Cassava Research Articles

REPORT OF PRACTICAL CLASS IN AGRICULTURAL AREA WITH THE BACHELOR CLASS IN AGRONOMY IN THE MUNICIPALITY OF TRACUATEUA-PA

Cassava (Manihot esculenta Crantz) is a highly consumed root and a significant source of carbohydrates in Brazil and around the world. In the state of Pará, cassava is vital to the local economy, especially in the municipality of Tracuateua. The culture involves family farmers and serves as an important source of income and subsistence. Different cultivars are used, such as BRS Tapioqueira and BRS Verdinha, which exceed 70 thousand kg/ha with good management. Adequate fertilization, pest control and weed management are essential for high productivity. Irrigation can significantly increase production. On the property of Mr. Benedito Dutra, member of the RENIVA project, the production of seed cassava and cowpea is highlighted. It uses cultivars developed by Embrapa, such as BRS Kiriris, BRS Formosa and BRS Novo Horizonte, which are recommended for industrial use. Dutra also grows cowpeas, using varieties such as BRS Guirá and BRS Natalina, which are highly productive and adapted to local conditions. The property has an irrigated area of ​​23 hectares per central pivot, ensuring crop hydration during dry periods. During the field visit, several areas of experimentation were observed. The experimental plots of cassava and cowpea showed good performance, with a high survival rate and resistance to pests. The integration of advanced soil management, pest control and irrigation practices highlighted the property as an example of innovative agriculture. The experience on Mr. Dutra’s property demonstrated the importance of innovation and adoption of advanced agricultural practices for sustainable and productive agricultural production.

Comparative transcriptome analysis, identification and expression analysis of sucrose phosphate synthase genes in high and low starch cassava (Manihot esculenta Crantz) genotypes

Comparative transcriptome analysis, identification and expression analysis of sucrose phosphate synthase genes in high and low starch cassava (Manihot esculenta Crantz) genotypes

Total replacement of maize with raw or heat-treated sweet cassava tuber meal on productive performance and egg quality parameters in Jumbo quail hens from 6 to 14 weeks of age

The impact of complete replacement of maize with raw or heat-treated sweet cassava (Manihot esculenta) tuber meal (CTM) on productive performance and egg quality of Jumbo quail hens was determined. A total of 240, six-week-old hens were randomly allocated to 60 cages (4 birds/cage) and assigned to five experimental diets with 12 replicates each. The diets were a standard layer mash diet without CTM (CON) and a standard layer mash diet in which 100% maize was replaced with raw (CTMR), boiled (CTMB), autoclaved (CTMA) and oven-dried CTM (CTMO). The highest overall feed intake, body weight gain and final body weight (P < 0.05) was observed from the CON group while the lowest was from the CTMB group. Overall FCR and mortality were not significantly influenced by the diets. Fourteen-week-old hens on CON had a higher (P < 0.05) rate of lay than CTMR. Eggs from CON had the brightest yolk colour values than all the treatment groups. Moreover, eggs from CON had the least shape index than those from CTMO. Diet CTMA promoted heavier (P < 0.05) eggshells than CTMR. Jumbo quail hens reared on maize-based diet showed better performance followed by autoclaving treatment, whereas boiling treatment compromised performance traits.

From cassava peel (Manihot esculenta) to hydrocarbon-rich bio-oil: Catalytic flash pyrolysis as a new valorization route

The valorization of agroindustrial residues for second-generation biofuels has garnered attention due to the increasing demand for low-carbon fuels aligned with transportation sector decarbonization efforts. In this context, cassava processing residues, particularly cassava peel, remain largely unexplored but offer a cheap, abundant, and renewable feedstock that can be converted into hydrocarbon-rich biofuel. Thus, the originality of this study lies in investigating the selective conversion of cassava peel into renewable aromatic hydrocarbons through flash pyrolysis catalyzed by an environmentally friendly MFI-type zeolite synthesized from rice husk ash and diatomite residue. A micro-pyrolyzer interfaced with chromatographic separation and mass spectrometry detection was used to compare the composition of condensable volatile products from catalytic pyrolysis over HZSM-5 with those from catalyst-free pyrolysis. Cassava peel, characterized by high volatile matter content (84.3 %), low ash content (3.19 %), and reasonable energy content (15 MJ kg −1), yielded a high content of valuable platform chemicals, such as carboxylic acids and furans, when subjected to catalyst-free pyrolysis. The catalytic upgrading pyrolysis vapors over the environmentally friendly HZSM-5 catalyst yielded approximately 56.0 % industrially relevant aromatic hydrocarbons and 39.9 % light organic acids. Other strengths of using HZSM-5 in upgrading pyrolysis vapors were its low selectivity for naphthalenes, precursors for coke formation, and the production of hydrocarbons in the gasoline range. Thus, HZSM-5 was an efficient catalyst for promoting deoxygenation and improving hydrocarbon content, with high selectivity for valuable aromatic hydrocarbons. In conclusion, cassava peel showed favorable prospects for conversion into hydrocarbon-rich bio-oil, serving as a valuable precursor for low-carbon biofuels.

