& i Publication of The College of Agriculture UNIVERSITY OF CALIFORNIA SEED PRODUCTION OF |!i ,^R^f* d ' ''■ MILTON D. MILLER LUTHER G. JONES : * \ fi'l&fc: VICTOR P. OSTERLI A. D. REED 5oPR„ M ?« lm? Bw^. o« ■ * EXTENSION SERVICE CIRCULAR 182 SEED PRODUCTION Ladino clover has quickly attained nation-wide prominence as a pas- ture plant because of its excellent productivity, palatability, and un- expectedly wide adaptation qual- ities/There is an expanding market for certified Ladino clover seed. • . . Ladino seed produced to meet this expanding market should be certified. Consumers now insist on certified Ladino seed because the seals and tags on a bag of certified Ladino are insurance they are getting true Ladino — not the inferior, less-productive common white clover. For complete informa- tion on how to meet the requirements for growing California certified Ladino seed, consult your local Farm Advisor. This circular tells how to grow Ladino seed — emphasizes new cultural developments — touches on some of the eco- nomic factors affecting the future market for Ladino seed. The Authors: Milton D. Miller is Farm Advisor in Glenn County Luther G. Jones is Associate Specialist in the Experiment Station (Agronomy), Davis Victor P. Osterli is Extension Agronomist, Davis A. D. Reed is Extension Economist, Berkeley OP LADINO CLOVER HE scientific name of Ladino is Tri- jolium repens var. latum. It is believed to be a naturally developed large form of common white clover. Seed of Ladino was first brought to this country by the United States Depart- ment of Agriculture about 1900, from the Province of Lombardy, in northern Italy. There, this giant strain (Ladino) had apparently developed naturally from common white clover, in the area near Lodi, after which Ladino is named. The original California plantings of Ladino clover were made from seed ob- tained from Oregon, Idaho and Italian importations. As early as 1911, Idaho began commercial production of Ladino. Ladino is a rapidly growing, long- lived, true clover, spreading by creeping stems called stolons. These stems elongate rapidly and take root at the joints if the soil is kept moist. Thus, sparse stands usually thicken up by the end of the first growing season. Leaves, stems, and flower heads of La- dino clover generally are from two to four times as large as common white clover. In shape, color and markings, the leaves and flower heads look like common white clover. The plants are usually shallow rooted and have the bulk of their roots in the surface 18 to 24 inches of soil. For this reason Ladino clover does well in soil considered too shallow for deep-rooted crops like alfalfa, sugar beets, or tree crops. On deep, open soils Ladino may root down to four or five feet. This Ladino clover stem shows the characteristic growth pattern. The creep- ing stems elongate and take root at the joints in moist soil. Note the growing point of the horizontal stem at the extreme right. Progressing to the left from the first flower bud are blossoms of increasing maturity. A seed crop comprises from three to six blossom sets. BASIC INFORMATION Young or thin stands thicken rapidly. When the growth is removed by grazing or clipping, recovery occurs in from 21 to 28 days. Ladino clover is very palat- able and widely adapted. When grown in association with grasses and other le- gumes it provides highly productive, nutritive pasturage. It is the basic legume in California's 600,000 acres of irrigated pasture. Although primarily a pasture crop, Ladino clover may also be used for hay and silage. In recent years, Ladino clover has come into prominence in the more humid east- ern half of the United States and in the west where irrigation is available. It has demonstrated an ability to survive the winters of most northern states, if given good management throughout the grow- ing season. Good management includes fertilization, well-timed grazing or mow- ing, and a compatible grass association. Use of Ladino clover will expand as more is learned of the managemept re- quirements. Seed production has nearly doubled in each of the past two years. Increased plantings of La- dino for forage purposes through- out the nation should create a con- tinuing demand for certified seed. A survey made by the Produc- tion and Marketing Administration of the United States Department of Agriculture in 1949 placed the es- timated needs by years for Ladino seed as follows : 1950— 9,012,000 pounds 1951— 9744,000 pounds 1952— 10,433,000 pounds 1953— 11, 162,000 pounds 1954— 11, 769,000 pounds 1955— 12,384,000 pounds 1960—14,855,000 pounds In 1951, domestic production was about equal to demand. Prices to seed growers declined 23 per cent in 1949 and further declines may be expected as production increases. In 1950 prices to growers for certified seed hovered about the $1.25 Govern- ment support level. Non-certified seed brought growers prices from $1.05 to $1.20 per pound. However, Ladino clover seed appears likely to be a profitable crop, especially for growers with efficient methods of production. Some sections of California are ideal for the production of certified Ladino seed. Where Seed is Grown. In Califor- nia, the industry is concentrated in the Sacramento and northern San Joaquin valleys. Principal California seed pro- ducing counties include: Glenn, Butte, Colusa, Mendocino, Placer, San Joaquin, Sacramento, Siskiyou, Stanislaus, Sutter, Tehama, Yolo, and Yuba. Glenn County is the leader, producing over 2,200,000 pounds of seed in 1950. Seed production is at present largely confined to irrigated regions of Califor- nia, Oregon, and Idaho — where weather conditions are exceptionally favorable for this crop. Satisfactory seed crops can probably be grown in most of California at eleva- tions under 3,000 feet except in regions of excessive summer heat. High winds at harvest time (July, August, and Septem- ber) can prove troublesome. Excessively foggy weather or rain and snow at har- vest time may interfere with harvest and lower seed quality. Soil Requirements. Ladino will do best on heavier clay or loam soils. It does well on shallow soil underlain by a tight clay layer or a hardpan, even if the re- stricting layer is within 18 inches of the surface or slightly less. Ladino does not do well on very saline soils. On deep, open, friable, fertile soils seed produc- tion is seldom successful, because the La- [4 Table 1. Ladino Clover-Seed Production* Year Acres harvested Yield per acre (lbs.) Production (cleaned seed) (lbs.) Price received by farmers (per lb.) California 1951 1950 1949 1948 1947 1946 1945 1944 1943 1942 1941 46,000 f 35,000 14,000 13,000 7,000 7,000 10,000 7,000 2,000 2,800 2,800 120 f 120 107 90 80 83 52 60 85 75 100 5,520,000f 4,200,000 1,500,000 1,200,000 560,000 580,000 520,000 420,000 170,000 210,000 280,000 $1.20f 1.20 1.30 1.60 1.50 1.25 1.40 1.75 1.00 .85 .40 United States 1951 1950 1949 1948 1947 1946 1945 1944 1943 1942 1941 1940 74,000 f 58,400 26,500 20,000 13,200 13,600 16,800 12,400 5,100 5,700 7,200 7,000 137 1 137 141 98 70 76 59 59 76 66 71 80 10,120,000f 8,040,000 3,740,000 1,950,000 920,000 1,030,000 990,000 730,000 390,000 375,000 510,000 560,000 1.20f 1.23 1.28 1.67 1.61 1.28 1.43 1.72 1.08 .78 .58 .45 * Data from reports of the California Crop and Livestock Reporting Service. t Preliminary official estimates. dino plants fail to produce an abundance of seed heads. The luxuriant vegetative growth, the sparse production of seed heads and excessive water losses make the production of seed less attractive on this type of soil. Ladino is comparatively shallow rooted. Root penetration may go down to five feet, varying according to soil depth