UNIVERSITY OF CALIFORNIA COLLEGE OF AGRICULTURE AGRICULTURAL EXPERIMENT STATION CIRCULAR No. 229 November, 1921 CORDON PRUNING By FREDERIC T. BIOLETTI INTRODUCTION Nearly all systems of vine pruning can be placed in one of two groups : the head systems and the cordon systems. In the former all arms or short ramifications of the vine arise from the top of a com- paratively short vertical trunk, giving the vine the form of a small shrub. In the latter the arms are scattered uniformly along the greater part of a comparatively long trunk which in some forms gives the vine or the row of vines some resemblance to a stretched rope or ' ' cordon. ' ' Various forms of cordons are used, differing in the shape and direction of the elongated trunk. In the vertical cordon, the trunk is upright. This is an unsatis- factory form because it is impracticable to make the trunk more than about five feet long and it is difficult or impossible to maintain the arms along the trunk. The lower arms tend to weaken and finally die owing to the shade cast by the growth from the upper arms and to the tendency of the growth of the vine to go principally to the highest point. This is the only form of cordon that has been much used in California and is the commonest form of pruning adopted for the Emperor. All the old Emperor vines pruned in this way have lost the "cordon" character with all its advantages and have become simply high "headed" vines. In the bilateral horizontal cordon, the trunk rises vertically for 2 to 3 feet and then divides into two branches which spread hori- zontally in opposite directions for 3, 4, or more feet. The vertical part of the trunk is kept bare and the arms are distributed every 8 or 10 inches along the upper side of the branches. This system is 2 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION preferable to the last but is somewhat difficult to establish and to maintain in good condition and is inferior to the next in most cases. It is used in modified and incomplete forms in a few California vine- yards. In the unilateral horizontal cordon, the trunk rises in a quarter circle from the ground to a height of from 2 to 3 feet and then extends horizontally 6, 7, or 8 feet until it reaches the upper part of the bend of the next vine. The curved part of the trunk is kept bare and the arms are distributed every 8 or 10 inches along the upper side of the horizontal portion. This is the system most commonly used in Europe and it has been adopted lately by several growers in Califor- nia. It has given good results with Emperor and, in experiment vineyards, with several other varieties, including the Cornichon, Ohanez, Zabalkanski, and Malaga, and it is recommended in prefer- ence to either of the other two systems mentioned. This is the only system to be described here. It is used extensively in Algeria. It has been in use to a limited extent in California for over 30 years. Here, however, it has not been very satisfactory ; both because it has not usually been carried out very skillfully and because it has been used for varieties and in districts to which it is not suited. Uses. The cordon system is most suitable for vigorous varieties of table grapes growing in rich soil in the warmer districts. Some vigorous varieties will not bear well when reduced to the size and shape of a small shrub. They require extension in the direction of the natural form of the vine, which is a far extending, climbing plant. Most of our table grapes have large bunches and large berries which do not ripen or color well, nor evenly, when massed together as they are in most forms of ' ' head ' ' pruning. They are also difficult to harvest when in this condition without much rough handling, which spoils their bloom, breaks many berries and injures their appearance and keeping qualities. The difficulty is much decreased by the hori- zontal cordon system. Disadvantages. — The proper training of cordon vines requires more careful and skilled hand work during the second, third, and fourth year than most forms of head pruning. However, when the cordons are established, by the fifth year, the pruning is perhaps as simple as that of any system. If the system is not carried out skillfully and carefully with a full knowledge of the proper methods, the vines may get into a con- Circular 229] CORDON PRUNING 3 dition which is worse than is likely with other systems. However, there is nothing very difficult to understand or to do in properly establishing a cordon, but the grower must be sure he understands the method and be prepared to do all that it requires if he is to make it a success. — ESTABLISHMENT Plan of the vineyard. — As