Agronomic potential of four cassava (Manihot esculenta Crantz) varieties grown on soils fertilized with cocoa shell compost and chicken droppings compost in Côte d’Ivoire

This study was conducted in the Lamto area to evaluate the effect of cocoa shell compost and chicken droppings compost on cassava agronomic variables. The main aim is to increase cassava production, which is in relative decline due to soil impoverishment through organic amendments. The evaluation led to the monitoring of plant development until harvest by measuring some agronomic variables of growth and yield of four varieties of cassava, Alleda agba, Bonoua, Six mois and Yacé each grown on soil fertilized with cocoa shell compost or chicken droppings compost. The experimental design used for this study was a complete randomized block design with 3 replicates. The results showed that the two fertilizers used, being rich in mineral elements, improved the agronomic variables of cassava, superior to the control. This was reflected in a high number of stems per cutting (3.62). However, the chicken droppings compost gave the best development in stem length for the Six mois variety (121.10 cm). The Bonoua variety gave the largest diameter stems (21.98 mm). This variety gave the highest number of leaves (59) and a wider span (109 cm) with wider (16.75 cm) and longer (17.96 cm) leaves. As for yields, the best was obtained with the Bonoua variety, respectively 27.13 t/ha and 35.26 t/ha with cocoa shell compost and chicken droppings compost compared with 12.77 t/ha for the control. Thus, compost and chicken droppings compost can be recommended to improve cassava productivity in Côte d'Ivoire.

FEEDING PROCESSED Vitamin A CASSAVA ROOT MEALS TO BROILER CHICKENS: PERFORMANCE CHARACTERISTICS, BLOOD INDICES AND ANTIOXIDATIVE STATUS

The emerging effects of climate change and the increasing cost of grains have been a serious issue to animal nutritionist in the tropics. This study evaluates the performance of broiler finisher chickens fed different processed cassava UMUCASS 36 (vitamin A) root meals (PCRM) as substitute for maize in the diets of 108 Arbor Acre (starter) finisher chickens for 21days. Six diets were formulated and the test diet was supplemented to the birds as partial and whole. The birds were fed T1 as the control, T2 had 25% each of oven-dried and sun-dried cassava root meal, T3 had 25% maize and 25% oven-dried cassava root meal, T4 had 25% maize and 25% sun-dried cassava root meal, while T5 had only 50% oven-dried cassava root meal, and T6 also had only 50% sun-dried cassava root meal respectively. Data were collected on the performance characteristics, blood indices and serum antioxidant of the birds. Performance characteristics of the birds revealed that T4 recorded significant (p<0.05) values of 2722.32 g, 1559.62 g and 1.61 final weight, weight gain and FCR respectively in comparison to the other treatments. The test diets did not show any adverse effect on the haematology and serum biochemistry of the birds. However, on the serum antioxidant status, T5 and T6 showed better values on the Aspartate aminotransferase and Alanine aminotransferase of the birds. The result on Superoxide dismutase and Malondialdehyde of the birds revealed that T4 and T6 recorded higher and lower values respectively. It was concluded that broiler finisher chickens could be fed up to 50% processed cassava root meal, inclusion using both techniques without detrimental effects.

