Forage Yield Comparison of Three Amaranth (Amaranthus hypochonriacus L.) Varieties at Different Harvesting Stages

Amaranthus L. is one of the oldest food crops in the new world. Earlier studies have predicted that the grain Amaranthus L. was domesticated in America. This crop has about 60 species of annual flowering plants distributed throughout the world’s temperate and tropical regions. Three species of Amaranth (Amaranthus hypochondriacus L., A. cruentus L. and A. caudatus L.) were domesticated in the new world, but spread to the old world where they became important crop plants. These crops have potential for higher nutritional value, better adaptability to various ecological zones, and better resistance to biotic and abiotic stresses than most other staple crops. Amaranthus is one of the native plants of Africa that in addition to the relative tolerance to drought, have high forage production potential.
The experiment was conducted at the Karaj research station belongs to Seed and Plant Improvement Research Institute of Iran during the spring of 2016. This research located at 320 34' N, 280 32' S, the soil type was sandy loam. The experimental design was a randomized complete block with four blocks in split plots factorial method. Treatments included as three varieties of Amaranth consists of Loura, Cim and Kharkovski and two harvest times which were initiation and the end of flowering. All amaranth varieties belonging to species A. Hypochondriacs L., Plots consisted of six rows with 6-meter length, between and within row spacing were 0.6 and 0.1 meter, respectively. Soil was prepared in early bloom and seeds planted on the firmed bed at 1-2 cm depth in mid-May. Fertilization, Irrigation, weed and insect control were followed like the other leafy forage crop. Ten randomly selected plants were collected at the harvesting time to measure growth parameters consisting, plant stems, height and diameter, leaf to stem rate and tiller per plants. Two middle rows were used for the yield determinations. Dry weights were recorded after drying the fresh forage at 650C in the oven for 48h. Analysis of variance for all traits was done by the MSTAT-C software and for mean comparison used Duncan’s multiple range tests.
Analysis of variance for all traits was done by the MSTAT-C software and for means comparison used Duncan’s multiple range tests. The results showed significant difference in cultivars fresh and dry forage yield but there was not any difference between harvest time and interaction effects. The means comparison showed that the Loura white 161.0 cm had the maximum stem length, Cim and Kharkovski whit 155.0 and 146.9 cm ranked in next categories. The maximum stem diameter equal 20.6 mm belongs to Kharkovski cultivar in class one and two-other cultivars stem diameter were 16.9 and 16.8 mm and placed in class b.
The results showed that the Loura amaranth variety was superior to the other two varieties. This variety had 150 cm stem height, 14.5 mm stem diameter, 1.4% leaf to stem ratio, 4.72 tillers per plant and it can produce 90.30, 13.05 tons per hectare fresh, dry forage yield tow cuts, and 111 days growth duration. The ccomparison of different harvesting times showed that harvesting at flowering initiation was better than the end of flowering. Comparing the amount of forage produced, showed that cutting at flowering initiation was better than cutting after the end of flowering. The growth duration of harvest at flowering initiation was 23 days less than harvest after the end of flowering. In terms of management and of having many opportunities to prepare the ground for the next crop, this issue is of tremendous importance.