cordons should be used only with very vigorous varieties growing in rich soil, the vines should be given abundant room. A suitable spacing is 7 feet by 14 feet. The 14 feet between the rows facilitates cultivation, irrigation and the hauling out of the crop. The 7 feet between the vines gives trunks about 10 or 11 feet long of which 7 feet is horizontal and supplied with bearing arms. Each vine will have 98 square feet of soil which is about right for a large vigorous plant. Direction of the cordons. — In determining the direction of the cor- dons, the slope of the land, the prevailing winds and the effect of the sun should be considered. The most perfect conditions are where the cordons can be run towards the south and in the direction of the irrigation and of the prevailing winds. As all these conditions can- not often be made to coincide, the best compromise possible should be made. None of these conditions is absolutely necessary but all are desirable. In most cases in the great valleys a north-to-south direc- tion is the best compromise, but it may be necessary to run the rows from west to east if the irrigation water cannot be made to flow in the other direction. THE FIRST YEAR The first year, as with any system, the best and most rapid results are to be obtained only by thorough preparation of the soil and by the use of first-class planting stock, properly handled. No stakes are necessary and no summer pruning or disbudding of any kind should be practiced. Every effort should be used to stimulate a large growth by thorough cultivation and timely irrigation. The growth should be principally early in the season and should slacken in August and September. By October the canes should be brown and well ripened, all the leaves mature and dark green and there should be no light 4 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION yellowish-green growing tips. If the vines are making new growth late in October or in November the wood will not mature when the cold weather comes and may be killed by an autumn frost. The vines should make a growth of several canes of from 2 to 6 feet, the first year and a correspondingly large root system. (See Fig. IB.) Fig. 1. — A. Top of young rooting directly after planting. B. Young vine after the fall of leaves. An average growth during the first season, c o c. Places where cuts are made in the first winter pruning. C. Top of young vine after the first winter pruning. THE SECOND YEAR Winter pruning. — In December or January, after the fall of the leaves, the vines should be pruned. Pruning consists in removing every cane but one with a pair of sharp pruning shears, taking care to cut as close as is possible without cutting into^the main part of the vine. The cane left should be shortened to two buds (see Fig. 1(7) unless it is very large, in which case it is better left as long as it is thick (% an inch) and mature. (See Fig. 8b.) Trellising. — As soon as the vines are pruned, the trellis should be put up. An economical and efficient form of trellis is shown in figure 2. A post is first put in at each end of each row. If the row is more than 200 to 250 feet long an extra post will be needed in the middle. An ordinary split redwood fence post, 5" X 7" or 4" X 5" and 7 feet long, is best. It should be placed with exactly 44 inches above the ground. This is most easily and accurately done by means of a post-hole digger. The posts should be well lined up and firmly tamped. At the end of the row from which the cordons run, the post should be 3 inches away from the vine. At the other end the post should stand 10 feet beyond the last vine. To allow a proper turning Circular 229] CORDON PRUNING space, therefore, the vine at one end of the row should be 10 feet farther from the fence or limit of the vineyard than at the other. A No. 11 smooth galvanized iron fencing wire should then be stretched between the two posts at 30 inches from the ground, leaving a loop or double wire of about 4 or 5 feet at each end. Grape stakes are then driven close to every second vine on the side away from which the cordons are to run. Five-foot grape stakes are exactly the right length and should be driven 18 inches into the ground, leaving exactly 42 inches above. Six-foot stakes can be used and driven a little deeper. The wire is then stapled on these stakes at exactly 30 inches from the soil. The staples should not be driven in tight but left just loose enough to allow the wires to slip through when it is tightened. If the wire has been stretched properly, it will not require tightening until the next year. T I If, 10 E= r \r ■ WW %L —M. |p- — : ' r U G5 V Fig. 2. — Form of trellis