Genome-Wide Identification and Expression Analysis of the MADS-Box Gene Family in Cassava (Manihot esculenta)

The MADS-box gene family constitutes a vital group of transcription factors that play significant roles in regulating plant growth, development, and signal transduction processes. However, research on the MADS-box genes in cassava (Manihot esculenta) has been relatively limited. To gain deeper insights into the functions of the MADS-box genes in cassava development, in this study, we undertook a comprehensive genome-wide identification of the MADS-box gene family in cassava. We identified a total of 86 MADS-box genes with complete domains in the cassava genome, designated as MeMADS01 to MeMADS86. Through bioinformatic analyses, we investigated the basic physicochemical properties, conserved motifs, chromosomal locations, and phylogenetic relationships of the cassava MADS-box genes. The MADS-box gene family of cassava exhibited conservation, as well as species-specific characteristics, with intron loss being a predominant mode of evolution for the MADS-box genes. Expression pattern variations in the MeMADS genes across different tissues offer insights into their potential functions. Time-ordered gene co-expression network (TO-GCN), transcriptome data, and RT-qPCR analysis suggested the responsiveness of the MADS-box genes to drought stress. Meanwhile, MeMADS12 might be involved in regulating flowering under drought conditions via an ABA (abscisic acid)-dependent pathway. These findings provide valuable resources for a deeper understanding of the biological roles of the MADS-box genes in cassava.

Genome-wide association study of cassava brown streak disease resistance in cassava germplasm conserved in South America

Cassava (Manihot esculenta Crantz) is a vital carbohydrate source for over 800 million people globally, yet its production in East Africa is severely affected by cassava brown streak disease (CBSD). Genebanks, through ex-situ conservation, play a pivotal role in preserving crop diversity, providing crucial resources for breeding resilient and disease-resistant crops. This study genotyped 234 South American cassava accessions conserved at the CIAT genebank, previously phenotyped for CBSD resistance by an independent group, to perform a genome-wide association analysis (GWAS) to identify genetic variants associated with CBSD resistance. Our GWAS identified 35 single nucleotide polymorphism (SNP) markers distributed across various chromosomes, associated with disease severity or the presence/absence of viral infection. Markers were annotated within or near genes previously identified with functions related to pathogen recognition and immune response activation. Using the SNP candidates, we screened the world’s largest cassava collection for accessions with a higher frequency of favorable genotypes, proposing 35 accessions with potential resistance to CBSD. Our results provide insights into the genetics of CBSD resistance and highlight the importance of genetic resources to equip breeders with the raw materials needed to develop new crop varieties resistant to pests and diseases.

Selectivity of pre-emergent herbicides in cassava (Manihot esculenta Crantz) and its relationship with the stem cutting planting system

Cassava (Manihot esculenta Crantz, Euphorbiaceae), an important source of food for millions of people in the world, is distributed mainly in Asia, Africa, Latin America, and the Caribbean. Weeds are important biotic constraints on cassava production, and herbicide application can provide effective weed control in this crop. However, the different possibilities of herbicide selectivity (factors associated and not associated with the plants) must be studied before implementation. The aim of this study was to evaluate the effects of the combination of different pre-emergence herbicides and two stem cutting planting systems (vertical and horizontal) on phytotoxicity and several agronomic traits of the cassava crop. The experiment was conducted through a factorial arrangement in a completely random design in Corrientes, Argentina. The factors studied were planting systems (horizontal and vertical position), weed control methods (hoeing or application of diuron, S-metolachlor, pendimethalin or clomazone, 625; 1920; 900 and 1000 g a.i. ha−1, respectively), and cropping seasons (2018–2019 and 2019–2020). The following variables were measured: phytotoxicity, plant height, relative plant stand, total weight of tuberous roots per plant, starch concentration of tuberous roots, and starch production per ha. The highest precipitations occurred in the 2018–2019 cropping season. The vertical planting system in combination with herbicides showed lower phytotoxicity values and higher values of plant height, starch concentration, and starch production per ha than the horizontal planting system. The highest phytotoxicity values were recorded with the application of diuron combined with the horizontal planting system and in the 2018–2019 season, with a 33.33% decrease in relative plant stand compared to the use of hoeing. Starch concentration remained unchanged with the use of clomazone and pendimethalin, whereas the effect of these herbicides on starch production varied with the cropping season, decreasing only in 2019–2020. Starch production was significantly lower with the use of S-metolachlor (up to 55.29% in 2018–2019) and of diuron (up to 60.57% in 2019–2020) than with the use of hoeing. In conclusion, phytotoxicity values were higher for the horizontal planting system than for the vertical system. The herbicide with the highest phytotoxic effect on the cassava crop was diuron; the effect increased when combined with the horizontal planting system in the cropping season with higher rainfall. This work provides the basis for integrated weed management concerning the use of herbicides and their selectivity according to planting systems for cassava crops.

