«ion of Agricu a I Sciences CALIFORNIA AGRICULTURAL Extension S CIRCULAR 482 ... . ' .,- nwm Variety tests of flax, grown on land of cooperating farmers, have been used as a guide in the selection of better varieties for commercial production. Commercial flax production in San Mateo County has been profitable since the end of World War II. Its success has been based on favorable growing conditions, improved cultural practices and disease control, and an increasing need for products using linseed oil and meal by the expand- ing population of California. This circular brings together up-to-date information, based on research, which will be helpful in raising flax successfully in the coastal regions of San Mateo County and neighboring areas with similar climatic conditions. THE AUTHORS: Paul F. Knowles is Professor of Agronomy and Agronomist in the Experiment Station, Davis. Bryan C. Sandlin was Assistant Agriculturist, Agricultural Extension, San Mateo County, Milton D. Miller is Extension Agronomist, Davis. OCTOBER, 1959 FLAX PRODUCTION IN SAN MATEO COUNTY PAUL F. KNOWLES • BRYAN C. SANDLIN • M. D. MILLER Flax production in the coastal area of California has been centered in the part of San Mateo County facing the Pacific Ocean. Its northern limit is Montara, and the southern limit Santa Cruz County. Plantings extend inland through all the principal valleys including Pescadero, San Gregorio, Tunitas, and Purisima. The entire area is subject to fogs during the summer when the flax is grown. In regions away from the ocean where sum- mer fogs do not occur — i.e., the part of the county facing San Francisco Bay — plantings have not been successful. Flax has occasionally been grown in similar areas of Santa Cruz and Monterey coun- ties. Most of the land used for flax is steeply rolling. Some level bottom lands are used for flax, but usually this land is reserved for vegetable crops such as artichokes or Brussels sprouts. Competing crops are barley, wheat, pastures, and both hairy vetch and oats for seed and hay. Some land in the county is still being reclaimed from brush, and flax is often the first crop sown. How flax grows Seeds of flax germinate very quickly in the presence of moisture. Under normal field conditions the seedlings appear above the ground in a week, though they may be delayed a few days longer by cool weather and deep planting. The seedlings are not vigorous nor strongly competitive with weeds. Blossoms appear about two months after planting; plantings in the early spring take longer. Plants increase little in height after blossoming commences, and are 24 to 30 inches high at maturity. Under most conditions, when grown dry- land, one central stem is produced, but if abundant moisture and nutrients are available strong branches will arise from the base of the plant. Smaller branches are abundant in the upper part of the plant, and these branches bear the flowers. Flax varieties grown in San Mateo County have blue or light blue flowers. In other varieties color may vary from white, through various shades of blue and pink, to dark lavender. Flowers may also vary in shape and size. Flowering will continue for about three weeks if [3] the plant has sufficient nutrients and moisture, with a maximum amount of bloom about a week after flowering starts. Flowers in San Mateo County will open about 9 or 10 o'clock in the morn- ing, and the petals will fall in the early afternoon. Each day brings a fresh lot of flowers. The bolls of flax may be closed tightly (indehiscent) or partly open (semi- dehiscent). Varieties such as Argentine with closed bolls are difficult to thresh without rolls on the combine. Rolls are advisable also for partly-open varieties, since they facilitate threshing and reduce injury to the seeds. Each boll can pro- duce up to 10 seeds, but normally the number varies from 6 to 10. An excep- tional boll may produce more than 10 seeds, but it has not been possible to develop a variety that will do this con- sistently. Seeds of flax may vary in color from yellow to dark brown, and in size from those that weigh 3 grams per 1,000 seed to those that weigh 12 grams. The seeds of San Mateo County varieties are brown in color, and the comparative weights of 1,000 seeds of the commercial varieties would be: for Argentine 8.0 