Coix: an underutilized functional food crop of Mizoram

Coix (Coix lacryma-jobi) comes under underutilized crops as it is neither cultivated commercially on a large scale nor widely traded. The Northeastern region of India harbours a rich diversity of Coix. This crop has diverse varieties from food to ethnic ornaments worn by the Mizo people. The soft-shelled type (var ma-yuen), locally called ‘Mim’ has been an important cereal crop among the Mizo rural communities for a long time. The grains are highly nutritious and its exceptional medicinal aspects have been extensively researched. Meanwhile, the seeds of the wild type (var lacryma-jobi) are excellent beads for ornamental purposes and are key components in making traditional head gear ‘Vakiria’ worn by Mizo ladies on festive occasions. It is recently gaining importance as a ‘functional food’, because it is a rich source of nutrients and bioactive compounds. Its grains are gluten free which benefits people with celiac disease. It is used for preparing flour, soups, porridge, gruels, salads, desserts, snack, wine, sweets, etc. It is found to have diuretic, anti-inflammatory, antidiarrheal, antioxidant, antipyretic, antiseptic, antispasmodic, analgesic, hypotensive, and sedative properties. Coix germplasm are rapidly disappearing from wild and jhum lands, and without conservation a large population of genetic diversity will be lost from Northeast India. Mizoram also possesses a wide array of germplasm which could potentially contribute to research priorities. However, the ignorance on nutritional value of the crop, lack of standard agronomic practice, unavailability of high yielding quality seeds, potential varieties suitable for Mizoram conditions, processing infrastructures and marketing have diminished the interest of farmers in popularizing this crop. In this regards, thirty-nine Coix genotypes were evaluated owing to their agronomic characteristics to identify promising genotypes suitable for Mizoram conditions. Based on the overall mean performances for yield and yield components, two genotypes RJT-1 (39.74 q/ha) and RJT-2 (35.27 q/ha) were found superior for seed yield and other yield-related traits under Mizoram conditions. In addition, the occurrence of invasive fall armyworm, Spodoptera frugiperda (J.E. Smith) on Coix was observed and the damage incidence ranged between 7.23 and 10.86% in the vegetative growth stages (45–75 days crop) from the last week of August to the end of September. To the best of our knowledge, this is the first report of fall armyworm occurrence on Coix crop from India.

porridge, gruels, salads, desserts, snack, wine, sweets, etc. It is found to have diuretic, anti-inflammatory, antidiarrheal, antioxidant, antipyretic, antiseptic, antispasmodic, analgesic, hypotensive, and sedative properties. Coix germplasm are rapidly disappearing from wild and jhum lands, and without conservation a large population of genetic diversity will be lost from Northeast India. Mizoram also possesses a wide array of germplasm which could potentially contribute to research priorities. However, the ignorance on nutritional value of the crop, lack of standard agronomic practice, unavailability of high yielding quality seeds, potential varieties suitable for Mizoram conditions, processing infrastructures and marketing have diminished the interest of farmers in popularizing this crop. In this regards, thirty-nine Coix genotypes were evaluated owing to their agronomic characteristics to identify promising genotypes suitable for Mizoram conditions. Based on the overall mean performances for yield and yield components, two genotypes RJT-1 (39.74 q/ha) and RJT-2 (35.27 q/ha) were found superior for seed yield and other yield-related traits under Mizoram conditions. In addition, the occurrence of invasive fall armyworm, Spodoptera frugiperda (J.E. Smith) on Coix was observed and the damage incidence ranged between 7.23 and 10.86% in the vegetative growth stages (45-75 days crop) from the last week of August to the end of September. To the best of our knowledge, this is the first report of fall armyworm occurrence on Coix crop from India.

