UNIVERSITY OF CALIFORNIA Agricultural experiment Station COLLEGE OF AGRICULTURE E, W. HILGARD, DIRECTOR BERKELEY, CALIFORNIA CIRCULAR No. 9. (January 4, 1904.) Report on Asparagus Rust Investigation By RALPH E. SMITH, Plant Pathologist. The present publication is not put forth in any sense as a final or complete report upon the investigation of the above subject, but is intended merely as a preliminary report, giving an account of some things which have been accomplished up to the present time, together with such recommendations as seem most urgent for the coming season. Owing to the rapid spread of tne asparagus disease and the swift de- struction which it causes when once established, it is important that growers and handlers of this crop should have, at the earliest oppor- tunity, the benefit of any new information of value, and this is the object of this circular. While a great deal remains to be done before the problem of combating this disease can be said to have been satis- factorily solved, many things have come to light already which will be of value to those having asparagus fields not yet ruined by the rust, or who wish advice as to increasing their acreage. A complete account of the asparagus industry of California, the disease which threatens it, and the quite extensive investigation of the same which is now going on, will be reserved for a later and more elaborate publication. The circumstances under which this investigation is being carried on, and the nature of the asparagus industry of this State, are no doubt familiar to most of those who will read this circular. It need only be explained that certain of the leading growers, canners, and handlers of asparagus in the vicinity of San Francisco, realizing last year the great danger which threatened their industry with the appearance of the rust, guaranteed to the University of California the sum of $2,500 for the pur- pose of carrying on the investigation which is now under way. Subse- quently, at a largely attended meeting of the asparagus interests, a general assessment of seventy-five cents per acre was voted by the growers represented, together with proportionate subscriptions by can- ners, commission houses, etc. By this means it was expected that a fund would be created sufficient to carry out a thorough investigation, extending over at least two years or until definite results were obtained. This assessment, entirely voluntary, of course, has been met by many intelligent growers with the utmost willingness, and while the results obtained will no doubt come eventually to the knowledge of all, they are to be regarded as peculiarly the property of those whose foresight lias instituted this work. We suggest to all growers desiring to avail themselves of these results, both now and in the future, the propriety of placing themselves upon an equal footing with those who have already done their part. Nature of the Disease. — The asparagus rust (Puccinia asparagi, D.C.) is a disease of the asparagus plant caused by a fungous parasite of the above name, which attacks the bushy tops coming up in summer after cutting for market has ceased. The disease has no connection with any insect, and while conditions of weather, moisture, soil, etc., have considerable influence upon its development when once present, these things alone can never produce the rust unless this particular fungus be introduced from an infected locality. The disease is readily recog- nized by one at all familiar with it, since its appearance is very char- acteristic and the cause is definitely known and easily seen. Fig. 1 shows the appearance of the rust upon affected plants, illus- trating the various forms which it assumes at different seasons or under various conditions. The large oval patches upon the three larger stalks, particularly the middle one, represent what is called the spring rust. This form is found only in spring and early summer, and consequently only upon young beds, old abandoned beds, or volunteer stalks. It is often quite abundant in such places, more so here than in the East, but in itself is of little importance. Its worst feature is the possibility of the disease being carried over in this way through the cutting season. The blisters seen upon the stalks in Fig. 1 represent the summer or red rust, which is the destructive form. This develops from the spring rust upon affected stalks, and, spreading from this or other sources to the grown- up cutting fields, causes a premature yellowing of the tops, breaks out in red, powdery blisters all over the surface of the stalks, branches, and needles, and in bad cases the tops are soon completely killed. Only a practiced eye will notice at first the red spots appearing here and there among the thick tops, but this soon spreads and a general yellowing and premature death take place. From the blisters upon the surface a red- dish, pollen-like powder escapes, which at the least disturbance of the tops flies away in a cloud of dust. This dust is composed of the minute spores or germs of the fungus, its seeds so to speak, as it is a plant growth; and to one who has walked through a badly infected field and seen the dust-cloud which arises and floats away Avith the wind, the rapid spread of the disease will be no surprise. The so-called black or fall rust appears particularly at the end of the season, when the affected