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.