L\tf "h UNIVERSITY OF CALIFORN CALIFORNIA AGRICULTURAL Experiment Station Extension Service CIRCULAR 423 WHERE LIMA BEANS ARE GROWN IN CALIFORNIA Major areas where standard limas are grown Major areas where dry baby limas are grown Production of Major Lima-Producing Counties (figures are number of bags for 1945) Standard Limas Dry Baby Lima Beans Los Angeles 156,886 Merced 24,509 Orange 403,736 Monterey 17,712 S. San Diego 71,684 Sacramento 13,042 ^V Santa Barbara 108,968 San Joaquin 136,818 >. Ventura 555,789 Solano 24,423 Stanislaus Sutter 415,963 219,196 A DISCUSSION OF CULTUR/ « MAP shows California lima bean production by counties, 1945. Note areas of concentration: standard limas along the southern California coast; baby limas in the Sacramento and San Joaquin valleys. More production figures are given on page 4. This circular is a step-by-step guide to production of dry edible lima beans in California. Written both for the experienced farmer — and for the man who may be thinking of planting this important California crop — this circular furnishes infor- mation about: o Adaptation: where limas are grown, temperatures and soils they need, place in the cropping system, varieties to grow — page 6. Culture: step-by-step tillage operations, planting, cultivation and irriga- tion, harvest — page 9. Q3 Post-harvest operations: storage, cleaning, grading — page 19. ^^ Diseases, pests, weeds: control facts — page 20. Lima bean seed production: how to avoid mechanical injury — page 24. THE AUTHOR: R. W. Allard is Associate Professor of Agronomy, and Associate Agrono- mist in the Experiment Station, Davis. PRACTICES STARTS ON PAGE 9^ f Production of DRY LI IBLE R. W. ALLARD Production facts . . . Acreage. The combined acreage of standard limas and baby limas varies from year to year, but has gradually in- creased from about 100,000 acres an- nually in 1919-23 to more than 150,000 acres in 1944-48. The acreage was 120,000 in 1951. Production. Production has gradu- ally increased from about 1,200,000 cwt.- bags annually in 1919-23 (a yearly average of standard and baby limas com- bined), to nearly 2,200,000 bags in 1944-48. The highest production was in 1949, with 2,648,000 bags. Most of this production increase has been in the Sacramento-San Joaquin Valley baby lima areas. Production in 1951 was 1,966,000 bags. Prices. Prices paid farmers have fluc- tuated widely. They have varied from less than $3.00 per cwt. for baby limas in 1931 to nearly $24.00 for standard limas in 1947 (fig. 1). Prices for 1951 were an estimated $11.45 for standard limas, $6.35 for baby limas. • • . and some background Production of limas in California as dry edible beans grew accidentally out of the seed industry. The early history of the large-seeded lima in the United States is rather obscure, but it indicates that this plant of Peruvian origin was introduced to this country several times before its general cultivation as a garden vegetable in eastern United States about 1825. Limas were grown in California as a garden vegetable as early as 1855. The success of small plantings for seed be- tween 1872 and 1874, together with the difficulties of seed production in the humid eastern states, prompted a larger California planting of limas for seed in 1875. Exceptional yields in this enter- prise led to the recognition that limas had a place in California as a market class of dry edible beans. Later, by trial and error, they were found to be well adapted to parts of Santa Barbara, Ventura, Los Angeles, Orange, and San Diego coun- ties, and they rapidly replaced barley as the predominant crop in the fertile coastal valleys of southern California. [4] ~1920 1925 1930 1935 1940 1945 1950 Production and price of both standard and baby limas in California from 1919 to 1951 The market class of baby limas also grew out of the seed industry. Baby lima beans were grown by the Indians in southeastern United States for several centuries before the white man came, and they considerably pre-date large limas as a vegetable plant in North America. But it was not until a few years after the then new baby lima variety, Henderson, was sent to California for seed increase in 1888, that the possibilities of baby limas as a market class of dry edible beans were recognized. When it became known that the Henderson could grow outside the fog belt, this variety soon came to occupy considerable acreage in the warmer in- terior valleys of southern California. Only with the development of irrigation districts in the upper San Joaquin and central Sacramento valleys in the decade after 1925 did baby limas receive the impetus by which production now some- times exceeds standard limas. Si 250 - 1 o 1000- e 750 500 250 □ Southern California Sacramento Valley San Joaquin Valley STANDARD LIMAS BABY LIMAS 1936 1941 1946 1936 1941 1946 1940 1945 1950 1940 1945 1950 [5J Production of standard and baby limas in Cali- fornia by areas, from 1936 to 1950. CONSIDER THE ENVIRONMENT ADAPTATION: lima beans are demand- ing of temperatures but tolerant of many soil types. Temperatures and Rainfall Temperatures are critical in the adap- tation of standard limas. Standard limas are a warm season crop, but are also very sensitive to blossom drop induced by high temperatures and low humidities. The exacting climatic needs are met in only one area in the United States, the equit- able climate of the strip, rarely more than 10 miles wide, along the coast of southern California. In fact, satisfactory climatic conditions for standard limas exist in only a few other areas on earth, such as in limited parts of Madagascar and Peru. Baby limas are not so restricted. A \, SACRAMENTO^" J J A S O N D Temperature and humidity records for typical standard and baby lima bean areas in Cali- fornia. number of varieties thrive in the hot dry summers of the interior valleys. Temper- ature and humidity records for typical lima and baby lima producing areas are given in the graph opposite. The rainfall pattern is an important factor in concentrating production of dry edible limas in California. The dry summers of California eliminate the moist-climate fungus diseases as a factor in production. Moreover, the normally light rainfall in the harvest season, inter- spersed with drying weather, makes har- vesting operations much less hazardous than in other areas of the United States. Soils Lima beans can be grown satisfactorily on a wide range of soil types. They are at their best on the loam soils, but have been produced successfully upon heavy clays and sandy soils. Limas