University of California— College of Agriculture. AGRICULTURAL EXPERIMENT STATION, E. W. HILGARD, Director. BENCH-GRAFTING RESISTANT VINES F. T. Bioletti and A. M. dal Piaz. 1— Solonis. 2— Rupestris St. George. 3— Riparia Gloire de Montpellier. BULLETIN No. 127. SACRAMENTO: A. J. Johnston, : : Superintendent of State Printing. 1900. BENCH-GRAFTING RESISTANT VINES. The conviction that the vineyardist has to deal with the phylloxera as a factor in the success or failure of his business becomes stronger every day. This applies both to the grape- grower who already has bearing vines and to the intending grape-grower who is engaged in planting his vines. Each succeeding year sees new vineyards and new localities attacked, and grape-growers who believed their vines safe on account of the richness or sandy nature of their soils, the practice of irrigation, or the isolation of their vineyards, are gradually being forced to change their belief by the sad fact of the death of their vines. Yet there are still many who fail to realize the true nature of this disease, and even now there are growers who are planting varieties of vinifera on their own roots in locali- ties adjacent to infected districts and even in the infected districts themselves. Even those who are thoroughly persuaded of the necessity of establishing their vines upon resistant roots are in doubt as to what species or variety to choose. When the phylloxera first invaded the lower parts of the .Sonoma and Napa valleys, over twenty years ago, the vine- yardists were completely unprepared for it and unable to combat it in any way; so most of them allowed the insect to have undisputed sway, with the result that the vineyards dis- appeared. A few of the more intelligent growers, however, tried the method, first practiced in France, of planting resistant stocks. The principal varieties planted were Riparia and Lenoir. Other varieties were planted in small quantities by a few growers, but most of them are at present of little interest. The results varied widely. Though a certain number of vine- yards were fairly or even perfectly successful, the majority were total or partial failures. This lack of general success was due to three principal causes : 1. Many of the soils and locations were unsuitable for the growth of either Riparia or Lenoir. _ 4 — 2. The Riparia cuttings used were not of one variety, some being very small growers, unable to support a large vinifera. 3. The Lenoir is not sufficiently resistant in all soils, and therefore failed to give full crops on any but the best soils. To these should be added, in many cases, ignorance of the methods of planting and grafting resistant stocks. Ten or fifteen years later the coast valleys south of San Francisco, which the vine-growers had hitherto considered immune for some mysterious reason, were attacked. They were just as unprepared as the vine-growers of Napa and Sonoma had been when their vineyards were attacked. It is in order to prevent any further unpreparedness and conse- quent costly mistakes that vine-growers of uninfected loca- tions are earnestly advised to commence now to test the most promising resistant stocks on their own places, in order to determine which of these is most suitable for the conditions of the soil, climate, and moisture that exist there. This is especially true of such localities as Fresno and others in the lower San Joaquin Valley, where there are large stretches of contiguous vineyards as yet uninfected. The phylloxera is as menacing a foe to the " raisin-grower " as to the "wine-grower," and it would be well worth while for every vineyardist in California, not only to test various resistants, but also to learn the methods of bench or cutting grafting and all the various processes of establishing a vineyard on resistant roots. Then, when the insect enters his own or his neighbor's vineyard he will know exactly what to plant and how to plant it, and not be obliged to experiment for three or four years or trust to the experience of some one else whose conditions may differ in some way from his and thus run the risk of making costly failures. The work of the Experiment Station in this line for the last two or three years has been to establish some general princi- ples to guide the individual grower in his own attempts and to narrow the scope of his experiments in order that he may not waste his time on methods and varieties which have already been proved valueless. Our conclusions have been based on observations of our own experiments and also of the successes and failures of grape-growers in various parts of the State. These observations have so far been directed principally to: - 5 — 1. The adaptability of various resistant varieties to different conditions of soil, climate, and moisture. 2. The best method of grafting for various varieties and conditions. 3. The growth of various vinifera varieties upon various resistant stocks. The problems presented by the phylloxera were studied by Prof. E. W. Hilgard very early at this Station, and a certain amount of attention has been given by the Station since then to methods of extermination of the insect and to resistant stock. The results of this work having already been pub- lished, the present article deals only with the work done dur- ing and since 1896. In that year Professor A. P. Hayne, of this department, imported the following resistant varieties, which were recommended as the best in France for soils similar to our California soils: Rupestris St. George, Riparia Gloire de Montpellier, Riparia grande glabre, Riparia Martin. These varieties were as widely distributed over the various vineyard districts as possible, and particular satisfaction was given by the first two mentioned. In 1897 the Station continued this work of distribution and put upon its "Distribution List" Rupestris St. George, Riparia Gloire de Montpellier, Riparia grande glabre, and Solonis. A more limited distribution was also made of Rupestris Martin, Rupestris Mission, Rupestris Ganzin, Champini ; and of three hybrids of Rupestris crossed with Riparia, viz, Rup. X Rip. 101 14 , Rup. X Rip. 3306, Rup. X Rip. 3309. In the same year the Station published an appendix to the Viticultural Report of 1896, entitled "Resistant Vines," by Professor Hayne, in which was given a summary of what is known in France of the practical selection and adaptation of resistant vines and also of the methods of grafting adapted to these vines. During the years 1898 and 1899 the two varieties which seemed to have given the most general satisfaction and for which there was the most demand were again placed upon the "Distribution List." These varieties were Rupestris St. George and Riparia Gloire de Montpellier. In 1898 the Station decided to make a series of practical experiments with these recently imported resistants and on various methods of grafting, in order to bring the matter before the vine-growers of California in a practical form, and also to — 6 - throw light on some doubtful points. This it was enabled to do by the public spirit of Mr. J. K. Moffitt of the First National Bank of San Francisco, who kindly allowed us to use a portion of his vineyard at St. Helena, Napa County, for our experiments. These experiments were planned on a somewhat elaborate scale, but unfortunately were almost a complete failure, on account of the bad condition of the resistant cuttings when they arrived from France. There were imported 9,300 cuttings of various varieties, and of these about eighty-five per cent were completely spoiled. They were packed with the greatest care, but had somewhere been exposed to too much heat (probably on the steamer) and had suffered a fermentation which had completely blackened the pith and inner bark. These were planted out in the nursery without grafting, but failed to grow. The remainder were a little better, but were full of dark streaks, showing that they also had suffered from the heat but in a less degree. These were grafted, and the ill- success of the grafts was undoubtedly due to this bad condition of the stocks. This showed the danger of importing large quantities of cuttings from so distant a place, and it was determined for the next year's experiments to use only cuttings grown in California. Adaptability of Various Varieties of Vinifera to Various Resistant Stocks. — One of the principal experiments made was to test the adaptability of certain vinifera varieties for different stocks ; that is to say, to test on which resistant stocks certain varieties did best. The negative results (the cases in which there was very poor or no growth) of course taught nothing, as it was impossible to tell whether the failure was due to lack of affinity of the scion for the stock, or simply to the bad condition of the stock. The positive results, where there was good growth and good unions, are however worth chronicling. The varieties which grew well and made good unions on Riparia Gloire de Montpellier were : Aramon Folle Blanche Mar-sanne Seedless Sultana Blue Portuguese Gros Mansenc Peruno Semillon Chardonay Kleinberger Petit Bouschet Valdepefias Those which did well on Riparia grande glabre were: Aramon Cornichon Marsanne Sultanina Cabernet Sauvig- Fresa Mataro Verdot non Gros Mansenc Mourisco Preto Vernaccia Chardonay Huasco Semillon Those which did well on Rupestris St. George were: Barbera Kleinberger Palomino Seedless Sultana Beba Mantuo de Pilas Peruno Valdepenas Cornichon Marsanne Petit Bouschet Vernaccia Franken Riesling #• All these made good growth, and the unions were all appar- ently strong and well formed. They were planted out in the spring of 1899 in three rows of twenty-five vines each, in order to watch their future development. Besides these were planted out two rows of twenty-five vines each, as follows: One row of Mondeuse grafted on Riparia grande glabre, one row of Mondeuse grafted on Rupestris St. George, and one vine of Mondeuse grafted on Rupestris X Riparia 3306. Eleven other rows of ungrafted varieties were planted, as follows : One row each of Pinot Cabernet du Lac, and Hybrid Franc; two rows each of Rupestris Martin, Rupestris X Riparia 101 14 , Rupestris X Riparia 3309, and Rupestris St. George; one row each of Vialla and Rupestris Mission. On December 29, 1899, the following notes were taken on the foregoing vines: Varieties Grafted on Riparia Gloire de Montpellier. Blue Portuguese Strong growth, canes 3 feet long, but not very well ripened. Chardonay. Medium growth. One dead. Fresa. Poor growth. Folle Blanche. Medium growth. Gros Mansenc. Good, strong growth, canes 3 feet long. Kleinberger. Medium growth. Marsanne. Good, strong growth, 3 feet long. One graft dead. Peruno. Medium growth, shoots still green, except at the base. Petit Bouschet. Medium growth. Seedless Sultana. Medium growth and wood still green, except at the base. Semillon. Medium growth. Valdepenas. Good growth of thoroughly ripened wood. Vernaccia. Medium to poor growth. Varieties Grafted on Riparia Grande Glabre. Aramon. Growth poor, about 1 foot. Cabernet Sauvignon. Growth good. Chardonay. Good growth, some shoots 3 feet long. — 8 — Cornichon. Medium growth, about 2 feet. Fresa. Medium growth, about 2 feet. Gros Mansenc. Growth about 1 foot. Huasco. Good growth, shoots about 3 feet long, but still green at the tips. Marsanne. Excellent growth of ripe wood. Mataro. From 1 to 2 feet of growth. Mourisco Preto. Good growth. Semillon. Growth about 2 feet. One graft dead. Sultanina. Many shoots, but green at the tips. Verdot. Poor growth. One graft dead. Vernaccia. Poor growth, thin shoots 2 feet long. Varieties Grafted on Rupestris St. George. Barber a. Medium growth. Beba. Fine growth. Cornichon. Medium growth. Franken Riesling. Long growth, tips still green. Kleinberger. Long thin canes. Mantuo de Pilas. Poor growth. Marsanne. Small growth. Palomino. Very vigorous growth of 8 or 9 canes to a vine. Peruno. Strong growth. Petit Bouschet. Vigorous growth, strong canes. Sultana. Good growth. Valdepenas. Good growth. Vernaccia. Medium growth. The one graft of Mondeuse on Rupestris X Riparia 3309 had made a very good growth. The row of Mondeuse grafted on Riparia grande glabre had grown well, with the exception of one graft, which was dead. The row of Mondeuse grafted on Rupestris St. George was more irregular. Two vines were dead and five had lost the Mondeuse scion, and the Rupes- tris was growing from suckers. Where the Mondeuse was growing, however, it was on the whole more vigorous than in the last row. Varieties on Their Own Roots. Pinot Cabernet du Lac. This variety made very poor growth. Most of the vines lived, but the canes were only a few inches long. The soil, which was black adobe, was evidently unsuited to this vine. Hybrid Franc. The growth of this variety was more irregular than that of the last, and no stronger. A few vines had made medium growth, but many were dead and the majority were very poor. Rupestris Martin. This resistant made a fair growth ; in some cases the canes were 4 to 5 feet long, but not thick. Rupestris X Riparia 101 u . Fair growth of 2 to 3 feet. Rupestris X Riparia 3309. Fair growth, somewhat longer and stronger than the last. Rupestris St. George. Growth good to very good ; many canes to each vine. Vialla. Good growth of*shoots 2 to 3 feet long. Rupestris Mission. Good growth, but the canes were rather thin. — 9 — Experiments Made in 1899. The experiments carried out this year consisted chiefly of tests of various methods of grafting and of planting in the nursery. The cuttings used as stock in these experiments were : 1. Rupestris St. George, 3,000 from Beringer Bros., St. Helena. 2. Riparia Gloire de Montpellier, 100 from John Swett & Son, Martinez. 3. Lenoir, 96 from G. Husmann, Napa. 4. American Rulander, 26 from G. Husmann, Napa. 5. Herbemont, 21 from G. Husmann, Napa. 6. Cunningham, 27 from G. Husmann, Napa. 7. America, 10 (rooted, 1 year old) from W. B. Munson, Texas. 8. Champini, 10 (rooted, 1 year old) from W. B. Munson, Texas. 9. Elvicand, 7 (rooted, 1 year old) from W. B. Munson, Texas. 10. Munson, 13 (rooted, 1 year old) from W. B. Munson, Texas. The following varieties were used as scions : 11. Zinfandel, from J. K. Moffit, St. Helena. 12. Mondeuse, from J. K. Moffit, St. Helena. 13. Tokay, from John Swett & Son, Martinez. 14. Ferrara, from John Swett & Son, Martinez. The following varieties were used for rooting experiments: 15. Rupestris St. George, from Beringer Bros., St. Helena. 16. Riparia Gloire de Montpellier, from John Swett & Son, Martinez. 17. Solonis, from John Swett & Son, Martinez. The main objects of this series of experiments were to ascertain the relative value of : (a) The English graft and the Champin graft. (b) Leaving two eyes on the scions and leaving only one. (c) Preliminary callusing in sand, and planting out in the nursery immediately after grafting. (d) Callusing in sand alone and in straw covered with sand. (e) Rupestris St. George, Riparia Gloire de Montpellier, Lenoir, Herbemont, Cunningham, and American Rulander as regards root formation when bench-grafted. (/) Rupestris St. George, Riparia Gloire de Montpellier, and Solonis as regards rooting when not grafted. Light was thrown on other points, such as the possibility of grafting successfully various varieties of different habit, such as the small-growing Zinfandel and the large-growing Ferrara, upon Rupestris St. George. — 10 — Grafting. Preparation of Cuttings for Grafting. — The Rupestris St. George cuttings used for grafting-stock were in excellent con- dition at the beginning of the grafting season, as they were kept under cover in moist sand during the winter. The cut- tings were less than two feet long, rather short jointed, and generally too thick at the lower end and too thin at the upper for grafting. This was doubtless due to the dry summer, which resulted in a short growth, and it was rarely possible to obtain more than one graft from a cutting. The sizes used for graft- ing varied from J to \ inch in diameter. The thin tips which could not be used for grafting were put out in the nursery for rooting. The cuttings were all treated in the same way for the various experiments, as follows: They were cut into sections of from 6 to 9 inches; the lower cut was made through the knot of the bud; the last internode of the upper end was left as long as possible, as the internodes were of rather short length, some- times scarcely long enough for the grafting cut. Special care was given to the perfect removal of all of the buds on the stock, a deep cut being made in order to remove not only the main bud, but also the small adventitious or dormant buds which surround its base and which often grow out when not care- fully excised and form suckers, which grow at the expense of the graft. The cuttings thus prepared were sorted into three sizes according to their thickness, put up in bundles, and placed vertically in a tub of water, so that the lower end was covered with water; the cuttings thus remained fresh and sappy, which facilitated greatly the making of cuts. The cut- tings remained in the water until they were