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Singh, B.P. and W.F. Whitehead. 1996. Management methods for producing vegetable amaranth. p. 511-515. In: J. Janick (ed.), Progress in new crops. ASHS Press, Arlington, VA.

Management Methods for Producing Vegetable Amaranth

Bharat P. Singh and Wayne F. Whitehead

    1. Planting Date Study
    2. Cultivar Selection Study
    3. Nitrogen Fertilization Study
    1. Planting Date
    2. Cultivar Selection
    3. Nitrogen Fertilization
  5. Table 1
  6. Table 2
  7. Table 3

Amaranth (Amaranthus spp.) is a new crop with ancient history. Members of Amaranthus spp. have been grown for centuries for vegetable and grain in different parts of the world (NRC 1984). Amaranth is consumed as vegetable in Africa, Caribbean, China, Greece, India, Italy, Nepal, and South Pacific Islands (Stallknecht and Schulz-Schaeffer 1993). Amaranthus species most commonly utilized as vegetable have short plants with wide leaves and small inflorescence (Huang 1980). However, it is common to find same plant type used both for leaf and grain (Saunders and Becker 1984; Tucker 1986).

The awareness in the United States of the potentiality of amaranth, mainly as a grain and to a lesser extent as a vegetable crop, was generated by the Rodale Research Center, Kutztown, Pennsylvania in the mid-1970s. Immigrants from the countries where vegetable amaranth is consumed widely, however, were the real impetus behind creating a demand for this vegetable in the United States. Since then, it has been realized that amaranth can also fill a void for fresh leafy vegetables during the summer months (Makus and Davis 1984; Singh and Whitehead 1993). Amaranth leaves are comparable to spinach (Spinacia oleracea L.) in taste (Abbott and Campbell 1982). They are also a good source of dietary fiber and contain high amounts of protein, vitamins, and minerals (Makus and Davis 1984; Teutonico and Knorr 1985; Willis et al. 1984). However, unlike spinach, an ideal season for producing amaranth in the temperate climate is during the hot months of the summer season. In addition, research has shown that green yields from amaranth produced at different locations in the United States are high enough to make commercial exploitation feasible (Berberich 1980; Campbell and Abbott 1982; Makus 1984; Sealy et al. 1990; Singh and Whitehead 1991). In this paper, we present results of cultural studies (planting date, cultivar selection, and N-fertilization) of vegetable amaranth.


Planting Date Study

Field experiments to determine the suitable time period for planting amaranth were carried out during 1992 and 1993. The experiments were conducted on a Dothan sandy loam soil (fine loamy, siliceous, thermic, Plinthic Paleuult). Amaranthus tricolor genotype RRC 241 was used for planting. Different planting dates comprised the treatments, which were arranged in a randomized complete block design with four replications. Each plot consisted of four 6.1 m long rows spaced 90 cm apart. Seeds were planted on six dates starting mid-Apr. to mid-Sept. Weeds were controlled mechanically. Plots were irrigated as needed. Crop was harvested 40-44 days from planting. Before harvest, height of five random plants per plot was measured. Two middle rows were used in the yield estimations. Plants were harvested below first leaf nodes and their fresh weight was taken. Dry weight was determined after drying the plant material at 70°C in a forced air oven.

Cultivar Selection Study

Field studies to identify culivars with maximum yield potential were carried out during 1994 and 1995 summer seasons. Soil and other conditions of production for these experiments were similar to the planting date experiments. A total of nine accessions, eight supplied by Rodale Research Center as potential vegetable type and one by the Plant Introduction Station, Ames, Iowa were evaluated. The lay-out of experiments was randomized complete block design with four replications. The plots were 6.1 m long with four rows spaced 90 cm apart. The accessions were planted in mid-June and harvested approximately 40 days after germination. Five randomly selected plants were collected at the time of harvest to measure growth parameters consisting of branch number, leaf number, leaf area, stem and leaf fresh and dry weight. Leaf area was measured with an area meter (LI-COR Model 3100, Lincoln, Nebraska). Height of five random plants per plot was measured. Two middle rows were used in the yield estimations. Fresh weight of the yield rows was taken immediately after harvest. Dry weight was recorded after drying the plant material at 70°C in a forced air oven. Leaf to stem ratios was calculated.