are moder- ately sensitive to salts, and there are sev- eral other crops which are likely to be more successful on saline soils. Place in the Cropping System Lima beans are a favored crop in most areas where they are adapted. Competing crops are sugar beets, vegetables, and alfalfa, and to some extent citrus and walnuts. Limas are usually not grown in a planned rotation, but rather yield to other crops under the influence of price relations and distribution of seasonal labor, water, and machinery require- ments. In major lima growing areas, beans are frequently the exclusive crop or the major crop of a particular farm. The high cost of equipment dictates large- [6] scale farming in limas. Most of the crop is produced on farms where more than 100 acres are planted, and even up to several thousand acres. Limas are frequently grown year after year on the same field. At least one field has been in limas continuously since 1882 with no apparent decline in yields. The only rotation consistently resulting in in- creased yield is with alfalfa. Response to alfalfa is usually for three or four years. Limas may occasionally be ro- tated with tomatoes or other row crops, such as sugar beets or melons. Still more frequently they are rotated with winter vegetables, but double-cropping on lima ground is rare because limas have a long growing season. Cereals are sometimes used in a rotation with limas to help con- trol root-knot nematode. Occasionally winter green manures are grown on fields to be planted to limas the following spring. Green manure species do not make much growth during the coldest part of the winter and they must be turned under shortly after the onset of favorable growing weather in the spring in order to start spring tillage operations. Hence, most of the growth will be obtained in the fall. This necessi- tates fall irrigation to start the green manure species in time for worthwhile growth to take place. Varieties Only three varieties, one standard and two baby limas, are certified by the Cali- fornia Crop Improvement Association. New varieties are constantly being tested by the University of California. The three described below are the only varieties which have so far proved satisfactory. Ventura is the only standard lima va- riety recommended for production in California. Like all other strains of stand- ard limas, such as Lewis, Young, and a multitude of other local strains, it was derived by selection from the somewhat variable strain originally introduced to California. Ventura differs from most of the other strains only in its slightly greater uniformity of maturity and size, of color, and of shape of seed. University of California plant breeders have main- tained the uniformity of this strain. Be- cause of its known purity, Ventura is to be preferred over other strains which are contaminated to various degrees by mix- tures and off-types. Ventura is a thick-stemmed, many- branched, indeterminate or vining vari- ety with large (2%" x 51/2"), dull-gray, variegated leaflets. The seeds are large (400 per lb.), flattened, and dull white to gray-green when they are dry. Ventura requires from 105 to 130 days from plant- ing to cutting in its areas of adaptation. In a few dry-farmed areas, standard lima types with slightly smaller seeds than Ventura have been selected by farm- ers and probably by natural selection also over a long period of time. Because these selections may be slightly earlier and otherwise better adapted than Ventura their use may be justified in the areas of limited moisture where they were de- veloped. Wilbur has been the preferred baby lima variety in the San Joaquin and Sac- ramento valleys for over twenty years. It is a fine-stemmed indeterminate type with small (2%" x 3%"), very dark- green, nonvariegated leaflets. The seeds of Wilbur are white when mature and average about 1100 to the pound. Wilbur requires 100 to 120 days from planting to cutting. Westan is a nematode-resistant vari- ety of baby limas. It is very similar to Wilbur and is difficult to distinguish from Wilbur at most stages of growth. It is often slightly less intense green in color. Westan usually produces a slightly heav- ier vine growth, its crown set is placed slightly higher than Wilbur, and while its seeds are generally very slightly smaller, they are somewhat more sensi- tive to mechanical injury than the seeds of Wilbur. Westan is also slightly later to mature than Wilbur, perhaps 2 to 3 [7] Leaves and seeds of Ventura and Wilbur varieties of lima beans. days. Westan can be distinguished easily from Wilbur when nematode infestations occur. Levels of nematode infestation which will cause Wilbur to fail completely will cause almost no damage to Westan. Under nematode-free conditions Westan and Wilbur produce about equal yields, but Wilbur is preferred because it is somewhat more dependable and easier to handle. Other baby lima varieties are grown occasionally in local areas. Hen- derson Bush, a determinate or bush type. was the major variety grown until re- placed by Wilbur. It is still grown oc- casionally as a dry edible baby lima variety, particularly in the inland valleys of southern California. A number of in- troductions from the Hopi Indian Reser- vation in Arizona were grown on nematode-infested areas before the re- lease of Westan. None of these varieties possess nematode resistance equal to that of Westan. For this and other reasons, the Hopi types are not recommended varie- ties. [8] WHAT IT TAKES TO GROW LIMA BEANS CULTURAL OPERATIONS include pre paring the land for planting and car- ing for the crop through harvest. Tillage Operations The various tillage operations used with lima beans are designed to accom- plish one or more of the following results : (1) incorporate bean straw or plant ma- terials into soil; (2) prepare soil to ab- sorb a maximum amount of water; (3) prepare soil for irrigation; (4) control weeds; and (5) prepare an adequate seedbed. A variety of different imple- ments and sequences of operations is suc- cessful. Any operations in excess of those necessary to accomplish the above objec- tives will be wasted. Disking, Plowing, and Subsoiling. In the fall it is usually necessary to re- duce the bean straw or litter of other preceding crops to clear the ground for subsequent operations. Also, unless plant materials are incorporated into the soil they cannot be expected to decompose satisfactorily during the winter. Disking once or twice will usually be sufficient. Disking is usually followed by plowing or subsoiling. Fall