and structure. Since it is shallow rooted it does not need a great depth of soil. Tight soils and soils having relatively im- pervious hardpans or tight clay layers tend to hold applied irrigation water within the root zones of Ladino plants, with practically no water percolation losses. Ladino usually requires irrigation about every 7 to 10 days during the heat of the summer. With irrigations so fre- quent, and water percolation losses greater on open type soils, the amount of water required to produce good seed on open soils may be from 2 to 3 times that needed on heavier type soils. On heavy clay soils the irrigation interval may vary as much as from ten to twenty- one days. [5 Lcidino seed production requires careful land preparation, costing up to $125 an acre in 1950. The purposes of land preparation are to provide for the most economic and uniform application of irrigation water, and to facilitate other cultural operations. The most widely used, and probably the best method of land preparation to pro- duce Ladino, is the strip-check system. Although the contour check system of irrigation, properly modified, is being used successfully for irrigated pastures, it is rarely used in connection with Ladino seed production. Except, that is, where each contour check can be immediately and completely drained following the ir- rigation to avoid seed damage through germination and drowning of plants. Sprinkler irrigation may be used where land leveling is not practical. Clover-seed fields require frequent irrigation and, for this reason, it is particularly important that the land be properly prepared to minimize labor costs. Preparing for Strip-Check Irriga- tion. More land leveling is required for strip checks than for any other type of flood irrigation. The cost of a good job of land preparation, however, is gener- ally repaid in reduced irrigation labor costs, savings on the amount of water used, harvesting costs, and higher seed yields. Strip checks require grade in only one direction — that in which the water flows down the check. This grade may or may not be uniform. Grades of 0.2 to 0.5 foot per 100 feet are desirable for covering the ground quickly. Steeper slopes are used in some districts where the soil resists erosion and where it would be inadvisable to level the field uniformly. The first step in preparing land for the strip-check method of irrigation is to do the necessary earth moving. This work should be based upon a contour map of the field showing the direction and per- centage of slope, and the location of cuts and fills indicating the amount of grad- ing, hauling, and filling required to level the field. After the land is leveled it should be plowed or disked and smoothed with a float or land plane before the border levees are built. In the land planing, it is best to plane diagonally across the field first, then lengthwise down the field. Fol- lowing the levee building, the field is ir- rigated to settle the fills. After this, it is sometimes desirable to plow or disc and plane the field a second time. Various types of equipment are used for constructing levees. Power ma- chines, such as road graders or special, custom-built attachments for tractors which build the borders and level the ground between them in one operation, are used in some areas. Disc ridgers, crowders, or alfalfa checkers are also used, but with these it is necessary to work the strip checks a second time to cross-level the land between the borders. The size and shape of the levees are im- portant. They should have a base width of about two feet and a settled height of about six inches. Levees of this size will be covered with clover plants so that the entire field will be productive and har- vesting equipment will easily move across them. When the levees are first con- structed, they are composed of loose earth and are irregular in shape. Before being seeded, they should be compacted and smoothed. This can best be done with a ring roller. The width and length of the checks and the desired slope to use will depend upon shape of the field, topography, amount of water available, and type of soil. All of these factors must be properly balanced for each field. On sandy soils with steep slopes, or on clay soils with only small flows of water available, it is sometimes desirable to have the checks as narrow as eight feet. On heavy soils, where large flows of water are available and the land is nearly flat, [6] PREPARING THE LAND -:V;v : .;;,:; SIS Field in preparation. Upper right: surplus water pit. Upper center: pit silo, home site. the checks may be as wide as 30 to 40 feet. It is common practice to have the di- rection of the runs made so that the water moves down the steepest slope. This re- duces the amount of cross-leveling that is required. If the field has a water pen- etration problem, this practice may not be desirable. Water penetration is gen- erally increased when the slope is re- duced. This can be accomplished by further land leveling or by altering the direction of the runs. If the land has con- siderable side fall, the strips should be made narrow. The difference in elevation between any two adjacent checks should not be over 0.2 foot. The length of the strips will depend upon the shape of the field and the rate at which water penetrates the soil. In sandy soil, a great deal of water may be wasted by deep percolation at the upper ends of the runs if the strips are too long. This difficulty can sometimes be partly overcome by increasing the amount of water turned into each check. Table 2 gives the recommended lengths of runs for checks of different widths and for various rates of flow. If the slopes are steep, strips longer than 800 feet should be limited in width to 15 feet or less. This table applies only to clay and clay loam soils. For porous loams and sandy loams, increase delivery rates for the sizes of checks given in the table from two to five times, or use shorter checks. This will permit the water to cover the ground quickly without too much being applied at any single irrigation. However, the ve- locity of the water should be kept low enough to prevent erosion. The first 10 feet of the checks may be left perfectly level so that the water will be uniformly distributed between the lev- ees before it moves down the checks. To insure uniform coverage over the full width of the checks, the land between the borders must be carefully cross-leveled. [7] PREPARING THE LAND The unit head (rate of delivery of water into each check) may vary from 0.2 to 1.0 cubic foot per second (90 to 450 gallons per minute). The unit head can be regulated by changing the number of checks irrigated at one time. The farmer has more control over this one factor than any of the other factors which make up his irrigation system. By experience, he will learn the size of stream to use to ob- tain the most efficient and uniform appli- cations of water. The lower ends of the checks should be left open to drain off any excess water. Ponding at the lower end of the runs rapidly drowns out the clover, and en- courages growth of undesirable, water- loving weeds, such as dock, plantain and sedges. Adequate drainage ditches should be built for collecting and removing sur- plus water from the low end of the field. The surplus water may be used for irri- gating other fields, or drained off. Cost of Preparing Land. The cost of preparing land for strip-check irrigation will vary depending upon the amount of earth moving required. Rough leveling work can be done for 8 to 12 cents per cubic yard of earth moved. Leveling which requires that the land be left with a finished surface within 0.1 foot of the desired