Introduction
Researchers are exploring alternate food sources which have the potential for human nutrition as a consequence of the expanding population, increasing hunger, limited food supply, widespread malnutrition and climate change. Around three billion people worldwide are currently unable to pay for healthy diets owing to the high cost of food and high levels of poverty coupled with income inequality (FAO, IFAD, UNICEF, WFP and WHO 2021). The transformation of food systems for food security, accessible healthy diets and better nutrition has become the primary concern of food production in recent years. Crop diversification towards the cultivation of a variety of nutrient-rich foods is needed to ensure food and nutritional security (Mustafa et al. 2019). Indigenous food systems are a reservoir of underutilized food crops which possess rich biodiversity, ensuring better impacts on human health from a diversified diet (Singh et al. 2022). These underutilized crops are mostly rich in nutrients, climate-resilient, widely adaptable, used medically and play an important role in local cultures and rituals (Mabhaudhi et al. 2019;Mustafa et al. 2019). These crops require more attention in conservation and research; and their boosted production can bring better nutritional security by providing balanced diet, battling micronutrient deficiencies and preventing hunger (Singh et al. 2022). Northeast India is a hotspot of biodiversity and endowed with diverse species of underutilized crops (Arora 1977). The varied topography, climatic conditions, and altitude contributes to the occurrence of a variety of crop species and their cultivation in Northeast India. Among them, Coix is one of the potential underutilized crops of Northeastern India, with its use widely ranging from food to ethnic ornaments of the Mizo tribe.
Coix is generally called Job's tears, adlay, adley, tear grass, adley millet, or coix millet, samkru (Hindi) and pingpih (Mizo). This crop has hard shiny tearshaped fruit which bear seeds that resulted in its recognition with the name "tear". It has potential to be utilized as a staple food to ensure food security and improve human health in the region (Laxmisha et al. 2022;Devaraj et al. 2020). The nutrient profiling of Coix suggested that the grains are rich in proteins, minerals and crude fat which are beneficial for health. The biochemical parameters such as starch, phenol, sugar, moisture and antioxidants primarily contribute to the diversity of Coix germplasm found in Northeast India (Laxmisha et al. 2022). Currently, Coix remains underutilized and unexploited due to rising popularity of maize and other cereals in the region (Roder 2006). However, before the adaptation of these crops in the cropping system, it was a major food crop in various Asian nations, such as Bhutan (Roder 2006). The major reasons for Coix being underutilized are the predominance of local types and non-availability of proper agronomic practices resulting in lower crop yield, despite the fact that Coix are highly nutritious, climate-resilient, less prone to insects/diseases, locally available and have medicinal importance (Devaraj et al. 2020). The limited and sporadic cultivation of local types and wild relatives of Coix in rural areas are now majorly concentrated only for medicinal and ornamental purposes. Considering the nutritional and medicinal value of Coix, this crop shares equal importance to major crops for exploitation in crop breeding programmes to improve production, so that processing and value addition of this crop can be realized at industrial level.
In the Northeast India, particularly in Mizoram, farmers have been cultivating Coix (C. lacryma jobi var ma-yuen), locally called 'Mim'. They would gather the seeds from wild and nurture them on jhum fields. This was a crucial crop during the Mizoram famine in 1959-1960 and subsequent years of famine occurrence when the supply of major food grains was limited and Coix grains were mixed with rice and cooked to meet the food requirement of the family. In recent years, the grain consumption is rare due to sporadic cultivation in the rural areas of Mizoram, despite the fact that the grains possess greater proteinto-carbohydrate ratio as compared to any other cereal, the extraction of flour is quite challenging due to its hard seed coat (Corke et al. 2016). It is cultivated as an annual crop or perennial in frost-free areas because of the nutritional quality as food and medicinal value. Thus, realizing the benefits and importance of this underutilized crop in the region, a potential food crop can be developed through crop improvement. Currently, the proper collection, documentation on this crop is lacking and also the scientific cultivation practice for the region is not standardized. In such scenario, the research priorities should focus on developing high yielding hybrids, more branching, high shelling percentage, soft-shelled, more grain filling, early maturing, lodging resistant, uniform maturing, highly nutritious genotypes with disease and insect resistance. Therefore, this paper is an attempt to review its taxonomy, geographical description and habitat, diversity of local genotypes, selection of suitable germplasms for this region, its importance, and scientific cultivation practices which will help to stimulate its importance at the regional and national level as well as boost research interest in this underutilized crop for further utilization.