plowing with a moldboard plow leaves the soil rough, cloddy, and in good condition to absorb winter rainfall. Plow- ing more than 6 or 8 inches deep is un- necessary. Over the winter, rainfall will soften clods and reduce airspaces in the soil, thus preparing it for spring opera- tions. Subsoiling is occasionally used with or in place of plowing. This particular till- age operation is intended to loosen the soil to a considerable depth and so to increase the penetration of irrigation water. Comparisons of subsoiled and un- subsoiled areas show that subsoiling will not increase water penetration except where compaction is extreme or shallow hardpans or plowsoles exist. On normal soils the evidence is not clear cut that this expensive operation can be justified. Leveling. Properly leveled land is es- sential for adequate irrigation (page 16) . Floats or landplanes properly used will eliminate minor irregularities which, if not removed, make for poor uniformity and increase the cost of irrigation. If possible, landplaning should be per- formed when the soil is dry because this heavy equipment will pack moist soil severely. If other tillage operations are carefully performed, especially plowing, landplaning every year may not be neces- sary. Preparing the Seedbed. The re- quirements for the germination of lima seed are: (1) adequate moisture supply; (2) adequate oxygen supply; and (3) proper temperature. Any tillage opera- tions in the final fitting of the seedbed which do not contribute to these require- ments are unnecessary unless they also contribute to the control of weeds. If win- ter rainfall has been inadequate, pre- planting irrigation will be necessary to provide an adequate amount of moisture. Once moisture supply is adequate in the soil, spring tillage operations should keep the soil sufficiently firm and free of air spaces to minimize evaporation of mois- ture, and at the same time avoid packing the soil to the point where subsequent operations are difficult and the oxygen supply is inadequate for planting. Work- [9] PREPARING THE SOIL FOR PLANTING A. The clods in this field were softened by winter B. Subsoiling sometimes replaces plowing. Many rains. Harrowing is being done in April to pre- doubt that this operation is justified except to pare the soil for pre-planting irrigation and to break up hardpan or claypan. destroy weed seedlings. *f C. Minor irregularities can increase the cost of irrigation unless removed by landplaning. D. Furrowing for a pre-planting irrigation. E. Here, the final fitting of the seedbed is done with a spiketooth harrow. [10] V \ d • ing soil that is wet is particularly un- desirable because the vital oxygen supply is easily squeezed from wet soils. Disks or other implements which loosen the soil excessively should be avoided in the late spring if moisture loss is to be avoided. Final fitting of the seedbed is usually ac- complished with spiketooth harrows although a number of tools are satisfac- tory for the purpose. Planting Seed. Good seed is the foundation of a successful crop. Use the best seed avail- able. The cost of the seed is a small pro- portion of the total cost of producing the crop. Hence the grower can afford to use the best possible seed. The use of Cali- fornia certified seed is recommended. This seed is produced under the supervi- sion of the California Crop Improvement Association. To be approved for certifi- cation, seed must meet established standards of genetic purity, germination, and freedom from weed seeds and other impurities. The cost of the insurance ob- tained in purchase of good seed will usu- ally not exceed 3 or 4 cents per hundred pounds of harvested crop with baby limas, and twice that amount for stand- ard limas. Certified seed is available from a number of sources in each major lima producing area. Lists of suppliers may be obtained from the California Crop Improvement Association at Davis. Some of the problems and dangers in seed pro- duction are discussed on pages 24 to 26. Seed Treatment. Lima seed is usu- ally treated with both a fungicide, such as Arasan or Spergon, and lindane, an insecticide. Arasan, Spergon, and similar fungicides have proved effective in con- trolling the seed-rotting fungi. Lindane is the essentially pure gamma isomer of benzene-hexachloride which is remark- ably effective in controlling wireworms and seed-corn maggots. With late season planting, when soil temperatures gener- ally approach the optimum for limas and are above optimum for seed rots and wireworms, seed treatment is less impor- tant. However, the cost of treatment is small in proportion to costs of replanting, and treatment is probably always justi- fied. Inoculation and Fertilization. The lima bean nitrogen-fixing bacteria are not the same as the ones which cause nodules on common beans. Artificial in- oculation of lima bean seed with nitro- gen-fixing bacteria has not given visible or measurable responses on either old fields or fields that have not been previ- ously cropped to limas or other beans. Upon fields previously not cropped to beans, nodulation is usually sparse the first year irrespective of inoculation. Nodulation increases during the second and third years, also irrespective of in- oculation. Beans almost invariably occupy fertile soils, and economical returns from fer- tilization have not been demonstrated except in cases where beans follow crops which seriously deplete nitrates, such as sorghums or barley. Time of Seeding. Because limas are a warm season crop, cold soil tempera- tures may inhibit germination. The effect of soil temperature upon the germina- tion of limas is shown in the accompany- ing table.