needed for grafting, that is to say for from 6 to 18 hours. The washing and placing in water had also the object of cleaning the cuttings from all adhering dirt and sand, which would blunt the edge of the sharpest grafting knife in a short time. The scions were prepared in a similar way, with the excep- tion, of course, that the eyes were left. Two kinds of scions were needed for the experiments: one with one eye, the other with two eyes. The first kind was cut through the second knot so as to leave the eye protected by a closed internode, which on — li- the one hand prevented penetration of moisture and of fungi, and on the other hand drying-out of the part above the eye. Scions of the second kind (with two eyes) were treated differ- ently in order not to make them too long, the upper cut being made about an inch above the second eye. The scions were also sorted into three sizes corresponding with those of the stock, tied up in bundles, and put in water to keep them fresh and sappy. Methods of Grafting. — Before grafting, the cuttings for both stock and scions having been carefully sorted into three sizes, and the eyes of those of the stock cut out deeply with a sharp knife in order to prevent the production of suckers, the greatest care was taken to prevent the slightest drying-out of the cut- tings and afterwards of the grafts. The raffia used for binding the grafts was soaked in a three per cent solution of bluestone (copper sulphate) for one day and then hung up to dry. Before using, it was thoroughly washed in running water to remove the superfluous bluestone. The raffia was cut into short pieces of 10 to 12 inches and then kept in a box, moist and ready for use. The grafting knife was not of the pattern generally used in California, but was one especially constructed for Champin and English tongue grafting; it had a wooden handle 4^ inches long to give the hand a firm grasp, a straight and very thin blade of excellent steel which was easy to sharpen and which kept its edge for a considerable time. A good hone and a razor strop were used for sharpening the knife. The object of the experiment in methods of grafting was to ascertain the advantages and disadvantages of the two most commonly practiced methods, viz: the English graft and a modification of the old Champin graft; the first is universally used in European vine-nurseries, the latter is less practiced there, but is frequently used in California. English Cleft or Whip Grafting. — This method was applied in the usual way, as shown in Fig. I. The stock and scion were chosen of equal size and were cut at the same angle. The length of the cut surface, in cuttings of solid texture and full size, was about three times the diameter of the cuttings, that is to say the cut was made at an angle of about 19°. This may 12 be taken as the maximum angle that can be used practically. For smaller cuttings the length of the cut was relatively somewhat greater, being about four times the diameter or about 14°, which may be taken as the minimum angle which should be adopted. The tongues were made by a longi- tudinal cut, care being taken not to split the wood, and usually commenced at about one third the distance from the sharp end of the cutting and to a depth about equal to the diameter. Thus when the two cuttings were placed together the sharp end of one corresponded exactly to the thick end of the other, so that no portion of the cut surface was exposed, and the maxi- Fig. I. English Cleft Graft. A. Proper angle of cut for large cuttings. B. Proper angle of cut for small cuttings. C, D. Proper size and angle of tongues. E, F. Method of uniting and tying graft. mum contact was obtained. The object of the grafter in mak- ing his cuts is to make them as straight as possible, but it will be found that a cut made by the most skillful hand is slightly concave. This is, however, no objection, as this extremely slight concavity is useful in allowing for the slight swelling in the middle due to the insertion of the tongues. This is proba- bly one of the reasons why hand grafting is generally more successful than grafting with a machine, as a machine makes a cut which is absolutely straight and the ends have thus a tend- ency to be drawn away from the cut surface of the other cutting. — 13 — The cut for the tongue is not made quite parallel to the grain of the wood in order to minimize the danger of splitting. Champin Graft. — Perhaps the commonest method of grafting used in California for small vines or cuttings is a modification of the Champin method. The Champin graft is made as shown in Fig. II below. The modified method is a compro- /? Fig. II. End-to-End and Champin Grafts. 1, 2. Method of making the End-to-End graft. 3, 4. Cross-section through the union of ihe above graft, showing how completely the stock unites with the scion on all sides. 5. Union of End-to-End graft. 9-12. Method of making Champin graft. mise between the true Champin graft and the English tongue graft. It is made in a way similar to that described for the latter, but the tongne is made much deeper and the end of the point (see Fig. II, No. 12) projecting over the cut of the opposite cutting is cut off. The Champin graft is based on the theoretical principle that — 14 — the greater the surface of contact between the two cuttings the greater the chances of union. Thus in the English graft the amount of possible contact is theoretically only about half that of the Champin. The latter is apparently twice as great as the former. In practice, however, it is found that the contact in the English graft can be made so much more perfect than in the Champin graft that the actual contact is usually greater in the former than in the latter. Moreover, the strip of bark on the long tongue of the Champin graft is more likely to become detached or injured than the well-supported bark on the English graft; and finally, the exposed cut at the end of the scion is almost sure to emit strong roots, while that on the stock prevents the complete and thorough union which is possible with the English graft. The tongue, therefore, should be reduced to the mini- mum, that is to say should be as short as possible, while giving solidity to the graft until union takes place. For purposes of comparison, parallel experiments were made with both methods. Another method, new and not thoroughly tested as yet, was tried with a few Rupestris St. George cuttings, Mondeuse being used for scions. This method originated in France, and is called "End-to-End" grafting. Its nature is shown in Fig. II. The ends of stock are cut at an angle of about 70° and are held together by a piece of galvanized iron wire which is pushed into the pith of each piece. The number of successful grafts was low, but those which did unite made such excellent unions that the method seems worthy of further trial. It is especially promising for machine grafting. Binding Grafts. — Raffia, treated as explained on page 11, was used for binding the grafts. The raffia seemed to have dete- riorated somewhat during the twelve months it had been allowed to hang in an open shed. It was weaker than usual and some of it rather brittle. It was cut into lengths of about 12 inches. It has been shown that the grafts would do better without any binding but for two reasons: first, because it is difficult to handle unbound grafts without disturbing the union; and, second, because the callus does not form simultaneously on all parts of the union and the first formed tends to push apart the stock and scion, thus making it difficult or impossible for all parts to unite. The object, then, in binding is to use as little — 15 — raffia as is compatible with the thorough firmness of the union. The free ends of both scion and stock should be made firm with about two turns of the raffia, and the rest with wide spiral turns which leave as much of the union in direct contact with the sand as possible. The sand, while keeping the union suf- ficiently moist, does not completely exclude the air, which is necessary to the formation of healing tissue. A somewhat closer tying than this was adopted in these experiments, on account of the weakness of the raffia used. The grafts were tied in bundles of ten and then treated in various ways to aid their uniting. Methods of Aiding Callusing. — The main reason for callusing the grafts before they are put in the nursery is that we can have more perfect control of the conditions which favor the formation of callus. Those conditions are an even and not too low temperature and a moisture content of