Assessment of the chemical composition of buriti (Mauritia flexuosa Liliopsida) and cassava (Manihot esculenta Crantz) residues and their possible application in the bioproduction of coconut aroma (6 pentyl-α-pyrone).

This work aimed to define strategies to increase the bioproduction of 6 pentyl-α-pyrone (bioaroma). As first strategy, fermentations were carried out in the solid state, with agro-industrial residues: Mauritia flexuosa Liliopsida. and Manihot esculenta Crantz in isolation, conducting them with different nutrient solutions having Trichoderma harzianum as a fermenting fungus. Physicochemical characterizations, centesimal composition, lignocellulosic and mineral content and antimicrobial activity were required. Fermentations were conducted under different humidification conditions (water, nutrient solution without additives and nutrient solutions with glucose or sucrose) for 9days. Bioaroma was quantified by gas chromatography, assisted by solid-phase microextraction. The results showed the low production of this compound in fermentations conducted with sweet cassava (around 6ppm (w/w)). The low bioproduction with sweet cassava residues can probably be related to its starch-rich composition, homogeneous substrate, and low concentration of nutrients. Already using buriti, the absence of aroma production was detected. Probably the presence of silicon and high lignin content in buriti minimized the fungal activity, making it difficult to obtain the aroma of interest. Given the characteristics presented by the waste, a new strategy was chosen: mixing waste in a 1:1 ratio. This fermentation resulted in the production of 156.24ppm (w/w) of aroma using the nutrient solution added with glucose. This combination, therefore, promoted more favorable environment for the process, possibly due to the presence of fermentable sugars from sweet cassava and fatty acids from the buriti peel, thus proving the possibility of an increase of around 2500% in the bioproduction of coconut aroma.

Characterization of extracted alpha cellulose from Manihot esculenta (cassava) peels as formulation aid for paracetamol tablet

Background: Alpha-cellulose as a pharmaceutical excipient can be employed as a binding agent in tablet formulation. Cassava peels husk are waste agricultural material and is being investigated for its α-cellulose for use in oral solid pharmaceutical formulation. Purpose: The objective of this study is to extract α-cellulose from cassava peels agro-industrial waste using a standard method, subject the extracted cassava peels cellulose and determine its phytochemical and physicochemical properties of formulated granules of paracetamol. Methods: Alpha-cellulose from cassava peel was extracted using alkali method. The fresh peels were prepared, milled into slurry and de-watered to obtain a coarse wet material, dried, milled and sieved to obtain very fine powdered particles. Phytochemical analysis and characterization of extracted α-cellulose powder were determined. Differential scanning calorimetry (DSC), scanning electron micrographs (SEM), and x-ray diffractogram (XRD) analysis of extracted cassava peel cellulose were done. Paracetamol granules was prepared by wet granulation using varying concentrations of the binders. Results: DSC and XRD results revealed a semi-crystalline material with amorphous and crystalline regions. while the SEM showed a lumpy structure and reticular shape. Pre-compression evaluations of the formulated batches of paracetamol granules showed that cassava peels cellulose (CPC) have similar flow properties with those of microcrystalline cellulose BP (MCC) and acacia BP (ACA) powders respectively. The granules have free flow properties with average angles of repose (CPC ≤ 27.60 MCC < 26.90 and ACA ≤ 25.60), compressibility index (CPC ≤ 25, MCC ≤ 23 and ACA ≤ 21.7%), Hausner’s ratio (CPC ≤ 1.32, MCC ≤ 1.31, and ACA ≤ 1.27) respectively. Conclusion: The extracted cassava peel α-cellulose was found ideal as pharmaceutical excipient binder in oral solid dosage forms.