tops turn black. This may occur at any time during the season, but it is most noticeable in the fall. The dark color is due to the black spores of this form of rust, which come out in eruptions upon the surface, as seen especially on the small branch in Fig. 1. It is in this form that the fungus passes the winter, the spores Fig. l. Asparagus stems, showing al tin ust. Puccinia asparagi, D.C. remaining upon the ground or on the remains of the old stalks, and starting again next spring. It should be understood that these various forms of rust are all stages of one and the same disease, which it assumes under various conditions in order to better adapt itself to such influences. The red rust is the destructive form ; the others would be of little account except for their carrying the parasite from one season to another. This. fungus develops only upon living asparagus plants. Similar rusts upon willow, tule, and smart-weed have occasioned more or less alarm among growers, but — 4 — they may rest assured that there is not the slightest danger of the infection of asparagus from these sources. Neither can the parasite exist in the soil except in the dormant spore form. Injury Caused by the Rust. — The marketable asparagus cut in the spring is not affected directly by the rust. The red spots seen upon the white surface, giving the stalks a rusty appearance and often becoming of serious consequence, have quite a different cause, which has been recently determined and will be thoroughly looked into during the coming season. This trouble is increasing in severity and is of consid- erable importance. The effect of the true rust is seen in a falling-off in the yield, both in quantity and in size of the stalks. The cause of this is to be Fig. 2. Asparagus root, showing condition in the fall after severe attack of rust. looked for in the weak condition of the roots, caused by the premature death of the tops in the preceding year. This is not simply a weakness of the plant due to its interrupted growth, but, with the dying down of the rusted stalks in the fall, a decay sets in at the base, which rots out the crowns, cuts off the roots and new eyes, and soon causes complete ruin, leaving the root in such condition that only a few feeble shoots, if any, are sent up in the spring. This is the worst feature of the rust in California; during the mild winter the plant is dormant, but decay of the crowns proceeds rapidly, so that a large part even of what growth was made by the affected plant during the summer and fall is lost before the beginning of the next season. T1h> whole subject of the effect upon the roots, winter condition of the rust, etc., is receiving close attention. Fig. '1 shows the average condition of the crowns in the fall, in beds where the tops died from rust and rotted down to the base. The absence of new eyes or buds for next year will be noted, and in such crowns a decay is already started which will be much worse by next spring. Fig. 3 shows the growth in a bed thus affected. Many crowns have been killed outright, and the remainder send up only a few feeble shoots. One year previous, when the rust came into this bed, the tops were as large'and full as the growth shown in Fig. 9. As to the actual loss caused by the rust it may be said that beds badly rusted one year, for the first time, usually show a shrinkage (averaging about 30 per cent of the normal) in the next year's crop. Fig. Asparagus fk-ld fully gi l»ut hadlv rusted The worst cases have lost 50 per cent the first year, which T meant prac- tical extermination. These figures relate to beds in which the tops were killed to the ground early in the fall. Attacks coming late in the season, or affecting only portions of the top, have a correspondingly less effect upon the yield next year. No grower should deceive himself by assuming that this disease, once present in his fields or vicinity, will not affect the production. He may attribute the loss at first to a bad season or other causes, or pretend to hope for better things next year without effort on his part, but history and experience are against him. This epidemic of asparagus rust has started on the Atlantic and has now reached the Pacific, and in no case has a bed once affected ever — () — come back to a production which would pay the expense of cutting, at California prices. Badly decayed roots can not produce a full crop or send up shoots which do not exist, no matter how favorable the season; and about three years has usually seen the practical extermination of badly affected fields. How the Rust Spreads. — There are two possible methods by which the disease may be disseminated: the spores may be carried in the air from one asparagus field to another, or they might easily be transported upon roots and seeds from an affected bed to other places. Indeed, when one observes the amount of spore-dust flying from badly rusted asparagus and clinging to everything in the vicinity, he may easily imagine that any communication between affected and unaffected regions would probably transfer some of the spores. A study of the actual spread of the disease shows that by far the most important, if not the only, method of spreading w r hich has occurred in the present epidemic is that through the air. The rust was first noticed on the Atlantic coast in the fall of 1896. Year by year it pro- ceeded westward