Adlay, or Coix lacryma-jobi, is a type of grain native to Asia. Early records show it was used to brew beer as early as 3000 B.C., while the hard grains were also used as beads for necklaces. This type of millet is a tropical perennial grain.
I. Appearance and Characteristics
Job’s tears (Coix lacryma-jobi), also known as adlay or adlay millet, is a tall grain-bearing perennial tropical plant of the family Poaceae (grass family). It is native to Southeast Asia and introduced to Northern China and India in remote antiquity, and elsewhere cultivated in gardens as an annual. It has been naturalized in the southern United States and the New World tropics. In its native environment it is grown at higher elevation areas where rice and corn do not grow well. Job’s tears are also commonly sold as Chinese pearl barley, though true barley belongs to a completely different genus.
There are two main varieties of the species, one wild and one cultivated. The wild variety, Coix lacryma-jobi var. lacryma-jobi, has hard-shelled pseudocarps—very hard, pearly white, oval structures used as beads for making prayer beads for rosaries, necklaces, and other objects. The cultivated variety Coix lacryma-jobi var. ma-yuen is harvested as a cereal crop, has a soft shell, and is used medicinally in parts of Asia.
Job’s tears may also be referred to under different spellings (Job’s-tears, Jobs-tears). The crop is also known by other common names in English, such as adlay or adlay millet. Other common names in English include coix seed, gromwell grass, and tear grass.
Job’s tear is a monoecious grass which is broad-leaved, loose-growing, branched and robust. It can reach a height between 1.20 m to 1.80 m. Like all members of the genus, their inflorescences develop from a leaf sheath at the end of the stem and consist partly of hard, globular or oval, hollow, bead-like structures. Job’s tear seeds differ in color, with the more soft-shelled seeds being light brown and the hard-shelled forms having a dark red pericarp.
The hardened “shells” covering the seeds are technically the fruit-case or involucre (hardened bract), with the bract also referred to as “capsule-spathe” or “sheathing bract” by some past botanical works.
These shells cover the bases of the flowers (inflorescences) which are male and female racemes/panicles; the male racemes project upright and consist of overlapping scale-like spikelets, with yellow stamens that pop out in-between, and there are one or two yarn-like female racemes drooping from the base.
II. How to Grow and Care
Sunlight
Adlay thrives best under full sun conditions, where the light is intense and sustains its growth throughout the day. Although it has a level of tolerance to partial sun, it should not be prolonged or the plant may experience suboptimal growth. Deviations from full sun can lead to decreased vigor and potential impacts on health, such as elongated stems or reduced seed production. While adlay doesn’t possess notable leaf adjustments, it is crucial to place it in locations outdoors that receive ample sunlight to ensure robust development. Indoor cultivation of adlay is typically not common due to its light requirements.
Watering
Thriving in humid environments, adlay has adapted to retain moisture efficiently. This species exhibits a preference for consistent hydration but can withstand short periods of dryness. Watering should align with its moderate needs, translating to twice a week to maintain soil moisture without oversaturation. Typically grown outdoors, adlay benefits from mulching to conserve water and reduce the need for frequent irrigation during its active growth season.
Fertilizing
For adlay, apply balanced nutrition fertilizers during the growing season for robust growth, and switch to high nitrogen fertilizers pre-flowering for optimal yield. Fertilize monthly, using quantities specified by the manufacturer, to ensure strong stems and hearty grains. In colder months, reduce frequency, tailoring to adlay’s slowed growth rates. Avoid over-fertilization to prevent root burn. Use slow-release granular fertilizer or dilute liquid forms for safe application and absorption. Essential for experienced and novice gardeners is to observe adlay’s response and adjust the fertilization regimen accordingly.
Propagation
Adlay is typically propagated through sowing. For successful propagation, selecting healthy seeds is crucial. An ideal practice includes pre-soaking the seeds to enhance germination rates. When sowing, embed the seeds in a rich, well-draining soil mix to prevent rot and to provide a stable environment for root development. Even moisture and warmth are important to encourage growth, but avoid water logging as it can cause fungal diseases. Once established, seedlings should be gradually acclimatized to outdoor conditions if they are to be transplanted.
Transplanting
The ideal time to transplant adlay is during late spring to early summer (S2-S3), as this season provides the best conditions for growth. Adlay requires a sunny, well-drained location for optimum growth. A friendly reminder: always fertilize the planting hole before transplanting for better root establishment.
Seedbed requirements and sowing
Soaking seeds with disinfectant has a positive influence on germination rate.
Planting can be done when the ground temperature is above 12 °C. And if it is not frost, sowing should be done as early as possible to lengthen the required days to emergence and days to anthesis. Adlay sowing is divided into strip sowing and hole sowing. The strip sowing refers to the uniform sowing of seeds in trenches with a spacing of about 50 cm and a depth of 4–5 cm. Hole sowing refers to sowing seeds in holes 3–5 cm deep, with 3-4 seeds per hole.