the soil in which the grafts are callused, not exceeding ten per cent and not falling below five per cent. Two methods of obtaining those conditions were tried: 1. Callusing in Sand. — The sand used was taken from Napa. Creek and was very suitable for the purpose. The grafts were put in the sand nearly vertically in bundles of ten, in rows.. The sand was moistened sufficiently to give it the compactness necessary for making the piles. The location of the sand pile was chosen on the south side of a building, which protected the sand from the north winds and rendered it possible to give the grafts the maximum amount of sun. A layer of about four inches of sand was put on the bottom and then the grafts were put in vertically and covered up as soon as they came from the grafting bench. The tops of the grafts were covered with a thin layer of sand (about two inches). The whole pile of sand with the grafts was then covered with a waterproof cloth, in order to protect the grafts from excessive moisture and to maintain the even temperature of the sand during coJd weather and at night. This cover was easily removable in order to facilitate watering if necessary, and to make it possi- ble to warm the pile on sunny days. This arrangement, somewhat improved, is shown in Fig. III. The grafts were put in the sand from March 7th to March < 18th, the time of grafting. — 16 — 2. Callusing in Straw or Moss. — To test this method, 360 grafts were placed in straw, moss not being obtainable at the time. Moss is considered somewhat better, on account of its superior hygroscopic power. The method of layering the grafts in straw was as follows : A large box without cover was laid on its side; a layer of about two inches of chopped straw was placed on the lower side and then a single layer of grafts. This was repeated until the box was full. The grafts were so placed that the scion was nearest the bottom of the box, which was then turned upright and still more straw pushed in between the layers of grafts until they were tightly packed. The box was then placed in the sand pile, two inches of straw Fig. III. Callusing Bed. placed on top, and the whole covered with sand, one inch of sand being placed over the top layer of straw. The straw was moistened before being used for layering the grafts. All the grafts were left for from six to eight weeks to callus, and then planted out in the nursery during the first week in May. Planting Grafts in the Nursery. Planting Immediately After Grafting: — There is no doubt about the disadvantage of planting freshly grafted vine-cuttings out. in the open nursery, as we have there no practical means of sufficiently controlling temperature and moisture. But in order to have definite data in regard to this method in com- -17 — parison with a preliminary callusing with more or less perfect control of temperature and moisture, the following experiment was tried: Three hundred and sixty grafted cuttings were planted out in the nursery directly after they were grafted. The soil of the nursery was in good condition. In planting, a trench was dug about 18 inches deep and 15 inches wide. The bottom of the trench was then filled in for a few inches with well- pulverized top soil, in order to facilitate the penetration of the roots. The grafts were placed 4 inches apart nearly vertically, in two rows (one on each side of the trench), sand being pre- viously placed on each side in order that the bases of the stock should be in favorable condition for root formation and growth. The trench was then completely filled by putting in soil and sand alternately in such a manner as to surround the grafts completely with sand. The point of union of scion and stock was placed at a level with the surface of the soil and was also carefully surrounded with sand. Sand was then heaped com- Fig. IV. Method of Planting in Nursery. pletely over the scions and the rest filled in with soil, thus making a bank which covered the grafts to a depth of about two inches; as shown in Fig. IV. The reason for completely covering with sand was to prevent the scions from being dried out by the wind. Planting the Grafts After Previous Callusing. — The grafts were planted in the nursery after they had been from six to eight weeks in the callusing bed. When the grafts were taken out of the callusing pile it was noticed that the unions of those which had been buried on the south side were much more complete than those buried on the north side, showing the effect of heat in promoting the forma- tion of healing tissue. In the warmer parts of the pile the 2v — 18 — buds of the scions had started — a disadvantage which was, however, more than counterbalanced by the good callusing, as was proved by their subsequent better growth. The only other difference noted was that the Riparia stock had developed more rootlets than the Rupestris at this time. The grafts were planted out in the nursery in trenches about 18 inches deep and 14 to 15 inches wide, as already described. The grafts were planted in a manner similar to that described on page 17, with a few modifications which were found to be necessary. The grafts first planted were put in the soil so as to bring the unions just level with the soil surface. But the loose soil soon settled about two inches so that the unions became actually deeper. The grafts planted later were placed with the unions about two inches above the surface to offset this settling. Moreover, some further precautionary measures had to be taken to prevent the soil from drying-out too much near the grafts. It was found best to make the bank of piled- up earth wider by putting more soil at the sides so as to pre- serve the moisture of the soil. The soil was moist enough when the grafts were planted, but the sand had to be moistened before putting into the trenches. A thorough plowing and harrowing were given the hard soil between the rows in order to prevent excessive evaporation. The nursery received but little care after the grafts had been planted. The soil received the same cultivation as that of the neighboring vineyard, was weeded once, and the grafts were irrigated in July. Removal of Scion-Roots and Suckers from the Stock. — About the middle of July the earth was carefully removed by means of a shovel and then the sand was taken away from the unions, partly by means of a trowel, partly with the hands, as circum- stances required. The smallest rootlets were still soft and could be rubbed off by the hand; the older and firmer roots had to be cut with a sharp knife. Great care was taken not to disturb the unions of the grafts, as they were still very brittle. Few suckers were found, as the eyes of the stock had been carefully cut out before grafting. In cases where the suckers came from the deepest eye it was found necessary to dig down to the base of the whole graft in order to cut the shoot at its — 19 — base as well as to properly remove the dormant eyes. The removal of roots was done without injury to the grafts, as they were covered up before they had a chance to dry out and the soil was irrigated immediately after; so that the grafts looked as fresh as ever the next morning. The soil was found dry to a depth of from 5 to 6 inches, but the soil below this had preserved sufficient moisture to keep the unions of the grafts from drying, as they were all in the moist region. The sand on the surface became very much heated in the middle of the day, which may account for the many tender young shoots and leaves which were found dry and withered. The second eye at the base of the scion had in most of these cases developed new shoots, so that the injury done was only in retarding the vegetation of the burnt plants. A thorough irrigation was found necessary at this time in order to prevent injury from the drought and heat of summer. The water was run in little ditches about one foot from the grafts and so applied that the soil around the unions was never thoroughly water-soaked, which experience has shown to be deleterious to the graft. The soil was cultivated as soon as dry enough after irrigation. The raffia in many cases was rotten already. Condition When Scions and Suckers Were Cut. — The following observations were made during July 14th to 18th, when the roots of the scions and the suckers were cut: English grafts with scions of two eyes; 180 Zinfandel on Rupestris St. George. Almost all the grafts had started to grow; about 50% of the grafts showed roots on the scions; 162 grafts had started, that is 90%. English grafts with scions of one eye; 180 Zinfandel on