Taxonomy
Coix lacryma-jobi L. is a tetraploid (2n = 20), quantitative short-day plant belonging to the family Poaceae having C 4 photosynthetic pathway. Coix greatly vary in terms of shape, colour, size and hardness of involucres. The botanical varieties of C. lacryma jobi can be generally distinguished based on the hardness and shape of the involucres, four varieties are described such as C. lacryma-jobi var lacryma-jobi L. (bony involucres, glossy, globose to ovoid), C. lacrymajobi var stenocarpa Oliv. (hard involucres, elongate, bottle-shaped), C. lacryma-jobi var puellarum (Balansa) E.G.Camus & A.Camus (hard involucres, globose, very small) and C. lacryma-jobi var ma-yuen (Rom. Caill.) Stapf. (soft involucres, elliptical, striate). The variety that has been most widely naturalized and most popular is variety lacryma-jobi. As a food grain, the variety ma-yuen is frequently grown (Jain and Banerjee 1974;Shouliang and Phillips 2006). It is likely that cultivation over thousands of years selected the soft-hulled form (var ma-yuen) due to its suitability for food (Jansen 2006).

Geographical distribution and habitat
It is a tall grain-bearing tropical crop that can be grown all around the world in tropical to sub-tropical regions. This annual grass has been widely cultivated for several 1000 years in Southeast Asia and is native to Malaysia, China, India, and Burma (Corke et al. 2016). Northeastern India and Myanmar, which is thought to be a potential site of origin for this crop, where it is cultivated for food and fodder and have been observed to have the largest diversity of wild forms (Arora 1977). It has been introduced for its attractive grains and as a cereal and forage crop in tropical and warm temperate regions. It has become naturalized and escaped cultivation in many countries (more than 90), frequently assumed as a weed in disturbed and humid sites, forest borders and nearby waterways, swamps and wetlands (Areces-Berazain and Rojas-Sandoval 2017). The rich germplasm collections of C. lacryma-jobi are available in 'The Institute of Plant Breeding of the University of the Philippines' at Los Banos, Philippines and 'The Institute of Crop Germplasm Resources (ICGR)' in Beijing, China (Jansen 2006).
The most widespread variety is 'lacryma-jobi', which may be found in most of America, Africa, and Oceania. The Northeastern part of India, Southern China, Myanmar, Philippines, Indonesia, Vietnam, and Papua New Guinea are all home to the 'stenocarpa' variety. The variety 'ma-yuen' naturally grows in India, Myanmar, Bhutan, China, the Philippines, Cambodia, Thailand, Laos, Japan, Korea, Indonesia, Malaysia and has also been brought to Honduras and Ecuador (Zuloaga et al. 2003;Shouliang and Phillips 2006), while the variety 'puellarum' is distributed in Myanmar, Malaysia, and Indo-China (Bor 1960). Wild hard-shelled types (C. lacryma-jobi var lacryma-jobi) are found scattered near riverbanks, roadside and watershed areas and commonly used for ornaments. Further, this crop has tolerance to several factors such as low pH, low photoperiod variation, lateritic soils, waterlogging and less prone to viral attacks, it has been regarded as an excellent potential genetic resource for crop improvement (Corke et al. 2016). Coix usually grow in rural regions and are also found wild in remote areas, riverbanks, waterways and nearby water sources in Mizoram.

Botanical description
Coix is propagated by seeds exhibiting a hypogeal type of germination. The seeds are pear or tearshaped shining capsules 7-13 mm long. Seed propagation provides deeper rooting. It can also be propagated through rhizome fragmentation and cuttings, and these methods are more preferred for producing fodder (Schaaffhausen 1952). Coix plant shows close resemblance with maize, sorghum and foxtail millet. It is a herbaceous tillering plant that grows up to a height of 2 m. The leaves of Coix are glossy deep green with narrowly lanceolate having 25-65 cm length and 1.5-5.0 cm width. Leaves are having slightly wavy edges with pinkish to red colour leaf margins having prominent midrib. The stems are erect and have white powdery deposition. The internode of culms is solid. It has seminal roots and lower nodes consists of prop-roots ( Fig. 1). It is a unisexual plant and bears a monoecious flower where both male and female flowers can be found on the same plant. All the spikelets remain fertile. Spikelets are terminal and in the upper axils. The glumes of the fertile spikelet are several-nerved that are enclosed in a bony bead-like involucre. Involucre contains two sterile and a fertile female flower. From the fertile flower, two feathery stigmata (thrumb) protrudes to collect pollen produced from the male spikelet. Male spikelets are formed on a slender stalk that extends from a tiny pore of bead (Fig. 2). Flowering occurs during September-October for July sown crop. Generally, pollination takes place with the help of wind. The fruit of mature plant is hard and colour varies from white, grey to black or light brown. Some of its selective cultivars are used as edible grains and others are used as beads and for other decorative purposes.