suitable for a cordon vineyard. FP. Straining end posts. GS. Five-foot grape stakes at every second vine. P. Forty-inch redwood picket at the intermediate vines. Height of lower wire 30 inches, height of upper wire 42 inches. A redwood picket, 1" X 1" X 40", is then placed by each vine unprovided with a stake. This picket should be driven 6 or 7 inches into the ground, leaving 3 or 4 inches above the wire to which it is tied or stapled. Another wire of the same kind but of No. 13 gauge is then stretched at 12 inches above the first. This wire will be just 2 inches below the top of the end posts and, if 5-foot stakes have been used, on top of the stakes. If 6-foot stakes have been used the wire must be stapled to the side like the first wire. The putting up of this second wire can be deferred until the next year, but is best put up at this time, especially where the vines are making a very strong growth. It is very important for the regularity and appearance of the vineyard that this trellis should be put up straight and even, A UNIVERSITY OF CALIFORNIA EXPERIMENT STATION ,T> /» X so simple guide (Fig. 3) can be made that much simplifies the placing of the wires and the driving of the stakes to exactly the same height. This guide consists of a piece of 1" X 3" batten, 42 inches long, with a cross piece 15 inches long nailed across the bot- tom and a nail driven into one edge at 12 inches from the top. (The figure is incor- rect. The nail should be 30 inches from the bottom of the cross piece.) Disbudding and tying. — This important operation is often done improperly and too late. As soon as the young vines start to grow, they should be watched carefully and before any have shoots more than 4 inches long all shoots and swollen buds should be rubbed off except the longest and strongest one on each vine. No shoot longer than 4 inches will be removed and most of them will be less than 1 inch. It will be necessary to go over the vineyard about twice for this first disbud- ding. Tying to the picket. — The effect of this reduction of the shoots to one on each vine will be that the one left will grow rapidly. (N.B. — This result is obtained only if the buds and shoots removed are very small. If they are 6, 8, or 10 inches long when removed, their loss stunts the vine and the shoot left may make less growth than if no disbudding had been done.) In the course of a few weeks, the reserved shoot will have grown 12 to 15 inches and must then be tied loosely to the picket or stake. When this is done, all new shoots which have started should be removed. (Fig. 4B.) This is usually the last disbudding that is needed or advisable. If extra shoots start after this they should be left but, if large, should be limited in their growth by pinching off 1 inch of the growing tip. (Fig. 5c.) This will be sufficient to prevent their becoming unduly large and robbing the main shoot, and their leaves will feed and strengthen the vine. :Z. © e Fig. 3. — Guide for insuring correct height of wires. Circular 229] CORDON PRUNING In tying the growing shoots, the string should not be drawn tight. There should be space enough between the string and the shoot to insert a finger after tying. If this is neglected the canes will be girdled and all the work of this season wasted. The reserved shoots about this time — May to June — will commence to grow rapidly. About the time they reach the bottom wire they should be tied again higher up. (Fig. 4(7.) Ara%**rr~->r-t4 Fig. 4. — Growth of v shoots at c o ("disbudd superfluous shoots c. C. ne during the second summer. A. Removal of superfluous ng"). B. First tying and removal of second growth of Second tying. Tying to the lower wire. — When the reserved shoot has reached about two or three feet above the bottom wire, the upper string should be removed and the shoot bent in a gentle curve to the wire to which it is then attached by a loosely tied string. (Fig. 5t'.) As this shoot increases in length it must be tied again two or three times. (Fig. 5t".) By turning the shoot around the wire as it grows the tying will be simplified and less likely to give way. The shoot must not be twisted tightly around the wire or it will be difficult to remove later without injury. Not more than two turns should be given in its whole length. 