grams, for Redwood 6.4 grams, and for B5128 also 6.4 grams. Flax seed is covered with a mucilaginous material that gives it a high gloss. It also causes the seeds to stick together if they are wet. The culture of flax in San Mateo County varies considerably from farm to farm, with equally good results in terms of yields. The nature of the weather- mostly the duration and amount of win- ter rainfall — determines the schedule of farm operations. What it takes to grow flax in the way of... Climate The climate of coastal areas of San Mateo County is favorable to the pro- duction of flax. The summer fogs keep temperatures low, with temperatures averaging about 70° F., and maximum temperatures rarely rising above 80° F. They also keep the relative humidity high, thus permitting flax usually to com- plete its development without suffering from drought. However, the high humidity has dis- advantages, too. It favors the increase and spread of diseases such as rust, pasmo and Botrytis blight; and it leads to difficulties at harvest time — combines often can only operate in the drier after- noon and early evening, and the flax seed may have a moisture content too high for safe storage and may have to be dried artificially after harvest. Rainfall is ample in the coastal areas, varying from 18 inches along the coast to 45 inches at the higher elevations around 2,000 feet. All or most of the rain falls during the winter and before the flax is planted in the spring. It is suffi- cient to moisten the soil to field capacity beyond the depth of normal flax root distribution. Actually, most farmers would prefer no more rain after plant- ing, since the rain will usually cause compaction or crusting of the soil and will encourage weeds. In some fields, spring runoff may lead to soil erosion; such erosion can occur after the flax is planted. Flax is never irrigated in San Mateo County. Frost is rare, and never has been known to damage spring-seeded flax dur- ing the growing season. [4] Soil Most soils of San Mateo County are suitable for growing flax. Highest yields are obtained on the deeper soils with a high water-holding capacity. Heavy soils that have been compacted do not give as high yields as medium-textured soils. Most soils in coastal areas are somewhat acid, with the pH sometimes going down to 5.0. Rotation Not many farmers in San Mateo County have a fixed rotation of crops; most of them choose their crops to some extent according to commodity-price outlook. Though some farmers have grown flax successfully for several years on the same field, this is not a recom- mended practice, and leads to depletion of organic matter in the soil, build-up in flax diseases, and possible damage from soil erosion. Oats and hairy vetch are often grown alternately with flax; they are usually grown for seed, sometimes for hay. Wheat or barley may also be grown. A good rotation would be: one year oats; one year oats and vetch; and one or two years flax. More and more of the land in San Mateo County is being planted to dryland permanent pasture. This trend has developed in response to increased livestock production and in order to pre- vent soil erosion. Ultimately, flax may be grown as a rotation crop on this pas- ture land. Varieties Argentine, though somewhat late, has been consistently good. It is not re- sistant to Fusarium wilt, but is resistant to rust. It is tall, and has large flat, light blue flowers. The bolls are closed tightly (indehiscent) ; the seeds brown and fairly large. Redwood is perhaps the most widely grown variety because it yields well, and is resistant to rust and most races of Fusarium wilt. Redwood is about the same height as Argentine, but has smaller and darker blue flowers. The bolls are partly open ( semi-dehiscent ) , and the seeds slightly smaller than those of Argentine. B5128 is a parent of Redwood and similar to the latter in appearance, per- formance and disease resistance. It is a few days later than Redwood, and there- fore has not been as popular for late plantings. Flax varieties have been under test in San Mateo County for over 10 years. Some of the data from these tests are Soil erosion sometimes occurs in fields of flax. Increased use of winter crops and permanent pasture in the rotation helps to control erosion and increase