Diversity in Mizoram
Mizoram harbours a great variability of wild and cultivated types of Coix. A wide diversity of wild types occurs in the Northeast hill tracts and Myanmar (Hore and Rathi 2006). The wild types 'Coix lacryma-jobi' vary from 150 to 360 cm in height with 4.5-6.0 branching bearing as many as 250-550 seeds/plant. The genotypes vary from branching inflorescence in every node to bearing inflorescences in the upper axils of the plant. The seed of wild types vary from white to greyish to greyish-black while cultivated genotypes have creamish-white, greyish, purplish or black colour seeds. The shape of the involucres also varies from roundish to tear drop to elongated shapes with smooth or striated surfaces. It is also important to investigate whether this variation contributes to the different chemical compositions of Coix. Coix lacryma-jobi var ma-yuen, locally called 'Mim' is widely consumed by the local people of Mizoram in recent past (Fig. 3). Population genetic analysis found wild and cultivated accessions could be clearly distinguished, and a strong bottleneck during domestication resulted in a loss of half the genetic diversity present in the wild population (Liu et al. 2020). Due to their significance as an important genetic resource, these landraces need to be conserved for use in future crop improvement programmes. The ignorance among the people towards the great nutritional properties of Coix, lack of standard agronomic practices, unavailability of high-quality seeds and high yielding varieties suitable for Mizoram conditions, processing infrastructures and marketing have diminished the interest of farmers in popularizing this crop. So, an investigation on Coix genotypes collected from different regions was carried out to identify high yielding genotypes for cultivation in Mizoram.  the cropping period. The soil is slightly acidic pH (5.0-5.5) and clayey loam with 1.2-1.4% organic carbon content. The genotypes were sown in randomised block design with three replications during the first week of July at a spacing of 45 cm × 15 cm accommodating 33 plants per plot. Five uniform plants were randomly selected from each plot and recorded for growth parameters.

Observations and data collection
Observations were taken for plant height-PH (cm), number of leaves/plant-NLPP, leaf area-LA (cm 2 ), leaf area index-LAI, number of tillers/plant-NTPP, number of seeds/plant-NSPP, 100 seed weight-HSW (g) and seed yield-SY (q/ha) at maturity. The LAI was calculated by dividing the one-sided green leaf area per unit of ground cover as per Yoshida (1976). General surveillance on pests and diseases were carried out through on-site visits of crop fields at weekly interval starting from crop emergence till crop maturity. The incidence of insect pest was recorded at weekly intervals from each plot. The percent incidence was calculated based on the number of plants damaged to the total number of plants in each plot.
For identification of insect pests, the feeding larvae were collected and reared on the host plant to confirm the identity of pest.

Field survey and data collection
Field surveys were carried out in Kolasib district, Mizoram from jhum land, forest and villages. Primary information on its distribution pattern, importance, ethnobotanical details and uses were collected through face-to-face interaction along with structured and unstructured questionnaires. The secondary information related to its taxonomy, geographical distribution, and botanical descriptions was collected from available literature and to supplement the primary information.

Statistical analysis
The descriptive statistics have been carried out through SPSS software version 26. The mean, range, standard error, and coefficient of variation (CV) were calculated for growth and yield traits ( Table 1). The Principal Component Analysis (PCA) was conducted using the software package FactoMineR (Husson