from State to State in regular order, being finally reported in California in 1902, although some sections of this State must have been affected earlier than that year. Furthermore, the spread in this State has been regular, so far as can be observed, from south to north. The rust has been in southern California for two or more years, at Milpitas at least two years, reached Bouldin Island in 1902, the Pearson District and Sacramento in 1903, and has not yet arrived at Marysville, Chico, and the north. Other points in the vicinity of these places correspond with the condition indicated. Since seed and roots have been continually imported from the East all over the State during the rust epidemic, there is little reason to suppose that the disease has been introduced in that way. At any rate such a method can not be at all common, or the rust would have appeared here and there all over the State at once. Much more could be brought out upon this point in a more extended discussion. The chief point is that at present the rust is spreading about the State by the spores being carried in the air from one bed to another,, and nothing can be done to prevent it from so doing. Every grower must expect the disease in his fields (most have it already) and prepare to act accordingly. Present Extent of the Rust in California. — At the close of the season of 1903 the rust was present to a greater or less extent in practically every asparagus field of any importance from Sacramento southward. Some are much worse than others, owing mostly to having had the dis- ease longer, and somewhat from the effects of various natural conditions- As the disease is still rapidly spreading and had last year reached many places (hitherto thought to be immune) for the first time and with disastrous results, it will perhaps be as well not to advertise to the world the various degrees of misfortune in the different sections, which no doubt will soon be largely equalized. The various growers are well informed as to the extent of the disease, and it is sufficient to say that no part of the State which has any considerable acreage of asparagus at present may hope to escape the rust. Natural Conditions affecting Asparagus Rust. — It is gratifying to announce the discovery of several methods by which the peculiarities of the California climate may be taken advantage of in preventing this disease to a degree impossible in any other asparagus-growing State. This comes about particularly in connection with the dry, rainless summer. Experience in the East has shown to a considerable extent the effects of moisture, both soil and atmospheric, upon the develop- ment of the rust. The Massachusetts Experiment Station early pointed out the greater susceptibility to the disease of asparagus growing upon light, sandy loams (the typical Eastern asparagus soil), particularly in dry seasons, and recommended planting upon heavier soils, even if otherwise not as well adapted to asparagus, and also urged the practice of irrigation in dry seasons. A tour of the Eastern districts at present, after seven years of rust, will readily convince one of the soundness of this theory. Another idea brought out was that heavy dewfall favored the disease, and that the amount of rust varied with the amount of dew. On account of the general occurrence of comparatively heavy dews in the East, this observation has never been of much practical importance. In this connection it may also be said that wherever the rust has occurred it has almost always been noticed that asparagus growing directly under the shade of trees remains free- from the disease when that in the open is badly affected. This had also been noticed in California. In this State it is well known that great differences occur as to sum- mer dews, from regions where they are frequent and heavy, to those where there is absolutely none, a condition not even approximated in the East. In observing asparagus rust about the State the fact has been positively established, that the amount of rust varies directly and exactly with the amount of dew, and that so long as there is little or no dew there can be no rust. As applied to those regions where practically no dew whatever occurs in summer, this means that asparagus can be grown there with no danger of the disease. In the dry country about Fresno, for instance, several small patches of asparagus are growing, free from rust, while in a river bottom near by, where moisture is plenty, the disease is at its worst. The same freedom from rust occurs in small asparagus fields in the Coachella valley near Indio, while at Riverside and all over southwestern California rust abounds. It is not intended by this to unreservedly recommend such places for asparagus culture. Freedom from rust is only one factor of success subordinate to many others which only experience can test. Furthermore, the present investigation was not undertaken to find hew regions for asparagus, but to help those already in existence. The above remarks may, therefore, be taken for what they are worth to those interested in the districts concerned. Considering the regions now devoted to extensive asparagus culture there is found a considerable difference as to the amount of summer dew. In some of the localities adjacent to the lower end of San Fran- cisco Bay conditions are almost as in the East, the asparagus tops being