A Detailed Guide to the Processing Techniques and Methods for Grass Cardamom
Job's tears, commonly known as coix seed, adlay, or medicinal corn, is an annual or perennial herbaceous plant in the grass family (Poaceae). It has effects such as clearing heat, promoting diuresis, resolving dampness, draining pus, tonifying the lungs, strengthening the spleen and stomach, fortifying the sinews and bones, relieving spasms, and lowering blood pressure. Recent research has revealed that Job's tears seeds contain coixol and coix ester, which have good anticancer effects. It is the most ideal dual-purpose tonic for both medicine and food, and is also a raw material for making refreshing summer beverages.
I. Growth Habits. Job's tears prefers a warm and slightly humid climate, but it is highly adaptable. It is not demanding about soil and can be grown in general soils, but sunny, fertile sandy loam is preferable. Based on the current state of agricultural production in our country, Job's tears, as a distinctive cash crop, is especially suitable for large-scale mechanized planting and production on extensive wetlands, barren hills, barren slopes, ridge land, and lake shoals due to its relatively short growing period, relatively low technical requirements, extensive management, and tight market supply, delivering good economic and social benefits.
II. The "Thin Shell, Red Coat" Job's Tears Variety. This is a mid-maturing shelled Job's tears variety developed by the research institute in 2004 from wild Job's tears, specially for export to Japan and South Korea. Its characteristics are: thin outer shell, 65% milling yield, light red or pale white inner seed coat, thick and sturdy stems, strong lodging resistance, and high yield. The fruit is oval, with a light brown or brown surface, a dark brown style at the top, and a slightly concave base, with a 1000-grain weight of 132 grams. It is suitable for large-scale standardized base planting, mechanical sowing and mechanical harvesting, extensive management, and wet-land cultivation.
III. Seed Treatment. Before sowing, sun-dry the seeds for two days, then soak them in water for 24 hours, remove and drain off the water, and treat them with 20% triadimefon at 0.4% of the seed weight. This can 100% prevent the damage to Job's tears from smut disease, which has occurred on a large scale in recent years.
IV. Sowing Methods. Sowing can begin when the daily average temperature stabilizes at 15°C. Either spring sowing or summer sowing is acceptable; for summer sowing, seedling raising and transplanting will give better results. For small-scale planting, direct sowing or hole sowing can both be used. For hole sowing, dig holes at a plant spacing of 27 cm and a row spacing of 30 cm, sow 4-5 seeds per hole, using 4 kg of seed per mu; for direct sowing, open shallow furrows at a row spacing of 50 cm with a furrow depth of 3 cm, keep the furrow bottom level, evenly scatter the seeds into the furrows, cover with fine soil just enough to cover the seeds, then cover with soil, level, and firm it down. Spring sowing is in mid-to-late April, summer sowing from late May to early June, and no later than late June. For large-scale planting, adopt mechanical sowing at a row spacing of 50 cm, using 2 kg of seed per mu, and more than 100 mu can be sown per day.
V. Field Management
1. Thinning and final spacing. When the seedlings grow 2-3 true leaves, carry out the first thinning, removing crowded, diseased, and weak seedlings, and maintain a plant spacing of 4-7 cm; when the seedlings have 5-6 true leaves, set the final spacing at 13-16 cm.
2. Cultivation and weeding. Generally cultivate and weed twice. The first time is when the seedlings are 6-7 cm tall, to encourage more tillering; the second time is when the seedlings are 16-20 cm tall; afterward, cultivate and loosen the soil in conjunction with fertilization.
3. Topdressing and earthing up. Topdressing is carried out in two applications. The first is when the seedlings are 4-7 cm tall, applying 1000 kg of dilute human and animal manure per mu to promote seedling growth and more, earlier tillering. The second is when the seedlings are about 35 cm tall or at the booting stage, applying 1500 kg of human and animal manure per mu to promote vigorous plant growth and benefit booting. If human and animal manure is unavailable, topdressing can use 10 kg of urea plus 20 kg of superphosphate each time. Earthing up is done when the seedlings are about 35 cm tall, in conjunction with fertilization, to prevent lodging and benefit root growth.
4. Watering to promote growth. Water management is the key to achieving high and stable yields of Job's tears. Job's tears is similar to corn and sorghum, and people habitually regard it as a dryland crop and also use dryland cultivation in production, thus resulting in low per-mu yields. Through many years of cultivation by our institute, it has been proven that Job's tears is not only a dryland crop but a marsh crop, a wet-loving plant. To achieve high and stable yields, one must break out of the mistaken approach of dryland cultivation and adopt the wet cultivation method. If planted on dryland, attention must be paid to watering, and the scientific method of "wet at both ends, dry in the middle" can be used when watering. That is, the early growth stage requires moist soil to promote uniform and strong seedlings; at the late tillering stage, drainage and field drying should be carried out to control ineffective tillering; at the booting stage, timely irrigation is needed, with increased irrigation volume; at the heading stage, frequent and sufficient irrigation should be given (if drought occurs at this stage, the number of heads decreases greatly, the number of empty and shriveled grains increases, and the yield drops markedly). Irrigation can be stopped 10 days before harvest to facilitate reaping.
5. Removing lower leaves. After Job's tears finishes jointing, remove the leaves below the first branch together with ineffective tillers, which helps ventilation and heat dissipation, promotes thick and sturdy stems, and has a certain effect on preventing lodging.
6. Supplementary pollination. Job's tears generally relies on wind for natural pollination, but the pollination rate is low, the yield is unstable, and there are many empty seeds. In recent years, we have adopted artificial supplementary pollination measures with good results. The specific method is, during the several days of the full flowering period of the Job's tears plants, to vibrate the plants every day between 9 and 11 a.m. with tools such as sticks or ropes, so that the pollen flies up, which has a clear effect on increasing the fruit-setting rate. Where conditions permit, a blower can also be used for artificial wind pollination, with better results.
VI. Harvesting and Processing. Job's tears has strong branching, and the seeds do not ripen uniformly. When the middle and lower leaves of the plant turn yellow and 80% of the seeds have ripened, it can be harvested. Harvest on a sunny day, and after reaping, stand the plants upright for a few days, then thresh with a threshing machine. For large-scale planting, after testing the machine in various ways, a combine harvester can be used for one-time harvesting. After harvest, spread the seeds on a clean drying yard and sun-dry them until fully dry. Then place them in a ventilated spot and winnow away empty shells and impurities, and pack the fuller shelled Job's tears from the upper wind side separately from the more shriveled and lean ones from the lower wind side, and they are ready for sale. If the quantity is large, a winnowing machine can be used for grading; the better-quality ones can be directly exported to Japan and South Korea, giving relatively high economic returns.