Effect of Soil Moisture Stress on the Emergence, Establishment and Productivity of Amaranthus (Amaranthus cruentus L.)

Dietary intake of vegetables is low in sub-Saharan Africa (SSA) compared to the world's average. This situation is worsened by low water availability for vegetable production especially in the dry season. However, amaranth which can be grown in the different agro-ecologies of Nigeria is a dual purpose crop with edible leaves and seeds rich in essential nutrients and proteins. The crop is also a drought tolerant C-4 plant which has the ability to survive under minimum soil moisture condition, hence the reason for its use in the study. This investigation was therefore conducted to discover the optimum water requirements in a screen house, and evaluation of different moisture stressed based on the derived optima in two subsequent field trials. In the screen house and field water stress treatments varied from: -6.0, -1.2 to -0.3 bar (the control). Results in the screen house study showed that optimum soil water potential for amaranth was reached at -1.2 bar, and that cultivar 'NH84/493' performed better than the others, in all growth and yield parameters measured. In field trials, bringing the moisture content from dry (-6.0 bar) to -1.5 bar optimum soil water potential favored seedling emergence better than all other treatment combinations. However, treatment combination -0.3, -1.5 bar when the soil was initially wet (-0.3 bar) then bringing it to the optimum (-1.5 bar) gave the best seedling establishment and productivity. Cultivar 'NH84/493' grown at -0.3, -1.5 bar performed better than all other interactions. We therefore recommend -1.5 bar and cultivar 'NH84/493' amaranth for the SSA vegetable industry, especially for improving dry season productivity.