* remp. . % . Av. No. °F Germination Days to Emerge 48 55 2 31.0 61 52 28.0 68 82 17.6 77 80 6.5 85 88 6.7 95 2 9.5 * Data kindly made available by Dr. L. D. Leach, Department of Plant Pathology, Davis. The table shows that unsatisfactory percentages of emergence occur at tem- peratures lower than 68° and at or above 95°. Further, although the percentage of emergence was satisfactory at 68°, nearly 18 days were required on the aver- age for emergence to occur, contrasted [12 to about a week at temperatures between 77° and 85°. Thus, soil temperatures be- low 70° or above 85° are unsatisfactory and the optimal temperatures lie between 75° to 85°. Limas have poor ability to emerge through crusts. Spring rains, besides causing crusts, may reduce soil tempera- tures to the danger point and favor the activity of seed-rotting fungi in the soil. Delay planting until the soil temperature at 3" depth is 70° or above, and until there is little danger of spring rainstorms. Proper soil temperatures and freedom from rain are usually attained in early May. Planting of large limas usually starts during the last week in April, reaches a peak in the first week of May, and is mostly completed by mid-May. In the baby lima areas of the San Joaquin Valley the season is about one week later ; it is still another week later, on the aver- age, in the Sacramento Valley. Methods of Seeding. Baby lima beans are very susceptible to mechanical injury. Standard limas are more so. (See "Seed Production" page 24.) For this reason plate-type planters have not proved satisfactory for seeding lima beans in California. Rather, indent-cup planters are used almost exclusively be- cause of the gentleness with which they meter out seed. The indent cups are mounted on sprockets rotated through hoppers, each with a capacity of approxi- mately 30 pounds of seed. As it passes through the bulk seed, each cup picks up a single seed which drops, as the sprocket rotates, into a tube leading into a furrow- type opener. Disk openers have not been satisfactory because the depth of planting is usually too great for efficient opera- tion. To reduce the moisture loss to a minimum, the furrow is usually packed immediately after planting. This may be accomplished with spring-mounted packer wheels or by pulling drags of various sorts behind the planter. The most common planter seeds 8 rows, although many 4-row and some 12- This is one unit of a Ventura-type indent-cup planter. row planters are in use. Tractor-mounted planters are gaining in popularity. Depth of Planting. Depth of plant- ing should be adjusted to place the seeds not less than 1" in moist soil; the danger of drying will be less if the seeds are about 1V>" to 2" deep in moist soil. Total depth of planting usually should not ex- ceed about 4" for baby limas and 5" for standard limas, especially in the heavier soil types. Avoid planting deeper than necessary to protect against drying out before emergence. Deeper planting increases the time required for emer- gence and hence the weather hazard, as well as the hazards of seed rotting and pre-emergence damping-off. With 2%" to 4" planting depths and average temperatures during the opti- mum planting periods in May, emergence [13] may be expected in 9 or 10 days. Should sufficient rain occur after planting to cause crusting, the crust must be broken. The usual tool for this purpose is the rotary hoe, although a light harrow is usually satisfactory if none of the plants has yet emerged. The rotary hoe can be used without damage to the stand up to 2 or 3 weeks after emergence, both for breaking crusts and controlling weeds started by rains. Breaking up crusts al- lows surface drying, which will control small weeds and those in the process of sprouting. The rotary hoe is particularly valuable because it controls even those weeds in the row that are otherwise inac- cessible except to hand-hoeing. Rates. The amount of seed required depends upon the percentage germination of the seed planted, the survival of seed- lings, and the desired density of stand. Good seed usually exceeds 90 per cent germination for baby limas; 85 per cent, standard limas. Minimum germination for California Certified Seed is 85 per cent for both types. Emergence of good seed under field conditions is unlikely to exceed 70 to 80 per cent and frequently will be less than 50 per cent. If high- germinating seed protected with fungi- cides and insecticides is used, 40 lbs. of baby lima and 80 lbs. of standard lima seed per acre are ample. If conditions are so adverse that ample stands are not ob- tained with these rates of seeding, larger amounts of seed are still unlikely to pro- duce an adequate stand. With seed of low germination, seeding rates must be heavier. Moreover, seeding rates required will increase more rapidly than laboratory germination rates de- crease. This is because many seeds which are too weak to emerge under field con- ditions are capable of germinating in laboratory tests. The following table shows the effect of different spacings in 30-inch rows upon the yield of baby and standard lima beans. Figures are in percentage of 4-inch spacings. ipacing Baby Standard inches % % 4 100 100 8 94 12 90 102 18 83 24 73 92 30 63 ... Both standard and baby lima beans are usually grown in rows 30 inches apart. The spacings within rows, however, are quite variable because of variation in seed quality, seeding rates, and soil, weather, and disease conditions at planting. Fre- quently stands of baby lima beans with one plant to each 8" to 12" and stand- ard limas with slightly sparser stands will be replanted as inadequate. The above table indicates that this practice is usu- ally not justified. Replanting is costly and in addition must usually be done after the optimum planting date, which leads to decreased yields and the weather haz- ards of a later fall harvest. If stands are more sparse than one plant per 18", re- planting is desirable. Inter-row Cultivation Inter-row cultivation accomplishes two things and two only: (1) controlling weeds; and (2) making the furrows necessary for irrigation. Cultivation usually starts about 35 days after planting. The sweeps or weed knives should be set as shallow as is con- sistent with cutting off weed seedlings. Deep cultivation stirs the soil, causing moisture loss, and may also cut off roots of the bean seedlings. At the cultivation preceding the first irrigation, furrowing shovels replace sweeps. Special flat shovels which push rather than throw the soil, reduce covering of the small seed- lings with soil. The first irrigation usually starts germination of large numbers of weed seeds. At least one post-irrigation cultiva- tion is necessary. If weeds are present, cultivations should be continued until no [H] '■ " ' ' " ■■■■ ■ ■ '* • 1 1 ii "rJ^'^'^^^^^^^o^BiliiS vu -£%„. J*y2£h;* ?'