Results and discussion
The thirty-nine genotypes of Coix showed high variability in terms of yield and yield related traits. Characterization and evaluation of germplasm are crucial for producing improved varieties (Nelson 2011;Andini et al. 2013 IC-12703 (22.22). The maximum 100 seed weight was reported in RJTGP-71 (34.60 g) followed by RJTGP-53 (32.84 g) and RJT-2 (30.30 g), while the minimum was reported in IC-540279 (12.96 g) with a mean value of 23.59 g among the genotypes. As seed is the economical part of the crop, the selection of genotypes with high seed yield will be beneficial. The variation in seed yield ranged from 3.28 to 58.43 q/ha with a mean value of 16.64 q/ha. Four genotypes viz., RJTGP-53 (58.43 q/ ha), RJTGP-71 (39.96 q/ha), RJT-1 (39.74 q/ha) and RJT-2 (35.27 q/ha) were found to contribute maximum for seed yield while the minimum seed yield was reported in IC-89384 (3.28 q/ha). Hore and Rathi (2006) characterized 29 genotypes of Coix collected from Northeast India and found great variability with respect to yield and nutritional content and suggested genotypes IC-012703 (31.8 q/ha), IC-089391 (30 q/ha) and IC-521338 (29 q/ha) as promising for cultivation.

Principal component analysis (PCA)
The purpose of this analysis was to determine the factor dimension of the data, which was used to simplify varietal information into a smaller number of factors and selecting the genotype(s) that would perform best for eight yield and yield-related traits.
With eigen values greater than one, the first three principal components (PCs) explained 75.78% of the total variance, with PC1 accounting for 33.60% and PC2 accounting for 24.54% (Fig. 4). From the biplot figure, traits like PH, NLPP, LA and LAI were found to have high positive association with PC1 whereas SY, HSW and NSPP exhibit positive association with PC2. NTPP was positioned close to the center of the biplot, which showed relative similar performance by the genotypes. Among those genotypes, RJTGP-90, RJTGP-50, RJTGP-89, RJTGP-92 and IC-540279 were identified as superior genotypes in PC1. In contrast, RJTGP-53, RJTGP-71, RJT-1, RJT-2, RJTGP-51, and RJTGP-81 were identified as superior genotypes in the PC2.

Correlation analysis
The correlation analysis determines the degree of character association between the various traits and generate information that are needed to be considered in the selection programme as selection of one or more traits affects the expression of several other traits. Pearson correlation coefficients among eight traits in the current study were shown in Fig. 5. The highest correlation coefficient was observed between LA and LAI (0.99**), followed by NSPP and SY (0.73**) and LAI and NLPP (0.56**). For yield traits, NSPP and HSW showed highly significant correlation with SY while traits like PH, LA, LAI and NTPP showed negative correlation with SY, however, exhibited insignificant values. Selection of genotypes which possess high NSPP and HSW will be beneficial for improving yield of crop. Based on overall mean performances, genotypes RJT-1 and RJT-2 gathered desirable and superior performances for several traits such as seed yield, number of seeds/plant and 100 seed weight. High seed yield/plant of these genotypes resulted from higher number of seeds/plant and 100 seed weight due to the highly significant positive association between the traits. It is imperative to select genotypes with higher yield and yield attributing traits.

Importance of Coix
Coix has multiple uses such as food, medicinal and traditional as follows: Coix as an important source of food Coix can be used in multiple forms viz., as a pseudo cereal, as a rice substitute in all dishes, and in cakes, breads, and pastries when the grain is roasted before being husked. The gluten-free nature of Coix flour makes it significant in bakery products to be used along with wheat flour (Keeratibunharn and Krasaekoopt 2013) will benefit people having celiac disease (Comino et al. 2013). It can also be used in preparation of soups, porridge, gruels, salads, desserts, eaten like peanuts and sweets. Matured dehulled seeds can also be cooked and consumed along with rice. They can be used as snacks of different flavours by cooking, drying, deep frying and baking. It is utilized by the Japanese and Nagas to make alcoholic beverages like a beer called 'Zhu' or 'Dzu' by fermenting whole seeds (Hore and Rathi 2006). Coix seeds along with glutinous seeds can additionally be used to make fermented glutinous wine (Wu 2010). It is also consumed as a drink or as a tea by grinding the seeds and mixing or boiling with water. Vinegar can also be prepared from Coix seeds. Coix is also found to be a nutritious feed for animals. Poultry is given the entire grain, bran, and flour as feed in the replacement of maize. Growing in the wild, its leaves are highly preferred and consumed by wild elephants. Coix is used as feed for cattle, buffaloes and horses as a fodder crop and has better potential to be used in both summer and dry winter seasons with proper management strategies since the grass can be used to produce silage (Jain and Banerjee 1974). In addition, the seeds can improve performance in growth and productivity by lowering gut pH and regulating the gut microbiota of post-weaning pigs when fed as a feed supplement (Li et al. 2019). This crop can be harvested in a short duration, easy to cultivate and need fewer requirements as compared to other cereal crops. The grains of Coix are found to be higher in protein, fat and fibre as compared to many other cereal crops. Coix grain contains 62.0% total starch content, 15.9% protein, 4.66% crude fat, 5.53% dietary fibre, 1.52% total soluble sugar, 0.73% GAE total phenol content, 0.24% phytate, 0.47% GAE antioxidant activity, and also 0.80 mg/100 g, 146 mg/100 g, 3.61 mg/100 g, and 13.60 mg/100 g of copper, calcium, zinc and iron, respectively (Laxmisha et al. 2022). It contains 100.25, 80.68, 50.00 and 44.55% higher protein than rice, maize, wheat and pearl millet, respectively. When compared to rice, it contains a calcium level that is twelve times higher. It also has 96.80% more dietary fibre than rice. It is also an excellent source of iron as compared to rice (0.65 mg/100 g), maize (2.49 mg/100 g), wheat (3.97 mg/100 g) and pearl millet (6.42 mg/100 g) (Longvah et al. 2017). As far as the nutrient composition is concerned, we can clearly conclude that Coix is a rich source of nutrients as compared to many staple food crops of the world and the inclusion of these healthy grains in our diet can address the nutrient deficiency problem around the globe. In the Philippines, the government is promoting Coix because of its high protein content and other nutrients including calcium, phosphate, iron, thiamine, riboflavin, and niacin (Magpantay et al. 2021).