Nitrogen Fertilization Study

Field studies from 1992-1994 were conducted to determine the effect of different rates of N on the vegetative growth of amaranth. The soil and other conditions of production were similar to other experiments. The genotype RRC 241 was used for seeding. The individual plots were 6.1 m long and four rows wide. The experimental design was randomized complete block with four replications. The N levels comprising the treatments were zero (control), 45, 90, and 135 kg/ha N. The N amount assigned to a plot was applied in split application, half at germination and the other half two weeks later. Harvesting and data collections for this study were similar to the cultivar selection study.


Planting Date

Seeds planted in mid-Apr. failed to germinate (Table 1). In all plantings from mid-May onwards, satisfactory amaranth germination was achieved. Mid-June planting produced tallest plants with highest green and dry matter yield, while these parameters were lowest for mid-Sept. planted seeds. The range for green yield was 0.70-12.28 Mg/ha and the dry matter yield varied from 0.15-1.24 Mg/ha. The tallest and shortest plants measured 6.9 cm and 49.1 cm, respectively.

Weather data for Apr. to Oct. during 1992 and 1993 indicate that amaranth seeds needed soil temperature about 25°C to germinate and air temperature above 25°C for optimum growth. According to Wagoner (1983), most amaranth species and cultivars germinate when the soil temperature reaches 18°C or above. Webb et al. (1984) found that temperature around 25°C was optimal for germination. Number of growing degree days during the growing season is a major determinant of amaranth plant growth.

Cultivar Selection

Green yield and dry matter yield of the nine plant accessions are presented in Table 2. Out of nine accessions, six were A. tricolor, and one each from A. hybridus, A. cruentus, and A. dubius. A. tricolor is the choice vegetable amaranth type in Asia, while A. hybridus, A. cruentus, and A. dubius are grown as vegetables in Greece, Africa, and Caribbean and South America, respectively.

A. hybridus and A. cruentus accessions were taller than other genotypes. A. dubius and A. tricolor accessions except PI 349553 were of similar height. A. tricolor accessions, RRC 389 and RRC 241 had maximum number of leaves and leaf area, respectively. RRC 241 also had the highest leaf fresh and dry weights. A. hybridus and A. cruentus accessions had the highest stem fresh and dry weights, and green and dry matter yields. RRC 241 produced maximum green yields among A. tricolor accessions.

In comparing the green yield among A. tricolor, A. hybridus, A. cruentus, and A. dubius species in Mississippi, Igbokwe et al. (1988) also found A. hybridus to be highest yielding. Our finding of A. cruentus producing higher green yields than A. tricolor does not agree with Daloz (1981). Among A. tricolor accessions, Kauffman and Gilbert (1981) and Makus and Davis (1984) have also reported RRC 241 to be top performer. A. tricolor accessions, PI 349553 and RRC 241 had the highest and A. cruentus and A. hybridus accessions, RRC 1034 and RRC 843 had the lowest leaf : stem ratios. While both leaf and stem are consumed in some parts of the world, plants with higher leaf : stem ratios are more in demand. Campbell and Abbott (1982) have also reported higher leaf : stem ratio in A. tricolor as compared to A. dubius and A. cruentus.

Nitrogen Fertilization

There was a linear increase in plant height from N-fertilization (Table 3). Leaf area increased with N-fertilization until 90 kg/ha. Stem and leaf fresh and dry weights increased linearly with N-fertilization. Quadratic equations provided the best fit for the green and dry matter yield. An R2 for green yield of 0.70 as compared to 0.51 for the dry matter yield suggested that a higher percentage of the increases in green yield as compared to the dry matter yield could be attributed to N-fertilization probably as a result of an increase in succulence.