*„" **- A rotary hoe is breaking a crust after a rainstorm that occurred immediately after seedling emergence. This operation also destroys many young weeds. PRE-EMERGENCE CULTIVATION An 8-row outfit is used to furrow for the first post-planting irrigation. w [15] longer possible because of the growth of the vines. After the vines have grown to- gether, their shade aids in control of weed seedlings. However, at least one hand-hoeing is usually necessary. In the sub-irrigated areas of the Sacra- mento Valley, the top 2 or more inches of soil become permanently dry shortly after planting. The seedlings of small- seeded weeds have difficulty in emerging. In that area a single very shallow cultiva- tion and a minimum of hand hoeing will frequently keep weeds under control, ex- cept where the protective mulch is dis- turbed. Irrigation Standard limas are historically a dry-farmed crop. With the development of irrigation facilities during the present century, it became standard practice to irrigate before planting in years of short rainfall. More recently one or occasion- ally two post-planting irrigations have been applied to insure adequate moisture during the entire growing season. About 40 per cent of the standard lima acreage is upon non-irrigated fields at present. Plantings of dry-farmed limas fluctu- ate widely in response to the adequacy of winter rainfall. Unless the soil is wet to a depth of 3 to 4 feet, depending upon its water-holding capacity, dry-farmed acreage cannot be planted. Baby Limas. Transpiration losses are much higher in the baby lima districts, necessitating heavier applications of water. Usually a pre-irrigation and two to four post-planting irrigations are re- quired. Most of the limas in the Sacra- mento Valley are grown in sub-irrigated areas. Constant moisture is supplied by regulating the water level in canals sur- rounding the fields and hence the water table. In some cases "spud" ditches in the fields are necessary to maintain the water table at the desired 18" to 24" level. Sprinkler irrigation is becoming more popular, particularly in the Sacramento Valley. The roots of limas penetrate the soil as deep as 5 feet. Irrigation water that penetrates deeper than the root zone will be wasted. A soil tube is desirable for determining that the amount of water ap- plied wets the soil throughout, but not deeper than the root zone. No more than the minimum number of irrigations re- quired to keep the plants in a healthy growing condition should be applied. Blossoms and the small pods of limas and, to a lesser degree, baby limas will drop if the plant suffers from lack of water. Irrigations should be planned to prevent water stress, which is indicated most conspicuously by "black" color and temporary wilting during the hot part of the day. Limas bloom in excess so that considerable blossom drop is normal. This should not be confused with that re- sulting from a deficiency of water. The last irrigation must be carefully timed. If applied too early, insufficient moisture to mature the crop may cause undersized beans. If the last irrigation is applied after the weight of the crop has pulled many pods close to the soil sur- face, water damage to the seeds may re- sult. The Wilbur variety, with its low crown set, is rather easily damaged by late irrigation. Late irrigations may also cause the plants to resume vegetative growth in the fall. This succulent new growth is difficult to dry and to harvest. Harvest Harvest consists of two major steps: (1) cutting and windrowing; and (2) threshing. The purpose of cutting is to sever the roots from the soil so that the plants can be placed in windrows to dry. Threshing the seeds cannot proceed until the plants are sufficiently dry. Limas can be cut when about three- fourths of the pods are dry and most of the rest have turned from green to yellow. Since limas are of indeterminate flower- ing habit, some pods will always be im- mature at cutting. Cutting too early will lead to an excessive number of under- [16] Water metered out to the furrows through pipe Siphons are used to meter out water to furrows of 2-inch diameter. from the supply ditch. wm^®M$®mw^«>\*~ Irrigation by metal surface pipes. Small slide Sub-irrigated field. This method is popular in gates control the flow of water to each furrow. the Sacramento Valley. TYPES OF IRRIGATION STRUCTURES USED Sprinkler irrigation is increasing in popularity in the Sacramento Valley. [17] sized beans. However, if cutting is de- layed to allow the later-setting pods to mature, shattering may be excessive, and weather hazards will increase. Many types of bean cutters are avail- able. All, however, employ steel knives about 4 inches wide by 3% feet long to do the actual cutting of the beans. These knives are set to cut off the roots 2 to 3 inches below the soil surface. Guide rods are used to center two field rows into a cutter row. Side-delivery rakes are used to place four cutter rows or eight field rows in a windrow. Cutting and windrow- ing must be done when the pods have been toughened by high humidity or dew, if excessive shattering is to be avoided. Usually these operations can start shortly after midnight and cannot be continued beyond midday. From 1 to 3 weeks, but usually about 10 days of windrow curing are necessary to dry the plants sufficiently for thresh- ing. The beans are threshed directly from the windrow. Nearly all of the crop is threshed with machines designed espe- cially for the threshing of beans. Low humidities prevail during most of the normal threshing season especially in the baby lima areas, and the beans are likely to be very dry and brittle. Considerable judgment is necessary in the management of threshing operations, if splitting of seed is to be avoided. General purpose combines can be used for threshing limas, but require particularly careful adjust- ment. STEPS IN HARVESTING Top— four-row tractor-mounted cutter has sickle- type dividers for cutting the vines in the row for passage of the cutter. Center— side-delivery rake places cut beans in windrows. ^V.V i ! .* ^ Bottom— this thresher is especially designed for ^~^A beans. [18] Storage, Cleaning, Grading During the decade 1940-1949 a nearly complete changeover was made from sack-handling of limas to bulk methods. After threshing, the crop is hauled to the local warehouse where it is stored until it can be cleaned. Thresher-run beans may contain trash of various sorts — broken, cracked, and discolored beans, and small clods and stones. A variety of machines is available for separating these foreign materials. The basic cleaning machine is the screen- air machine, which will remove straw, dust, stones, broken beans or other ma- terials differing in size or density from beans. Gravity machines are useful in re- moving some foreign materials that can- not be separated by screen-air machines. Some clods and broken beans can be re- These boxes of beans are stored temporarily outside a warehouse. When moved, they will be handled with fork trucks. Grade Requirements for the Classes Lima and Baby Lima Beans Maximum limits of — Grade Blistered, wrinkled, skinned, and /or broken Splits Defects consisting of damaged beans, contrasting classes, and foreign material Other Total Badly damaged beans Contrast- ing classes Foreign material classes that blend Total Stones U. S. Extra No. I 14 .. 