Coix for medicinal uses
Coix plant has been used for a long time and is documented in Indian Ayurveda and traditional Chinese medicine. It consists of many miraculous medicinal properties. It is known to be useful in removing kidney and bladder stones (Hore and Rathi 2006). Furthermore, it is taken due to its effectiveness in treating respiratory tract infections, appendicitis, and allergic disorders. Its use for women as a remedy to a menstrual disorder such as excessive bleeding or irregular menstruation along with its effect in stimulating ovulation and inducing fertility is also reported. Recent research studies on the anti-cancer properties of Coix have shown encouraging results against cancers of the blood, breast, colon, liver, lung, and pancreas (Kumar et al. 2014). From the seed oil of Coix, 'Kanglaite' an anticancer medication, was developed. The drug is currently being investigated in the USA as a possible treatment for prostate and pancreatic cancers. It is already approved in China to treat a number of cancers (Xi et al. 2016). Coixenolide, a fatty acid ester having anticancer action, is the main bioactive component (Ukita and Tanimura 1961). Several studies have demonstrated that regular intake of grains of Coix balances human blood cholesterol levels and lowers the risk of cardiovascular diseases like atherosclerosis and myocardial infarction (Zeng et al. 2021). It is also reported to have diuretic and blood-purifying properties (Schaaffhausen 1952). Its demand has been rising day by day as a result of its high medicinal properties as an ideal 'functional food'.
In Mizoram, the rural communities have been using decoctions of roots as well as leaves for treating urinary tract infections. Reports show that decoction of the roots is being used to treat dysentery, gonorrhoea and as a vermifuge. The sap from the stem is utilized to treat insect bites, while a decoction of the leaves is used to treat rheumatism, headache and diabetes. The seeds of Coix can revitalize the spleen, expel mucus and pus, drains dampness, clear heat, get rid of edema, and decrease body weight (Yu et al. 2011). The seeds are additionally reported to be used in treating arthritis, neuralgia, warts and chapped skin (Shih et al. 2004). The fruits have diuretic, antiinflammatory, antidiarrheal, anti-oxidant, antipyretic, antiseptic, antispasmodic, analgesic, hypotensive, and sedative properties. Contrary to its multiple health benefits, caution is advised during pregnancy and breastfeeding as the seeds of the plant have abortifacient activity (Patel et al. 2017).