The N needed for the growth of a crop will vary depending on the N status of the soil and potential for mineralization. Therefore, optimum N amount reported for maximum amaranth growth by different researchers are substantially different. The reported range varies from 50-200 kg N/ha (Keskar et al. 1981; Subhan 1989; Ramachandra and Thimmaraju 1983). All studies agree that supplemental N is required for optimum amaranth yield.


The results suggested that for highest yields, amaranth should be seeded in June. A. hybridus and A. cruentus produced significantly higher green yield than A. dubius and A. tricolor. RRC 241 yielded the highest among A. tricolor accessions. Nitrogen fertilization applied at the rate of 90 kg/ha produced highest vegetable amaranth yields.


Table 1. Plant height, green yield, and dry matter yield of amaranth at six planting datesz.

Planting dates Plant height
Green yield
Dry matter yield
Apr. 12 0dy 0.0d 0.00e
May 12 18c 1.9bcd 0.33cd
June 15 49a 12.3a 1.24a
July 14 35b 4.1b 0.62b
Aug. 15 30b 3.6bc 0.59bc
Sept. 14 7d 0.7cd 0.15de
z1992 and 1993 experiments combined.
yMean separation within column by Duncan's multiple range test, P = 0.05.

Table 2. Vegetative growth parameters and yield of nine amaranth accessionsz.

Plant weight (g/plant)
Stem Leaf
Accession number Species Plant height (cm) Leaf number (no./plant) Leaf area (cm2/plant) Fresh Dry Fresh Dry Leaf:stem ratio Green yield (Mg/ha) Dry matter yield (Mg/ha)
Hinchoy GL A. tricolor 40by 89bc 1336bc 65b 6.3bc 58bc 10.4b 0.90b 7.3bc 0.91de
RRC 389 A. tricolor 48b 133a 1362bc 65b 7.4b 52bcd 9.2bc 0.82b 7.4bc 0.96de
RRC 701 A. tricolor 46b 75cd 1069cd 56bc 5.7bc 46cd 9.0bc 0.84b 6.9c 1.00cd
RRC 843 A. hybridus 72a 91bc 1351bc 112a 10.2a 67ab 11.7ab 0.61c 11.9a 1.37ab
RRC 1034 A. cruentu 67a 105b 1308bc 104a 10.3a 69ab 12.2ab 0.68c 11.1a 1.40a
RRC 1186 A. dubius 43b 76cd 1350bc 51bc 4.8bc 56bcd 9.6bc 1.12a 8.4bc 1.10bcd
Hinchoy VL A. tricolor 45b 80cd 1503ab 72b 7.3b 64ab 12.0ab 0.93b 6.9c 0.96de
PI 349553 A. tricolor 30c 64d 910d 34c 3.7e 40d 7.2c 1.16a 4.3d 0.69e
RRC 241 A. tricolor 43b 93bc 1819a 70b 6.6b 78a 13.8a 1.14a 9.2b 1.25abc
z1994 and 1995 experiments combined.
yMean separation within column by Duncan's multiple range test, P = 0.05.

Table 3. Vegetative growth parameters and yield of amaranth at four N-fertilization ratesz.

Plant weight (g/plant)
Stem Leaf
N-rate (kg N/ha) Plant height (cm) Leaf number (no./plant) Leaf area (cm2/plant) Fresh Dry Fresh Dry Leaf:stem ratio Green yield (Mg/ha) Dry matter yield (Mg/ha)
0 30 57 1013 37 3.2 53 7.6 1.50 5.5 0.83
45 33 71 1484 47 4.5 64 9.9 1.45 8.8 1.21
90 36 71 1766 66 5.4 82 10.2 1.33 12.0 1.57
135 39 82 1705 74 6.3 85 11.1 1.18 12.6 1.53
Significance L** L** Q* L** L** L** L** L** Q** Q*
z1992, 1993, and 1994 experiments combined.
*, ** Significant at P = 0.05 (*) or 0.01 (**) level.

Last update June 24, 1997 aw