8 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION Production of laterals. — If this shoot reaches the next vine by July 30 and is still growing vigorously it should be pinched ; that is, an inch of the growing tip should be removed. This will have the effect of stimulating an abundant growth of strong laterals. (Fig. 5?.) None of these laterals should be removed. They feed the main shoot, make it stout and if they grow large enough can be utilized the next year for the production of fruit and arms. Laterals which start from the shoot at any point between the ground and the place where the shoot becomes horizontal should be "tipped' when they are 12 to 15 inches long. (Fig. 5c, c.) If any of the laterals on the horizontal part grow long enough two or three of them should be tied to the top wire. (Fig. 51.) This will prevent the swaying and turning over of the main shoots in windy weather. None of the laterals on the horizontal part should be removed or tipped. Fig. 5. — Growth of vine during the secbnd summer (continued), t' t" '. Places and methods of tying the main shoot to the lower wire. I. Supporting lateral tied to the upper wire, c c. Low growing laterals tipped to diminish growth. All suckers from below ground and from the old wood of the previous year should be kept off. The smaller they are when removed, the less their removal will restrict the growth of the vine. Danger of late growth. — There is great danger in the second year of the vines growing too late. If they are. still growing strongly in late October they may be killed by an early frost. Even when frosts do not occur, the weather may become too cool for the shoots to ripen and harden and they may be injured by winter frosts or fail to grow in the spirng on account of a lack of reserve food. The canes should be hard and brown, the buds plump and firm, and the leaves com- mencing to turn yellow while the weather is still warm in October. By judicious management of the irrigation this can usually be brought about. Circular 229] CORDON PRUNING THE THIRD YEAR A well-grown vine at the end of the second growing season, after the leaves have fallen, will consist of a single cane extending from the ground in a gentle curve to the upper wire, then horizontally along this wire to the next vine and then on for several feet. This cane will usually be supplied with several or many laterals of various sizes and lengths. Winter pruning. — Such a vine is pruned by cutting off the end of the cane at the point where it reaches the top of the curve of the next vine. (See fig. 8a.) Where the cane is cut it should be at least Ys of an inch thick, firm, well ripened and supplied with large, firm, well developed buds. Canes which do not meet these specifications must be cut back shorter. It is better to cut them back too much than not enough. Thus, on some vines the cane after pruning will extend the complete length of the cordon, some will extend %, %, or % of the way and some it may be necessary to cut back to or below the bend. In any case, nothing should be left but vigorous healthy, well-grown wood. The cane should be cut so as to leave the swelling at the end of the first joint but not the bud. This is for convenience of tying. (Fig. 6.) 'h Fig. 6. — Method of tying cane to lower wire. a. End of cane pruned so as to remove the bud but to leave the enlargement, b. Firm tie between the enlargement and the last bud e. o. Loose tie in all places except the end of the cane. If the laterals are small they should be removed completely. If any are as large as a pencil or larger, one, two, or three of them should be left long enough to reach to the top wire. (Fig. 81.) Tying. — The vines are then ready to tie to the wire. If this is done properly much future trouble will be avoided. (See Figs. 6 arid 8.) The end of the cane is tied firmly to the wire by means of a clove hitch (Fig. 6b) or other secure knot. This tie should be placed between the swelling left at the end of the cane (Fig. 6a) and the end bud. (Fig. 6e.) No tie should be drawn tight below a bud. The cane should then be given the proper shape and direction by several ties between the end and the curve. (Fig. 8.) These ties should be loose enough to allow for the growth of the cane. (Fig. 6c.) If 10 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION there are any strong laterals one or two may be left long enough to reach to the top wire and tied firmly. (Fig. SI.) This will help to keep the cane in place and prevent its turning over as described later. All buds should be removed from these laterals. This is most easily done in the spring when they start. At that time they can be rubbed off with the hand. Fig. 7. — Growth of vine during the third summer, c c. Shoots on lower side of cane tipped to diminish growth, c'. Extra vigorous shoot on upper side of cane pinched to equalize its growth with that of the slower or less vigorous shoots. Summer treatment. — During the third growing season the cane that has been tied to the lower wire (Fig. 