elevation will cost 14 to 20 cents per cubic yard. The cost for leveling land may be as little as $20 or as much as $95 per acre. In 1950 one Glenn County rancher spent $38.37 per acre for level- ing, while another spent $94.55 (see table 3, page 9). After the earth-moving work, the soil is usually plowed and sometimes chiseled. This is to break up hard spots and to pro- mote a good seed bed. The cost of chisel- ing will be about $4 per acre; plowing may cost slightly more, based on 1950 prices. The cost for land planing depends on how many times the machine goes over the land. Once over, the cost will be from $1 to $1.50 per acre, depending upon the width of the blade and efficiency of the operator. Most farmers plane their land two to four times. Levees can be constructed for about $4 per acre. Harrowing and rolling the field after levee construction will cost about $1 per acre. The cost of construct- Table 2. Sizes of Strip Checks for Clay Loam and Clay Soils Flow delivered to each strip Length of check for various widths of strip 10 ft. wide 15 ft. wide 20 ft wide 25 ft. wide Cu. ft. per sec. Gals, per min. feet feet feet feet 0.2 90 440 0.3 135 660 440 0.4 180 880 660 440 0.5 225 880 660 440 440 0.6 270 1,320 880 660 440 0.7 315 1,320 880 660 440 0.8 360 1,320 880 660 0.9 405 1,320 880 660 1.0 450 1,320 880 1.2 540 1,320 880 1.5 675 1,320 [8] Table 3. Cost per Acre to Develop Land and Plant Ladino Clover for Seed; Glenn County, 1950 Acres Well Pump Canal or pipeline and turnouts Total Irrigation . . Surveying Leveling Drainage Total Land De- velopment Landplane Chisel Build checks Total Land Prep- aration Seed Seeding Total Seeding Total Cost Grower's serial number 40 $6.64 6.64 3.00 31.25 4.12 38.37 10.00 7.00 3.50 20.50 9.30 1.10 10.40 $75.91 50 $4.80 4.80 60.00 60.00 6.00 4.00 10.00 6.00 1.00 7.00 $81.80 90 $7.40 7.40 4.30 90.25 94.55 6.00 4.00 3.00 13.00 7.75 .55 8.30 $123.23 160 $65.60 65.60 3.00 33.60 2.00 38.60 10.00 4.00 14.00 7.50 .50 8.00 $126.20 74 $20.47 23.65 37.84 81.96 2.03 28.00 2.70 32.73 3.80 3.80 8.75 .53 9.28 $127.77 140 $40.00 8.00 48.00 2.00 63.39 65.39 2.00 3.00 4.00 9.00 8.00 .40 8.40 $130.79 40 $13.33 10.00 j 43.75 67.08 1.87 43.00 44.87 7.00\ 7.00 1 4.00 18.00 5.40 .78 6.18 $136.13 Av. $43.26 15.49 40.21 2.31 49.93 1.26 53.50 8.86 3.76 12.62 7.53 .69 8.22 $114.55 These costs were obtained in 1950, but include plantings made over several years previous to that. The records are well scattered over Glenn County and cover various soil types and topographies. The acreages shown are those on which costs were reported by growers and may or may not include their total acreage of Ladino clover. In cases where costs are not shown for some items, they are usually included in some other operation. For example, drainage facilities may not be separated from the leveling costs. Those records not showing expenses for wells and pumps obtained water from irriga- tion districts. Costs for seed show those reported by growers and include several different years. The amount of seed used varied from 4 to 5 pounds per acre and the price from $1 .35 to $2.00 per pound. Most of the planting was by plane, the cost of which varied from 50c to $1 .00 per acre plus flagmen employed at the rate of .05 to .1 man-hours per acre. [9] PREPARING THE LAND ing head ditches will vary from $1 to $4 per acre. Turnout structures from main ditches into checks will cost $2.50 to $4.50 (installed) per acre. As of 1950, the total cost of preparing land in California for the strip-check method of irrigation, exclusive of land and the cost of developing water, varied from $30 to as much as $130 per acre. (See table 3.) A good seedbed, the proper planting time, and careful management during germi- nation will bring best results. Seedbed Preparation. A fine, firm seedbed (the same as used in planting ir- rigated pastures) , is recommended. Such a seedbed has a firm, moist bottom cov- ered by two to three inches of moist, well- worked soil free from big clods and large air pockets. The surface soil should be firmed by cultipacking before seeding. A loose, cloddy seedbed filled with air pockets may result in a patchy, poor stand. A trial irrigation before planting set- tles the fills and reveals potholes and other irregularities that can be corrected be- fore seeding, firms the soil, and provides an even and dependable moisture supply for germinating seed. It is not always essential to pre-irrigate, however, if there has been enough rainfall just before seed- ing. After the irrigation or rain, the field should be leveled if irregular settling has occurred. A final harrowing should be given the field just before it is seeded. A broadcast application of 200 pounds per acre of 16-20 ammonium phos- phate just before the final harrowing is used by many growers, especially on newly leveled land. On most California soils where clover is grown for seed, La- dino responds to applications of phos- phorous fertilizers. Seedling clover also responds to light nitrogen applications. Time to Plant. Depending upon local conditions, seeding should be done be- tween September 15 and November 15. Planting in the early fall insures larger and more productive Ladino plants in the first crop year. Seed yields the first season of from 100 to 350 pounds per acre have been obtained from early fall planting. Spring seedings are preferable if fields are foul with winter weeds, although the chances of obtaining a satisfactory seed crop are fewer. In areas subject to severe winter frosts, planting should be completed early enough in the fall to insure seedling es- tablishment before the first hard freeze. Inoculate Seed. Ladino clover seeded on newly leveled fields should be inocu- lated with nitrogen-fixing bacteria before being sown. Companion Crops. The use of com- panion or nurse crops is not recommended for fall seedings. Barley or oats may be used as a nurse crop for spring-sown La- dino on very tight soils which seal or cake when exposed to the baking sun. .Growers report that the nurse plants re- sult in better spring-sown stands because they provide shade which prevents the surface moisture from drying out. In turn, the germinating Ladino plants are better able to get through the moist soil. The nurse crop should be mowed promptly when a satisfactory clover stand has been established. Otherwise it may offer severe competition to the slowly de- veloping Ladino plants. Plant Only Certified Seed. Only certified, registered or foundation seed may be used to grow certified seed. Fields seeded with common Ladino are not eli- gible for certification. On such fields a four-year period in the production of other crops is required to insure the de- struction of all common clover. California [10] certified Ladino seed is usually available from local seedsmen and certified seed growers. Varieties or Strains. At the present time there are no distinct varieties or strains of Ladino clover in commercial production. The certified seed, however, of each producing state is identified by the state name; for example, California Certified, Oregon Certified, etc. Califor- nia produces two grades of certified La- dino. Seeding — Rates — Equipment — Methods. The usual seeding rate by plane or ground equipment is four pounds per acre, although some growers sow 5 and 6 pounds per acre. Airplanes are generally used to seed fields over 15 acres in size. Planes are especially useful in seeding fields while the seedbed is still wet. Early fall plant- ing (September 15 to October 15) usu- ally requires light irrigations every 4 to 10 days until fall rains eliminate this need. The cost of airplane seeding per acre runs from 50 cents to $1, exclusive