flax yields. i||:. :, Wim§«m 00 H tH tH c 8 00 a CN CO Sn C o c c CT CT CT CO IO CN CN CN CN O CC CO Tf "* OC CN CC IC CO 0) * c O C C c C CT c Oi • s cn CN CN Cs ^r CT I> t- u CN to in tH Tf ir: CC CN CO CT o Q. E (1) CN t- t- ^ ^f 1 rH CN CN "^ bo V ^ CO CO ■^ rr "<* x* "^ ^ . -S3 a u tf» .2 00 CO iH O IO rH cc CN ■^ o CO cn 00 O lO O rH W CO CO u T3 * o_ •o O O o CT CO i- CD CN 00 t> IO "^ CN £ 0) .c > > » >» h Cfl ee c c8 pq pq 'C PQ o c O 2 g £ (= g O g ° ^ O A S £ a, a tH OS ki o. H rl H ^ <» s2 O O O O CO o o o m o a r-i iH iH c 3§ • co ■ m oo 2 "3 • CT • O O ♦- • tH CN CN U) O O h- "0 0) 0) • O • 00 -<* c o o 03 ■ iH • O O TJ O 0) a o » E CN CN 00 O t- o a) co co m o ^ u u bo t> 00 CO o o &« iH tH o P i- CN CN 00 CN CT > a CO O CO CO 00 1. 9 CN CN CN CN CN PQ c 2 * . T si's in in ai w w i~, t-, i_ t-, >_ >>>»>>>*>> °^ CN -^ CN CN CO o 2 o m "^ • t- n h h in iH iH • tH u H H • tH •c c« > t- CO ■^ ^_; m O ^2 .2 ^2 ^_; eS "^COCNOcOinOcN" • O O © © OJ ' o o o cn cn o) rH ■ CN CM N (N H • • CN CN CN rH rH rH to • CM c CO OJ CN ■ O lO O H M 00 « • OC 0! 00 CO i- • OJ CO CO rH O CN -<* • W C CO -^ r* • CO CO CO ^ Tj< ^ C£ 00 OC t> CO t- Tt c CO O CO CM t- 00 CN C •^ M CM CN rH CM CN (N CM cc CO CM CN CM ^ CO CO -f— M?3 ++ -M- ++ -1-1- = CO « cc w to v OC >>»>»>»>>>»>»o: OJ Ol oj o: OJ OJ OJ CN (N cr t- ih w i- 1 m • CO 00 T- o r- t- oo cc CR D 1 <33 P i Eh i 4 o a 73 P 12 cd 73 d o i«c • S I S^O "2 -o a c a> a, ■S « W w 03 3 .St? bo "-'■ Q ~ bo bo ® 2 2 given in the tables on these two pages. Varieties produced in other parts of the nation will be tested as they become available, in the hope to develop a va- riety particularly well adapted to the county. Until 1952 Punjab was the principal variety grown, with Argentine of sec- ondary importance. Much of the plant- ing seed of Punjab was brought into the county from Imperial Valley and the San Joaquin Valley where Punjab was the main variety. Punjab 47 and Imperial, both selections of Punjab, were released in Imperial Valley about 1947. Though not grown commercially in San Mateo County, in test plots they have been found to be similar to Punjab in yield and behavior. Punjab 53 is a wilt-resist- ant variety developed from a single plant of Punjab surviving on wilt-infested soil in San Mateo County in 1948. It is also similar to Punjab under San Mateo County conditions. Unfortunately Pun- jab and all the varieties developed from it are susceptible to rust, and are not recommended for coastal areas. The same is true of New River, a wilt-resist- ant variety recently developed for Im- perial Valley. Dakota, at one time a widely-grown variety of the Northern Great Plains, was found to be a good variety for late plant- ings because of its early maturity. How- ever, it proved to be susceptible to rust. Time of planting Plantings are made from November to May 15. Though the best planting time varies from year to year, the most successful date has been about April 1. Pasmo has usually caused extensive dam- age in fall plantings, and frequently has reduced the yields of flax sown in Feb- ruary and early March. Yields are gen- erally reduced by planting after April 1, but delays may be necessary if the soil is slow in drying out after winter rains. [7] Local and Imported Seed Gave Similar Yields in Limited Tests, 1956 Source of seed Halfmoon Bay test La Honda test Variety Yield Oil content Iodine value Yield Oil content Iodine value Redwood B5128 Local North Dakota Local North Dakota bu./A. 32 2 33 6 34 2 36 5 per cent 39 4 41.6 41.8 40.7 202 200 196 192 bu./A. 20 5 19 4 19.7 19 8 per cent 40 6 41.1 40 9 40.6 202 202 197 196 Seedbed preparation The land is plowed in January or Feb- ruary; disked in February or March; and reworked with a spring-toothed har- row just prior to seeding to kill weeds that have germinated. A spike-toothed harrow is used also to level the seedbed. The timing of these operations depends on the pattern of the winter rains and the date selected for planting. It is im- portant that the seedbed be well worked down, firm, and free from weeds or volunteer grain. Moist soil should be close to the surface. Seed Most locally-grown seed has a high moisture content and therefore is not suit- able for planting. Much of the planting seed is imported from the Northern Great Plains, principally