Control the number of seedlings per hole when the seedlings have 3-4 true leaves, and leave 2-3 well-grown plants in each hole.
Tillage at least 3 times during the whole crop growth. The 1st tillage is to be done when the seedlings are 5–10 cm high and needs to be cleaned of weeds to promote tillering. The second tillage is done when the seedlings are 15–20 cm high. The 3rd plowing is done when the seedlings are 30 cm high, combined with fertilizer and soil cultivation to promote root growth and prevent collapse.
III. Uses and Benefits
Crafts
The hard, white grains of Job’s tears have historically been used as beads to make necklaces and other objects. The seeds are naturally bored with holes without the need to artificially puncture them.
Strands of Job’s tears are used as Buddhist prayer beads in parts of India, Myanmar, Laos, Taiwan, and Korea according to Japanese researcher Yukino Ochiai who has specialized on the ethnobotanic usage of the plant. They are also made into rosaries in countries such as the Philippines and Bolivia.
- Japan
In Japan, the grains growing wild are called juzudama (数珠玉) ‘Buddhist rosary beads’), and children have made playthings out of them by stringing them into necklaces. However, juzu-dama was a corruption of zuzu-dama according to folklorist Kunio Yanagita. A type of Buddhist rosary called irataka no juzu, which were hand-made by the yamabushi ascetics practicing shugendō training, purportedly used a large-grain type known as oni-juzudama (鬼数珠玉) ‘oni(ogre) rosary beads’. Although this was published as a separate variety, C. lacryma jobi var. maxima Makino, it is now regarded as synonymous to C. lacryma jobi var. lacryma-jobi according to taxonomical databases (World Checklist of Selected Plant Families).
It was contended by Edo Period scholar Ono Ranzan that the soft-shelled edible type called shikoku-mugi was not introduced into Japan until the Kyōho era (1716–1736), as opposed to a hard-shelled edible type called chōsen-mugi (lit. ‘Korean wheat’) which needed to be beaten in order to crack and thresh them. This type has been published as a separate species, C. agrestis in the past, but this is now recognized also as a synonym of C. lacryma jobi var. lacryma-jobi. Thus Japanese consumption of the crop attested in pre-Kyōho literature presumably used this hard-shelled type in the recipe.
Yanagita contended that the use of the beads predated the introduction of Buddhism into Japan (552/538 CE). And the plant has not only been found at sites dating to approximately this period at the Kuroimine Site, but in Jomon period sites dating to several millennia BC.
- Ocean Road hypothesis
Yanagita in his Ocean Road hypothesis argues that the pearly glistening seeds were regarded as simulating or substituting for cowrie shells, which were used as ornaments and currency throughout Southern China and Southeast Asia in antiquity, and he argued both items to be part of cultural transmission into Japan from these areas.
Later scholars have pursued the validity of the thesis. Yanagita had reproduced a distribution map of the usage of ornamental cowries throughout Asia (compiled by J. Wilfrid Jackson), and Japanese ethnologist Keiji Iwata alluded to a need for a distribution map of ornamental Job’s tears, for making comparison therewith.
- Thailand and Myanmar
The Akha people and the Karen people who live in the mountainous regions around the Thai-Myanmar border grow several varieties of the plant and use the beads to ornament various handicraft. The beads are used strictly only on women’s apparel among the Akha, sewn onto headwear, jackets, handbags, etc.; also, a variety of shapes of beads are used. The beads are used only on the jackets of married women among the Karen, and the oblong seeds are exclusively selected, some example has been shown from the Karen in Chiang Rai Province of Thailand.
Strands of job’s tears necklaces have also been collected from Chiang Rai Province, Thailand and it is known the Karen people string the beads into necklaces, such necklaces in use also in the former Karenni States (current Kayah State of Burma), with the crop being known by the name cheik (var. kyeik, kayeik, kyeit) in Burmese. Job’s tears necklace has been collected also from Yunnan Province, China, which has a population of Akha-Hani people and other minorities, but the Wa people of Yunnan also used the plant seeds (tɛ kao; lit. ‘fruit-Coix’) sewn onto fabrics and bags, etc.
The Wa people and other minorities like the Taungyo ethnic group use the beads in apparel in Shan State, Myanmar.
- Borneo
In Northern Borneo Malay (Dayak group) ethnic tribes such as the Kelabit people of Sarawak state (and North Kalimantan, Indonesia), the Dusun people and Murut people of Sabah state all use the plant beads as ornament. The Kayan of Borneo also use job’s tears to decorate clothing and war dress.
- Philippines
Job’s tears (Tagalog: tigbí) are otherwise known by many local names in the Philippines (e.g. Bikol: adlái in Visaya Islands). The beads strung together have sometimes been used as rosaries, or made into bead curtains (e.g. the Tboli people on Mindanao), or woven into baskets and other vessels.
