Data on assessment of flours from advanced genotypes and improved cassava varieties for industrial applications

The data presented in this article are related to the research paper “Physicochemical parameters and functional properties of flours from advanced genotypes and improved cassava varieties for industrial applications” [1]. The genotypes were collected from a multi-location (Uniform yield Trial) trial of the IITA breeding program in Malawi. The data were obtained using multiple analytical techniques and methodology such as oven-drying, sieving, colorimetry, titration, acid hydrolysis method, the Kjeldahl procedure, UV/VIS spectrophotometry, and centrifugation.The data set contains physicochemical parameters described dry matter (on fresh weight basis), moisture content, pH and total titratable acidy, the content of ash, bulk density; chemical properties were described by total cyanogen potential, total starch, amylose, amylopectin, crude protein and total carbohydrates; functional properties were described by swelling power, water solubility, water binding capacity and oil absorption capacity. The presented data are valuable for cassava breeders, food scientists, nutritionists, and other researchers working on breeding and processing cassava for innovative product development from cassava flour.

Optimizing root yield of cassava under fertigation and the masked effect of atmospheric temperature

BACKGROUND

Fertigation is a rare and an expensive method of fertilizer application to cassava, and hence there is a need to optimize its efficiency for profitability. This study's objective was to optimize root yield of cassava through fertigation using a logistic model.

RESULTS

The field treatments were six fertigation concentrations against three cassava varieties, selected according to their maturity period. The logistic model predicted 52%, 116% and 281% benefit of fertigation for the varieties Mweru, Kampolombo and Nalumino, respectively. Furthermore, only half of the amount of fertilizer applied for Mweru was required to achieve twice the root yield of Kampolombo. During the experiment, an unknown importance of atmospheric temperature to cassava and its relationship to fertigation was observed. An elevation of 3.7 °C in atmospheric temperature led to 226%, 364% and 265% increase in root yield of Mweru, Kampolombo and Nalumino, respectively. Conversely, shoot biomass and root yield declined when the average atmospheric temperatures dropped by 3.6 °C. However, the cold temperatures affected the short-growth-duration (Mweru) and medium-growth-duration (Kampolombo) varieties earlier, 22 days after the drop, than the long-growth-duration variety (Nalumino) - 50 days after the drop.

CONCLUSION

Fertigation induced resilience of the shoot biomass production to cold which was most pronounced in the root yield of Mweru in response to the highest fertigation concentration. Thus, while fertigation improved cassava's resilience to cold, it only did so effectively for short-growth-duration variety, Mweru. Also, enhanced performance of cassava under increased atmospheric temperature indicated its importance as a climate-smart crop. © 2020 Society of Chemical Industry.

Genome of the African cassava whitefly Bemisia tabaci and distribution and genetic diversity of cassava-colonizing whiteflies in Africa

The whitefy Bemisia tabaci, a species complex consisting of many morphologically indistinguishable species divided into distinct clades, is one of the most globally important agricultural pests and plant virus vectors. Cassava-colonizing B. tabaci transmits viruses that cause cassava mosaic disease (CMD) and cassava brown streak disease (CBSD). Half of all cassava plants in Africa are affected by these viral diseases, resulting in annual production losses of more than US$ 1 billion. Here we report the draft genome of the cassava whitefly B. tabaci Sub-Saharan Africa - East and Central Africa (SSA-ECA), the super-abundant population that has been associated with the rapid spread of viruses causing the pandemics of CMD and CBSD. The SSA-ECA genome assembled from Illumina short reads has a total size of 513.7 Mb and a scaffold N50 length of 497 kb, and contains 15,084 predicted protein-coding genes. Phylogenetic analysis suggests that SSA-ECA diverged from MEAM1 around 5.26 million years ago. A comprehensive genetic analysis of cassava-colonizing B. tabaci in Africa was also conducted, in which a total of 243 whitefly specimens were collected from 18 countries representing all major cassava-growing regions in the continent and genotyped using NextRAD sequencing. Population genomic analyses confirmed the existence of six major populations linked by gene flow and inferred the distribution patterns of these populations across the African continent. The genome of SSA-ECA and the genetic findings provide valuable resources and guidance to facilitate whitefly research and the development of strategies to control cassava viral diseases spread by whiteflies.

Cassava response to the integrated use of manure and NPK fertilizer in Zambia

Cassava is Africa's second most important food source in terms of calories consumed per capita. However, farmers use little or no fertilizer on cassava and scant information is available regarding the cassava yield response to mineral and organic fertilizer inputs in Zambia. This study was undertaken to determine the response of cassava to the integrated use of organic and inorganic nutrient sources in two contrasting agroecological zones of Zambia; Mansa located in Zone III and Kabangwe located in Zone II. The treatments consisted of a factorial combination of four NPK rates (unfertilized control, 50N-11P-41.5K, 100N-22P-83K, and 150N-33P-124.5K kg/ha) with four rates of chicken manure (0, 1.4, 2.8, and 4.2 t/ha). The treatments were laid out in a randomized complete block design with three replications. Cassava height, stem girth, canopy diameter, leaf area index, and chlorophyll index were monitored over time and roots were harvested at 12 months after planting (MAP). Growth parameters and yield varied significantly (p < 0.01) both with NPK, manure application, and their interaction effects at 12 MAP. The combined application of 4.2 t/ha of chicken manure and 100N-22P-83 K kg/ha of mineral fertilizer resulted in the highest yields of 35.2 t/ha at Kabangwe. But, the highest average yield of 34.4 t/ha was recorded with the application of 2.8 t/ha manure and 100N-22P-83 K kg/ha mineral fertilizer at Mansa. This increased treatment yield by 24 and 29% over the sole NPK fertilizer application at Mansa and Kabangwe sites, respectively. Harvest index (HI) was higher when 2.8 t/ha chicken manure was applied in combination with 50N-11P-41.5K kg/ha at Kabangwe. But, the highest HI at Mansa site was achieved with the combination of 2.8 t/ha manure and 100N-22P-83 K kg/ha. This combination also resulted in the highest agronomic efficiency of N, P and K at both sites. It is concluded that cassava productivity and nutrient use efficiency can be improved through the integrated use of NPK and manure in Zambia.

Cassava virus diseases: biology, epidemiology, and management

Cassava (Manihot esculenta Crantz.) is the most important vegetatively propagated food staple in Africa and a prominent industrial crop in Latin America and Asia. Its vegetative propagation through stem cuttings has many advantages, but deleteriously it means that pathogens are passed from one generation to the next and can easily accumulate, threatening cassava production. Cassava-growing continents are characterized by specific suites of viruses that affect cassava and pose particular threats. Of major concern, causing large and increasing economic impact in Africa and Asia are the cassava mosaic geminiviruses that cause cassava mosaic disease in Africa and Asia and cassava brown streak viruses causing cassava brown streak disease in Africa. Latin America, the center of origin and domestication of the crop, hosts a diverse set of virus species, of which the most economically important give rise to cassava frog skin disease syndrome. Here, we review current knowledge on the biology, epidemiology, and control of the most economically important groups of viruses in relation to both farming and cultural practices. Components of virus control strategies examined include: diagnostics and surveillance, prevention and control of infection using phytosanitation, and control of disease through the breeding and promotion of varieties that inhibit virus replication and/or movement. We highlight areas that need further research attention and conclude by examining the likely future global outlook for virus disease management in cassava.