of seed cost. On a calm day, from 300 to 500 acres can be seeded. When seeded dry, subsequent fall and winter rains dissolve the clods, covering the seed. Best results, however, are usu- ally obtained if the dry field is cultipacked following seeding. Harrowing, if the im- plement is adjusted to barely cover the seeds, gives satisfactory results. Disking should never be employed, as the seeds will be buried too deeply. Ground seeding equipment that may be used includes: (1) an endgate broad- cast seeder mounted on the bed of a truck or wagon; (2) a grain drill with special grass-seeding attachments or alfalfa drill; (3) hand-operated cyclone seeder. Properly adjusted, all can be used satis- factorily. Seed-covering precautions rec- ommended in airplane seeding apply to these methods. CULTURAL MANAGEMENT Great care is needed to develop good stands quickly. Wise management of old stands increases seed yields. Care of New Stands. Ladino is slow to become established. Allowing the sur- face soil to dry out during the germina- tion period accounts for more failures to obtain satisfactory stands than any other single factor. To get the crop well started, early fall and late spring seedings require frequent light irrigations. These irrigations should be timed to keep the surface soil moist, preventing crusting and enabling the ger- minating plants to emerge. Fall seeding is favored because frequent rains may nor- mally be expected to help in the germina- tion process. Regardless of the date of planting, the surface soil should never be permitted to dry out for more than a day or two until a satisfactory stand is at- tained and the clover plants have at least four or five true leaves. First-year stands should not be grazed, except perhaps near the end of the first growing season, and if no seed is to be harvested. Grazing first-year fields too early results in severe injury to the stand. If weeds become a problem in the first season, the field should be mowed in early May, before the weeds produce seed. Selective dinitro-type sprays when timed and applied properly are effective in con- trolling broadleaved weeds in seedling stands. (See Weed Control.) The pres- ence of many weeds in new stands may result in (1) thinning of the clover stand by weed competition, (2) a clover-seed harvest contaminated by weed seed. Weedy new stands should either be mowed or sprayed. In some localities annual weeds such as ryegrass, burclover, canarygrass, etc., are such a problem that they prevent se- curing a satisfactory stand of clover. In such cases spring sowing of clover is [in CULTURAL MANAGEMENT recommended. Winter-germinated, these troublesome weeds can be destroyed dur- ing spring seedbed preparations, thus minimizing the competition for the en- suing clover crop. Grazing or Mowing Old Stands. Grazing or clipping the early lush spring growth in stands two years of age and older is generally practiced. Grazing or clipping is usually completed by May 15. This practice helps to control weeds and promotes a subsequent even, abundant flowering and a more uniform set of seed. Since Ladino cut for hay dries slowly the clippings are generally ensiled rather than cured for hay. It is customary to add from 70 to 80 pounds of cane molasses per ton of green clippings going into the silo. The molasses improves the quality and feeding value of the ensuing silage. Weed Control. Grazing or mowing seed fields in late April or early May (but not later than May 15) is helpful in con- trolling weeds. Most fields which have been grazed should be mowed, following grazing, for weed control and to even up the stand. Chemical control of weeds in Ladino clover-seed fields is gaining rapidly in popularity. In seedling stands dinitro selective sprays such as Dow Selective and Sinox Selective have proved effective against broadleaved annual weeds like mustard, chickweed, shepherd's purse, wild radish, etc. The dinitro selective sprays should be used with caution on seedling Ladino if the air temperature is above 85° F. For information on rates, follow the man- ufacturer's recommendations. In old Ladino seed fields which are past the first full season of growth the following weeds may be troublesome: (1) dock, (2) buckhorn (plantain), (3) chicory, (4) sedge, and (5) dodder. Properly used, 2,4-D has proved quite effective in reducing these weeds in La- dino seed fields. The following points are important when spraying seed fields with 2,4-D: 1. Timing is important. Spraying may delay the seed harvest as much as 30 days if done after late May. The best time to spray appears to be in March and April, after the clover has really started grow- ing. Dormant clover (Nov., Dec, Jan.) should not be sprayed. 2. Use from % to % pound of actual 2,4-D acid per acre. If buckhorn is the principal weed to be controlled, use % pound of actual 2,4-D per acre. 3. The amine form of 2,4-D appears to be safer to use on clover than does the ester form. 4. Ground-rig equipment appears to give very good results providing not less than 20 to 50 gallons of water per acre are used. 5. All 2,4-D-sprayed fields should be kept well irrigated following spraying. For best control of buckhorn, the field should be grazed or mowed back before spraying to expose the prostrate-growing buckhorn plants. Dock and chicory ap- pear to be readily killed by 2,4-D in nor- mal unmowed or ungrazed stands. The sedges may require treatment for several years before they are checked. Ryegrass usually volunteers freely in seed fields, even though only pure Ladino may be seeded. IPC (O isopropyl, N phenyl, carbamate) applied in late Feb- ruary at the rate of 3 to 5 pounds of active material per acre as a spray in 60 to 100 gallons of water per acre, has given excellent control of this weed. If applied too early (December), the IPC may be leached from the soil by winter rains. If applied too late, it may not be carried down deep enough into the soil. Timing to get it on when most of the ryegrass is just germinating or in the seedling stage is an important consideration as well. Bermudagrass is a troublesome weed [12 1 CULTURAL MANAGEMENT in Ladino and there is no selective spray that can be recommended for its control. Through regular and repeated oiling with diesel oil during the growing season spot infestations can be eliminated. Infested irrigation ditches and larger areas may be treated with TCA at the rate of 90 to 120 pounds per acre. Dodder should be controlled promptly if it puts in a late appearance after the April 2,4-D spray. Spraying with diesel oil and burning dodder-infested spots is recommended. No seed field containing growing pri- mary noxious weeds like camelthorn, hoary cress, or Russian knapweed is eli- gible for certification. Any infestations which might develop in a seed field should be promptly treated with a soil sterilant like Atlacide or Polybor chlorate (mix- ture of borax and sodium chlorate) .These spots should be regularly checked to pre- vent any regrowth of the noxious plants. Fertilization. It is a customary an- nual practice to fertilize most California Ladino seed fields with chemical fertiliz- ers. No chemical fertilizer should be used until, by field test, the grower has become convinced the practice is profitable. New seedings of clover frequently respond to nitrogen as well as to phos- phorus and sometimes to sulfur. It there- fore has become customary to broadcast chemical fertilizer containing both nitro- gen and phosphorus just ahead of the seeding operation. Many growers use about 200 pounds per acre of 16-20 ammonium phosphate or its equivalent at that time. In addition from 100 to 300 pounds of agricultural sulfur may be