the wind to other plants, where new disease spots are produced; but as the autumn advances a final form of spore appears in the ruptures that is quite different in shape and color from the first ones produced through the summer. The spores of late autumn, from their dark color, give an almost black appearance to the spots.

There is another form which the rust fungus a.s.sumes not usually seen in the asparagus field, but may be found in early spring upon plants that are not subjected to cutting. This is the cl.u.s.ter-cup stage, so named because the fungus produces minute cups from the asparagus stem, and in small groups of a dozen to fifty, making usually an oval spot easily seen with the naked eye. This stage of the fungus comes first in the order of time in the series, and is met with upon volunteer plants that may grow along the roadside or fence row, or in a field where all the old asparagus plants have not been destroyed.

METHODS OF TREATING THE RUST

All the cultivated varieties of asparagus are readily affected by the rust, although it has been found that some varieties, notably Palmetto, are less susceptible to its attacks than others. The most effectual means of controlling the disease are spraying, burning of the brush, cultivation, and irrigation.

_Spraying._--Dr. Halsted, in his first experiments, used soda-bordeaux, hydrate-bordeaux, and potash-bordeaux. The spraying began June 2d, and ten sprayings were applied during the season. The applications were made with a knapsack pump, and therefore were far more expensive than they would have been if the sprayings were made with horse-power. With the fungicide costing $5.00 per acre, and a machine that would spray two or more rows at a time, it would be possible to reduce the cost to $10.00 per acre, or even less. In effectiveness the soda-bordeaux stood first.

Between the other fungicides there was but little difference. The best results showed a reduction of rust of about one-quarter, which is not as satisfactory a result as had been expected.

In the spraying work conducted by Professors G. E. Stone and R. E.

Smith, at the Ma.s.sachusetts Experiment Station, the results were more encouraging. The solutions used were pota.s.sium sulfide, saccharate of lime, and bordeaux mixture. The spraying was done with a knapsack sprayer, provided with a Vermorel nozzle, and after the first application it became evident that the practice was of little importance on account of the difficulty in making the solution stick to the plant.

For successful spraying of asparagus a finer nozzle is required than any that is now in the market.

In some other experiments carried out on a small scale the asparagus plants were practically covered with solutions, when they were put on with an ordinary cylinder atomizer, and the lime solutions showed excellent sticking qualities; but with the ordinary coa.r.s.e nozzle the solutions would run off of the glossy epidermal covering of the plant very readily. Should the spraying of asparagus ever become a necessity, then some apparatus which can be strapped to a horse's back should be used. The narrow s.p.a.ce between the rows forbids the use of the ordinary mounted appliances, and if spraying is to be carried on upon a large scale, it would be better to have the spraying mixture carried in some manner on the horse's back. In this way it would be possible to carry some thirty or forty gallons of mixture through the narrow rows.

_Burning the affected tops._--There can be no doubt that by the burning of the infested brush, after the cutting season, innumerable rust spores are destroyed. But if this is done before the stalks are entirely dead new ones will spring up at once, and in a few days will be as badly affected as the first. The burning of the tops in the summer has, moreover, a decidedly injurious effect upon the roots, seriously weakening their vitality, and making the growth of the following year still more susceptible to the infection.

In the autumn, however, after the stalks are dead and dry, this damage does not prevail, and the spores upon old brush can be destroyed by burning the asparagus stems either as they stand in the field or by cutting and throwing the brush into piles. By the latter method many of the smaller branches will be broken off and scattered upon the ground, giving a suitable place for the spores to remain over the winter. For the same reason it is an advantage to burn the brush in autumn instead of the spring, and thus prevent the large loss of spores that would obtain. In other words, burn the plants as soon as they become brown and lifeless, for any delay means the breaking up of the brittle, rusty plants, and a heavy sowing of the spores upon the ground. If the fire could go over the whole field of standing brush, that would be the most effective destruction. At best, with these precautions, many of the spores will get scattered upon the soil, and it would be well to sprinkle a thin coat of lime upon the ground and leave it there during the winter. If this could be followed by a turning under of the surface soil in the spring, it would bury the spores that might still be living, so that they would be out of reach.

_Cultivation and irrigation._--It has been observed that the injury to asparagus plants, as a result of rust, has been confined to dry soils, although there are places where beds in close proximity showed remarkable differences as to infection; and that robust and vigorous plants, even where cultivated on apparently dry soil, are capable of resisting the summer or injurious stage of the rust.

In view of all the experiments so far made, and the experiences of practical asparagus growers, Stone and Smith conclude that: "The best means of controlling the rust is by thorough cultivation in order to secure vigorous plants, and in seasons of extreme dryness plants growing on very dry soil with little water-retaining properties should, if possible, receive irrigation."

From a knowledge of the occurrences of the rust in Europe, and from observations made in Ma.s.sachusetts, they are led to believe that the outbreak of the asparagus rust is of a sporadic nature, and is not likely to cause much harm in the future, provided attention is given to the production of vigorous plants.

ASPARAGUS LEOPARD SPOT

Attention was called to this new disease by Prof. W. G. Johnson, in Bulletin No. 50, Maryland Experiment Station, September, 1897. It was observed in a limited area in the asparagus growing section on the eastern sh.o.r.e of Maryland. The disease belongs to the group of anthracnoses, and is regarded by Dr. B. D. Halsted as a new species. In some places growers have mistaken it for the work of asparagus beetles.

In general appearance it is very striking, the characteristic spots resembling the coat of the leopard. It has, therefore, been called "asparagus leopard spot," to distinguish it readily from rust. The disease has been found only in a comparatively small area, but, no doubt will be found in other places later. Asparagus growers should, therefore, be on their guard and watch it. The remedies thus far successfully used are the same as those for rust.

