The authors have declared that no competing interests exist.
The Andean region is the centre of origin and domestication of at least 9 species of native root and tuber crops in addition to several species of native potatoes. Within this group, Mauka – also known as Miso or Taso ‒ (
The plant is described with emphasis on its agronomic traits and according to its propagation forms (seed or vegetative); in terms of its agroecology, phenology, growth dynamics and their indices, crop management, harvest and post-harvest processes. It is concluded that important advances in the understanding of the agronomy of Mauka have been accomplished. Furthermore, the review highlights aspects requiring further research, in order to develop improved production technologies to ensure its future use and conservation.
In 1965, Julio Rea and Jorge León reported on the discovery, in a remote community in Bolivia (Yokarguaya, Italaque, Camacho province), of a new cultivated plant unknown to science: ‘Mauka’ (
The tuberous root of Mauka is an important food source ‒ high-yielding and rich in nutrients, particularly calcium (
Nutrient | Amount | Source | |
fwb | dwb | ||
Carbohydrate | 10.4‒20.2% | 70% |
|
Carbohydrate ‒ amylose | 21% |
|
|
Protein | 4.4% |
|
|
Calcium | 111 mg 100 mg-1 edible part |
|
|
Phosphorus | 283 mg 100 mg-1 edible part |
|
It has promising potential as a forage species
The National Research Council (NRC)
Twenty-nine years later, we can conclude that the second statement made by the NRC
Although existing studies demonstrate that Mauka has many beneficial properties, its full potential has yet to be realised. In a pilot experiment facilitated by Gendall in 2016
Fifty-three years after its discovery as a cultivated plant, we present a synthesis of the agronomy of the Mauka, incorporating insights from ethnobotanical studies and the results of scientific research advances that have taken place on the subject to date.
The cultivated Mauka is a herbaceous plant, perennial, erect when young and decumbent or prostrate and open, to maturity. Propagated from seed, the primary root is axonomorphic, thickened, branched from an early age, with small fine rootlets on its surface that have an absorption function
The thin stems (Ø = 0.5 to 3 cm at the base) are green or purple-green and can reach lengths of 80 to 140 cm, with ramifications of the first, second and third order. Their number per plant varies from 5 to 17, depending on whether the plant originates from seed or vegetative propagation. The leaf nodes are prominent and the internodes up to 16 cm long. Generally, only one of the two axillary buds at each node (opposite leaves) develops while the other atrophies. Just below ground level the base of the stems thicken and form short, bulging and globose corm-like internodes with depressed nodes.
These corms constitute the principal source of propagules for vegetative propagation as typically used by the farmers. At the base of the stems (neck of the plant) a crown is formed from which the roots emerge downwards and the stems upwards. The opposite, cordate-ovate or elliptical leaves are light green or dark green with or without purple pigmentation
The inflorescences are aggregated cymes with the terminal inflorescence unit a cyme with 3 to 5 densely grouped flowers. The pentamerous and sympetalous flower buds are yellow, brown or purple, 3‒4 mm long while 5‒6 mm in diameter at anthesis. The synsepalous calyx consists of five plicate, green, sepals; they are persistent covering the gynoecium at it grows and at fruit maturity almost completely, i.e. anthocarpous. The perianth is formed by five sympetalous tepals, lilac, white or white coloured with slight violaceous pigmentation. It has three free stamens and anthers with two reniform thecae containing 25‒30 pollen grains each. The style is longer than the stamens and curved at the apex. The stigma is capitate-papillate, and the ovary is superior, monocarpellary, unilocular, central placentation, single ovule.