7) develops into a permanent trunk. On this trunk grow shoots which develop into canes from which the spurs of the next year and the permanent arms are formed. A considerable crop should be obtained this year. During this year there is great danger of spoiling the cordon unless the work is done properly. Each eye of the cane may grow and produce one or more shoots. Nearly every one of these shoots may bear one or two bunches of grapes. A strong cordon during the third year may produce more than 20 fruit-bearing shoots, and 30 to 40 flower clusters. If all these develop into bunches of grapes the vine will be incapable of properly nourishing them. They are likely to be small, poorly colored, late in ripening, and inferior in sugar and flavor. Moreover, the vine may be so weakened in the attempt to bear this large crop that it may be dwarfed for one or two years and the production of paying crops may be much delayed. To avoid this danger only as many bunches should be allowed to develop as the vine is capable of bringing to perfection and means should be used to encourage strong growth in the shoots which are to form the spurs and produce the crop of the following year. Circular 229] CORDON PRUNING 11 Another serious danger is that all shoots will be on the underside of the cordon. This will injure the bunches by bringing them into contact with the soil and they will be too much shaded to color well. A worse, because a more permanent defect, will be that all the new wood will be on the under side of the trunk at the next winter prun- ing. The upper side of the trunk will be bare and exposed to sun- burn and it will be impossible to develop strong upright arms on the top of the trunk where they ought to be. All these dangers may be avoided by proper attention to the vines during the third spring and summer. (See Fig. 7.) As the buds start and grow in spring, the vineyard should be gone over two or three times. All buds within 20 to 24 inches of the ground should be rubbed off before they have grown more than one or two inches. All other buds should be allowed to grow until they have formed shoots at least 8 to 10 inches long. At this time the shoots from which it is desired to develop arms should be chosen. All others should be "pinched,' that is, one inch of the growing tip removed with the thumb and finger. (See Fig. Iccc.) As a rule only shoots on the lower side of the cane should be pinched. This will tend to divert the growth into the canes on the upper side which it is desired to have grow strong. As the shoots grow long enough, two or three of the strongest on the upper side of the cane should be tied to the upper wire. (See Fig. 7.) This will insure their remaining in that position and they will serve for supports for the other shoots which will attach themselves to them by their tendrils. In this way the grapes will be kept off the ground and the growth will be on top where it is required for the winter pruning. This tying must be done early, before the shoots have commenced to bend over by their weight or by that of their grapes. After the grapes have set and grown to the size of small peas, it may be necessary to thin them. If there seem to be more bunches than the vine can bring to perfection some should be cut off. Where there are two bunches to a shoot the upper one may be removed. If a weak shoot is growing in a place where it is desired to develop an arm, the removal of the fruit will make it grow stronger. • More bunches should be left on large strong vines and spurs than on weak. 12 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION THE FOURTH YEAR Winter pruning. — At the end of the third growing season, all vines should have a well-established trunk. The largest trunks will be of the full length of 10 feet, reaching the next vine and resting on the upper part of its bend. Fig. 9.) Others will extend along the wire various distances. (Fig. 8b.) In cases where the trunk does not reach the next vine, a strong cane must be used to lengthen it. This cane should be as near the end of the trunk as possible but must be strong and well ripened. The part of the trunk beyond where this cane starts should be cut off. (Fig. 9p, o.) All canes below the upper part of the bend should be removed entirely. Of the other canes, enough of the strongest should be retained to form spurs about every 8 to 10 inches along the trunk. These canes should, wherever possible, be on the upper side of the trunk. All canes not needed for this purpose should be removed. (Fig. 9.) The canes which are retained, except two or three, should be cut back to spurs of 1, 2, 3, or 4 buds, according to their size and