from North and South Dakota. Only certified seed has been, and should be, imported. Locally-grown seed, with a moisture content below 10 per cent, has been used successfully for planting (see table above) . Such seed has come from the southern end of the county where there is more sunshine at harvest time. Select locally grown seed carefully, and give it a germination test before planting. The cost of planting seed has varied between 10 and 13 cents per pound during recent years. Seed treatment Treat all seed with an organic mer- curic fungicide such as New Improved Ceresan or a similar product at the rate recommended by the manufacturer. Seed treatment kills the spores of disease car- ried on the surface of the seed and, for the first few days after germination, pro- tects the seed from diseases generally present in the soil. Planting Where planting conditions are ideal, % of a bushel, or 42 pounds, of seed per acre should be sufficient. Where some of the seed will not germinate because it drops in dry soil, or where rain may crust the soil, increase the seeding rate to 50 pounds per acre. Highest Yield Resulted from 6-inch Spacing (Pescadero, 1957) Row spacing Yield Oil content Iodine value of oil Amount of corn spurry 6 12 18 inches bu. A. 14.3 11.8 10.7 per cent 43 5 43 8 43 5 192 189 190 Moderate Abundant Abundant 8] Use a regular single- or double-disk grain drill with 6-inch row spacings. Wider row spacings have given lower yields (see the table on page 8 bottom). Set the drill to plant the seed into moist soil, but no deeper than necessary. A depth of 1 inch is preferred, and no more than 2 inches. It is customary to ring roll (cultipak) after seeding, if no rain is expected within a few hours after seed- ing. This leaves the ground in smooth condition for harvest and firms the soil around the seed, improving chances for even germination. Cultivation after planting Heavy rains immediately after seeding will often cause the soil to crust. Seed- lings have difficulty getting through the crust, and a thin stand frequently results. Growers have found that a light harrow- ing as soon as possible after a rain will break the crust and improve the stand. If the seedlings are partly emerged when the soil dries, the harrowing may do more harm than good. In this case, if the stand is very thin, replant after a shallow cultivation. Fertilization Fertilizers of the nitrogen, phosphorus, potash and combination types are used on flax both on a field scale and in ex- perimental plots. The flax often responds markedly to the fertilizer in early stages of its development, but the yields of fertilized and unfertilized areas have shown little difference. To date the use of commercial fertilizer on flax in this area has not been profitable. Flax, after a crop of oats and vetch which had been given a phosphorus fer- tilizer, has sometimes shown an increase in yield. Weed control Weeds are a problem in all flax-pro- duction areas. Herbicides greatly facili- tate their control, but a rotation and good cultural practices may keep down weed control expenditures. The principal weeds of flax in San Mateo County are annual radish {Raphanus sativus) , mus- tard (Brassica arvensis) , red pigweed (Amaranthus hybridus), corn spurry {Spergula arvensis), and wild oats (Avena fatua) . The most effective herbicide in the control of the broadleaf weeds is 2,4-D ( 2,4-dichlorophenoxyacetic acid) — a hormone type herbicide which, in sus- ceptible plants, causes severe plant dis- tortion or death within one to three weeks. It should be applied to flax in the following manner: 1. Use the amine salt of 2,4-D. It is sold as a liquid and goes readily into solution in water. The sodium and am- monium salts are as effective as the amine, but are more difficult to handle because they are solids. Ester formula- tions of 2,4-D are too toxic to flax. 2. Use 3 to 4 ounces of acid equivalent per acre. This will be % to % pint if the formulation contains 4 pounds per gallon. Applications with a ground rig may be made in as little as 15 gallons of water per acre, and by airplane down to 5 gallons of water per acre. Pressures in the nozzles of ground rigs should be 25-30 pounds per square inch. The cost of the material varies from 24 to 32 cents per acre, and the cost of