3 2 1 0.5 0.2 0.2 Trace 2 U. S.No. I 24 5 3 2 1.0 0.5 0.5 0.2 5 U. S.No.2 34 8 4 3 1.5 1.0 1.0 0.3 10 U. S. Substandard. . . U. S. Substandard shall include beans of any one of these classes which do not come within the requirements of the specifications for the grades U. S. Extra No. 1, U. S. No. 1, or U. S. No. 2 or for the grade U. S. Sample grade. U. S. Sample grade . . 17. S. Sample grade shall include beans of any one of these classes which are musty, or sour, or heating, or hot, or weevily, or ma- terially weathered, or which have any commercially objection- able odor, or which are otherwise of distinctly low quality. 1 The beans in the grade U S. Extra No. 1 of the class Lima may contain not more than 20 per cent of beans that will pass through a No. 30 sieve, which 20 per cent may include not more than 5 per cent of beans that will pass through a No. 28 sieve. 2 The beans in the grade U. S. No. 1 of the class Lima may contain not more than 25 per cent of beans that will pass through a No. 28 sieve, which 25 per cent may include not more than 5 per cent of beans that will pass through a No. 24 sieve. 3 The beans in the grade U. S. No. 2 of the class Lima may contain not more than 40 per cent of beans that will pass through a No. 28 sieve, which 40 per cent may include not more than 5 per cent of beans that will pass through a No. 24 sieve. 4 The beans in the grade U. S. Extra No. 1, IT. S. No. 1, and U. S. No. 2 of any one of these classes shall be well screened. [19 moved only by adobe rolls or by the re- cently developed clod picker. Occasion- ally hand-picking may be necessary to remove discolored beans and foreign ma- terials not removed by machine cleaning. Electric-eye sorters have replaced some hand labor. The material removed from field-run beans in cleaning is usually about 5 per cent of total weight. Of this dockage, only the cull beans have value. They are usu- ally sacked and sold for stock feed. Standards for beans have been estab- lished by United States Department of Agriculture. Grade requirements for lima and baby lima beans differ from the requirements for other classes of beans, and are shown in the accompanying table. Diseases, Pests, Weeds Diseases, pests, and weeds are prob- lems in all lima bean growing areas of California. Some of them are widely dis- tributed and cause economic losses every year. Others are more localized in distrib- ution and more sporadic in the damage done. By far the most important fungus diseases of lima beans in California are seed rot, damping-off, and root rots caused by Rhizoctonia solani and similar fungi; the root-knot nematode and wire- worms are the most serious pests; and water-grass, morning-glory, and the ground cherry are among the most dam- aging of the weeds of lima fields. Diseases Seed rot, damping-off, and root rot are three phases of a group of diseases caused by soil-borne fungi {Rhizoctonia solani, Pythium ultimum, and Fusarium solani). The symptoms caused by the various fungi are similar, and for prac- tical purposes they may be considered to be a single disease which attacks lima beans at several stages of development. When these organisms attack seeds, rot- ting them in the soil, the disease is called seed rot. Young seedlings may be at- tacked both before and after emergence. Rhizoctonia solani caused these root-rot lesions. At this stage of development, the disease is called damping-off. Finally, these or- ganisms can attack the hypocotyls and roots of bean plants at later stages of development, causing root rot. These fungi are present in most if not all soils. While their seriousness on beans may be reduced by rotations with dif- ferent crops, the organisms cannot be eliminated in this way. Seed treatment with fungicides, such as Arasan, Phygon, and Spergon will markedly reduce seed rotting and pre-emergence damping-off. Lima bean seed should always be treated with one of these seed protectants. Both dust and slurry methods of treatment have been successful. No effective control measures are yet available for the root rots caused by these organisms, although promising progress is being made in de- veloping resistant varieties. Pests Root knot is the most serious pest of lima beans, ranking with root-rot dis- ease in economic importance. It is caused by an eelworm or nematode, a small white worm barely visible to the unaided eye. These small worms invade roots 20] Plants from adjacent rows showed: left, galls caused by root-knot nematode in the Wilbur variety; right, root of the nematode-resistant Westan variety. where they stimulate the development of large galls, which disrupt the normal functioning of the root. The aboveground symptoms of the disease are stunting, yel- lowing, and abscission of the leaves, and frequently death of the plant. Nematodes prefer warm areas and are particularly serious in southern Califor- nia and the San Joaquin Valley. They have recently been observed in the Sac- ramento Valley. They cause more damage on sandy and loam soils than on heavier soils. Nematodes are soil-inhabiting and can live for many years in the soil even when susceptible crops are avoided. The root-knot organism attacks a great vari- ety of crop plants and weeds, only the grasses as a group being resistant. Crop rotations with cereals can drastically re- duce nematode populations in the soil. However, cereals are not a popular rota- tion in most lima bean areas for economic reasons, and the benefit of a cereal rota- tion seldom persists more than one sea- son. Alfalfa is popularly regarded as resistant to root-knot. While alfalfa is rarely injured by root-knot, the root-knot organism attacks its roots and reproduces abundantly. Because of its deep-rooting habit alfalfa tends to reduce nematode populations in upper soil levels and in- crease their abundance at lower levels. Shallow-rooted crops, such as beans, are thus given temporary relief by following alfalfa, but alfalfa cannot be considered a satisfactory rotation for controlling nematodes; in reality, it only succeeds in further spreading the pest. There are two methods of control. Treatment of the soil with dichloropro- pene-dichloropropane and similar soil fumigants gives temporary relief, one treatment sometimes allowing two or more bean crops to grow without dam- age. However, the popularity of chemical treatment