frequently drenched with dew until late in the forenoon, even in August. In such places the rust becomes abundant on asparagus as soon as it grows up, at any time in the season. This condition is not equally bad in all the Bay region, as the upper portions are more exposed to the trade-winds, which have a drying effect. Coming to the island district, above the straits at Port Costa, this strong west wind blows almost steadily during midsummer over the country between Mount Diablo and the Livermore hills on the southwest, and the Mon- tezuma hills on the northeast. It is strongest and most constant in the range of Antioch, Brentwood, and Sherman and Jersey islands, well sustained at Andrus and Bouldin islands, and considerably weaker, but by no means lacking, from upper Grand Island up to Sacramento. Continued observation has shown that in this wind there is more help for the asparagus-growers in the sections mentioned than in any other one factor now known. Although lying so low as to require pro- tection by extensive levees, mostly below the river level, these islands and adjacent country have a comparatively dry atmosphere in summer, owing to the prevailing wind. The amount of irrigation has, of course, an important local influence, and this and the matter of windbreaks are of foremost importance in respect to the rust. Most of the existing plantations of asparagus are just inside the levees, heavily irrigated, and sheltered by willows and bends and coves in the levee. These places have proven in almost every case to be the starting points of the rust. Fig. 4 shows just what is meant. In such corners, sheltered by wil- lows on the west, dew is quite abundant and the rust gets a vigorous start, often three or four weeks before appearing out in the open. The advisability of avoiding such places is therefore obvious. The cutting- 1 1 <nr a of all willows and other growth forming such shelter is most strongly urged. Nothing so simple and at the same time so effective in checking the rust can be done. Besides this, all low spots should be avoided in planting new beds, as these also favor dew and give the rust an earlv start. Another important feature is seen in the direction of the rows and their distance apart. Fields with rows running north and south (across the wind) rust considerably sooner on the sheltered, east side of each row than those in which the rows run with the wind so that it can blow down the roAV on either side. For the same reason it is advisable to plant the rows ten feet apart in this windy country, to secure the full benefit. Repeated demonstrations prove conclusively that by planting a little back from the levee, in level, open country, keeping down all windbreaks and running the rows as described, the rust can be held back at least a month in the river district. Were it not for the old beds with their sheltered corners starting the infection long before it Fig. 4. Corner of asparagus field in island district, sheltered on north and west. Typical starting-place of rust. would otherwise occur, this would be even more effective, and growers are urged to grub out such places as soon as they become affected, or, better than nothing, keep the tops cut in summer. The matter of irrigation is also very important. In much of the river country water is applied abundantly and often excessively all through the summer. For the prevention of dew and the resulting rust the less irrigation after cutting ceases the better. A good wetting up to July first, followed by thorough cultivation through the season, will carry through any of this land and keep the top of the ground dry. Dryness of the soil is also desirable in this region, in order to check the contin- ual coming up of the new shoots, which goes on all through the fall. Fig. 5 shows a method by which the rust may be absolutely pre- vented, but, of course, is not applicable to commercial asparagus — 10 — growing. This consists of a simple cheesecloth tent placed over the bed when cutting stops. In regions of heavy dew two thicknesses of the cloth w T ill be required to prevent the rust entirely. The present scarcity of healthy asparagus roots for planting suggests the use of such a method in seed-beds, where at comparatively small expense plants free from rust could be easily produced. The Bay regions where dew is abundant have an asparagus soil of a sedimentary nature, wet in winter and usually heavily irrigated in the cutting season, but quickly drying out in summer. Many of these beds are given little attention after the cutting season, and become choked with weeds and extremely dry. Here the conditions existing in the East come to light. Moisture being abundant in the air, heavy dews are frequent and remain late in the forenoon, even on the driest Fig. 5. Tent over asparagus; a rust preventive. soil. Here are repeated the conditions wdiich occur in New Jersey, eastern Massachusetts, and Long Island; the plants suffer for water (in the soil), while the rust spores find an abundance (in the air). Conse- quently, the parasite thrives upon the weakness of the plant. In every case observed in this district the wettest beds remained green the longest, while good cultivation helped out in no small degree. The next figure (Fig. 6) shows a striking case where 'the plants next the ' ditch were green and vigorous long after those farther back were dead