Coix as traditional items and other uses
Coix gives the most perfect beads for various ornamental purposes. The seeds obtained from wild types have been used by rural folks to make different kinds of ornamentals-earrings, rosaries, garlands, rings, bracelets, belts, photo frames, and curtains (Fig. 6). They are used in fashion apparel by sewing the beads onto bags, jackets and head gears. The traditional head gear of the Mizo women called 'Vakiria' is decorated with Coix seeds. The seeds of Coix can also be of value in making musical instruments such as Shaker's gourd by covering hollow gourds with a loose net strung with beads of Coix (Biswas and Das 2022). They may be woven into baskets and vessels to add their aesthetic values. Coix seeds are an excellent 2154Genet Resour Crop Evol (2023) 70:2143-2159 source of natural jewellery as it has a hole in the centre through which wire or thread can easily pass. The roots are reportedly used for rituals to contain the spread of smallpox (Jain and Banerjee 1974). The stems can also be used to make mattings. A type of compost can also be made from the leaves by leaving them in piggeries, trampling and mixing with mud (Arora 1977). Additionally, its straw and leaves are utilized for thatching purposes. Moreover, this plant is a good choice for wastewater treatment in tropical areas because it is effective at eliminating inorganic nitrogen from polluted waterways (Jampeetong et al. 2013).

Cultivation practices
Coix is propagated by seeds and cultivated as an annual crop. It is a macrophyte that prefers soil moisture. Land selection for sowing should be low-lying with proper drainage facilities. In case of moisture stress, supplementary irrigation may be given in the early growth and flowering stage. The climatic requirement for Coix is similar to Maize and can withstand wet or waterlogged conditions for a short time span. Sowing should be done during monsoon preferably from May to June and sometimes in July at a seed rate of 6-10 kg/ha having a 1000-grain weight of 80-90 g by dibbling at 4-5 cm depth with a spacing of 60 cm × 60 cm or 60 cm × 45 cm or 45 cm × 15 cm. 40 kg N, 20 kg P 2 O 5 , and 20 kg K 2 O are recommended as general dosages of NPK per hectare. Out of this, 20 kg of nitrogen and a full dose (20 kg) of phosphorus and potassium are applied as basal during land preparation. The remaining dose (20 kg) of nitrogen should be top-dressed one month after sowing. The growth of crop during the early stage is slow hence, weeding is necessary up to 2 months after sowing or up to a crop height of 40 cm. Coix is a tillering crop and all tillers bear inflorescences two to three months after sowing (Fig. 7).

Pests and diseases
Among the diseases, the leaf blight caused by Bipolaris coicis is the most devastating disease of Coix (Jansen 2006). In addition, the diseases like rust caused by Puccinia and smut by Ustilago and Tilletia have also been reported (Corke et al. 2016). The Job's tears smut is caused by Ustilago coicis which infects the ovary of flowers and leaves and is known to cause damage to crops in India, Thailand and China (Titatarn et al. 1983;Zhang et al. 2013). The rust disease is caused by Puccinia operta and leaf spot by Phyllachora coicis to the Coix in Iran (Ahmadpour et al. 2013). Recently, the stem rot diseases of Coix lacryma-jobi caused by Fusarium incarnatum were reported in China (Hou et al. 2022). Besides, viral diseases viz. the southern rice black-streaked dwarf virus (Pu et al. 2012) and maize chlorotic dwarf virus, Coix also hosts some bacterial diseases like leaf scald of sugarcane caused by Xanthomonas albilineans and gumming disease of sugarcane by Xanthonomas axonopodis pv. vasculorum (Hayward 1993). Further, Coix is also attacked by number of insect pests such as Asian corn borer Ostrinia furnacalis, Asiatic rice borer Chilo suppressalis and rice skipper Pelopidas mathias (Ahmadpour et al. 2013;Kalaisekar et al. 2017). The infestation of root-knot nematode, Meloidogyne incognita has also been reported in Coix plants (Duke 1983). Recently, the invasive fall armyworm Spodoptera frugiperda was found infesting Coix in China (Zhou and Yang 2019).
In our study, no disease incidence was observed on Coix plants. However, we recorded the infestation of fall armyworm, Spodoptera frugiperda (J.E. Smith) on Coix at the farms of ICAR-Research Complex for NEH, Mizoram Centre. The damage incidence of fall armyworm ranged between 7.23 and 10.86% in the vegetative growth stages (45-75 days crop) from the last week of August to the end of September. Fall armyworm larvae were found feeding on the leaves and leaf whorl of the Coix plants (Fig. 8). To the best of our knowledge, this is the first report of fall armyworm occurrence on Coix from India. However, fall armyworm infest more than 350 host plants including economically important cultivated grasses such as maize, rice, sorghum, sugarcane and wheat; also other vegetable crops and cotton (Montezano et al. 2018). The occurrence of fall armyworm on Coix was reported in China after its invasion of Asia (Zhou and Yang 2019). Besides Coix, the fall armyworm prefers to feed on maize, however, in the absence of a preferred host, it can feed on other host plants such as Coix due to its polyphagous nature.