application from $1.00 to $2.00 per acre. 3. Apply when the flax is 2 to 4 inches high, and no higher than 8 inches. After treatment the flax may have twisted stems, fused leaves at the plant tip, and deformed bolls. Late applications will show more distortion, and very late ap- plications will destroy buds and blos- soms with a serious reduction in yield. The timing of the application is ex- tremely important. The best kill of weeds will be obtained when the weeds are not more than 5 inches high and growing vigorously. [9] Spots of Fusarium wilt in flax. Weeds often occupy the area killed by wilt. MCP ( 2-methyl-4-chlorophenoxyacetic acid) is similar to 2,4-D in its effect on most plants, but costs about twice as much. Limited data from other areas would indicate that it is less toxic to flax than 2,4-D, and about as effective in con- trolling weeds. Rates, timing, and other Wilt nursery south of Pescadero. The bags on the plants protect selected plants from bird damage. The flax on the horizon (Redwood) is free from rust, and that in the foreground around the test area (Dakota) is badly infested with the disease. procedures for using MCP are the same as for 2,4-D. IPC (Isopropyl-N-phenyl carbamate) has been successfully used in Imperial Valley to control wild oats. Its use in San Mateo County for the control of this weed or other grasses is not recommended because it must be washed into the soil by rain or irrigation water to be effective, and the cost will approximate $10 per acre. Very little moisture in the form of rain usually falls on the flax after seed- ing, and the crop is dry farmed. Disease control Several diseases affect flax in San Mateo County, and every effort should be made to control them through seed treat- ment, resistant varieties, and good cul- tural practices. The more important dis- eases are Fusarium wilt, Rhizoctonia wilt, Botrytis blight, rust, and pasmo. Fusarium wilt (Fusarium oxysporum f. lini) is a disease that is widespread throughout the flax-growing areas of the United States. In San Mateo County it was first found in 1948, in an area that had been planted to flax some 50 years before. Wild flax growing in the area pre- sumably had been the host plant. This disease usually appears first as small patches of dead flax. Patches one or two feet in diameter indicate that the disease had been present for about two years. With every crop of flax the patches will increase in size, and usually become irregular in shape because of movement of the fungus by cultivation or runoff water. Plants may be killed at any stage. Keeping flax off fields having this dis- ease will not reduce its severity appreci- ably, since it is able to persist in the soil indefinitely. Where Fusarium wilt is present, use the resistant varieties Redwood and B5128. Seed treatment will kill spores of this disease carried on the seed, but will not kill the disease inside of small bits of stem that may be present in the seed. ■■:■" §|||il| ^ ¥ 5 i* *r ^ *- '^'.*. •*•> * ~ « - % ■IHiHMSBUH9HBGaH9HKSi <■ ^i Left: Fusarium wilt tests in the greenhouse at Davis indicate the varieties most resistant to this disease. Right: Characteristic of the wilt are curled tips. Rhizoctonia {Rhizoctonia solani), like the Fusarium wilt organism, is soil- borne and attacks the plants at the crown (not through the roots) . It is most severe in early stages of the plant growth. The fungus is favored by relatively warm, moist soil. In some cases stands have been reduced as much as 25 per cent. Where damage from this disease is expected, delay plantings until most of the winter rains are past. Seed treatments will give some degree of control. No vari- eties are known to have resistance to this disease. Botrytis blight or gray mold [Bo- try tis cinerea) is the most widespread disease in San Mateo County. Spores are present everywhere, and it attacks many other crops as well. It is favored by high humidity, and usually gains access to the plant through a dead, adhering petal. Because of this means of entrance, it usually attacks individual bolls, causing them to be empty or to contain shriveled seed at harvest. On close examination a cottony brownish fungus may be seen on the surface of the boll. When the variety Punjab was widely grown, damage was as high as 50 per cent