with rust. Irrigation alone will not suffice to save these beds from rust, but' will be of great assistance. It should be resorted to, however, only in the district about Milpitas and Alviso, or wherever the dews are heavy all summer and the winds uncertain. Without dew no amount of dry- ness in the soil can bring about rust. — 11 — Nature of the Soil m Rdntion to the Rust. — Along this same line it should be said, in addition to the above, that, other things being equal, asparagus on the more substantial sedimentary soils has shown more resistance to the disease than that upon pure peat. The latter takes up large amounts of water and produces a quick-growing, tender, suc- culent asparagus very desirable in canning; but this type appears to have little stamina and more easily succumbs to the rust than that on solid, sedimentary ground, although the difference is not very great. Furthermore, in the peat soils the asparagus roots decay more rapidly, and the destruction wrought by the disease is thus more sudden and Fig. G. Effects of irrigation in Milpitas district. complete than elsewhere. Beds on this soil are naturally shorter-lived than on sediment. Varieties of Asparagus as related to the Rust Problem.— Of the various varieties of asparagus commonly grown it may be stated conservatively that some are considerably less susceptible to the rust than others, although no one is by any means "rust-proof," as is sometimes claimed. The experience in the East has been, that in the first violent epidemic of rust ,all varieties were badly affected, but that after a few years the resistant qualities of certain kinds became more and more pronounced. Much more difference in the various varieties appears there now than in California, or than was perceptible there a few years ago. The choice of varieties is, therefore, of more importance in planting new — 12 — beds than can be judged from the condition of the various kinds in the old ones. This part of the question is complicated in California by the requirements of the canning industry, since very few varieties are suitable for producing the "extra white" quality for which the State has become famous. Palmetto. As to rust-resistant qualities, this variety and the next mentioned are somewhat less affected and considerably less injured than any others now cultivated in this country. The Palmetto is not very desirable in canning, however, on account of the yellowish color when cooked and its somewhat coarse texture. French, or Argent euil, appears to be equal to the last in resistant qualities, but becomes darker colored when cooked and is, therefore, more objectionable for canning white asparagus. Barr's Mammoth is somewhat more affected than the foregoing, but less so than some others. It is desirable to a limited extent in supply- ing the demand for very large stalks, but otherwise is coarse and of poor quality, while its rust-resistant qualities are very slight. The shape of the stalks is also undesirable, particularly for bunching. Conover's Colossal is the canning asparagus, being productive, of good size and flavor, tender, and of finest color as grown in the best districts, but unfortunately it is one of the most susceptible to rust. In the Eastern districts, where this variety was formerly grown exclu- sively, it is now completely exterminated. Moore's Cross-Bred quickly succumbs to the disease, and has nothing to recommend it under present conditions. Columbian White, a sport from the Conover, seems to be the most susceptible of all varieties to the rust. For the present planting the Palmetto must be the first choice. It has good size and productiveness, less pounds to the acre but fewer stalks to the pound, and, therefore, cheaper to cut and pack than the Conover, is of fair flavor, strong growth, and has considerable rust resistance, which appears to become more pronounced in fields put out after the rust epidemic has started. When cooked it takes a yellowish color and in unskillful hands sometimes becomes nearly black in the can, which is very objectionable to those desiring an extra white asparagus. Moreover, it possesses neither the delicate flavor nor texture of the Conover, but since the latter has been exterminated in the East and is going very rapidly in this State, its extensive planting can not at present be recommended. Palmetto and Argenteuil are now prac- tically the only varieties existing in the East, all the new beds being of these varieties, with the preference, among those who have both, in favor of the former. For fresh asparagus there is little choice between them, although the Palmetto is by some considered rather more pro- ductive than the Argenteuil. For canning, the color of the latter is — 13 — more objectionable, so far as limited tests have shown, than that of the Palmetto. Efforts are being made to obtain or produce a desirable canning variety of greater rust-resistant qualities. To this end seed has been saved from individual plants showing desirable features, and all European varieties obtainable are being imported. In this way it is expected to obtain the most rust-resistant variety -possible which will be suited to our requirements. It must be said, however, that white y asparagus and rust-resistance are at the opposite extremes of nature's intentions. Whatever is developed in this way will be turned over to the growers who