Rupestris 'St. George. A lower percentage than of the above had developed shoots (78%); but the roots on the scions were less developed and fewer in number. Champin grafts with scions of two eyes: 180 Zinfandel on Rupestris St. George. The scions had well-developed shoots, but also a good many strong roots on the bases of the scions. Of the 180 grafts, 165 were growing, that is about 92%. Champin grafts with scions of one eye; 180 Zinfandel on Rupestris St. George. This lot was better developed than that with two eyes left on the scions; less strong roots were — 20 — found on the scions, but only 150 were growing, that is about 83%. Champin grafts with scions of one eye; 180 Zinfandel on Rupestris St. George; planted out immediately after grafting. The unions of the grafts that were growing seemed to have joined very well; the soil near to the scions was dry, so that but few roots had developed; the 75 grafts growing made but a low percentage of the whole, about 42%. Champin grafts with scions of two eyes; 180 Zinfandel on Rupestris St. George; planted out immediately after grafting. The grafts were in about the same condition, but showed a higher percentage of growing grafts; of the 180 grafts, 98 were growing, that is about 54%. Champin grafts with scions of one eye; 180 Zinfandel on Rupestris St. George; grafts callused in the straw. The scions showed small and few roots,- and the number of growing grafts was 154, that is about 85%. Champin grafts with scions of two eyes; 180 Zinfandel on Rupestris St. George; grafts callused in the straw. The grafts of this and the foregoing experiment (callusing in straw) looked the best of all the grafts made, and had very well-devel- oped shoots, with an average length of 10 inches; the proportion of growing grafts was 90%. America grafted with Zinfandel; English graft with scions of two eyes on one-year-old rooted stock. The grafts showed good growth; six grafts of the ten had started, that is 60%. Munson grafted with Zinfandel; one-year-old rooted stock, scions of two eyes, English graft. The grafts showed good growth; a few only showed small rootlets on the scions;, eleven, or 85%, were growing. Champini grafted with Zinfandel; one-year-old rooted stock, scions of two eyes, English graft. The scions did not take in most cases, the proportion being about 30%. Elvicand grafted with Zinfandel; one-year-old rooted stock, scions of two eyes, English graft. The grafts showed very poor growth, and only about 29% growing at all. Mondeuse on Rupestris St. George; Champin graft, scions of tw r o eyes. The shoots were found to be short, about 5 or 6 inches long. Only a few rootlets were found on the scions, and many of them were already dead. The proportion of growing - 21 — grafts was about 63%. Altogether the Mondeuse were growing less vigorously on Rupestris St. George than the Zinfandel. Lenoir grafted with Zinfandel; English graft, scions of two eyes. Many of the grafts did not grow, they were found dry and dead; the few growing were backward in development; the nourishment came apparently from the reserve food in the cuttings, as there were few or no roots on the stock. Only 28% were growing. American Rul'ander grafted with Zinfandel; English graft, scions of two eyes. Neither scions nor stock had developed roots; a few were growing somewhat by means of reserve food; in all 19%. Herbemont grafted with Zinfandel; English graft, scions of two eyes. A few started to grow (about 24%), but no roots were found on the scions or the stock. Cunningham grafted with Zinfandel; English graft, scions of two eyes. No roots had formed on the scions. The growth was small, and only 26% showed any. Riparia Gloire de Montpellier grafted with Zinfandel; Cham- pin graft, scions with two eyes. The green shoots were 5 to 6 inches long, some even smaller (that is, shorter) than those on Rupestris St. George. But few rootlets were found on the scions. The proportion of growing grafts was 58%. Tokay on Rupestris St. George; Champin graft, scions of two eyes. The grafts were very well developed, showing abundant foliage. Not many roots were found on the scions, and 87% were growing. Ferrara on Rupestris St. George; Champin graft, scions of two eyes. The grafts showed very good growth; but many roots were found on the scions and most of them were already well developed. The proportion growing was 96%, which is higher than in any of the other experiments. Condition When Raffia Was Cut. — The following observations were made from the 28th to the 30th of August, when the raffia was cut: In the case of many of the grafts the raffia should have been cut earlier (two to three weeks), the raffia having prevented the proper development of the covered unions. In all those cases where the raffia had prevented the proper enlargement of the union, though the parts below and above the raffia showed — 22 — good development, the scions had developed strong roots. These roots favored in some cases an unusually heavy growth of the green parts, often as much as two to three feet. In these extreme cases when the raffia w T as cut and the roots of the scions removed, the thin, undeveloped union was unable to support the heavy top and broke off at a touch of the spade or a puff of wind. In the first row worked there was a loss of about 3% from this cause. It was found before the other rows were touched, however, that this loss could be avoided by a heavy pruning-back of the green shoots. This not only les- sened the weight of the top, thus preventing breaking, but diminished the evaporating surface of leaves, which was too great for the roots of the stock after those of the scion had been removed. The raffia on many grafts (about 20%) was quite rotten, and cutting was not needed; very good unions could be observed in all these cases. In other cases the raffia did not show any sign of decaying and was strong enough to prevent the devel- opment of good unions, and was therefore cut. The raffia of the grafts which were planted out immediately after grafting was, contrary to all expectations, still strong, apparently be- cause nearer to the surface and therefore drier. Undoubtedly the raffia should have been cut at least one month earlier on these. Condition When Grafts Were Removed from Nursery. — The following observations were made from the 26th to the 30th of December, when the grafts were taken out of the nursery: English grafts with scions of two eyes; 180 Zinfandel on Rupestris St. George. Most of the unions were very well joined. The average length of the shoots was from 1 to 2-$ feet; the wood was mature. The roots were well developed and grew mostly straight down to a depth of 3 feet, the fine rootlets even deeper, 4 or 5 feet; 83 grafts had made good unions, that is 46%; 11 grafts showed imperfect unions. English grafts with scions of one eye; 180 Zinfandel on Rupestris St. George. The difference in the development of the grafts with two eyes and with one on the scion was very slightly in favor of the first, and the shoots as well as the roots of the successful grafts looked nearly alike; 51 grafts had developed fine unions, that is 28%; 12 grafts made imperfect — 23 — unions. This experiment shows clearly the advantage of using scions of two eyes for grafting, as 20% of grafts were lost by using scions with only one eye. Champin grafts with scions of two eyes; 180 Zinfandel on Rupestris St. George. The unions with this method of graft- ing did not develop so well as those of the English graft, and though the number of passable unions was 116, they were not of so perfect a character as those of the first experiment, and the number of imperfect unions was greater; the growth of the shoots was short when compared with the parallel experiment with English grafting. The root-system of the stock was well developed, the main roots always going down, with the smaller rootlets mostly horizontal. The main roots had an average length of 3 to 4 feet, the shoots a length of about 2 feet. There w r as 64% of good unions. Champin grafts with scions of one eye; 180 Zinfandel on Rupestris St. George. The unions in this experiment were somewhat inferior to those of the last. A good many roots had formed; all were of smaller diameter than those mentioned above, but, like them, going straight down with an average length of 3 feet. The roots were, as a whole, less developed than those of the foregoing experiment. The quality of the unions in this case was decidedly inferior to the parallel experiment with English grafts; 58% of the grafts made suf- ficiently good unions. Champin