XVI

ASPARAGUS CULTURE IN DIFFERENT LOCALITIES

ASPARAGUS IN NEW ENGLAND

Asparagus was grown in Concord, Ma.s.s., in a limited way as early as 1825. Mr. Edmund Hosmer used to carry it to market in season on his milk wagon. Timothy Prescott and F. R. Gourgas grew garden patches before 1840. To John B. Moore belongs the credit of growing and improving asparagus in this section of the State. Mr. Moore selected the most promising shoots, and by a judicious system of culture succeeded in placing on the market a valuable variety in the shape of Moore's Cross-bred. Most of the "giant" asparagus grown in Concord to-day could be traced to the plants produced by his skill. A sample bunch of twelve stalks, twelve inches long, from Moore's Cross-bred plants weighed four pounds eight ounces. In 1872 the first bed of asparagus of any size was set out by Mr. George D. Hubbard, who was laughed at by his neighbor farmers, who saw only ruin for the young man. The next year Mr. Hubbard set out more, so that for twenty years he was probably the largest grower in Ma.s.sachusetts.

Most of the leading varieties are grown in Concord, but the farmers are looking for a rust-proof variety and hope to find one. The Palmetto has not rusted as badly as other kinds, but has not been grown so extensively. One-year-old roots should be set by all means, as they start sooner, grow more vigorously, and in the end pay better. The roots should be carefully selected from vigorous stock. A very large part of Concord asparagus is planted on sandy soil--_i.e._, good, rich, mellow corn land. This kind of land needs more manure, but then the crop is more satisfactory and the labor bill is not so high. The land previous to setting to asparagus should be well tilled and manured.

Land for asparagus beds should be plowed late in the fall, and if stable manure can be afforded should be applied liberally. In the spring plow again early and harrow well. The roots should be planted in April as soon as the ground can be worked. After determining the direction of the rows a number of laths, four feet long, are placed in line where the first row is to be. It is very important to get the rows straight and an even distance apart. A good strong pair of horses and a large plow are used, a board being so placed above the mold-board of the plow that the loose soil will not fall back into the furrow. Drive the horses so that the middle of the evener will just come to the lath, then change the lath over its own length, if the rows are to be four feet apart, and that will mark the next row. Change each lath as you come to it, and when your first furrow is completed your second row will be all marked out. Return in the first row to make it deeper and also to straighten any bends. Shovel out the ends for a few feet and you will have a proper furrow to set asparagus roots in. Proceed with the other rows in the same manner, and you will have a good-looking plantation.

The larger growers in Concord set the plants two feet apart in the row and have the rows four feet apart. The plants are set in the bottom of the furrow, covered two inches, and should level up by fall so that the crowns will be six or seven inches below the surface. The furrows may be made very deep, so that manure can be placed in the bottom, or fertilizer may be strewn before the plants are set or after. The roots should be spread out carefully in the bottom of the furrow, care being taken to have them in line. The bed should be cultivated with a fine-tooth cultivator or weeder often enough to prevent the growth of weeds. Keep the bed clean and do not have the trenches filled in before the last of September. The tops should not be cut in the fall of the first year, as the snow will be held by them, and thereby protect the roots to some extent. Some growers spread coa.r.s.e manure on their beds in the fall to prevent the soil from being blown away and also to prevent winter killing, which, however, is rare.

In the second year the bed may be plowed or wheel-harrowed in the spring as early as possible. Concord growers use animal manure or chemical fertilizers, as the case may be or as the bed may require. The bed should be smooth harrowed just before the new shoots appear, and good clean cultivation given during the season. After harrowing or plowing in the third year, sow your chemicals or fertilizer broadcast and harrow in. A good formula for asparagus is: Nitrate of soda, 300 to 400 pounds; muriate of potash, 400 pounds; and fine ground bone, 600 pounds per acre. The shoots will appear about May 5th, and should be cut for about two weeks; then let them grow up and cultivate well during the season.

Home-mixing of fertilizer is practiced by some of the growers in this vicinity, as it is cheaper and better. Any intelligent farmer can, with a little study, purchase and mix the raw materials to advantage. Not so much fertilizer is used as formerly by our growers, who are beginning to think that we use more plant food than the crop needs, thus throwing away many dollars each year. The cost of an acre of asparagus when properly planted and manured is about two hundred dollars, varying with the cost of help, manure, etc. The average product of asparagus beds is about two hundred and eighty-eight dozen bunches per acre--probably less since the rust appeared in 1897.

Asparagus is grown largely on Cape Cod. There the roots are planted in rows six feet apart and four or five feet in the row. Seaweed is used largely in connection with fertilizer and manure. Various grains, oats, rye, etc., are sometimes sown to prevent the soil being blown away. The method of culture is much the same as elsewhere.

At Concord the asparagus season opens usually about May 5th. The shoots are cut two or three inches under ground and should be about eight inches in length. These are laid in handfuls on the ground by the cutter, each one cutting two rows. The product of four rows is laid in one row, making what is called a "basket row." These "basket rows" are gathered in baskets, boxes, or wheelbarrows, and taken to the packing-shed. The asparagus is placed on a table and packed in racks of uniform size, pa.s.sed to the person who ties, and then to be b.u.t.ted off.

The bunches are then washed and set up in troughs ready for market.

Water is added in season to swell the bunch tight and it is then packed in bushel boxes for market, going in by teams each night.

Asparagus was free from pests until 1889, when the asparagus beetle made its unwelcome appearance. Methods of fighting the beetle were unknown to growers generally at that time, but necessity soon taught us. Chickens and hens are used with good results, also Paris green dry was applied with an air-gun when the dew was on the foliage. Cutworms sometimes do the asparagus crop severe damage, but chickens and hens are a sure remedy--in fact, hens are a decided benefit in an asparagus field, keeping down many weeds.