have supported this investigation. As to the Time of Cutting Asparagus. — Much attention should be paid to the important matter of cutting asparagus, both in regard to the crop in the spring and to removing the tops in the fall. Ordinarily, the spring cutting continues until the middle or last of June; the tops then grow up and remain until killed by frost in late November or December. There is room for considerable latitude in this respect, and this should be carefully considered in relation to the rust. In all the asparagus regions the spring months are moist and favorable to the disease. Spring rust develops very commonly upon all asparagus not cut, and is abundant everywhere at the end of the cutting season upon volun- teer growth or uncut beds. Could such growths be entirely suppressed in whole districts, there is no question that the rust would thereby be much hindered in its development. The important point to determine is whether all the summer rust on the cutting fields spreads from spring rust on volunteer, etc., or whether the spores of the fungus from one year, after being in the soil over winter, persist long enough the next season to infect the beds after cutting has stopped, without going on to the volunteer. Here are several months when it would not be impos- sible to prevent practically all growth of asparagus above ground in large districts, if by so doing we could be sure of profitable results. This point is being carefully studied, and it is hoped that another year's experience will show just how the rust passes from December of one year to July of the next. Meantime, as it has been shown beyond doubt in the past season that volunteer or wild grow r th near an aspara- gus field often gives the rust several weeks start in the adjacent portion when it grows up, it is strongly recommended that the growth of all aspar- agus above ground previous to when cutting stops he suppressed as much as possible, and that about a week before the end of the cutting season all tops which have been growing up to that time be cut off close to the ground, or if possible grubbed out by the roots, and burned. This will not entirely prevent the rust, but in many beds having a fringe of volunteer around the edges or any spring growth in the vicinity, the — 14 — disease in the past season could have been set back several weeks by this means. The time when the cutting season should stop is of great impor- tance. Theoretically, of course, the earlier the tops are allowed to grow up the better growth they will make, but if they come up only to be killed at once by rust little or nothing will be gained. For this reason it is of little use in the Milpitas section to recommend any change from the ordinary practice until we are able to protect the tops from rust to some extent by artificial means. With the great preva- lence of the disease there in June and July, part of the beds coming up early would only serve to start the rust and spread it at once to the others when they come on. If the present experiments in preventing Fk Rusted asparagus, showing green at bottom. the rust by artificial treatment prove as successful as they now promise to be, then a short cutting season w r ill be very advisable in this sec- tion to recuperate the affected beds; but under present conditions little profit can be hoped for by such a practice. Growers in the river country are urged very strongly to stop cutting this year by June first and to let the tops grow up. Here there is little danger of rust, except in the moist, sheltered, or low places, until nearly October, and this great natural advantage should be made use of to the utmost. In four months the plants can make a mature growth, ripen their berries, and become much less susceptible to injury by the disease, whereas those cut until July are caught before maturity and are badly injured. The continual growing up of new shoots in the — 15 — moist soil of much of this district has been previously alluded to and should be prevented as much as possible by withholding irrigation after July first. The matter of cutting the tops early in the season when badly rusted has received attention all over the country, and the conclusion is unanimous that this is worse than useless. Early cutting stimulates the roots to send up new tops, which, coming up fresh and tender just at the most rusty time of year, draw largely on the reserve strength of the roots, soon become rusty again, and thus the plant receives a double Fig. 8. Block Uotreau asparagus treated in various ways in center of large field. attack of the disease instead of one. In most cases in this State the tops are not at first affected completely to the ground, but the shade of the upper part protects the lower, so that about six inches of green brush remains for a long time just above ground, as shown in Fig. 7. This naturally is of much benefit to the roots, and so long as any green remains at the bottom the tops should not be cut. At the end of the season, usually in November, the last green parts succumb and the stem turns black and rots down to the crown, falling into a state of soft, mushy decay, instead of drying away as it should normally. At this time the tops should be cut off, before the condition just described becomes gen- — 16 — eral. In neglected, uncultivated fields the tops when rusted die down clear to the base very