Food Science and Agriculture: Research Highlights Vol. 9

Indonesia's staple food system remains organised around rice, and successive administrations have proposed root and tuber crops as the principal vehicle for reducing that dependence. Cassava (Manihot esculenta Crantz), sweet potato (Ipomoea batatas (L.) Lam.), taro (Colocasia esculenta (L.) Schott), the yams (Dioscorea spp.) and the elephant foot yams (Amorphophallus spp.) are simultaneously described as climate-resilient insurance crops, as nutritionally deficient inferior goods, and as industrial feedstocks, and these characterisations are rarely reconciled. This review critically evaluates the evidence underpinning the proposition that tubers can function as an alternative staple food source in Indonesia, drawing on agronomic, nutritional, postharvest, behavioural and policy literature published between 1998 and mid-2026, together with foundational earlier work. Evidence is strongest for three propositions: that tuberous crops tolerate marginal soils and erratic rainfall better than irrigated rice; that their unprocessed forms are energy-dense but protein-poor and, apart from carotenoid-rich sweet potato genotypes, micronutrient-poor; and that postharvest physiological deterioration of cassava storage roots is an oxidative wound response amenable to genetic and chemical intervention. Evidence is considerably weaker, and frequently contradictory, on the questions that determine policy outcomes: whether tuber-based products can displace rice in habitual diets, whether smallholder returns are competitive once industrial demand is accounted for, and whether large-scale tuber cultivation on converted land is agronomically or socially sustainable. Much Indonesian evidence consists of small, single-season, single-district studies with limited statistical control and no replication, while the strongest mechanistic and clinical evidence originates outside Indonesia and may not transfer. Substitution framings that treat tubers as caloric replacements for rice are poorly supported; complementary framings that position tubers within diversified diets, fortified composite products and non-food value chains have stronger empirical foundations but weaker policy uptake. Priorities include multi-season varietal trials in Indonesian agroecologies, controlled feeding studies of tuber-based composite staples, and longitudinal analysis of household demand under realistic relative prices.