broadcast ahead of seeding. On established seed fields many growers are now making annual applica- tions of from 200 to 600 pounds per acre of single superphosphate (or its equiva- lent of treble superphosphate), broad- cast usually in February or early March. In areas where sulfur is deficient, they may also broadcast from 100 to 300 pounds per acre of agricultural (soil) sulfur at this time or earlier. In addition to its value as a fertilizer, the soil sulfur may be helpful in killing over-wintering mites (red spiders), particularly if the temperatures are high. Rarely are nitro- gen or potash or so-called complete fer- tilizers used very extensively on old fields. Established, well-inoculated clover is supplied with nitrogen through the ac- tion of nodule-forming bacteria that are associated with the roots of clover plants. The soil in most California seed growing areas generally has enough potash, so that it need not be applied. Because Ladino clover is shallow rooted, the available supply of phos- phorus and sulfur may be rapidly de- pleted in the active root area. The de- creased availability of these plant nutri- ents in unfertilized clover-seed fields may account for the diminishing seed yields following the second or third season. In addition, many of the Sacramento and San Joaquin Valley soils on which seed is produced are known to be deficient in phosphorus and in some cases sulfur. In these cases, it pays to make annual ap- plications of these materials. Animal manures, unless they are known to be weed-seed free, should not be used on seed fields. Although animal manures have a very high fertilizing value, the resulting weed problem in seed fields often proves serious. Irrigation. Watch the clover plants closely for clues as to proper timing of irrigations. When the leaves begin to cup together, it is time to irrigate. This may occur in only a few spots — the sandy or hard spots, at first. If these areas consti- tute an important proportion of the field, then they should be used as guides. Other- wise, plant condition in the field in gen- eral should be considered. It is hazardous to withhold irrigation until the entire field is in a state of wilt. [13] •■^1,; Spring mowing reduces weeds. Right: mowed. Left: unmowed. A heavy weed infestation WEEDS-WHAT THEY WILL DO TO YOUR LAD Johnsongrass Yellow Star Thistle . ¥rmA '> ■ ■ , Ryegrass control (IPC). Right: sprayed. Left: unsprayed. INO FIELD/ AND HOW TO IDENTIFY THEM • ■■-. ■■■..,. . . > ■•■ ■ / N^ti*>** Dog Fennel Knotweed [15 CULTURAL MANAGEMENT Under average conditions, irriga- tion water will have to be applied every seven to twelve days throughout the heat of the late spring and summer. On sandy or gravel soil it may have to be applied more frequently — every five to ten days. On heavy soils of high moisture-holding capacity, the irrigation interval may be longer, varying from ten to twenty-one days. A soil tube, such as is shown on page 17, is an excellent aid in determining whether irrigation is needed. Do not intentionally dry up a field which has a good developing seed crop. This practice will reduce seed yield and result in a large amount of shriveled seed, and will lower the percentage of germi- nation. While Ladino clover requires frequent irrigation, its annual total water require- ment usually does not exceed that of alfalfa. In most seed-producing areas of California, Ladino requires from 3 to 5 acre-feet of water per acre per year. In the interior valleys on open, permeable soils as much as 6 to 9 acre-feet per year may be required. Each irrigation should be sufficient to replenish the soil moisture to the depth of the Ladino roots. Growers should ex- amine their soil and determine the depth of soil and the zone of root distribution. From 1 to 3 acre-inches of water per ir- rigation will usually be sufficient to re- plenish the moisture supply. Larger applications will not only be wasteful but may even be harmful. Pond- ing of water at the lower ends of the field in hot weather results in drowning out large areas which otherwise would be productive. Good drainage is essential for maximum seed production of Ladino clover. Seed fields are usually irrigated promptly following harvest. The first ir- rigation following harvest is preferably given in late afternoon or at night to avoid injury. At present there are at least four different insect and insectlike pests which are recognized as being troublesome. New and more effective chemicals for control are being rapidly developed. For complete, up-to-date information on rec- ommended control measures growers should consult their local Farm Advisors annually. Before applying any insecticide other than sulfur to a clover-seed field, the seed producer should notify his local Agricul- tural Commissioner and any beekeepers who may be operating within the imme- diate vicinity of the field. Bees are impor- tant to Ladino seed producers as pollina- tors. Indiscriminate use of insecticides will result in reduced seed yields for the seedsman and serious monetary losses for the beekeeper. Mites, or spider mites — frequently known as red spiders — cause widespread damage. Beginning about May 1 each year, they may become troublesome in most districts. Four different species may be involved, including: Atlantic mite, Brown Almond mite, Pacific mite, and the two-spotted mite. The local Farm Advisor can identify them or have them identified, and discuss suggested control measures. Dusting sulfur at the rate of 30 to 40 pounds per acre, applied immediately following the spring grazing or mowing, has been useful as a preventive or delay- ing measure in some areas where only the Atlantic mite is involved. The microscopic mites which attack Ladino are usually on the undersides of the leaves. Infested leaves become cupped, yellowish and spotted. Heavily infested fields rapidly take on a dried-out, reddish- brown appearance. As soon as any seed field shows signs of infestation, it should be treated for control. [16] Right: Handy soil tube used for checking field moisture for adequate irrigation. Center: Improper leveling of land causes drowning of plants and loss of revenue. Bottom: Good leveling, even distribution of water. Surplus runs to drainage ditch. V ■:/■■'■■ PEST CONTROL Plane insecticide applications must be carefully done to get complete coverage. Where a field is not heavily attacked by mites until late June or early July, it may be cut promptly for seed. The seed crop should be quickly harvested and the field given a very heavy flood-type irri- gation to promote rapid regrowth. Very rarely do mites become a problem in the regrowth which produces the second seed crop for that same year. The field should, however, be treated and kept well irri- gated as a preventive measure. Where fields are attacked during late May, early June, or later, various chemi- cals may be used to control mites. If only the Atlantic mite is involved, dusting sul- fur applied by ground rigs at 30 to 40 pounds per acre may be helpful, especi- ally if the field is kept well irrigated fol- lowing sulfuring. For sulfur to be fully effective, daytime temperatures should be 80° F. or above. Aramite and Ovatran sprays and dusts have proved very effective against spider mites. Both Aramite and Ovatran are safe to use as they are almost nontoxic to bees. Two TEPP sprays applied 5 to 7 days apart have also killed mites in clover- seed fields. If the clover is in bloom, TEPP should be applied only after 8:00 p.m. or by 7:00 a.m. If TEPP is applied during the day the field force of bees may be seriously damaged. Because it is so lethal to bees, parath- ion is not recommended for pest control on clover in