The flower opens only once, and in conditions of the valley of Cajamarca, the anthesis starts between 05:30 and 06:00 and terminates at midday between 12:00 and 13:00s. Its reproduction type is fundamentally autogamous, with 6‒25% cross-pollination. Cross-pollination is entomophilous, mainly carried out by species of the genera
The fruit is an elliptical or ovoid achene, 3 mm long × 1.7 mm Ø; grey, black or brown in colour, wrapped by the fleshy anthocarp of the persistent calyx and covered by glandular gum containing hairs most abundant at the apex. The gum allows the fruit to adhere to any surface when detached from the plant and be transported by animals and humans, i.e. an adaptation to epizoic dispersal. At maturation, it is common to find insects, and even birds or mice trapped between the plants. The achenes are the unit of dispersal. The seeds have white or crystalline endosperm and have epigeal germination. One hundred seeds weigh 0.6‒1.2 g
The Mauka plant, a perennial geophyte that – in a similar way to other tuberous species – has evolved in the Andean environment, marked by a wet-temperate season alternating with a dry and cold season. In its natural environment, the abundant reserves stored in its roots and the base of its stems enables it to survive under adverse growth conditions. In addition, the thickened basal stems, i.e. corms, serve as a means of regeneration
Its cultivation in Bolivia, Ecuador and Peru probably dates from the pre-Inca period. Findings and collections, since 1965, indicate that in the three countries it is cultivated at altitudes of 2300–3500 m a.s.l.
It responds better to soils of frank and sandy-loam texture, with a pH between 6.8 to 7.2, with a good proportion of organic matter (≥ 3%). Cultivated in association with crops such as potatoes (
Five distinct landraces (I, II, III, IV and V) have been characterized by Seminario and Valderrama
The plant has shown high adaptability to environments outside the Andes, and in recent decades has been successfully introduced in the Czech Republic and Belgium
Mauka is, as mentioned above, propagated both by seeds and vegetatively (
The advantage of propagation by cuttings is that the multiplication rate is higher than with underground stems. An evaluation carried out using the purple landrace, at seven months of age, found that each mother plant produces 266 cuttings, with four nodes each (eight buds); meanwhile 100 plants are needed to plant one hectare at the density of 0.90 m × 0.50 m, i.e. 22 222 plants ha-1
Under greenhouse conditions, Alva
Treatment | Cuttings with root and bud (%) | Height of shoot (cm) | No. roots | Root size(cm) | No. Leaf pairs |
Landrace III, soil + humus | 78 | 10.3 | 6 | 4.8 | 17 |
Landrace III, soil + sand + humus | 80 | 9.3 | 5.4 | 3.9 | 18 |
Landrace III, sand | 93 | 13.3 | 7.2 | 5.0 | 20 |
Landrace I, soil + humus | 65 | 10.3 | 3.8 | 3.8 | 16 |
Landrace I, soil + sand + humus | 66 | 7.4 | 4 | 4.2 | 14 |
Landrace I, sand | 73 | 11.5 | 4.3 | 4.1 | 19 |
Landrace IV, soil + humus | 45 | 7.5 | 3.3 | 3.5 | 15 |
Landrace IV, soil + sand + humus | 42 | 6.0 | 3.4 | 4.8 | 12 |
Landrace IV, sand | 53 | 9.6 | 5.4 | 4.3 | 15 |
Average | 66 | 9 | 5 | 4 | 16 |
SD | 17.0 | 2.2 | 1.3 | 0.5 | 2.5 |
Sample: 15 plants per treatment. Landrace I (purple), landrace III (bright green), landrace IV (Puno). Source:
Component | Soil | Lumbricus humus | River sand |
PH | 6.9 | 8.2 | 7.40 |
Organic matter (%) | 4.0 | 25.0 | 0.22 |
Phosphorus (mg kg-1) | 11.8 | 10 000.0 | 1.90 |
Potassium (mg kg-1) | 239.5 | 3222.0 | 350.00 |
Source: Soil analysis laboratory, Universidad Nacional de Cajamarca (client code: LS-303-2005).