in some locations, the damage being more severe because Punjab tended to hold its petals. The varieties Redwood, B5128 and Argentine are not seriously affected. Rust (Melampsora lini) appeared in San Mateo County for the first time in 1952. Presumably it came in on seed from the Northern Great Plains. Sus- ceptible varieties in the following year, fortunately being grown on a small pro- portion of the total acreage, suffered considerable damage. With the use of the resistant varieties Redwood, B5128. and Argentine the disease persisted only on volunteer plants of susceptible varie- ties, and has not been seen since 1955. Symptoms of pasmo disease — dark brown areas on the stem. * ', # Botrytis blight has attacked the two bolls on the right. Such bolls produce little or no seed. The spores of this disease may be car- ried on seed, or may survive the winter on flax straw. As a consequence, seed should be treated before planting and a flax field infested with rust should be planted to some other crop for a year. Once rust becomes established in a flax field there is nothing that can be done to control it. The spores are spread rapidly and widely by wind. Pasmo ( Sphaerella linorum) has been frequently observed on flax in San Mateo County, but has rarely caused severe damage. Damage in excess of 50 per cent has been observed in flax sown in the fall and in February. In both cases the crop had been exposed to large amounts of rain which facilitates the spread of the disease. Affected plants frequently have a banded appearance, with green tissue alternating with brown and dis- eased parts. Plantings made after the first of April usually do not suffer from this disease. Do not plant seed from dis- eased fields, and sow diseased fields to some other crop for one year. Browning or stem break (Poly- spora lini) has never appeared in epi- demic amounts, and is usually detected when infected plants break over at the soil line. Brown lesions appear on the lower portions of the stem and lower leaves, and spread upward. The entire plant may turn brown, and small patches in the field may be affected. It is usually introduced on seed, and seed treatment will destroy the spores on the surface of the seed. Spores inside the seed are un- affected by seed treatment; for this rea- son do not plant seed from affected fields. Insects Insect damage has never been severe on flax in San Mateo County, and con- trol measures are not necessary. Slight damage has been caused by the varie- gated cutworm, the yellow striped army- worm, and the omnivorous leaf tier. The harvesting and marketing of flax All flax in the county is harvested di- rectly by combine. Most of the machines have 5- to 12-foot cutter bars, and all are equipped with rubber rolls. Machines with self-leveling mechanisms are being used to great advantage in the steeply rolling fields. Bulk equipment is increas- ing, but a large part of the crop is sacked and delivered in this form to the proc- essor. Do not start harvesting until the bolls and straw are dry — usually in early Sep- tember. The minimum level of moisture for safe storage is 11 per cent, and the farmer's selling price is based on this moisture content. Actually in some areas of the county it is difficult to reduce the moisture to 11 per cent, and some of the flax is harvested with a moisture content as high as 16 [12] per cent. The processing company re- ceiving such flax must arrange either to process it immediately or dry it. All of the flax seed has been delivered by truck to the processor in San Fran- Disposal of flax straw Flax straw does not disintegrate read- ily in threshing, and usually persists after harvest as tangled clumps or wind- rows. Where the stand is heavy, these are difficult to incorporate into the soil by tillage. The incorporated straw de- composes very slowly and interferes with the planting of subsequent crops. Many farmers have elected to burn the threshed windrows even though they realize that they are destroying organic matter in the process. Burning destroys many dis- ease spores in and on the straw that would be carried over to infect the fol- lowing flax crop. Until better methods for disposal are developed, burning ap- pears to be the only economical way to handle the straw. USDA Grades for Flaxseed Grade