Harvesting
Crop usually matures in 4-5 months from the date of sowing depending upon cultivars and climatic conditions of the region. For good harvests, there must be enough rain during the early growth stages and dry weather is required during grain setting (Corke et al. 2016). At maturity, whole plants are cut at the basal region like rice using a sickle or dao and kept for sun drying. The grain is separated from the dried plant by threshing. Large size local wooden mortar (Mizo: sum) and pestle (Mizo: suk) are used to crush the dried seeds to remove the shell. The yield of husked grain generally ranges from 2 to 4 t/ha having a hulling percentage of 30-50% and fodder yield from 25 to 30 t/ha. If the stubble is left in the field, new growth and fresh leaves can be utilized as an excellent fodder. Several cuts are possible if cultivated for fodder purposes. Under humid conditions, it is better to store unhusked grain than husked grain. The seeds of wild types are highly demanded by Art and Culture Department and other cultural clubs to make traditional head gear and other traditional ornaments and these are sold at Rs. 400-500/kg seeds (4.90-6.16 USD).

Problems and prospects of Coix in Mizoram
Coix cultivation is very sporadic in Mizoram and its importance has been decreasing day by day and currently being replaced with high-yielding cereals like maize and rice etc. Due to poor market demand, difficulty in processing due to the presence of hard seed coat, lack of knowledge on processing, non-availability of suitable varieties, ignorance on crop value and lack of scientific cultivation practices resulted in poor attention of Mizo farmers towards its cultivation. There is a lack of systemic knowledge on processing and processed products of this crop. Although, Mizoram is blessed with rich biodiversity, collection and proper documentation of genetic diversity are yet to be explored. Coix is closely associated with the socio-cultural importance of the Mizo community. This crop is hardy towards pests and disease attacks and can be grown in a less fertile area where other crops are unable to perform well and require lesser care. It is highly nutritious and promising medicinal properties fetch more research attention. At the same time, there is an increasing demand for Coix grains and products among health-conscious developed countries as a 'functional food'. Therefore, the collection of germplasm, conservation, evaluation and selection of best performing genotypes are important for improving yield and quality with higher harvest index, dual-purpose types, early and synchronous maturity and lodging-resistant properties. Utilizing genetic resources will also guarantee great productivity and good adaptability to the hilly terrain of the Mizoram ecosystem.

Conclusion
Considering the search for major crop substitutes that can contribute to food and nutritional security under diverse agroclimatic conditions, Coix can be popularized as a functional food, both for human and Fig. 8 Attack of fall armyworm in Coix a coix crop damaged by fall armyworm; b fall armyworm caterpillar feeding on coix leaves; c adult fall armyworm animal consumption. The wide array of wild species of Coix are rapidly disappearing, so, their conservation is needed as they constitute an important genetic resource for crop improvement. The non-availability of location specific varieties, quality seeds, lack of knowledge on scientific cultivation practices and processing, ignorance on the importance of the crop, poor market facility, etc. have contributed to lower cultivation and production of this crop. Identification of potential genotypes for cultivation as well as a candidate for crop improvement is important. The genotypes RJT-1 (39.74 q/ha) and RJT-2 (35.27 q/ ha) were identified with higher seed yield and yield components and these genotypes can be recommended to the farmers of Mizoram for cultivation to get higher production. Although, Coix is naturally hardy towards pest infestation, our pest surveillance recorded infestation of fall armyworm on Coix during the cropping season. To the best of our knowledge, this is the first report of fall armyworm occurrence on Coix from India. Farmers should monitor their Coix crop carefully during the months of August and September for potential infestation from Spodoptera frugiperda. Research priorities on this climate resilient crop is necessary to exploit the full potential of the crop to meet food and nutritional demand of the burgeoning population.