grafts with scions of two eyes and one eye, as in the last two experiments, but planted out immediately after grafting without previous callusing in sand; 360 Zinfandel on Rupestris St. George. The unions of the grafts in this experi- ment were of medium quality, and an especially high amount of second-class grafts were noticed in the lot of 180 grafts with two eyes. The grafts with scions of one eye did, in this experi- ment, comparatively better than in other parallel experiments, as there was less difference in the percentage of unions; 28% of the grafts with two eyes left on the scions had made good unions, and 24% of the grafts with one eye, while in the first case there were found 17% of grafts with imperfect unions and in the other only 9%. Champin grafts with scions of two eyes and one eye, as in last two experiments, but callused in straw; 360 Zinfandel on Rupestris St. George. The unions of the grafts in this experi- — 24 — merit were in every respect inferior to those of the grafts cal- lused in sand, though the shoots were well developed (average length, 2 feet) and the roots proportionately. There was very little difference in the general appearance of the grafts with two-eye scions and of those with one-eye scions. The per- centage of grown and well-developed grafts of the two kinds was also close together: 88 grafts grew of the first kind with two eyes, that is at the rate of 49%; and 76 grew of the second kind, that is 43%. The second class grafts with imperfect unions grew at the rate of 17% and 8% respectively. America grafted with Zinfandel; 10 one-year-old roots, scions of two eyes, English graft. Only three grafts had started, and showed imperfect unions and poorly developed shoots. Munson grafted with Zinfandel; 13 one-year-old roots, scions of two eyes, English graft; 9 of the 13 grafts grew, that is 69%. The unions were mostly good and strong. The grafts showed a strong root-system, but the shoots did not show a propor- tionate growth. Champini grafted with Zinfandel; 10 one-year-old roots, scions of two eyes, English graft. Only a few showed growth, and the unions were very imperfect. Elvicand grafted with Zinfandel; 7 one-year-old roots, scions of two eyes, English graft. None had made a good union. Mondeuse on Rupestris St. George; 910 Champin grafts scions of two eyes. The unions of this kind formed better than those of Zinfandel on Rupestris St. George; most of them were well formed and strong. The shoots were well developed and the roots more numerous than those of the grafts of Zinfandel on Rupestris St. George with the same kind of treatment. The water-level at the time of digging was at a depth of 3 feet, so that the roots could only be followed to a depth of about 4 feet, but they undoubtedly went deeper. It was also observed here that the roots of the Rupestris St. George penetrated the soil vertically through alternating layers of compact soil and layers of coarse but fertile sandy soil without the slightest deviation, and sent out an equal growth of secondary rootlets into all layers, except that most of the finer rootlets and roothairs were formed on the lower parts of the main-roots, three and mpre feet deep; 452 grafts made first-class unions, that is a total of 54%. Moreover, about 10% made unions that were more or less imperfect. — 25 — Lenoir grafted with Zinfandel; 96 English grafts, scions of two eyes. Most of 'the grafts had formed no roots and only three had started growth, one of which was a strong, good graft with long, thick roots. American Rulander grafted with Zinfandel; 26 English grafts, scions of two eyes. The grafts were all dead. Herbemont grafted with Zinfandel; 21 English grafts, scions of two eyes. The grafts w T ere all dead. Cunningham grafted with Zinfande]; 27 English grafts, scions of two eyes. Two grafts showed good unions. They had a well-developed root-system with thick roots, which grew horizontally at first and then straight down. Only 7% grew in all. Riparia Gloire de Montpellier grafted with Zinfandel; 100 Champin grafts, scions of two eyes. The unions were not of very good quality. The shoots were short and thin and altogether of scanty growth. The roots were mostly thin and branching, but often very long; most of the main roots did not penetrate the soil, but grew more or less horizontally and scarcely deeper than 1^ feet below the surface. It was noticeable that the roots of the Riparia Gloire de Montpellier followed the softer layers and streaks in the soil and lacked the penetrating power of the Rupestris St. George. Only 15% of the grafts had made good unions, and 12% of them showed imperfect unions. Tokay on Rupestris St. George; 100 Champin grafts, scions of two eyes. The unions were nearly all good and strong. The average length of the shoots was 3 feet. The grafts showed a finely developed root-system with strong penetrating roots, which went directly down into the subsoil. The percentage of well-developed grafts was 60, which is better than the Zin- fandel and Mondeuse with the same kind of treatment. There were found only 6% of imperfect grafts. Ferrara on Rupestris St. George; 100 Champin grafts, scions of two eyes. The unions of this lot were nearly always found to be well formed, and they were really the best^unions in the whole plot. All the shoots were more than 2 feet long, many 3 feet, and a few even 4 feet. The root-system showed the same fine development and was fully proportionate to the upper development of the grafts; 75% of the grafts made perfect unions, and 9% made imperfect unions. — 26 — Tabular Review of Grafting Experiments. Proportion of Unions. Nature of Experiment. 1st 2d Remarks. Class. Class. Champin grafts.... 44% 11% English cleft grafts.. 37 6 Unions very complete. Scions with two eyes 46 13 Scions with one eye 38 7 Grafts callused in sand 61 7 Grafts callused in straw 46 12 Unions weak. Grafts not callused 26 13 Growth rather short. Zinfandel on Rupestris St. George 64 11 Good growth. Mondeuse on Rupestris St. George 54 10 Good growth. Ferrara on Rupestris St. George 75 9 Very strong growth. Tokay on Rupestris St, George 60 6 Strong growth. Rupestris St. George as stock _. 64 11 Riparia Gloire de Montpellier as stock 15 12 Small growth. Herbemont Lenoir . 1 2 Cunningham.. 7 4 American Rulander Munson, rooted vines 69 Good growth. America, rooted vines 30 Champini, rooted vines Elvicand. rooted vines The figures in the above table must not be taken as repre- senting the exact relative values of the various methods and varieties compared, but taken in connection with the following remarks they may be considered as valuable indications: A word of explanation is perhaps necessary with regard to certain figures. The 44% of successful grafts given as the aver- age for Champin grafts and the 37% for the English cleft grafts are somewhat low, on account of the fact that they include various experiments, some of which were comparative failures and made only for the sake of comparison and not to attain the maximum number of good grafts. The proportion of successful Champin grafts, as shown by the table, is slightly greater than that of the English cleft. The successful English cleft grafts, however, were considerably superior to the other in the matter of completeness and strength of the union. The lower percentage is probably due to the fact that the English cleft grafts were placed in the northerly end of the callusing sand heap, where the temperature was too low. (See page 15.) The experiments with two-eye and one-eye scions on the whole were in favor of the use of two eyes. The additional Fig. V. Vine on left: An average graft of Zinfandel on Rupestris St. George. Vine on right: An average graft of Flame Tokay on Rupestris St. George. — 28 — chance of success given by two eyes when the first eye is in- jured by frost or other cause no doubt accounts for the higher percentage of success in this case. In the case of the grafts planted out immediately after grafting, the one-eye scions made on the whole the strongest growth. This seems, however, to be due to the fact that the upper eye of the two-eye scions started and broke through the sand early enough to be killed by the spring frosts, while the one-eye scions, being more deeply buried, were later in emerging and escaped the frost. This gave the latter an earlier start and therefore a longer period of growth, for there was a check of growth and an interval of waste time in the former case between the killing of the upper bud and the starting of the lower. The remedy here, therefore, if