Influence of the stand organization on the yield and quality of amaranth above-ground biomass (Amaranthus hypochondriacus L.)

In the experimental years 1994-1996 the yield and some qualitative characteristics of above-ground biomass of amaranth (Amaranthus hypochondriacus L.) were investigated. Trials were performed at experimental station of Slovak University of Agriculture in Nitra (locality Dolna Malanta). The experiment site (Dolna Malanta, south-western part of the Slovak Republic) belongs to warm and moderate arid climatic region (the maize-growing region) with average annual sum of precipitation amounting 561 mm, for the growing season 327 mm. The annual average temperature is 9.7 degree C, within the growing season 16.2 degree C. Soil of experimental site is represented by loam, in the subsoil horizon by clay loam luvisol, with medium content of humus (2,16%), pH in the arable layer amounts 5.36 (in the subsoil 6.37) with high content of nutrients (104 mg P, 270 mg K and 220 mg Mg per kilogram of soil). Amaranth was seeded on the 1.6.1994, 5.5.1995 and 17.5.1996 in two row spacing - 0.250 and 0.375 m. After full emergence, the plants were thinned to 300 and 400 thousand of plants per hectare. Experimental plots were arranged by the method of randomised blocks in four repetitions. The size of harvest area was 12 m2 (3x4 m). During the vegetation, approximate in two-weeks intervals, the formation of above-ground biomass of amaranth was evaluated. The portion of individual plant parts of amaranth (leaves, stems, inflorescences) in the yield of dry matter and content of organic matter (crude protein, fibre, soluble carbohydrates and fats) were analysed in the taken samples of the plants. The dry matter yield of Amaranth (7.09 - 11.76 t/ha) was highly significant influenced by atmospheric conditions in the experimental years. Influence of the stand organisation was not significant. Content of crude protein (114-183 mg/g) and fibre (172.0 - 157.8 mg/g) in amaranth dry matter were again highly significant influenced by years. Stand density on the content of crude protein was also significant. Influence of row spacing was not significant. Neither stand organisation, nor atmospheric conditions in the years had not significant influence on the content of soluble carbohydrates (19.6 - 54.9 mg/g) and fats (31.5 - 46.7 mg/g) in amaranth dry matter