Landrace | Length (mm) | Width (mm) | Weight 100seeds (g) | % Germination |
Days to germination |
Days to first pair of true leaves |
I | 3.1 | 1.7 | 0.55 | 85 | 11 | 19 |
II | 2.9 | 1.6 | 0.52 | 88 | 12 | 21 |
III | 3.0 | 1.7 | 0.57 | 92 | 10 | 20 |
Average | 3.0 | 1.7 | 0.55 | 88 | 11 | 20 |
SD | 0.10 | 0.06 | 0.03 | 3.51 | 1.00 | 1.00 |
in Petri dish on paper,
sown in substrate of soil, sand and humus (1:1:1). Source:
A first noticeable difference between plants raised from seed and vegetative propagule (corms or stem cuttings), refers to the origin of the tuberose root, which is the harvestable part. In the first case, the tuberous root is the result of the lengthening and thickening of the radicle and hypocotyl, which form a single tuberous axis (
On the other hand, in plants from propagule, the tuberous roots are adventitious and numerous, originating from the corm, i.e. the crown or base of the stems. Whether from seed or propagule, in plants with this type of tuberous roots, i.e. without independent fibrous roots, of which the primary function is to absorb the photosynthates which are destined to the apical meristems of the fibrous roots and the stems are translocated through the tuberous roots. In the same way, both water and mineral nutrients must be transferred through the tuberous root to the leaves
The Cajamarca field experiments were carried out at the National University of Cajamarca UNC, located at 7° 29'45'' S and 78° 10'12'' W, at 2 656 m a.s.l. with an average daily temperature of 14 °C, 65% of RH and an annual rainfall of 650 mm. These experiments involved the comparison of three landraces, raised from both seeds and propagules (
Characteristics | Type of propagation material | |
Seed |
Vegetative |
|
Growth period (days) | 326.00 | 312.00 |
Type of root | Axonomorph | Fasciculate |
Root length (cm) | 26.00 | 20.00 |
Greatest root diameter (cm) | 6.00 | 4.00 |
No. of roots plant-1 | 7.00 | 17.00 |
Root weight plant-1 (kg) | 1.35 | 2.50 |
No. of stems plant-1 | 4.50 | 17.00 |
Maximum leaf area (dm2 plant-1) | 287.00 | 327.00 |
Maximum IAF | 8.00 | 8.00 |
Weight of above ground part (kg plant-1) | 0.17 | 0.67 |
Root yield (kg ha-1) | 31,433.00 | 59,133.00 |
Harvest index (%) | 52.00 | 49.00 |
Data from
Data from
Soil is prepared for planting Mauka in much the same way as when it is prepared for planting maize ‒ with which it is frequently intercropped. This process generally involves ploughing using a tractor, yoke or ‒ at the smaller scale ‒ using a hand tool such as a pick-axe. If planting seed it is recommended to raise plantlets in a seedbed and to transplant these to the planting site once they have developed one to two pairs of green leaves. If using basal stems as propagules these are separated from the mother plant and either planted directly or exposed to the sun for a period of time, as previously mentioned, and then planted. Aerial stem cuttings are best planted after they have been rooted in a nursery.
On average Mauka produces five stems if propagated by seed and up to 17 stems per plant if vegetatively propagated. In both cases, the stems of the decumbent plants branch profusely and can measure up to 1 m in length. These characteristics should be taken into account when considering planting density. Seed should be sown on ridges spaced at 0.8 m, with 0.4 ‒ 0.5 m distance between plants, i.e. 31 250 ‒ 25 000 plants ha-1.
Meanwhile, if using propagules, these should be planted at 0.9 ‒ 1 m between ridges and 0.5 ‒ 0.6 m between plants, i.e. 16 666 ‒ 22 222 plants ha-1. Further study is required to assess the yield of tuberous roots, foliage and corms, in relation to landraces and crop husbandry factors. Also, to harvest roots and foliage most efficiently, it will be necessary to identify the point of equilibrium between the production of underground and aerial parts. Because local farmers typically cultivate and are familiar with no more than one landrace of Mauka, and are accustomed to planting the crop on a relatively small scale, these aspects can not be assessed through ethnobotanical inquiry alone.
In traditional Andean agriculture, livestock manure is used to fertilise crops. However, due to the scarcity of this resource, it is primarily applied to the main crops, e.g. potatoes and maize. Marginal crops such as Mauka are usually not fertilised. Albeit, there are only few studies of Mauka’s response to the application of manure, compost or chemical fertiliser.
Zapana
Treatments | Plant height (cm) | Seed yield (t ha-1) | Root yield (t ha-1) |
7.5 t ha-1 manure* | 50.7 | 7.2 | 46.4 |
60-40-0 N, P, K | 66.3 | 11.3 | 78.5 |
Control | 39.6 | 4.6 | 31.6 |
Source:
In the study by Zapana et al.
Weeding is necessary during the first months following planting. The frequency of weed removal depends on the conditions during the cropping season, i.e. wet or dry, and the conditions at the site. Removing weeds as they appear, before they become competitive to the crop, is generally recommended. After four to five months the Mauka plants should cover the furrows between ridges and outcompete the weeds on their own accord.
