Amaranth is a very important vegetable worldwide. Its leaves are consumed and the seeds are processed into various food products. Its production in the tropics is threatened by low yields which has a major impact on global production. A research aimed at improving the yield of this vegetable was carried out at lady bird organic farm Broga, 2.9450N 101.8740E, Semenyih, Selangor, Malaysia by studying the effect of genotype and organic fertilizer on the following growth indicators, red:far red ratio below canopy, stomatal conductance, leaf temperature, and dry weight. These growth indicators were monitored on a weekly basis over a period of six weeks. Three genotypes namely, Amaranthus caudatus, 3388 (green round leaf), Amaranthus caudatus, 3233 (green long leaf) and Amaranthus cruentus, 888 (red leaf) were grown on soils to which organic fertilizer was added at three different application rates (0 t/ha, 7.5 t/ha and 15 t/ha). There was no significant interaction effect of genotype and organic fertilizer on the growth indicators; however, each of these factors had significant effect on the growth of amaranth. A strong negative correlation occurred between dry weight and red:far red ratio below canopy likewise, between stomatal conductance and leaf temperature. Over a cultivation period of five weeks, the green long leaf genotype was superior showing that it is better adapted to growing in the rainforest agro ecological zone of Malaysia than the other two genotypes. Organic fertilizer application at a rate of 15 t/ha produced the lowest leaf temperature, after 4 weeks of cultivation implying better water status than 0 t/ha and 7.5 t/ha application rates. This study clearly shows that genotype and organic fertilizer have significant effect on the growth of amaranth. Therefore, these factors can be manipulated in order to enhance amaranth production.
If the inline PDF is not rendering correctly, you can download the PDF file here.
Akparobi O. (2009): Effect of farmyard manures on the growth and yield of Amaranthus Cruentus. Agricultura Tropica et Subtropica 42: 1-4.
Arannilewa S. Ekrakene T. Akinneye J. (2006): Laboratory evaluation of four medicinal plants as protectants against the maize weevil Sitophilus zeamais. African Journal of Biotechnology 5: 2032-2036.
Asia-Pacific Association of Agricultural Research Institutions and Asia-Pacific Consortium on Agricultural Biotechnology (2009): Expert consultation on biopesticides and biofertilizers for sustainable agriculture. Proceedings of Asia-Pacific Association of Agricultural Research Institutions and Asia-Pacific Consortium on Agricultural Biotechnology pp. 1-24.
Botto J. Smith H. (2002): Differential genetic variation in adaptive strategies to a common environmental signal in Arabidopsis accessions: phytochrome -mediated shade avoidance. Plant Cell and Environment 25: 53-63.
Casal J. Sanchez A. (1992): Physiological relationships between phytochrome effects on the internode extension growth and dry matter accumulation in light-grown mustard. Photochemistry and Photobiology 56: 571-578.
Chia P. Kubota C. (2010): End-of-day far-red light quality and dose requirements for tomato rootstock hypocotyl elongation. Horticultural Science 45: 1501-1506.
Gonzalez-Dugo M. Moran M. Mateos L. (2005): Canopy temperature variability as an indicator of crop water stress severity. Irrigation Science DOI 10.1007/s00271-005-0023-7
Law-Ogbomo K. Ajayi S. (2009): Growth and yield performance of Amaranthus cruentus influenced by planting density and poultry manure application. Notulae Botanicae Horti Agrobotanici Cluj-Napoca 37: 195-199.
Liu F. Stutzel H. (2002): Leaf expansion stomatal conductance and transpiration of vegetable Amaranth (Amaranthus sp.) in response to soil drying. Journal of American Society of Horticultural Sciences 127: 878-883.
Liu X. Ren G. Shi Y. (2011): The effect organic manure and chemical fertilizer on growth and development of Stevia rebaudiana bertoni. Energy Procedia 5: 1200-1204.
Makinde A. Ayeni S. Ojeniyi O. (2010): Morphological characteristics of Amaranthus cruentus L. as influenced by Kola pod husk organomineral and NPK fertilizers in south western Nigeria. New York Science Journal 3: 130-134.
Mascarini L. Lorenzo G. Vilella F. (2006): Leaf area water index and red: far red ratio calculated by spectral reflectance and its relation to plant architecture and cute rose production. Journal of American Society for Horticultural Science 131: 313-319.
Mazzella M. Zanor M. Fernie A. Casal J. (2008): Metabolic responses to red: far red ratio and ontogeny show poor correlation with growth rate of sunflower stems. Journal of Experimental Botany 59: 2469-2477.
Mbonu A. Arifalo S. (2006): Growth and yield of Amaranthus cruentus L. as directed by organic amendments. Port Harcourt Nigeria. Nigerian Journal of horticultural Sciences 11: 44-46.
Neher D.A. (1999): Soil community composition and ecosystem processes. Agroforestry Systems 45: 159-185.
Oikeh S. Asiegbu J. (1993): Growth and yield responses of tomatoes to sources and rates of organic manures in ferralitic soils. Bioresource Technology 45: 21-25.
Oparaeke A. Dike M. Amatobi C. (2005): Evaluation of botanical mixtures for insect pests management on Cowpea plants. Journal of Agriculture and Rural Development in the Tropics and Subtropics 106: 41-48.
Pisarikova B. Zraly Z. Kracmar S. Trckova M. Herzig I. (2006): The use of Amaranth (genus Amaranthus L.) in the diets of broiler chickens. Veterinarni Medicina 51: 399-407.
Stagnari F. Bitetto V. Pisante M. (2007). Effects of Nitrogen fertilizers and rates on yield safety and nutrients in processing Spinach genotypes. Scientia Horticulturae 114: 225-233.
Weil R. Kroonje W. (1979): Physical conditions of Davidson clay loam after five years of poultry manure application. Journal of Environmental Quality 8: 387-392.