is limited by its expense. The most satisfactory control is by using re- sistant varieties. Only one such variety, the Westan baby lima, is available at present, but nematode-resistant versions of Ventura and Wilbur will be available in a few years. The Westan variety is not immune to root-knot, but has sufficient tolerance to make satisfactory yields in fields where Wilbur or other susceptible varieties fail completely. [21 The background area of this field has Wireworms are the larval stage of click beetles. These beetles lay their eggs in the soil; the eggs hatch into small wormlike larvae that take two to five years in the soil to reach the pupal and then adult stages. It is during the period of rapid growth of the larvae, usually during the second year of the larval stage, that the appetite of the worm is greatest, and damage to crops occurs. The larvae feed on seeds, underground portions of young plants, and occasionally on the underground portions of older plants. They usually cause the most damage in the 2 to 3 weeks following planting and sometimes cause nearly complete failures of stands. Because the worms move to deeper soil levels when temperatures in- crease in the late spring, they are usually less serious in fields planted later and in the warmer years. Very effective control measures have been developed since 1946. Lindane af- fords practically complete protection when small amounts are placed on the seeds before planting. Dosage recom- mendations of the manufacturer should be carefully observed because lindane, the essentially pure gamma isomer of benzene-hexachloride, is toxic to beans. Since the toxic effects of the chemical are reduced by such fungicides as Spergon and Arasan, it is recommended that benzene-hexachloride always be applied in combination with a fungicide. Soil treatments with DDT, chlordane, and a number of other insecticides are also known to have been effective in control- ling wireworms. Red spiders cause some damage to standard lima beans nearly every year, and spectacular damage in certain years. Baby limas are much more tolerant and are rarely damaged. Several closely re- lated species of these small mites can at- tack limas, but all species cause similar symptoms and damage. The mites suck the juices primarily from bean leaves, but also attack the stems or pods. Cen- ters of infection usually arise near dusty roads, in areas where the plants are suf- fering from lack of water or where plants are not growing vigorously for other rea- sons. No completely satisfactory control measures exist. However, dusting with sulfur, the organic phosphates, or other [22] newly developed chemicals appears to provide control in some cases. Lygus bugs can cause damage to beans by piercing the flowers and small pods, causing abscission. The insect also feeds on older pods, causing small unat- tractive spots on the seed coat of the en- closed beans. Occasionally this insect may become sufficiently prevalent to justify the application of control measures, the most effective of which is DDT dust. Thrips usually feed upon the lower leaf surfaces of lima and baby lima bean leaves. These small, black and white or straw-colored insects are easily visible to the unaided eye. Characteristic dark spots of excreta left by the insect on the leaf surface aid in recognizing its pres- ence. Thrips cause the most damage fol- lowing barley in rotations, or in portions of bean fields adjacent to barley stubble. They are also likely to attack plants which have been inadequately irrigated, at- tacked by nematodes, or which, for other reasons, are not growing vigorously. DDT and sulfur dust and several other insecticides have given satisfactory con- trol. Leaf miner in the larval stage invades the leaves of bean plants to feed on the tissues under the epidermis. It leaves characteristic and easily recognized tun- nels. Damage of economic importance has not been reported. Bean weevils rarely infect limas in California, but can infect them both in the field and in warehouses. Weevily seed should not be planted or permitted on the premises. Weevily limas are placed in sample grade; hence, control of this in- sect is important. The pest can be killed in beans in warehouses by fumigation with methylbromide or with a number of other chemicals. Lima bean pod borer, in the larval stage, can invade the immature pods of lima beans and attack the seed. This insect usually eats only part of the seed, leaving large unsightly holes. Large- seeded varieties are much more fre- quently damaged than the smaller-seeded varieties. Damage from the lima bean pod borer is also much more severe on late-planted limas. No completely effec- tive control measures are available, but various insecticides will reduce popula- tions of this pest. Weeds Barnyard grasses, commonly known as watergrasses, are among the most troublesome weeds of lima bean fields, particularly in the irrigation districts of the San Joaquin Valley. There are several types of these annual grasses, some bearded and others beardless. They differ considerably in maturity, height, and size of stems, panicles, and leaves. Water- grasses are best controlled by a combi- nation of crop rotation, pre-planting tillage, and careful irrigation and inter- row cultivation. Careful irrigation to prevent flooding will aid in preventing watergrass from germinating in the rows. Cultivation should be timed to kill water- grass in the seedling stage because older plants with sizable crowns are difficult to destroy with ordinary cultivation. In fields where watergrass has not become severe, the occasional plants should be removed by hand before they set seed. Spraying canals and ditchbanks can ef- fectively limit the spread of seed in irri- gation water. Fence rows and head lands should also be kept clean to prevent field infestation. Morning-glory is a perennial weed important in all lima bean growing areas. Soil fumigation with carbon-bisulfide has long been used in its control and is still useful for treatment of small localized patches of the weed. Although lima beans are sensitive to 2,4-D, several methods of application have been devised, which avoid serious injury to the crop. Effective use of this herbicide depends on the pres- ence of adequate aboveground growth of the morning-glory, usually not at- tained until after lima beans must be planted. If spring tillage operations are 23] carefully planned, it is sometimes pos- sible to apply a 2,4-D spray before plant- ing. Pre-irrigation between spraying and planting will help