No. Minimum test weight per bushel Maximum limits of damaged flaxseed* 1 pounds 49 47 per cent 20 2 30 Sample grade Sample grade shall include flaxseed which does not come within the requirements of either of the grades No. 1 or No. 2; or which contains fire-damaged flaxseed; or which contains more than 11 per cent of moisture; or which is musty, sour, heating, or hot ; or which has any commercially objectionable foreign odor; or which is otherwise of distinctly low quality. * Damaged flaxseed shall be seeds and pieces of seeds of flaxseed which are heat damaged, sprouted, frosted, badly ground damaged, badly weather damaged, or otherwise materially damaged. Flaxseed Prices in Dollars per 100 Pounds Price paid farmers Support price Year Average San Mateo Average California Average U. S. Average California San Mateo U. S. 1948 1949 1950 11.16 7.14 6 70 7.68 7.14 6 43 5 98 5 96 6 07 5.76* 11.04 7 04 6 89 8.46 7.57 6 82 5 93 5 96 6.52 5.71 10 20 6.48 5 96 6 64 6 64 6 50 5 45 5 18 5 34 5 39 10.82f 7 05f 4 96f 5.18f 7.04 7 32 6 20 5 66 6 03 5.77 10 93| 7 16f 5 07 f 5 29f 7 30 7 36 6 21 5 79 6.14 5 88 10 27 6 68 4 59 1951 4 73 1952 6 73 1953 6 77 1954 5 61 1955 5 20 1956 5 52 1957 5 21 * Estimated price of No. 1 flaxseed produced in San Mateo County delivered at Richmond, California. t Estimated from terminal support rate at San Francisco and Los Angeles. Note: 1 bushel = 56 pounds. [13] Marketing flaxseed One company purchases most of the flaxseed grown in San Mateo County. This company guarantees the farmers a market for their flax, and in recent years has set the price before harvest on the basis of the price of flaxseed in the Minneapolis market and the prevailing prices for linseed oil. Flax price relation- ships for recent years are given in the table on page 13, bottom. Grades. The three U. S. official grades which have been established for flax- seed are given in the table on page 13, top. Most of the flax sold in San Mateo County has been on a grade basis. The moisture content must be 11 per cent or less for the flax to qualify for Grades No. 1 and 2. The distinction be- tween these numbered grades is based on bushel weight. The grade is not affected by "dock- age" — foreign material such as broken stems and chaff that is harvested with the seed. Even so, set your combines to re- duce dockage as much as possible, since it costs money to transport trash. Products from the flax plant Linseed oil The oil from flax seed — linseed oil — is used for a variety of products. Most of it goes into the paint and varnish in- dustry. The oil after appropriate treat- ments or additives dries quickly into a tough film. It is also used in products such as linoleum, oil cloth, molds for castings, and printers ink. The oil is not used in food, partly because it tends to develop undesirable flavors rather quickly after processing. Flax seed, as grown elsewhere, may contain from 32 to 42 per cent oil. Well- developed flax seed in San Mateo County yields from 39 to 41 per cent oil. The usual method of processing does not remove all the oil; a small amount re- mains in the meal. Iodine value or iodine number is an index of the drying quality of the oil. The greater the number the better the drying properties. Linseed oil from San Mateo County is unusually high in iodine value, reaching above 200 in many in- stances (see tables on pages 6 and 7). Currently there is no premium paid by the paint and varnish industry for high iodine-number linseed oil, though this industry does have certain minimum standards for iodine value that must be met. Linseed meal The crude protein content of the meal or cake varies from 30 to 38 per cent, and usually averages around 34 per cent. The amount of oil in the meal depends upon the method of processing. The meal is popular with livestock feeders not only because of the high protein content (see table on page 15), but because of its good palatability and slight laxative effect. Feed value of flax straw Flax straw is rarely fed to livestock. If mature and of good quality, it is about equal to oat or barley straw in feed value. It can be used safely as the only roughage for cattle. The fibers are digested like other fibrous materials and do not ac- cumulate in the stomach to form indi- gestible balls. Green flax straw should