vigor. The two or three which are not cut back should be tied firmly to the upper wire (see Fig. 9s s) and these cut off just above the wire. These are to help support the trunk and to prevent its turning over with the weight of grapes in the summer and autumn. The extra upper buds on these supporting canes should be removed at the prun- ing or as soon as they start in the spring. Where spring frosts are feared all the spurs may be left long with 3 or 4 extra buds. These can be removed in spring after danger of frost is past. Their presence delays the starting of the lower fruit buds ten days or more. Summer treatment. — During the fourth growing season some care will be necessary to encourage strong growth on the spurs that have been left along the upper side of the horizontal trunk. All buds starting on the under side of the trunk should be rubbed off by hand before they have grown more than two or three inches. This will make it necessary to go over the vineyard two or three times during the spring. Any shoots from the upper side or the spurs which grow with extra vigor should be pinched when they are about 18 inches long to throw more strength into the less vigorous shoots. (Fig. 7c'.) Circular 229] CORDON PRUNING 13 14 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION Pruning the mature vines. — At the end of the fourth growing season the cordons should be complete and the vines in condition to yield a full crop the following year. The treatment from this time is simple for anyone who understands the ordinary head pruning. The spurs along the top of the trunk (Fig. 9) will produce fruit and canes for the next year's pruning. The canes, except one, from each spur, are cut off at the winter pruning and the one reserved cut back to a spur of one, two or three buds, as in ordinary spur pruning. In this way arms are gradually built up along the upper side of the trunk. These arms gradually increase in length but much more slowly than in vase-formed vines. An effect of the cordon system is to make the lower buds of the canes more fruitful so that the spurs can be cut shorter. A vigorous Emperor which requires spurs averaging 4 to 5 buds on a vase-formed vine bears equally well with spurs of 2 to 3 buds on a cordon. Some varieties which require 2 to 3 buds with ordinary methods will bear well if cut back to a single bud on a cordon. VARIETIES AND CONDITIONS SUITED TO CORDON PRUNING 1. The cordon method should be used only with vigorous varieties, growing in rich soil, abundantly supplied with water. 2. Emperor, Cornichon, Ohanez, Black Monukka, Zabalkanski have given better results with cordons in our experiments than with any other method of pruning. 3. Malaga, Golden Queen, Molinera, Askari, Paykani have given as good results with cordons as with any other method of pruning. 4. Any very vigorous variety of table grape with large bunches and berries will probably give good results with this system where the soil and water conditions are favorable. STATION PUBLICATIONS AVAILABLE FOR FREE DISTRIBUTION BULLETINS No. 185. 241. 246. 251. 253. 261. 262. 263. 266. 267. 268. 270. 271. 273. 275. 276. 278. 279. 280. 282. 283. 285. 286. 290. 294. 297. 298. 299. 300. 301. No. Report of Progress in Cereal Investiga- 302. tions. Vine Pruning in California, Part I. 304. Vine Pruning in California, Part II. Utilization of the Nitrogen and Organic 308. Matter in Septic and Imhoff Tank Sludges. Irrigation and Soil Conditions in the 309. Sierra Nevada Foothills, California. Melaxuma of the Walnut, "Juglans regia." 310. Citrus Diseases of Florida and Cuba 312. Compared with Those of California. 313. Size Grades for Ripe Olives. 316. A Spotting of Citrus Fruits Due to the 317. Action of Oil Liberated from the Rind. 318. Experiments with Stocks for Citrus. 320. Growing and Grafting Olive Seedlings. 321. A Comparison of Annual Cropping, Bi- 322. ennial Cropping, and Green Manures 323. on the Yield of Wheat. Feeding Dairy Calves in California. 324. Preliminary Report on Kearney Vineyard Experimental Drain. 325. The Cultivation of Belladonna in Cali- fornia. The Pomegranate. 326. Grain Sorghums. 328. Irrigation of Rice in California. 329. Irrigation of Alfalfa in the Sacramento 330. Valley. 331. Trials with California Silage Crops for 332. Dairy Cows. 333. The Olive Insects of California. The Milk Goat in California. Commercial Fertilizers. 334. The June Drop of Washington Navel Oranges. 335. Bean Culture in California. The Almond in California. 336. Seedless Raisin Grapes. The Use of Lumber on California Farms. 337. Commercial Fertilizers. 