Morphological characteristics, growth and yield of elite grain and leaf Amaranth in Northern Tanzania

Amaranth is considered one of the most commonly produced and consumed indigenous vegetables on the African continent. In Tanzania amaranth constitutes about 6% of total hectares of vegetable planted annually. The genus consists of nearly 60 species, several of which are cultivated as leaf vegetables, grains or ornamental plant. Most of cultivated varieties of amaranth are relatively low in terms of leaf and grain yield, mainly due to lack of improved varieties. This study was conducted to: a) To evaluate amaranth lines for both leaf and grain production potential. b) To identify at least two lines with high potential for grain yield and one line with both leaf and grain yield potential. c) To generate yield information needed for breeding and improvement of amaranths and d) To conduct participatory research as a demand-driven strategy to meet farmers‟ needs. An experiment was thus carried out at the World vegetable center (AVRDC) in Arusha, Tanzania in two seasons; from February to May and May to September 2012. Fourteen lines (RVI00007, RVI00130, RVI00089, RVI00138, RVI00090, RVI00116, RVI00002, RVI00001, RVI00117, RVI00022, INCA, RVI00086, RVI00121 and RVI00021) were used in a randomized complete block design. Data were collected on leaf yield, seed yield, morphological characteristics and participatory selection. Results indicated that over the seasons, leaf yield differed significantly (p ≤ 0.01) among the lines. Line RVI00117 had higher leaf yield of 21 t/ha, while line RVI00089 had the lowest yield of 12 t/ha over the two seasons respectively. Grain yield obtained after leaf harvesting revealed a significant difference (p ≤ 0.001) among lines. Line RVI00021 had the highest seed yield of 1929 kg/ha, while line RVI00121 had seed yield (2920 kg/ha) over the seasons in plots where leaf was not harvested. Thirty-three agro-morphological traits for plant characteristics observed in both seasons indicate similarities in the traits such as germination rate, growth habit and sex type, absence of spines in leaf axils, seed coat type and presence of axillary inflorescence. However, variability was observed in the rest of the traits. Cluster dendrogram analysis grouped the lines into three main clusters according to their similarities. In this study line RVI00121 appeared to be preferred most by farmers following participatory selection whereas out of five criteria agreed by farmers, the line was selected in top three in the four criteria. This study found that line RVI00007 was the best for dual purpose (leaf and grain), while line RVI00121 and RVI00001 was the best for grain production. However, further investigation was recommended to determine how timing and harvesting frequency affects the grain yield. Similarly, the performance of lines when leaf harvested indefinitely without consideration of seed yield needs investigation. Probably repeating the experiment in different agroecological zones would also be necessary to reach a broad conclusion.