be fed with caution, because immature flax may con- tain poisonous amounts of prussic acid. The danger is greater if the immature flax is frozen. Volunteer flax appearing after harvest may be unsafe as pasture because it may possibly contain this poisonous material. [14] Linseed Meal is High in Protein* (Feed value comparisons with flax straw) Total dry matter Average total composition Digest- ible protein Total Protein Fat Fiber N-free extract Mineral matter digestible nutrients per cent per cent per cent per cent per cent per cent per cent per cent Flax straw 92 8 7.2 3.2 42 5 32 9 7 5 8 38 1 Oat straw 89 8 4.1 2 2 36 3 40 9 6 3 7 44.8 Barley straw . . . 90 3 7 1.6 37 7 41.0 6 7 42.2 Linseed meal (o.p.)t 91 35 1 4.5 9 36 7 5 7 30 5 75 3 Linseed meal (s.p.)t 90 1 36 6 1.0 9 3 38 3 5 8 30 7 70 3 Cottonseed meal J 92 8 43 3 5.1 11 27.4 6 35 9 72 6 * Data from Morrison, F. B., "Feeds and Feeding," Morrison Publishing Co., Ithaca, N.Y., 1956. t o.p. = old process, using hydraulic press or expellers; s.p. = solvent process. $43% protein grade. Seed flax straw a source of fiber Large amounts of seed flax straw are processed each year in the United States to obtain fiber. The fiber content of straw is about 10 per cent, and the fiber is con- tained in the bark. The extracted fiber is manufactured into high-grade types of paper such as cigaret paper, Bible paper, carbon paper and air-mail bonds. Not enough flax is grown at present in San Mateo County to justify the estab- lishment in the area of a processing plant to remove the fiber. The high humidities may make it difficult to separate the fiber from the rest of the stem. Fiber flax for San Mateo County Linen, one of the finest of fabrics, is made from flax that has been developed for that purpose. Such flax has long fine stems that produce a high-quality fiber. For several reasons, however, a fiber-flax industry is not feasible in San Mateo County, all of them related to the time and cost to remove the fiber from the stems. Plants must be pulled by hand and with a special machine, and tied into sheaves. The sheaves are "retted" — soaked in a tank of water until the non- fibrous portions of the stem have rotted in part — then dried and stored for proc- essing. The yield of the fiber would not be above 400 pounds per acre, with the price not much above 40 cents per pound. [15] Costs of production The table on this page outlines the rela- sentative of the average costs of growin tive costs of the various operations con- the crop there. Moreover, a given opei nected with farming flax in San Mateo ator usually does not find it necessary t County in 1957. It was prepared as a perform all these operations every cr. sample from actual farming records. The year. For example, he may not need t- normal miscellaneous charges including float his field before planting. After taxes, depreciation, interest in the in- planting it may not be necessary to cuiti- vested capital, etc., have been appor- pack the field. Rent costs vary; in. tioned among the various operations. cases sampled here, some of the op These data are useful only as a general ators obviously had negotiated especia'' guide to flax-production costs in coastal favorable leases, districts and are not necessarily repre- Flax Production Costs in San Mateo County (Sample 1957. Assumptions: size of operation 300 acres and 900 lbs/acre yield) — — . _ Operation Cost per &• Plowing $ AC' Disking (once) 2 5G Spring-tooth harrowing (once) 2 . 5V Floating or landplaning 3 OC Planting 2 CO Seed 6.CC Cultipak 2 OC Herbicide application 2 GO 2,4-D amine .30 Harvest 7 . ( Hauling (22^ cwt— 900 lb./A.) 2.i Burning straw 1.5 Rent 7.00 Total costs $41 . 80 Note: The above costs are computed to include overhead costs such as repairs, taxes on equipment, compe. - sation and other insurance, depreciation and interest on investment including that in equipment. No charge 1: s been made for sacks since bulk handling is assumed. Co-operative Extension work in Agriculture and Home tconomics. College of Agriculture, University of California, and United States Department of Agricul ure co-operating. Distributed in furtherance of the Acts of Congress of May 8, and June 30, 1914. George B. Alcorn, Director, California Agricultural Extension Ser ice. 7i*n-10,'59(A0760)JF