Abstract:

Cassava (Manihot esculenta) is the primary source of carbohydrates for the poor people of the tropics. It is replacing upland rice in many Asian countries, and is a major food crop in Africa. People and livestock consume mostly the cassava roots as a calorie source, while cassava leaves are eaten as a nutritious vegetable by some people. Both dry root chips and leaf silage are excellent feedstocks for animals - up to 30% of their daily ration. Cassava is a hardy crop that can survive even in poor soils and a varying climate, though root yields are very low (2–3 metric tons per hectare). In addition, continuously declining soil fertility and the increasing soil erosion which accompanies a changing climate pose serious problems to cassava production in both Asia and Africa. This IAEA Guidelines for improving cassava production in Asia and Africa is designed to help farmers to adapt their cassava production practices to different soil and agroclimatic conditions that are expected to accompany a changing climate. It also highlights the use of isotopic techniques to study nitrogen use efficiency. Key improved cassava production practices are given below. Improved cassava varieties: Plant the best available locally adapted ‘improved’ cassava varieties. Improved cassava varieties will have lower cyanogen glucosides and be fortified with vitamin A, iron and have higher protein levels. Their use will help improve the nutrition of mainly the poor, who consume cassava roots as their main source of carbohydrate. Preparing healthy planting materials: Plant healthy, disease-free, 15–20 cm long stem cuttings. Prepare the stem cuttings only from high-yielding cassava mother plants that are 812 months old. Take the lower and middle parts of the stems for preparing cuttings. For most cassava varieties, these cut stems can be stored vertically in the shade for 1–2 months before planting in the soil. Land configuration: Flat land is plowed, harrowed, leveled, and 75–100 cm wide ridges are formed either manually or with the help of furrow openers attached to a tractor. The furrows are made to gently slope along the natural slope of the field to help drain excess rainwater, if necessary.