bloom. Lygus bugs usually tend to build up rapidly in Ladino seed fields in late May, June, and July. They are sucking insects which do considera- ble damage to the flower parts and developing seed. The adults are small greenish to yellowish brown Lygus bug [18] bugs and have a distinguishing raised "V" on their backs. The young lygus bugs are green-gray in color. Both adults and young are extremely quick in their movements. Where lygus bugs are the only troublesome insects involved, DDT sprays or dust at the rate of 1.5 pounds of actual DDT per acre have proved very effective in protecting Ladino seed fields. In cases where spider mite infestations are likely, a 5 per cent DDT, 50 per cent sulfur dust application of 25-30 pounds per acre may be used. Time to start is when two lygus bugs (either immature or mature) per sweep are caught with a standard insect net. Grasshoppers of various species at times move into Ladino fields in dis- astrous numbers. In some instances high, dry checks and borders, and fence rows within seed fields serve as centers of in- festation. Adjacent vacant dry fields may be breeding grounds. As soon as an in- spection shows that a field is being dam- aged it should be promptly sprayed with recommended chemicals. Toxaphene, al- drin, and chlordane have proved very effective. Chlordane and aldrin are, how- ever, very toxic to bees, and steps should be taken to protect the bee population. Follow the manufacturer's rate recom- mendations for most efficient usage. Yellow-striped armyworms at times cause considerable damage to seed fields. Uncontrolled, the worms may strip a field in 3 or 4 days. In 1950, 3 quarts of 25 per cent DDT emulsive in 30 gal- lons of water per acre gave quick control of this pest in infested clover fields. To protect fields from advancing army- worms, DDT, DDD, or toxaphene dust barriers around uninfested fields proved beneficial. Barriers of 5 or 10 per cent DDT dust 6 inches wide and %- mc h deep were successfully used. Where the in- vasion lasted longer than 7 days it was necessary to re-treat the barriers. PEST CONTROL Multiple Pest Control. Frequently, two or more types of troublesome insects will infest a seed field at the same time. It therefore becomes necessary to use modified control measures directed at all types of insects involved. As an example, a combination lygus bug and grasshopper infestation can be handled with a mixture of DDT and toxaphene. Likewise, spaced 5 to 7 days apart, two applications of TEPP have proved very effective in con- trolling mites and lygus bugs as well as a light grasshopper infestation. A mix- ture of Aramite and DDT has proved effective against mites and lygus. Polli- nating bees must be protected or moved out of fields being sprayed with TEPP. How to Apply Insecticides. For two reasons, presently available insecticides are most effective when applied as sprays for insect control in Ladino seed fields: ( 1 ) spray residues seem to be less harm- ful than dusts to the pollinating bees; (2) properly applied sprays seem to give better residual effect. Good coverage is particularly important in the case of mites. Ground sprayers are the most effective means of applying miticides to Ladino clover. Plane applications of miticides are less effective because of inability to secure uniform coverage and the hazard of spray drift due to strong winds. Plane applications of insecticides for other types of insects seem to give good results if properly applied. Ducks, Some Sacramento Valley seed producers find it necessary to place night lights in clover fields to protect stands against excessive damage by ducks in the winter months. Some have used airplanes to herd the ducks from their fields during the daytime. Unprotected fields may be practically denuded in a matter of a few hours. Diseases. To date, no serious diseases of economic importance have affected the Ladino crop in California. 19] BEES AS POLLINATORS Honeybees are the most effective pollinators of Ladino, due to their numbers and manageability. For seed formation, Ladino clover flowers must be cross-pollinated. Wind is not an effective pollinating agent. Bumblebees and other beneficial insects are useful as pollinators but their numbers are usually too small and their distribution so sporadic that they cannot be relied upon for effective pollination. Most seed growers now use a minimum of one strong honeybee hive per acre. A few use 3 or 4 strong hives per acre. Re- sults of recent tests strongly indicate the use of 1 to 1% hives per acre is sufficient for complete pollination. A strong hive is one which has brood in not less than seven combs and bees which cover not less than 15 frames in a two-story hive. Cooperation. Because honeybees are important in seed production, it pays seed growers to gear applications of insecti- cidal dusts and sprays so as not to injure bee populations. If insecticides harmful to bees are to be used, there should first be a conference between the seed growers and beekeepers involved so that the bee populations may be protected. Pollination Service. Various finan- cial arrangements for the special use of bees as pollinators are made between seed producers and beekeepers. In some cases a cash payment of so much per hive is used. Usually, the more hives supplied per acre, the higher the charge per hive. In other instances, arrangements are made on the basis of the increased seed production. In still other cases, seed pro- ducers reimburse the beekeepers for the reduced honey production plus any in- creased bee management costs. Any agreement developed between seed pro- ducers and beekeepers should be on the basis of strong hives. Weak hives are not effective pollinators. Usually local seeds- men, beekeepers, Farm Advisors, and Agricultural Commissioners are informed on current financial arrangements for honeybee pollinating service. Bees should be moved into seed fields just as soon as blossoming starts, usually within 2 to 3 weeks after the spring graz- ing or clipping has been completed. In most California seed fields, bees are moved in about May 10, and are kept there through the blooming period, which may be until late August or September. The beehives should be well distributed around and through the fields. They must be placed where they will remain dry dur- ing irrigation and where the beekeepers can reach them easily for maintenance. Some pre-harvest costs for producing Ladino seed. A wide variation exists in the pre- harvest costs incurred by various seed growers because of differences in effi- ciency of the use of equipment and man- agement practices. Table 4, page 22, may be useful as a guide to the pre-harvest inputs of labor and materials required per acre of the crop. It is based on a study made in 1950 in Glenn County. To harvest Ladino seed economically requires specialized equipment, skill, and experience. Harvesting Decisions. One seed crop per season or two? Most growers use the period from about May 15 to August 15 to grow a single cutting for seed. It gen- erally takes from 8 to 10 weeks to mature a crop under this system. This single-seed crop is made up of a series of flowering periods or seed sets, all of which suc- cessively mature. Blooming periods may be from 12 to 20 days apart and fre- quently overlap. Thus the field may ap- pear to be constantly in bloom during [20 HONEYBEES-THE BEIT POLLINATORS Above; Typical placement of beehives Below: A rich Ladino seed field in full for Ladino production. Note those in dis- blossom, the result of good fertilization, tance. Suggested: 1 to 1 Vi hives per acre. good irrigation, and good weed control. vV v ■£ "*' 'S¥*l& ***** * v» « # * - ^ HARVESTING