Effect of soil fertility amendment, planting density and growing season on Chenopodium quinoa Willd (Quinoa) in Zimbabwe

Abstract

Chenopodium quinoa Willd (quinoa) is a crop that originated from the Andes and has been recently introduced in Zimbabwe so the agronomic performance is unknown yet. A 3-year field experiment was carried out at the Women’s University in Africa research farm, Marondera, Zimbabwe. The research evaluated the response of quinoa to different cattle manure application rates, plant population ha−1 and growing seasons. A 3 × 3 × 2 factorial in a completely randomized block design with three replicates was used in the experiment. Cherry Vanilla Quinoa variety was established under three cattle manure application rates (0, 9 and 18 t ha−1), three planting densities (29629, 55555 and 80 000 plants ha−1) and two growing seasons per year (summer and winter). Analysis of variance was done to compare the effects of the treatments on quinoa growth parameters. There was significant (P < 0.05) interaction on cattle manure application rates × plant population ha−1 × growing season in all the measured response variables. The vegetative phase was higher on soil fertility amended than unamended plots in summer than winter regardless of the planting density. Highest grain yield (2.5 t ha−1) and thousand grain weight (T.G.W) (2.5 g) were recorded in winter at 9 t ha−1 + 55,555 plants ha−1 while lowest T.G.W (0.2 g) and grain yield (0.1 t ha−1) were noted in 18 t ha−1 + 80,000 plants ha−1 in summer. Quinoa can be grown in winter or summer with 9 t ha−1 + 55555 plants ha−1 for grain or biomass, respectively.