this expla- nation be true, is a deeper layer of sand over the scions, and not the use of only one eye. The difference between previously callusing the gfafts in sand and planting them directly in the nursery as soon as made is very striking. Those previously callused produced 61% of good unions, while the others produced but 26%. There was also a difference in the growth of the grafts in favor of those callused in sand. The grafts callused in straw were a disappointment, for, though when planted out they seemed to have callused more successfully than those in sand, they produced only 46% of sufficiently good unions, and these were weaker than those of the grafts callused in sand. The cause of this was probably the growth of molds and wood-rot fungi around and in the unions while they were in the straw. The influence of scions of different varieties on the growth of the grafts is well shown by the four varieties tested: The Mondeuse, though quite satisfactory, gave a smaller percentage of successful grafts than any of the others. They started later than the Zinfandel, and though the growth and root-system were somewhat stronger, the wood was not quite so well matured. The Zinfandel did very well, giving 64% of good grafts and making good growth. The black Ferrara, however, made almost phenomenal growth and yielded 75% of first-class unions. The growth of the Tokay was almost equal to that of the Ferrara, but the number of successful grafts rather less, 60%. Fig. V shows an average Zinfandel graft upon Rupestris St. George in comparison with an average Tokay upon the — 29 — same stock. It will be noticed that the larger growth of top is accompanied by a corresponding development of the root-system. This dispels the doubt that our very heavy- growing varieties, especially table and shipping grapes, would succeed upon resistant vines, at least as regards Rupestris St. George. The greater adaptability of Rupestris St. George for bench- grafting than of Riparia Gloire de Montpellier is well shown in these experiments. Where the Rupestris St. George gave 64% of first-class grafts the Riparia Gloire de Montpellier gave only 15%. This is due, in great measure, to the difference in texture in the wood of the two species. The Rupestris has thick, firm wood with short joints and small pith, while the wood of the Riparia is softer, more pithy, and longer jointed. In con- sequence of this difference it is much easier to make a well- fitting, firm union with the Rupestris than with the Riparia. It would appear from this experiment that grafting in the vineyard when the Riparia is two or three years old would be the best method for varieties of this species. Of the other stock tested, including Lenoir, it is plain, with the possible exception of Munson, that they are unadapted to this method of grafting. This is to a great extent due to the difficulty of making roots with many of these varieties and their consequent failure to properly feed the scion. The Munson not only gave a high percentage of first-class grafts, but the unions were particularly good. As this variety's resistance to phyl- loxera has not been thoroughly tested, however, this success in grafting must not be construed as a proof of its utility as a resistant stock. The effect of failing to cut the raffia or other binding material early enough in the season is well shown by the middle graft of Fig. VI. The graft, as can be seen, had made a perfect union, but the raffia had been imperfectly removed, one or two turns having been left uncut. This is of course an unusual case, as when the raffia is cut in one place it is usually loosened com- pletely. The same thing occurs, however, when the raffia is not cut at all, except that the constricted part is longer, as is the case with the two outer-vines. The swelling of the vine above the constriction is due to the difficulty which the food, elaborated by the leaves, finds in passing the part where the — 30 — bark is compressed by the raffia. The large swellings on the two outer vines below the raffia are due to another cause. They are doubtless indicative of disease, and resemble very closely the black-knot which attacks older vines, especially in wet soils. The nature of this disease is not well understood, but as it usually accompanies an excess of water in the soil, it was doubtless due in this case to heavy rains in late spring after the grafts were planted. The accumulation of food material above a constriction of the bark and the consequent starvation of the lower part and Fig- VI. Effect of Black-Knot and of Failure to Cut the Raffia. root-system are similar to what occurs when a vine is girdled. Fig. VII shows an excellent example of this. The vine repre- sented is a Rupestris St. George in the spring after the year it was planted. The first year it made an excellent growth, as evidenced by the roots on the lower part. In the spring of the following year, however, the growth, though at first vigorous, soon stopped and the leaves became yellow. On digging up the vine it presented the appearance shown in the figure. The upper part of the vine had grown to twice the thickness of the previous year down to a point about 4 or 5 inches below the — 31 — <• surface. Below this point there was no growth at all, and although the roots were still alive they were no larger than the year before. A closer examination revealed the fact that at the point where the change took place the vine had been completely girdled by wire- worms, which had eaten off the bark for about half an inch. It is unusual for wire-worms to attack such plants as the vine, but the explanation was quickly found. The land in which these Rupestris St. George cuttings were planted had been in grass and hay for several years before, and the roots of grasses being a favorite food of wire-worms, they had increased to large numbers. In the spring of the year in which the vines were attacked the land was so thoroughly and carefully cultivated that not a weed was left for the many wire-worms still left in the ground. For this reason they were obliged to attack the only living vegetable sub- stance present. Vines injured as badly as that in the figure died, but the rest were saved by simply digging around each vine and destroying the wire- worms which were congregated near each vine at about the same distance from the surface. The effect of neglecting to cut the roots which are sent out by the scions is shown in Fig. VIII. In the vines shown there, the union was good and the top vigorous, but owing to the fact that the roots of the scion were allowed to grow, the stock failed to develop. The descending food, Avhich is necessary to the growth of the roots, FlG,VIL Effect of Wire-Worms on Young Vine. Fig. VIII. Effect of Failing to Cut Off the Roots of the Scion. — 33 — entered the roots of the scion more easily than it could traverse the irregular and abnormal tissue of the union. Thus there was left a vinifera on its own roots with the resistant stock starved and killed. Comparative Experiments in Rooting Cuttings of Resistant Stocks. Rupestris St. George. — 580 cuttings were planted out in the nursery on April 18, 1899. Most of those cuttings were the thin tips which could not be grafted on account of their small diameter. No attention beyond the plowing and cultivation given to the vineyard was given them during the growing period, except that they received one irrigation and one hoeing in June. The roots were nine months old when taken from the nursery. The average length of growth of the shoots was 2 feet, usually several were formed on a single plant. The root- system was well developed, and from four to six main roots could be counted in most cases on one vine. All the roots were long, strong, and tough, and grew to a depth of 3 to 5 feet; 480 cuttings had made good rooted vines, that is 83% of the cuttings planted. Riparia Gloire de Montpellier. — 40 cuttings were planted and received the same care as the cuttings of the Rupestris St. George. The vines showed scanty growth when taken out of the soil. The average length of the shoots was from 1 to 2 feet, but only a few developed on each vine. The root-system was entirely different from that of the Rupestris St. George. Very few of the main roots went down to the moist regions of the soil; most of the main roots were superficial, growing about one foot below the surface and sending out many small root- lets. The roots were not strong, but rather brittle, and broke easily; 32 cuttings out of 40 were well rooted, that is 80%. Solonis. — 45 