AND THRESHING the period. Maximum bloom generally is reached from 4 to 6 weeks after the last spring grazing or clipping. New stands are never harvested twice the first year. Rarely are stands older than two years ever harvested twice in the same season. There are two principal reasons for not harvesting two seed crops per year from the same field. One is the high per-acre cost of harvesting. The other is the serious damage resulting to clover stands while drying out the field to facilitate harvest. Occasionally growers will profitably harvest two seed crops per year from ex- ceptionally good second-year clover and (as described on page 18) in instances where stands are heavily attacked by mites in late June or early July. Occasion- ally in old fields the clover ceases to bloom, in others the vegetative growth is so luxuriant that, by July first, the new blossoms are unable to get up through the mat of clover, thus curtailing seed production. When these conditions de- velop by early July, it may be advisable and profitable to harvest the field promptly and to endeavor to produce a second seed crop during the remainder of the summer. When to Start Harvest. The crop is ready to cut when about 90 to 95 per cent of the visible heads are brown and the flower stems (seed stalks) have started to dry. In the Sacramento and San Joaquin Valleys this normally would be in late July and August. The decision to mow a field for seed harvest should be based upon a thorough examination of seed heads throughout the field. In some cases the percentage of immature heads will be too high and har- vesting should be delayed until the young heads have matured. In other cases, an examination may reveal the seed in the matured heads so light that it will be essential to wait for additional produc- tion if harvest is to be worth while. Fre- Table 4. Pre-harvest Inputs per Acre for Ladino Clover Seed; Glenn County, 1950 Operation Crew and equipment Acres per hour Hours/acre Material/acre Labor Tractor Irrigation system maintenance 1.0 8.4 .2 .2 .7 .1 .2 .7 Irrigation Fertilizing Spraying, 2 times Clipping 1 man per 200 A., weekly, April 1-October 31 2 men, tractor, broadcaster 1 man, tractor, sprayer 1 man, tractor, mower 10.0* 5.0 1.5 Superphosphate 300 lbs. per acre Insecticide 3.0 lbs. active ingredients per acre Total 10.5 1.0 * If a fertilizer spreader is used instead of a broadcaster, the operation will be done only half as fast as with an endgate broadcaster. However, only one man is required to drive a tractor and pull the spreader. For planning purposes, then, if a spreader is used the tractor time required for fertilization should be double that shown above, but the man-hours can remain the same [22] HARVESTING AND THRESHIN6 quently, inexperienced seed growers have harvested fields that could be used more profitably as pasture. The examination determines not only the percentage of green heads, and the quality of seed, but also the percentage of matured heads which may be resting near the soil level that irrigation water may cause to germi- nate. It is generally customary to withhold irrigation for 4 to 10 days just before a field is cut for seed. Harvesting Procedure. In Cali- fornia, the crop is normally harvested by one of three methods: (1) direct com- bining, (2) combining from the wind- row, or (3) by stationary thresher. Mowing and Windrowing. Clover for seed is cut as closely as possible to the ground. The mower should be equipped with a bunching attachment, swather, or windrowing device. (See photographs.) Occasionally, a side delivery rake is used for windrowing immediately following mowing. Sufficient space should be left between swaths or windrows to provide passage room for the wheels of subse- quent harvesting machinery. Some growers prefer swath drying. Then the windrowing is done a night or two before threshing. To prevent shatter- ing, raking should be done at a slow rate of speed and in the case of swath drying must be done when the material is tough, the result of high humidity or dew. Ladino is difficult to mow because it is usually tough and matted. Mowers should be adequately powered, and kept in top- notch operating condition while mowing clover. Curing. Normally, following a period of 4 to 5 days after mowing, the clover plants are cured and ready for threshing. Curing may be hastened by turning the windrows. This should be done during the night when losses from shattering will be at a minimum. As in the case of wind- rowing, turning should be done at a slow rate of speed. Sufficient acreage is turned each night to keep ahead of the threshing operations. Some growers do not turn the swaths or windrows if curing conditions have been particularly favorable. Threshing. Ladino clover-seed thresh- ing requires skill, experience, and pa- tience. Threshermen must make a heavy financial investment in the harvesting equipment required, and relatively few Californians have specialized in this field. Most seed growers contract with these specialists to thresh their crops. In California there are wide variations in the methods of threshing the Ladino seed crop. Basically most methods can be fitted into the following pattern : Picking up the windrows. Threshing. Rethreshing of the straw and chaff from the first threshing, usually with a stationary thresher. Vacuuming the field and threshing the material picked up by the vacuum machine. Three different methods are used to pick up the windrowed dry clover: 1. Pickup Combines. These are equipped with regular or locally adapted forage pickups and straw blowers. The straw blower facilitates moving the straw into tightly covered and screened vans, drawn behind the combine. The material accumulated from the combine is usually rethreshed by a stationary thresher lo- cated at one corner of the field. 2. Field Chopper. Some operators pick up the windrowed clover with field choppers. The chopped material is blown into a covered van. This material is then threshed and rethreshed with a stationary thresher. 3. Hay-Hog. The "hay-hog" machine utilizes the suction principle in picking up the windrow. The partially chopped, [23] HERE ARE THREE TYPES OF MACHINES USED FOR MOWING AND WINDROWIN6 LADINO Mowing and wind- rowing with a curler attachment, one of several types cur- rently used. , m ■* 9- ;a Shown here is a pickup reel, another aid in mowing Ladino for seed production. Windrowing with a wheel-type rake is an easy one-man oper- ation. Note efficiency. Combine equipped with pickup, straw blower, seed cleaner, and seed-tight van. THIS TYPE OF EQUIPMENT CAN BE BOUGHT OR BUILT OR CONVERTED IN YOUR SHOP Picking up Ladino clover windrows with a field chopper and seed-tight van. The hay hog uses the suction method to blow unthreshed straw into the van. HARVESTING AND THRESHING unthreshed straw is blown into a covered van. The material in the van is then threshed and rethreshed by a stationary thresher. Just as soon as the windrowed clover has been picked up, by whatever means, the field is then vacuumed with custom- made, locally adapted machines. The seed recovered from the material picked up in the vacuuming process ranges from 10 to 40 per cent of the total seed harvested per acre. Many vacuum machines simply blow the suctioned material into a cov- ered van. This material is then threshed by stationary threshers. More recently, custom-made suction machines have been built into self- propelled combines. The suction unit re- places the entire header assembly. In most machines of this type, the material from the cyclone of the suction unit feeds directly into the cylinder of the threshing unit. After threshing, the debris from the rear of the