to eliminate the resi- dual 2,4-D which may affect germination of the beans. Careful shielded spraying between bean rows has showed little ef- fect on the beans and good control of morning-glory. In fields with heavy in- festations of morning-glory, a crop rota- tion is necessary if 2,4-D is to be used. Barley, corn, sorghums, and a number of other crops which are highly tolerant of 2,4-D make satisfactory rotation crops for this purpose. Ground cherry and nightshade are serious annual weeds of beans. Their ber- ries are juicy at harvest, breaking in the thresher, and causing discoloration and sticking together of the beans. Suit- able crop rotations, careful cultivation, and hand-hoeing are necessary for con- trol. Because of the succulence of these plants, immature berries will frequently mature their seeds after the root has been severed. The plants should be removed from the field when hoed late in the season. Pigweed, lambs-quarters, Russian thistle, and a number of other annual seeds infest many lima bean fields. They can be kept under satisfactory control by a combination of pre-planting tillage op- erations and careful cultivation. If some plants escape these methods of control, careful hand-hoeing to prevent any plants from seeding can effectively prevent their coming up again. SEED PRODUCTION THIS OPERATION is now dependable with modern equipment and carefully timed cleaning. Because of the size and structure of lima bean seed, it is vulnerable to mechan- ical injury in harvesting and cleaning. The large size of the seeds, particularly in standard limas, means that the seed gains high momentum in certain parts of the threshers, cleaners, and other equip- ment. Thus the seeds hit with an impact heavy enough to cause injury. Even im- pacts insufficient to crack or visibly dam- age the seed will, further, frequently break the stem of the embryo plant. This is because the embryo is located at one end of the seed in a highly vulnerable position. The most frequent place of breakage is immediately above the point of attachment of the cotyledons to the stem. The cotyledons are the fleshy modi- fied leaves which make up the bulk of the seed. When breakage occurs at this point most of the stem of the plant is lost, and while the seed may germinate, a new stem must be formed from one of the two embryonic buds in the axils of the cotyle- dons. Plants of this type, called "bald- heads," are much delayed in maturity and produce poor yields. If the break occurs below the point of attachment of the cotyledons, all the buds are lost and the plant is not capable of producing a new stem. The damage that machinery can do to lima beans is brought home by the fact that dropping lima seeds of low moisture content a single foot onto a solid surface will reduce germination about 20 per cent. Such treatment does not cause visi- ble injury to the seed. Seed production of high-germinating lima beans is consequently difficult. This is particularly the case if the seeds are very dry and brittle from exposure to high temperatures or low humidities dur- ing curing. Under such conditions, spike- [24] The embryo is located between the cotyledons near one end of the seed. Because of its vulnerable location, the embryo is easily damaged. Main stem has been broken off, so . . . development must take place from buds in leaf axils Baldhead is the result of a break in the stem of the embryo immediately above the place of attachment of the first leaves of the plant (cotyledons). Baldheads are delayed in maturity and produce low yields because the growth must come from buds in the axils of the cotyledons, as shown in the plant above. nn tooth threshers are almost certain to re- duce germination substantially, even if cylinder speeds are reduced to the point where visible damage is minor. Special seed threshers, which replace the toothed cylinder with rubber rolls, will aid in keeping the damage within acceptable limits. However, much of the damage oc- curs in other parts of the threshers, or in cleaning equipment. Equipment de- signed for seed production has reduced elevator speeds, does not allow seeds to drop more than a few inches, and makes liberal use of sponge rubber padding to break the force of impacts. With use of such equipment, and particularly if cleaning is delayed until high humidities prevail in midwinter, seed of high germi- nation can be produced even in dry in- land areas. MARKETING The marketing of lima beans is about equally divided between grower co-oper- atives and local buyers and dealers. There are two grower co-operatives, each com- posed of a number of local units. The individual grower belongs to the local unit which has representation on the board governing the central organization. The local unit is responsible for receiving the crop from the individual grower, for cleaning, and for warehousing. The central organization sells the crop and distributes the net proceeds to the indi- vidual members. Advertising and promo- tion are also a responsibility of the central organization. All lima-producing areas are well rep- resented by dealers and buyers through whom it is possible for the grower to dis- pose of his crop. [26 In order that the information in our publications may be more intelligible, it is sometimes necessary to use trade names of products and 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. Cooperative Extension work in Agriculture and Home Economies, 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. 10/»-3,'53(A2424)JB [27] IT JUST COULD BE . ♦ ♦ that the farm problems troubling you have also troubled others. And it's also possible that with a little help from the right source your problems can be eased, if not cured. Here's how to go about getting help. Take your problems to your County Farm Advisor. He's an agricultural specialist with a background of practical knowl- edge about farming in your lo- cality. He will help you if he can ... or he will get the information you need from someone who does know the answers. Ask your Farm Advisor for a copy of AGRICULTURAL PUBLI- CATIONS— a catalog that lists the bulletins and circulars pro- duced by the University of Cali- fornia College of Agriculture, or write to the address below. You'll be amazed at the wide range of information covered in these publications. Yes ... it just could be that your problems aren't nearly as hard to solve as you think. Make use of the free services of your University. Office of Agricultural Publications 22 Giannini Hall University of California Berkeley 4, California