- Americas
The plant was known as calandula in Spanish, and the hards seeds were strung together as beads or into rosaries in parts of New Spain, e.g., Puerto Rico.
In both the Eastern Band of Cherokee Indians and the Cherokee Nation in Oklahoma, the beads of Job’s tears are called “corn beads” or “Cherokee corn beads” and have been used for personal adornment.
Medicinal uses
Job’s tears are used with other herbs in traditional Chinese medicine or folk medicine.
The plant is noted in an ancient medical text Huangdi Neijing (5th–2nd centuries BCE) attributed to the legendary Huangdi (Yellow Emperor), but fails to be noticed in the standard traditional materia medica reference Bencao Gangmu (本草綱目)(16c.).
Culinary uses
- Food
Throughout East Asia, Job’s tears are available in dried form and cooked as a grain. Job’s tears grains are widely eaten as a cereal. The cultivated varieties are soft-shelled, and can be easily cooked into gruels, etc. Among the Zomi in Southeast Asia, miim festival (Job’s tears festival) was held annually to pay tribute to the departed souls.
Some of the soft-shelled types are easily threshed, producing sweet kernels. The threshed (and polished) “kernels” or ren (Chinese: 薏苡仁; pinyin: yiyi ren; Wade–Giles: i i jen) are used in traditional Chinese Medicine (see infra).
The threshed grains are generally spherical, with a groove on one end, and polished white in color. In Japan unpolished grains are also sold, and marketed as yūki hatomugi (‘organic job’s tears’).
In Cambodia, where it is known as skuay (ស្គួយ), the seeds are not much used as a grain, but used as part of herbal medicine and as an ingredient in desserts. In Thailand, it is often consumed in teas and other drinks, such as soy milk.
It is also a minor cereal crop and fodder in Northeastern India.
The grains of Job’s tear can be used the same way as rice. It can be eaten cooked or even raw, as it has a slightly sweet taste. Further, the grains can be used for the production of flour. Job’s tear grains can be processed in the same machine as rice. For the soft hulls, it is enough to press them over a sieve. The advantage of Job’s tear over rice is that the grains do not need to be polished, as is the case with rice. Through this process, the rice loses its vitamins. This makes Job’s tear a valuable food for undernourished populations in rural areas.
- Beverages and soups
In Korean cuisine, a thick drink called yulmu cha (율무차, literally “Job’s tears tea”) is made from powdered Job’s tears. A similar drink, called yi ren jiang (薏仁漿), also appears in Chinese cuisine, and is made by simmering whole polished Job’s tears in water and sweetening the resulting thin, cloudy liquid with sugar. The grains are usually strained from the liquid but may also be consumed separately or together.
In Japan, the roasted kernels are brewed into hatomugi cha (ハトムギ茶), literally a “tea”. This is drunk for medicinal value and not for enjoyment, as it does not suit the average consumer’s taste, but a more palatable brew is obtained by roasting seeds that have been germinated, which reduces the distinctive strong odor.
In southern China, Job’s tears are often used in tong sui (糖水), a sweet dessert soup. One variety is called ching bo leung in Cantonese (Chinese: 清補涼; pinyin: qing bu liang), and is also known as sâm bổ lượng in Vietnamese cuisine. There is also a braised chicken dish yimidunji (Chinese: 薏米炖鸡=薏米燉鷄).
- Alcoholic beverages
In both Korea and China, distilled liquors are also made from the grain. One Korean liquor is called okroju (옥로주; hanja: 玉露酒), which is made from rice and Job’s tears. The grains are also brewed into beers in northeast India and other parts of southeast Asia.
IV. Harvesting and Storage
Harvest and post-harvest operations
When nearly 80% of adlay grains turn brown, the panicle will be harvested by cutting the stems and leaving three nodes above the ground. The harvest period varies with the different varieties and local environment. Because of the uneven height and grain distribution, the use of machines for harvesting is limited and harvesting has been done by hand in many regions in Southeastern Asia. Then the harvested panicles are threshed by hand or using a treadle thresher. For manual threshing, it is normally used when the harvested grains are at lower moisture content and easily shatter. Threshed grains are sun dried or placed in drying facilities where they utilize forced warm air to gradually reduce the moisture content to 14% suited to storage before the adlay moves to the milling process. The adlay can be consumed as grains and flour after being milled through corn and rice mill. The milling recovery is about 60% depending on the cultivars.
The yield is harvested in early October and is easily influenced by the weather. If there is dry and hot wind in the initial phase, the pollen loses its vitality, therefore can’t be pollinated. This leads to hollow seeds, which results in yield reduction in light cultivars and zero yield in heavy cultivars. Early maturing varieties are sown in early March, middle maturing varieties are sown from late March to early April, and late maturing varieties are sown from late April to early May. Sowing should be early rather than late. If sowing is too late, it will affect the yield and even the seeds can not mature after autumn.