338. California State Dairy Cow Competition, 1916-1918. Control of Ground Squirrels by the Fumi- gation Method. A Study on the Effects of Freezes on Citrus in California. I. Fumigation with Liquid Hydrocyanio Acid. II. Physical and Chemical Pro- perties of Liquid Hydrocyanic Acid. I. The Carob in California. II. Nutritive Value of the Carob Bean. Plum Pollination. Mariout Barley. Pruning Young Deciduous Fruit Trees. The Kaki or Oriental Persimmon. Selections of Stocks in Citrus Propagation. The Effects of Alkali on Citrus Trees. Control of the Coyote in California. Commercial Production of Grape Syrup. The Evaporation of Grapes. Heavy vs. Light Grain Feeding for Dairy Cows. Storage of Perishable Fruit at Freezing Temperatures. Rice Irrigation Measurements and Ex- periments in Sacramento Valley, 1914- 1919. Brown Rot of Apricots. Prune Growing in California. A White Fir Volume Table. Dehydration of Fruits. Phylloxera-Resistant Stocks. Walnut Culture in California. Some Factors Affecting the Quality of Ripe Olives Sterilized at High Tem- peratures. Preliminary Volume Tables for Second- Growth Redwoods. Cocoanut Meal as a Feed for Dairy Cows and Other Livestock. The Preparation of Nicotine Dust as an Insecticide. Some Factors of Dehydrater Efficiency. Selection and Treatment of Waters for Soraying Purposes with Especial Ref- erence to Santa Clara Valley. CIRCULARS No. No. 70. Observations on the Status of Corn 155. Growing in California. ' 157. 76. Hot Room Callusing. 158. 82. The Common Ground Squirrels of Cali- 159. fornia. 160. 87. Alfalfa. 161. 110. Green Manuring in California. 164. 111. The Use of Lime and Gypsum on Cali- 165. fornia Soils. 113. Correspondence Courses in Agriculture. 166. 114. Increasing the Duty of Water. 167. 115. Grafting Vinifera Vineyards. 168. 126. Spraying for the Grape Leaf Hopper. 127. House Fumigation. 169. 128. Insecticide Formulas. 170 129. The Control of Citrus Insects. 130. Cabbage Growing in California. 172 135. Official Tests of Dairy Cows. 173. 138. The Silo in California Agriculture. 174. 139. The Generation of Hydrocyanic Acid Gas 175. in Fumigation by Portable Machines. 144. Oidium or Powdery Mildew of the Vine. 176. 148. "Lungworms." 151. Feeding and Management of Hogs. 177. 152. Some Observations on the Bulk Handling 178. of Grain in California. 179. 153. Announcement of the California State Dairy Cow Competition, 1916-18. 181. 154. Irrigation Practice in Growing Small 182. Fruits in California. Bovine Tuberculosis. Control of the Pear Scab. Home and Farm Canning. Agriculture in the Imperial Valley. Lettuce Growing in California. Potatoes in California. Small Fruit Culture in California. Fundamentals of Sugar Beet Culture under California Conditions. The County Farm Bureau. Feeding Stuffs of Minor Importance. Spraying for the Control of Wild Morning- Glory within the Fog Belt. The 1918 Grain Crop. Fertilizing California Soils for the 1918 Crop. Wheat Culture. The Construction of the Wood-Hoop Silo. Farm Drainage Methods. Progress Report on the Marketing and Distribution of Milk. Hog Cholera Prevention and the Serum Treatment. Grain Sorghums. The Packing of Apples in California. Factors of Importance in Producing Milk of Low Bacterial Count. Control of the California Ground Squirrel. Extending the Area of Irrigated Wheat in California for 1918. CIRCULARS — Continued No. 183. Infectious Abortion in Cows. 184. A Flock of Sheep on the Farm. 185. Beekeeping for the Fruit-grower and Small Rancher or Amateur. 188. Lambing Sheds. 189. Winter Forage Crops. 190. Agriculture Clubs in California. 191. Pruning the Seedless Grapes. 193. A Study of Farm Labor in California. 198. Syrup from Sweet Sorghum. 201. Helpful Hints to Hog Raisers. 202. County Organizations for Rural Fire Con- trol. 203. Peat as a Manure Substitute. 205. Blackleg. 206. Jack Cheese. 208. Summary of the Annual Reports of the Farm Advisors of California. 209. The Function of the Farm Bureau. 210. Suggestions to the Settler in California. 214. Seed Treatment for the Prevention of Cereal Smuts. No. 215. Feeding Dairy Cows in California. 217. Methods for Marketing Vegetables in California. 218. Advanced Registry Testing of Dairy Cows. 219. The Present Status of Alkali. 220. Unfermented Fruit Juices. 221. How California is Helping People Own Farms and Rural Homes. 222. Fundamental Principles of Co-operation in Agriculture 223 The Pear Thrips. 224. Control of the Brown Apricot Scale and the Italian Pear Scale on Deciduous Fruit Trees. 225. Propagation of Vines. 226. Protection of Vineyards from Phylloxera. 227. Plant Disease and Pest Control. 228. Vineyard Irrigation in Arid Climates. 229. Cowdon Priming. 230. Testing Milk, Cream, and Skim Milk for Butterfat. 231. The Home Vineyard.