machine is discharged back onto the field. This feature is considered to be a distinct advantage over the system in which the suctioned material is hauled off the field for threshing. California threshermen usually pur- chase standard-make threshers and mod- ify them. A common difficulty with the standard threshers is that they do not have sufficient screening or sieving ca- pacity to handle the great mass of clover straw properly, thus necessitating the re- threshing operation. Some California farmers have recently built clover com- bines and threshers in their own farm machine shops with greatly increased screening capacity. In a few instances, seed cleaners are being mounted on field threshers. Most threshermen believe, however, that seed cleaning can best be done under ware- house conditions. An Economic Comparison of Sev- eral Threshing Systems. Because of the wide variations in methods of thresh- ing, the examples of inputs by various methods shown in table 6, page 27, are given as relative guides only. Seed Yields. The average production of Ladino clover seed in California is about 100 pounds per acre. Seed yields vary tremendously depending upon man- agement and age of stand. Early fall- planted, well-managed stands may pro- duce 100 to 300 pounds or more of seed per acre the first season. Some spring- planted stands do not produce any seed at all the first year. Second-year clover generally is the most productive. Well- Table 5. Labor and Tractor Inputs for Mowing and Raking Ladino Clover Seed; Glenn County, 1950 Operation Crew and equipment Acres per hour Hours /acre Man labor Tractor Mow Rake Turn windrow 1 man, tractor, mower 1 man, tractor, side-delivery rake 1 man, tractor, side-delivery rake 1.0 2.0 5.0 1.0 .5 .2 1.0 .5 (ahead of thresher) .2 Total 1.7 1.7 [26] HARVESTING AND THRESHING managed second year stands may pro- duce from 250 to 500 pounds of seed per acre. Beginning in the third year, seed yields usually decline rather rapidly under cur- rent customary management. Rarely are fields used to produce seed after the fifth or sixth year. The encroachment of weeds, including ryegrass, is considered to be a contributing cause to declining seed yields beginning in the third year. New, improved weed-control methods de- Table 6. Labor and Tractor Inputs for Threshing Ladino Clover Seed; Glenn County, 1950 Operation Crew and equipment Acres per hour Hours per acre Man labor Tractor Equipment Hay-hog aod Stationary Thresher Picking up with hay-hog 1 man, tractor, hay-hog 3.0 .3 .3 .3 Hauling 1 man, tractor, wagon 3.0 .3 .3 .3 Threshing 4 men, thresher 3.0 1.2 .3 Rethresh 4 men, thresher .8 .2 Vacuuming .... 1 man, tractor, vacuum 2.0 .5 .5 .5 Hauling 1 man, tractor, wagon 2.0 .5 .5 .5 Threshing 4 men, thresher Total 2.0 2.0 .5 5.6 1.6 Field Chopper and Stationary Thresher Chopping. . . Hauling. . . . Threshing. . Rethreshing Vacuuming . Hauling . . . Threshing. . 1 man, tractor, chopper 1 man, tractor, wagon 2 men, thresher 2 men, thresher 1 man, tractor, vacuum 1 man, tractor, wagon 2 men, thresher Total 2.0 2.0 1.0 2.0 1.5 1.5 1.5 .5 .5 .5 .5 2.0 1.0 1.4 .7 .7 .7 1.4 7.5 2.4 .5 .5 1.0 .5 .7 .7 .7 Combining from Windrow Combine Hauling Rethreshing . Vacuuming. . Hauling Threshing . . 1 man, combine 1 man, tractor, wagon 2 men, combine 1 man, tractor, vacuum 1 man, tractor, wagon 2 men, thresher Total 2.0 .5 .5 2.0 .5 .8 .5 1.4 .7 .7 1.4 .7 .7 1.0 2.0 5.2 2.4 .5 .5 .8 .7 .7 1.0 [27] HARVESTING AND THRESHING ^ *■ This small combine is being utilized as a stationary threshing machine. scribed on page 12 of this circular may tend to lengthen the life of seed-producing fields. The excessive drying out of stands during harvest undoubtedly kills many Ladino plants, thus weakening stands. Weeds easily invade drought-injured stands. The possibility of using chemicals to prepare well-irrigated clover for seed harvest may help to overcome this drought-induced damage to stands. Field-Handling Threshed Seed. As the seed comes from the thresher, it is usually temporarily sacked into heavy- weight, closely woven cotton bags in good condition. Ladino seed is so small that it will spill from coarsely woven bags. Bags are filled to about three-quarters ca- pacity to facilitate handling from har- vester to cleaning plant. If a certified grower plans on handling harvested seed in bulk, he must make prior arrangements with his Farm Advisor and Agricultural Commissioner in order to maintain and protect identity of his seed. AS MUCH AS SO% OF THE SEED HARVEST IS A type of self-propelled suction unit and combine. Pull-type combination HARVESTING AND THRESHING A power cable-pulley rig automatically unloads the seed-tight van, as shown. Wise fall management of seed fields will improve seed yield in the following season. Irrigation water should be turned into clover fields promptly after the vacuum- ing process is completed, to revive the drought-stricken clover. Frequently, irri- gators and harvestermen will be seen in the same field. If this practice is followed, damage to the stand because of the har- vest drying out will be minimized. More- over, growers will be rewarded with greatly increased, valuable fall pastur- age. Irrigations should be given fre- quently in the fall until the regular rains begin. In districts subject to severe frosts, clover-seed fields should enter the cold period of the year with not less than 6 to 8 inches of growth. A good cover of clover plants protects the stand against excessive frost damage. In milder sec- tions, the seed fields are successfully COVERED WITH THESE "VACUUM CLEANERS n machine and harvester. grazed well into the winter months with- out serious damage to the stands. Processing and Selling the Seed. Threshed seed moves from the field di- rectly to seed warehouses, where it is cleaned and prepared for marketing. Most California Ladino seed-producing districts are fortunate in having very modern, efficient, commercial seed-proc- essing facilities available. These plants are equipped with the latest seed-cleaning machines and have well-trained personnel on their staffs. This service is an integral part of a sound seed industry. The processed seed is sold by growers under two systems. Reputable seed firms with national outlets annually contract with local growers for their crops. The California Ladino Seed Growers Associa- tion, which is a recognized farmer co- operative, markets Ladino seed for grower members. In order that the information in our publications may be more intelligible it is sometimes neces- sary to use trade names of products or equipment rather than complicated descriptive or chemical identifications. In so doing it is unavoidable in some cases that similar products which are on the market under other trade names may not be cited. No endorsement of named products is intended nor is criticism implied of similar products which are not mentioned. 20m-ll,'51(7582)LB [30] SIGNPOST FOR THE FUTURE- AGRICULTURAL EXTENSION SERVICE UNIVERSITY OF CALIFORNIA AGRICULTURAL INFORMATION guide lor today Thousands of farmers — this year and every year — are using the services of their County Farm Ad- visors. These specialists know your county, your crops, your farming problems. They are interested in helping you. The service is yours — use it. CALIFORNIA AGRICULTURAL EXTENSION SERVICE COLLEGE OF AGRICULTURE • UNIVERSITY OF CALIFORNIA Cooperative Extension work in Agriculture and Home Economics, College of Agriculture, University of California, and United States Department of Agriculture cooperating. Distributed in furtherance of the Acts of Congress of May 8, and June 30, 1914. J. Earl Coke, Director, California Agricultural Extension Service.