Physico-chemical and nutritional characteristics of 12 varieties of cassava (Manihot esculenta Crantz, 1766) grown in the Republic of Guinea

Cassava is a distinctive contributor to food security and a source of income for smallholder farmers. Despite the importance of this agricultural product, very little data is available in Guinea, especially concerning the varieties grown and their nutritional composition. The aim of this research was to study the physico-chemical and nutritional characteristics of 12 varieties of cassava grown in Guinea with a view to selecting varieties that could be used to produce a <<Gari>> of better quality. Cassava tubers were collected in 6 regions in Guinea. The physico-chemical analyses were carried out on the pH and moisture content of the cassava paste from each of the 12 varieties, while the nutritional quality was determined on the basis of the composition of the varieties in carbohydrates, proteins, lipids and minerals. In general, pH values ranged from 6.29 to 7.29 while moisture levels ranged from 51.64% to 58.94%. In addition, all the varieties analysed were those rich in carbohydrates (with levels between 42.36% and 51.17%) but low in fat (values between 0.30% and 3.56%). On the other hand, three varieties, namely Farawoulen, Konko and Samouya, are the richest in protein with values of 8.05%, 5.48% and 4.23% respectively. In short, these cassava varieties produced in Guinea could be used, taking into account their biochemical composition, in future gari production work.

Probiotic Potential of Bacillus Strains Isolated from Traditional Cassava Ferments (Manihot esculenta Crantz)

ABSTRACT: Probiotic potentials of Bacillus strains isolated from traditional cassava ferments, notably their growth at different pH, bile salts, temperatures, NaCl and antibiotics, their inhibition of pathogenic bacteria, non-production of hemolytic enzymes as well as the formation of biofilm were studied. These different probiotic parameters were determined according to the referenced methods. The results obtained showed that all Bacillus strains resisted acidic pH with the highest growths (7.29± 1.40) × 108 CFU/mL and (5.14±0.15) × 108 CFU /mL obtained with Bacillus toyonensis respectively at pH 2 for 24 hours and at pH 3 for 4 hours. All Bacillus strains grow well at 37°C and 44°C, despite their optimum growth temperature of 30°C. They also showed good growth at different bile salt concentrations and were multi-resistance to antibiotics Ciprofloxacin (100%), as was B. subtilis to Rifampicin (100%) but they were multi-sensitive (100%) to Amoxicillin, Imipenem, Gentamycin, Penicillin, Vancomycin, Chloramphenicol and Rifampicin except B. pumilus and B. methylotrophicus which were sensitive to Rifampicin (77%). Bacillus strains inhibited more than half of the pathogens (80.27% with S. aureus and 65.09% with E. coli). No strain showed hemolytic activity but rather a good capacity to form a biofilm (optical density ranging from 0.663 ± 00 to 3.15 ± 02 nm).

Multi-scale and multi-receptive field-based feature fusion for robust segmentation of plant disease and fruit using agricultural images

The accurate and fast assessment of plant diseases and fruits is important for sustainable and productive agriculture. However, typically manual methods are adopted for the assessment of plant diseases and fruit, which is a time-consuming, resource-intensive, and error-prone approach. A few artificial intelligence (AI)-based methods have been introduced to automate this process, but they show limitations in attaining high performance in challenging imaging conditions such as occlusions, poor lighting, noise, indistinctive boundaries, and excessive morphological variations. Moreover, current approaches also lack in providing computationally efficient solutions. To overcome these issues, two novel architectures are developed to segment plant diseases and fruits with higher segmentation performance and less computational requirements. The efficient feature fusion segmentation network (EFFS-Net) is the base network, and a multi-scale dilated feature fusion segmentation network (MDFS-Net) is the final network of this study. EFFS-Net uses an identity skip path-based feature fusion mechanism with an efficient grouped convolutional depth (EGCD) to provide satisfactory segmentation performance with high computational efficiency. MDFS-Net uses a multi-scale feature fusion mechanism and fuses low-level information in the EGCD and other sections of the network to learn detailed input features for delivering promising performance even in challenging imaging conditions. MDFS-Net also applies multiple receptive fields to the low-level information in the effective receptive field processing (ERFP) block for fusion near the pixel classification stage for further performance enhancement.Both networks are evaluated using a Brazilian Arabica coffee leaf (BRACOL) image dataset, an Australian Center for Field Robotics orchard fruit (apple) dataset, and a necrotized cassava root cross-section image dataset. The proposed method provides a promising segmentation performance, achieving dice similarity coefficients of 88.81 %, 95.01 %, and 86.04 % with performance improvement of 3.5 %, 2.6 %, and 1.07 % on the three datasets, respectively, with approximately ten times less number of required trainable parameters compared with the state-of-the-art methods.