Observing Mauka’s growth habits under various experimental planting arrangements since the late 1980s (again conducted at the UNC experimental fields) indicates that hilling, i.e. the placement of additional soil around the base of each plant several months into its growth cycle, is not of fundamental importance for the production of Mauka roots, although local farmers have reported that the practice is beneficial to cultivation
Hilling up soil around the base of the Mauka plants instead appears to stimulate the growth in number and thickness of the underground parts, at the expense of the growth and thickening of the roots themselves ‒ which are the principal product. This effect is seen in the first drawing of a Mauka plant cultivated in Bolivia, published by Rea and León
Mauka is a crop grown by smallholder farmers at high altitudes in the Andes, where its cultivation is subject to and synchronised with the rainy season, i.e. September to April. As such it tends to be irrigated only occasionally, as and when the main crops are irrigated in those areas that have access to water for this purpose.
Mauka's water consumption behavior has not yet been compared across different climatic and soil conditions. Further inquiry into these aspects would be highly relevant for the development of the crop.
With regards to stress, the greatest risk to Mauka plants is probably excess water, which can cause root rot. This can occur as a result of abundant rainfall combined with poorly drained soils
Low temperatures can also induce stress in Mauka plants. In the Cajamarca Valley, where temperatures fall below -2 °C, frost has been known to damage the entire leaf area. However, sustained by its underground reserve and abundance of buds originating from the underground corms ‒ with the addition of weekly irrigation ‒ it can typically recover within 30 days.
The phenology of three landraces (I, II and III) propagated by both corms and seed (
Landrace | VegetativeStage (days) |
Reproductive stage (days) | Planting to physiological maturity (days) | |
Sub-stage early |
Sub-stage late |
|||
I | 206 | 52 | 54 | 312 |
II | 213 | 52 | 55 | 305 |
III | 192 | 53 | 60 | 305 |
Average | 204 | 52 | 56 | 312 |
SD | 10.7 | 0.6 | 3.2 | 7.5 |
Plant with a single floral bud visible;
Floral bud visible till anthesis;
Anthesis till physiological maturity. Source:
In a field trial at the UNC, the growth dynamics of Mauka plants and their organs were evaluated and compared across three different landraces, originated both from corms
For example in landrace III (light green), when the vegetative propagule was used the maximum leaf area was recorded at 210 days (
Landrace | Vegetative stage (days) |
Reproductive stage (days) | Planting to physiological maturity (days) | ||
Planting till emergence | Emergence till first floral bud | Sub-stage early |
Sub-stage late |
||
I | 18 | 190 | 62 | 63 | 333 |
II | 15 | 185 | 58 | 60 | 321 |
III | 13 | 183 | 60 | 62 | 323 |
Average | 15 | 186 | 60 | 62 | 325 |
SD | 2.5 | 3.6 | 2.0 | 1.5 | 6.4 |
Plant with a single floral bud visible;
Floral bud visible till anthesis;
Anthesis till physiological maturity. Source:
In an evaluation of three landraces propagated by corms, conducted at the UNC (
Landrace | Age (days) | LAI | Stage (days) | RLGR(dm2 dm-2) | CGR(g m-2 d-1) | RGR(g g-1-d-1) | NAR(g dm-2 d-1) |
I | 60 | 0.24 | 60‒120 | 0.045 | 7.71 | 0.031 | 0.061 |
120 | 3.63 | 120‒180 | 0.006 | 18.57 | 0.018 | 0.042 | |
180 | 5.27 | 180‒240 | 0.005 | 5.89 | 0.003 | 0.013 | |
240 | 3.79 | 240‒300 | -0.002 | 37.54 | 0.012 | 0.009 | |
300 | 3.74 | 300‒360 | -0.027 | -4.08 | 0.000 | -0.022 | |
360 | 0.71 | ||||||
II | 60 | 0.24 | 60‒120 | 0.050 | 11.85 | 0.040 | 0.087 |
120 | 4.13 | 120‒180 | 0.008 | 29.88 | 0.019 | 0.056 | |
180 | 6.72 | 180‒240 | 0.003 | 8.45 | 0.002 | 0.011 | |
240 | 8.20 | 240‒300 | 0.000 | 29.87 | 0.006 | 0.039 | |
300 | 5.37 | 300‒360 | -0.02 | -7.79 | -0.001 | -0.029 | |
360 | 1.07 | ||||||
III | 60 | 0.28 | 60‒120 | 0.048 | 12.44 | 0.041 | 0.074 |
120 | 5.25 | 120‒180 | 0.006 | 22.66 | 0.016 | 0.035 | |
180 | 7.92 | 180‒240 | 0.005 | 25.96 | 0.008 | 0.028 | |
240 | 10.57 | 240‒300 | -0.007 | 24.65 | 0.005 | 0.068 | |
300 | 6.79 | 300‒360 | -0.028 | -6.95 | -0.001 | -0.026 | |
360 | 0.98 |
Sample: Each data represents the average of 12 plants in full competition.