cuttings were planted in the spring and were treated like the preceding. The following observations were made on the vines when taken out in winter: The shoots were thin and of an average length of 2 feet. The roots were well developed and grew down to the moist depths, although not so straight as the roots of the Rupestris St. George. The small rootlets and roothairs were only formed at the end of roots, 3v — 34 — 3 to 4 feet deep in the soil. The main roots were thicker than those of Rupestris St. George and Riparia Gloire de Mont- pellier. The difference in character of the root-systems of Rupestris, Riparia, and Solonis is well shown by Fig. IX. These are average specimens of the vines rooted at the St. Helena plot in 1899. The tendency of the Riparia to send out horizontal, or even slightly rising roots, is illustrated. In extreme cases the roots were found to start toward the surface at an angle of about 45°, and after rising in this way for several inches to become horizontal. About two thirds of the roots took this horizontal direction, and the remainder went down at various angles, some being nearly vertical. The cause of the failure of the Riparia in the upper part of the Napa Valley is evidently to be found here. The heat and continued drought of summer penetrate to these horizontal roots, destroy the roothairs, and deprive the vine of water exactly at the time it is most needed. The more deeply pene- trating roots are too weak and too few to supply the amount of water needed by the evaporating leaf surface. This lack of adjustment of the supply of water to the demand is increased when the Riparia is grafted with strong-growing vinifera varieties. This is evidenced by the many grafted vines which die in their second or third year. The deeply penetrating roots of the Rupestris, shown in the figure, explain the resistance of this species to drought. All the roots in this young vine penetrated deeply into the soil in a direction more or less approaching the vertical. As the vine grows older, as we have found by the examination of three- year-old Rupestris St. George vines, secondary roots are sent out in a direction more approaching the horizontal. These utilize the upper layers of soil, but as they constitute but a small part of the whole root-system any injury to them is not severely felt by the vine. An injury to the lower roots, however, is more injurious to the Rupestris. This explains the unsuitableness of this species for badly drained soils, and for soils where the water-level is high for a long time in winter and spring, and especially for those irrigated districts where the water-level" rises during the growing period of spring and summer. The standing water — 36 — causes the roothairs on the main part of the root-system to decay, and, deprived thus of its only means of obtaining water, the Rupestris dies of drought as truly as does the Riparia when the main part of its rootlets and roothairs are destroyed by the heat and dryness of summer. The strong, sturdy growth of the Rupestris St. George, as compared with the comparatively slender growth of what seems to be the best of the Riparias, is also well shown by the figures. This makes the Rupestris St. George particularly valuable as a stock for our heavy-growing varieties of vinifera. This heavy growth of the grafts on Rupestris St. George has been found in France to have a tendency to make them bear poorly and "go to wood." This, however, may be considered a "good fault," as it is easily counteracted by more generous pruning, by leaving a larger number of buds, and thus, by diverting the whole vigor of the vine into a larger number of shoots, decreasing the vigor of each and increasing their fertility. Some grape-growers, especially in the south of France, report enormous crops on vines grafted on Rupestris St. George. Following are descriptions of the three varieties of resistant stock which at present give the most promise of being adapted to California. The leaves of the three varieties are shown on the title-page: Riparia Gloire de Montpellier. (Synonyms: Riparia Por- talis, Riparia Michel, Riparia Saporta.) This is one of the most vigorous of all the varieties of Riparia and is equaled only by the Riparia grande glabre and the Scribner Riparia. The stem or trunk is thick; canes spreading, long, with elon- gated internodes of medium thickness, slightly bent at the nodes (giving the canes a faint zigzag appearance), of a light nut color, smooth, rather shining, and a little pruinose near the eyes when the wood is well ripened; young shoots of a light purple; leaves large to very large, thick, elongated, somewhat bulging between the main nerves, dark green and shining on the upper surface, lighter green on the under side, with a few stiff hairs on the ribs; the petiolar sinus is open, U-shaped; the upper lobes are well marked by large, elongated teeth, the lower barely marked at all; the teeth are sharply pointed and in two series (see figure on title-page). The roots are slender and spreading like all varieties of Riparia (see Fig. IX). Resistance to phylloxera, 18. — 37 — Rupestris St. George. (Synonyms: Rupestris du Lot, Rupes- tris Phenomene, Rupestris Sijas, Rupestris Monticola, Rupestris St. Georges erige, Rupestris Lacastelle, Rupestris Colineau, Rupestris Reich, Rupestris Richter.) This variety is extremely vigorous and produces a very strong, thick stem; canes erect (the main laterals spreading), with short internodes and prom- inent nodes; leaves small, wider than long, with metallic sheen, undulating edges, and relatively thin, those of the laterals often very small and somewhat bronzed near the tips. In hot weather the leaves fold in two at the mid-rib, but less than most varieties of Rupestris. The roots are long and strong and not so slender as those of other varieties of Rupestris. Resistance to phylloxera, 16. Solonis. A vigorous, strong grower; canes spreading, with patches of whitish hairs, which become light brownish-gray in autumn; leaves of medium size, upper lobes marked by very long teeth, lower lobes lacking; teeth very long-acuminate, in two series; petiolar sinus widely open. The leaves are covered with white web-like hairs above when young, becoming almost glabrous when old, except on the ribs and petiole. Roots strong and intermediate in direction between those of Riparia and Rupestris (see Fig. IX). Resistance to phylloxera, 14. Summary. 1. Every grape-grower should insure against phylloxera by testing the most promising resistant vines on his own place and by learning the methods of bench-grafting. 2. It is unsafe to attempt operations on a large scale with cuttings imported from abroad, on account of the danger of injury to such cuttings on the journey. 3. A cutting-graft of suitable varieties makes as large and vigorous growth as a simple cutting, so that by the method of bench-grafting no time is lost in establishing a resistant vine- yard. 4. Resistant varieties which are difficult to root but easy to graft when old, such as Lenoir, should not be bench-grafted. 5. Care in callusing, planting, and treatment in nursery, and especially in keeping the grafts moist from the time the} 7 are made till they are in the callusing bed, will enable even an — 38 — inexperienced grafter to obtain at least 60% of good, grafted plants. 6. The bluestone should be washed off the outside of the raffia before tying, or it will injure the bark of the graft. 7. Callusing in sand insures more perfect unions and a larger percentage of successful grafts than planting directly in the nursery. 8. The moisture in the callusing bed should not be exces- sive, and the temperature should be relatively warm. 9. The growing grafts should be watched closely in order to see that the roots of the scions are removed before they become large, and that the raffia is cut before it strangles the graft. 10. The English cleft graft is preferable to the Champin graft, because it gives more perfect unions and can be made with more accuracy and rapidity. 11. Scions of two eyes are preferable to those of one eye, as they give more chances of success. 12. Rupestris St. George seems to be remarkably adapted to California soils (except the heaviest clays) and conditions, and is to be preferred to any variety yet tested here wherever deep penetration of roots is possible and desirable. 13. All the eyes of the Rupestris stock should be cut out deeply and carefully. 14. A vigorous and large-growing vinifera scion promotes an equally vigorous and large growth of Rupestris St. George used as stock.