early, but in beds properly taken care of this rarely takes place before November. A great difference in next year's crop will be made whether the stems rot down to the crown from the rust, or are kept green at the butt and are cut off in time to die out naturally, but no sooner than is necessary. Treatment by Spraying, Etc. — The subject of treating asparagus for the rust by spraying and similar methods has received and is receiving much attention in this work. The only treatment at all successful, hitherto devised, that of spraying the tops with the Bordeaux mixture at frequent intervals through the summer, has been thoroughly tested, along with many other methods of a similar nature. While several different liquid sprays have been found which produce a decided dif- ference in the amount of rust, the difficulty and expense of spraying asparagus tops thoroughly and with only partial success at the best, give little hope of any such treatment ever becoming profitable in our large California fields. The same conclusion has been reached in the East. A full report of spraying experiments will be given in a later publication. Fig. 8 shows the corner of one of the experiment plots, in which it can be seen that there is considerably more foliage than in the remain- der of the field. In Figs. 9 and 10 are represented the results, on a small scale, of the most successful and seemingly practical method of treatment thus far devised. Fig. 9 shows the side of a treated row, while in Fig. 10 is represented an adjoining untreated row directly opposite. When it is considered that the row in Fig. 9 was surrounded on all sides by tops in the condition shown in Fig. 10, and to the right in Fig. 8, being in the midst of hundreds of acres of the worst rusted asparagus in the State at the time, it must at least be concluded that this is worthy of more extended trial. The method is cheap and practical of application, but will not be made public until more thoroughly tested on a large scale by the growers who are supporting this investigation. All such will be given an opportunity to try this treatment at the proper time during the coming season. Disinfection of Seed and Roots. — Many inquiries have come in as to the necessity or advisability of disinfecting asparagus seed and young roots before planting, and in regard to putting out plants which have already been affected with rust in the seed-bed. The matter of disin- fecting healthy seed or roots is of little importance at present, no matter from whence they come or how thoroughly the operation might be done, as the disease is now so generally distributed and spreads so — 18 — rapidly that there is no hope of keeping it out from any locality where conditions are favorable. It is much more important to obtain seed from healthy stock in order that the young plants may be as vigorous as possible. The danger of the seed being; from weak and prematurely matured or rusted plants is greater than that of transporting the rust itself. The same is true in regard to roots, as many seed-beds become badly rusted the first year and the plants thus greatly weakened, and no doubt many such are put on the market. Those planting exten- sively should insist on seeing the plants in the fall before the tops are cut. or get reliable information as to the same, and plant nothing which was badly affected early in the season. Plants which have had no rust whatever are by far the most desirable, but in the present scarcity these are not obtainable in large quantities. The fact that the tops were somewhat rusty need not condemn the roots entirely for planting, as it has never appeared that the disease enters the roots or is carried in that way. . The size and vigor of the plants should be the guide, in so far as this corresponds with the rustiness of the tops. Each grower must judge for himself in this respect, keeping in mind that the danger of the disease being in the roots is very slight, but that success will depend very much upon strength and vigor at the start. Fertilizing the Soil. — The application of various fertilizers to asparagus for the purpose of making it more resistant to the rust has been tried quite extensively in the East. No success has been obtained in respect to any particular substance having a decided effect upon the disease, and observations in this State lead to the same conclusion. Most of the asparagus grown on a large scale in California receives no fertilizer whatever except the application of barnyard manure in some localities. Nitrate of soda is also coming into use to a limited extent. While most of the asparagus soils are of great natural fertility and produce large crops, a dressing of manure is to be recommended in every case where it can be readily procured, as by this means the plants are invigorated and the production increased, although no direct effects upon the rust can be seen. Nitrate of soda is of value in hastening and stimulating the crop and is to be recommended to those cutting especially for the early market, or on exhausted beds. Its benefits are not lasting, and those cutting through a long canning season appear to have received but little benefit in applying this substance. In general, it may be said that growers should aim to keep their beds in as vigorous a condition as possible by good cultivation and whatever fertilizing seems practical under