I: purple, II: dark green, III: light green. LAI: leaf area index, RLGR: relative leaf growth rate, CGR: crop growth rate, RGR: relative growth rate, NAR: net assimilation rate.
Source:
The allocation of the dry matter to the plant organs was similar for plants vegetatively propagated and those generated from seed, but this aspect did vary according to landrace (
Farmers typically harvest the Mauka crop after one year of maturation, although some report harvesting it as early as 8 months. Yellowing foliage, shedding leaves and the stickiness of its inflorescences are said to indicate that a Mauka plant is mature enough to harvest. However, as a marginal crop, the harvest of the main crop tends to determine the timing of the Mauka harvest, i.e. Mauka will usually be harvested together with main crops, or just after them. Nevertheless, because Mauka is a subsistence crop with a flexible vegetative period, it is important to note that farmers often harvest it as and when it is required, plant by plant. The practice of digging to remove just a few roots and allowing the plant to continue growing has also been reported. In this sense, Mauka can be conceived of as a sort of ‘living larder’
From observing the root growth dynamics of the three most common landraces in northern Peru, it is inferred that tender and fresh roots can be harvested from 7.5 months. In the valley of Cajamarca ‒ as indicated above – at 240 days plants have accumulated more than 60% of their total root dry weight; at 270 days they manage to accumulate more than 80% of their dry weight and; at 300 days the growth of these reserves practically ceases (
Experimental studies in several locations in several locations of Peru, Ecuador and Bolivia (
Locality, country | Yield (t ha-1) | Plants ha-1 | Source |
Cajamarca, Peru | 12‒52 | 22 222 |
|
Cajamarca, Peru | 43‒52 | 25 000 |
|
Cajamarca, Peru | 44‒72 | 25 000 |
|
Quito, Ecuador | 2.1‒15.3 | 09 569 |
|
Quito, Ecuador | 16‒25 | 10 000 |
|
Chullina, Saavedra, Bolivia | 32‒40 | Not indicated |
|
Cajamarca, Peru | 30‒37 | 28 571 |
|
Cajamarca, Peru | 31 | 28 571 |
|
Cajamarca, Peru | 45‒137 | 25 000 |
|
Quito, Ecuador | 13‒40 | Not indicated |
|
Cajamarca, Peru | 21‒39 | 20 833 |
|
Tambopata, Puno, Peru | 32‒79 | Not indicated |
|
Plant spacing approx. 1 m × 1m.
in agroforestry system.
However, the observations of five Peruvian landraces over several plantings and years (
Landrace | Plant height (cm) | No. Roots | Root length (cm) | Root weight(kg plant-1) | Yield (t ha-1) | Foliage weight(kg pant-1) |
I | 73.3 | 16.5 | 12.91 | 1.80 | 39.10 | 1.60 |
II | 77.6 | 14.4 | 15.60 | 0.90 | 20.50 | 1.50 |
III | 81.2 | 12.7 | 12.90 | 1.60 | 33.80 | 1.70 |
IV | 47.0 | 10.5 | 13. .0 | 1.40 | 29.10 | 0.60 |
V | 59.3 | 14.0 | 12.90 | 1.60 | 33.20 | 1.70 |
Average | 67.68 | 13.62 | 13.46 | 1.46 | 31.14 | 1.42 |
SD | 14.23 | 2.21 | 1.19 | 0.34 | 6.19 | 0.46 |
Sample: Each data is the average of three crops and five plants per harvest, multiplied by the number of entries in each landrace: 17, 13, 8, 1 and 1, for landraces I, II, III, IV and V, respectively.
