Accumulation and distribution of dry matter in relation to root yield of cassava under a fluctuating water table in inland valley ecology

Cassava an important staple food is grown both in upland and inland valley in the tropics. A trial to assess dry matter production and partitioning in relation to root yield was conducted in 3 positions along inland valley toposequence using 4 x 4 Latin square design. Dry matter partitioning differed among cultivars, toposequence positions, sites and years due to differences in water table depth and weather conditions. High dry matter partitioning to leaves, stems, fibrous roots and rootstocks reduced yield, while high biomass allocation to storage roots increased yield. High dry matter partitioning to leaves reduced yield more in the landrace likely due to low sink capacity. Partitioning high dry matter to leaves reduced yield more at deep than shallow water table depth. Excess moisture stress increased dry matter accumulation in rootstock, fibrous and storage roots, but decreased partitioning to stems and leaves. Drought stress reduced dry matter allocation to storage roots, but increased partitioning to rootstocks, fibrous roots and stems. TMS 91/02324 and TMS 91/02327 with lowest dry matter accumulation in stems and fibrous roots and highest in storage roots had the highest yields and therefore better adapted to inland valley conditions

Effect of different temperature regimes on physiological changes associated with early growth of cassava stem cuttings

No Abstract Available Discovery and Innovation Vol.15(3&4) 2003: 150-15

Cassava Growth And Development In Two Contrasting Environments Of Ibadan And Jos

Twelve cassava (improved and local) genotypes were grown at two locations in Nigeria (Ibadan and Jos). Leaf area development and dry matter partitioning were studied from 1994 to 1996. Destructive samplings for growth analyses were done at 3, 6, 9 and 12 months after planting (MAP). Genotype, environment and genotype x environment effects were significant for leaf area index (LAI), total dry matter and total dry tuberous root weight. At Ibadan, LAI was 3.6 and 2.1 at 6 and 12 MAP, respectively, while at Jos LAI values of 0.5 and 2.0 were recorded at 6 and 12 MAP, respectively, in the 1994/1995 planting season. Dry matter production and total dry tuberous root weight were significantly less at Jos than at Ibadan. This was attributed to the lower temperature regime and reduced solar radiation levels recorded at Jos plateau. Patterns of dry matter partitioning to the leaves, shoots and roots were similar in both locations. Dry matter partitioning to the roots was controlled by plant age and solar radiation while dry matter partitioning to the leaves was a function of plant age and temperature. These results indicate that dry matter partitioning of cassava to the roots and leaves are dependent upon solar radiation and temperature in higher altitudes. The data may be useful for validation of models of cassava growth being designed for higher altitudes. Agro-Science Vol.2(1) 2001: 67-7

Rooting for cassava:insights into photosynthesis and associated physiology as a route to improve yield potential

(Table presented.). Summary: As a consequence of an increase in world population, food demand is expected to grow by up to 110% in the next 30–35 yr. The population of sub-Saharan Africa is projected to increase by > 120%. In this region, cassava (Manihot esculenta) is the second most important source of calories and contributes c. 30% of the daily calorie requirements per person. Despite its importance, the average yield of cassava in Africa has not increased significantly since 1961. An evaluation of modern cultivars of cassava showed that the interception efficiency (ɛi) of photosynthetically active radiation (PAR) and the efficiency of conversion of that intercepted PAR (ɛc) are major opportunities for genetic improvement of the yield potential. This review examines what is known of the physiological processes underlying productivity in cassava and seeks to provide some strategies and directions toward yield improvement through genetic alterations to physiology to increase ɛi and ɛc. Possible physiological limitations, as well as environmental constraints, are discussed. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trus