local conditions. In this way the diseased beds may be kept up longer than they would otherwise last, and new ones will have more general vigor and resistance. Clean cultivation seems to be much more effective on most of our asparagus soils than fertilizers. — 19 — Parasites on the Rust. — Several parasites affecting the rust fungus have been observed in the East, and these also occur here; but appar- ently have little effect upon the disease, although in the course of several years they may reduce it somewhat. There has developed, however, during the past season in some fields of this State, a mould-like fungus parasite not known in the East, which gives the greatest promise of checking the rust very materially if it can be developed in abun- dance and generally introduced. This parasite is certainly much more effective than anything hitherto recorded, and great efforts will be made to encourage and spread its development as much as possible. . It may also be mentioned in this connection that the asparagus rust has been known for a century in Europe, but causes no material damage there now. The reason for this condition w r ould be well worth knowing. The Present Outlook. — In general, it may be said that the asparagus- canning industry is at present in a critical condition, and only a deter- mined effort on the part of those interested in the business can prevent its falling into a condition where it will cease to be of profit or importance. This conclusion is reached not simply from the brief his- tory of the rust in this State, but from a knowledge and observation of what has happened in every asparagus-canning section in the country during the past seven years. Unquestionably a large acreage of old beds is already lost, and growers, canners, and handlers of asparagus generally should prepare themselves to expect some short crops and more or less readjustment of the business. Prices are bound to rise, the demand will increase as the supply decreases, but the cost of pro- duction will become greater, labor troubles will come in, and the asparagus business will probably never again be what it has been in this State for easy profits. Growers who can readily substitute some other fairly profitable crop for their asparagus are advised to begin to do so, as it may prove much to their advantage. This applies particu- larly to those with a small acreage of valuable land who can not readily start new beds of asparagus. Persons of no experience in growing the crop who are thinking of planting any considerable acreage, attracted by the profits of the business in the past, are most strongly advised not Ao do so. The day of bonanza asparagus farming has passed and only ) the thorough knowledge and experience of the specialist can hope to /cope Avith present conditions. The grower who is largely interested in asparagus, thoroughly familiar with its exigencies, and equipped particularly for growing this crop as a specialty, is advised to continue planting as largely as seems to him advisable, under the methods herein described. His best hope is for the future. Old beds now seriously affected are beyond saving by any means and can at best only be expected to bridge over the time — 20 — necessary for starting new ones. It is hoped that the results of the present work will make it possible to thus start anew with fair pros- pects of success, but this will only be attained by close attention to every detail. The haphazard, "spread eagle" methods hitherto so largely in vogue have had their day. The following remarks from Professor Halsted, of the New Jersey Experiment Station, the leading authority upon asparagus rust, are worth quoting in this connection : "The best growers are taking better care of the fields than formerly, and this has resulted in their favor. * * * The threatening enemy has led to a more careful consideration of their fields on the part of the better class of growers, while the careless have in many cases turned their attention to less exacting crops. * * * In so far as the rust has brought about a more rational treatment it has been a lasting benefit to the best class of asparagus-growers." Canners and handlers of asparagus should realize fully the danger which threatens to curtail or even ruin their business. Should any have doubts of this they have only to turn to the East for an example. While under no obligations to make unnecessary or unreasonable con- cessions, they may rest assured that unless the condition of the grower is met by them in a broad and fair-minded manner, keeping in touch with new conditions as they arise, the end of the asparagus-canning business is in sight. The readjustment which is bound to come must be appreciated and shared in by all alike. The work of this investigation is going on continuously, occupying practically the entire attention of the writer, and will continue as extensively as possible during the coming season, when it is hoped that much further advance may be made. As all the growers interested can not often be seen in person, the present circular is issued as a report of progress, and each one who has helped to support the work may be certain that his interests will be fully considered and should feel at liberty to call for any particular advice or assistance which he may desire. Printed at the State Printing Office, Sacramento, W. W. Shannon, Superintendent.