Source:
In addition to tuberous roots, the Mauka plant also yields leaves and stems (
An evaluation carried out over three agricultural seasons, which assessed production levels for 40 different accessions of Mauka (5 plants per accession), produced forage yields which averaged 1.6 ± 0.6 kg plant-1
In order to assess forage production, Bazan et al.
Using these studies as a starting point, further research on forage production from Mauka can be carried out compared to the production levels of other forage species, as suggested by Kritzer Van Zant
Statistics | No. stems | Forrage fresh weight (kg) |
Minimum | 4.5 | 0.25 |
Maximum | 17.5 | 9.25 |
Average | 9.5 | 1.95 |
SD | 3.5 | 1.65 |
Sample: 60 plants, randomly sampled. Source:
The roots, dense clustered with low water content, are resistant to handling. Post-harvest they are seldom attacked by pathogens, and their tissues show no changes of the kind that might inhibit consumption, as with other roots, such as arracacha (
The roots can be kept outdoors for several weeks without deterioration, and, if they are left to dehydrate in a dry environment, can remain unchanged for many years (
Both pre-cooked and raw products can be used in savoury and sweet preparations, or they can be ground to obtain flour or starch for various uses.
Farmers wash the roots and peel them either prior to cooking by scraping the thin skin off with a knife, or after cooking ‒ usually by hand. They typically consume the roots boiled as an accompaniment to other food, in the same way that yucca/manioc is eaten Mauka is also served unaccompanied; boiled and washed down with coffee for breakfast or lunch, in place of bread or potatoes. Other dishes made with Mauka mentioned by farmers include ‘mazamorra’ (a sweet pudding), ‘picante de cuy’ (spicy stew made with guinea pig), soups and broths, and ‘pachamanca’ or ‘huatia’ (an earthen oven which entails burying the roots in the ground with hot coals)
Over half a century has now passed since the (re-)discovery of the cultivated Mauka plant, and during that time important advances in the understanding of its agronomic traits and potential have been accomplished. The sum of this research forms an empirical and theoretical basis for the promotion and development of Mauka as a commercial crop. So far, studies have focused mainly on the biology of the Mauka plant in agricultural systems, its propagation methods, phenology, and analysis of its growth.
The less studied aspects are its response to organic and chemical fertilisers, variation in productivity across different environments, recommended planting densities ‒ especially in association with other crops ‒ the timing of harvest and the simultaneous optimisation of root and fodder production. Field trials assessing these qualities could further improve the productivity of Mauka, while taste trials examining the variation in astringency and sweetness of various landraces could improve its culinary prospects.
Ethnobotanical surveys have been carried out, which have significantly enriched our understanding of the versatility of Mauka, but the full distribution range of the crop in its cultivated form is still incomplete and the local significance and history of Mauka across the Andean region remains poorly understood. Efforts to map its current range and collect both cultivated and wild germplasm for conservation should be widened to underexplored areas of Peru and, most urgently, to Bolivia ‒ where no material is conserved ex-situ.
In order to prevent genetic erosion and the conservation of traditional ecological knowledge, it is necessary not only to maintain Mauka in genebanks, but also to promote its continued cultivation in-situ by local farmers. This endeavour can be supported by the application of findings from the agronomic research accumulated so far, and from further research aimed at improving sustainable production techniques. This way, it is hoped that Mauka will be more widely appreciated as both a biological and a cultural resource; and its role as a resilient, nutritious and profitable crop plant secured not only for future generations of Andean farmers but also as an important contributor to the food sovereignty of Andean communities, which merits its study and conservation.
The International Potato Center (CIP) and the Swiss Agency for Development and Cooperation (COSUDE) are gratefully acknowledged for funding research via the Andean Roots and Tubers Biodiversity Program on Mauka and other tuber crops during the decade from 1993 to 2003. Thanks to the Universidad Técnica del Norte-Ecuador for the space given for the implementation of conservation fields of miso at the Pradera Biological Knowledge Center. This will allow carrying out future research related to the crop. We also give warm thanks to the farmers who have shared their knowledge with the authors and other researchers over the years.