Effects of cassava root meal on the growth performance, apparent nutrient digestibility, organ and intestinal indices, and slaughter performance of yellow-feathered broiler chickens.

With the global population growth and shortage of food, the competition between humans and animal for food will become increasingly fierce. Therefore, the development of unconventional energy feed cassava feed is of great significance. The objective of this study was to investigate the effects of cassava root meal (CRM) on the growth performance, apparent digestibility, and organ and intestinal indices of broiler chickens. A total of 140 one-day-old chicks were randomly assigned to four dietary treatment groups [control diet (CT), 15% CRM (CRM15), 30% CRM (CRM30), and 45% CRM (CRM45)] with five replicates of seven birds per replicate. The results showed that the body weight of broiler chickens fed diets containing CRM were significantly lower than that in the CT group at 21 and 42days of age, the average daily gain and average daily feed intake in the CRM group were significantly lower than those in the CT group from 1 to 21days of age. However, from days 22 to 42, there were no significant differences between CRM15 and CT birds regarding average daily gain and average daily feed intake. but there was no difference in feed conversion rate between the CRM15 and CT groups. At 42days of age, there were no significant differences between CRM15 and CT birds in in body measurements, the slaughter performance and the percentage of semi-eviscerated yield. The addition of CRM reduced the proportion of breast and thigh muscles during the feeding period, although we detected no significant difference between CRM15 and CT regarding the apparent digestibility of nutrients. Collectively, our findings indicate that 15% cassava was the optimal proportion for supplementing diets for broiler chicken production.

Nutritional Quality of Enriched Bitter-Cassava Flour Porridge (Manihot esculenta) for Feeding Infants and Young Children (6-23 months) in South Sudan

Nutritional Quality of Enriched Bitter-Cassava Flour Porridge (Manihot esculenta) for Feeding Infants and Young Children (6-23 months) in South Sudan

Effect of the Digestibility of Cassava Flour (Manihot esculenta Crantz) by Enzymes Extracted from Corn Malt.

The aim of this study is to determine the effect of the digestibility of cassava starch by the enzymes extracted from corn malt, which will constitute one of the answers to the problem of integrating local products into the process in a modern brewery. Cassava starch solutions of different concentrations (E0: 0g/L; E1: 1g/L; E2: 1.1g/L; E3: 1.2g/L; E4: 1.3g/L; E5: 1.4g/L and E6: 1.5g/L) were prepared and subjected to two treatments (gelatinized and non-gelatinized) and 5mL of each were placed in a test tube. Three millilitres (3mL) of the solution containing amylases extracted from malt corn was then added to each of the test tubes containing the cassava flour solutions. All the treatments were subjected to three temperature stages (50°C for 15min, 90°C for 20min, and 100°C for 75min). Twenty-eight (28) objects (two duplicates) were experimented in a complete factorial design (2 treatments × 2 temperature levels). The results obtained showed that gelatinization had no effect, which could be due to the high optimum temperatures of corn enzyme activity. The concentrations also did not have significant differences which shows that these concentrations can well be used on an industrial scale to digest cassava starch by corn malt enzymes.

Driveway Detection for Weed Management in Cassava Plantation Fields in Thailand Using Ground Imagery Datasets and Deep Learning Models

Weeds reduce cassava root yields and infest furrow areas quickly. The use of mechanical weeders has been introduced in Thailand; however, manually aligning the weeders with each planting row and at headland turns is still challenging. It is critical to clear weeds on furrow slopes and driveways via mechanical weeders. Automation can support this difficult work for weed management via driveway detection. In this context, deep learning algorithms have the potential to train models to detect driveways through furrow image segmentation. Therefore, the purpose of this research was to develop an image segmentation model for automated weed control operations in cassava plantation fields. To achieve this, image datasets were obtained from various fields to aid weed detection models in automated weed management. Three models—Mask R-CNN, YOLACT, and YOLOv8n-seg—were used to construct the image segmentation model, and they were evaluated according to their precision, recall, and FPS. The results show that YOLOv8n-seg achieved the highest accuracy and FPS (114.94 FPS); however, it experienced issues with frame segmentation during video testing. In contrast, YOLACT had no segmentation issues in the video tests (23.45 FPS), indicating its potential for driveway segmentation in cassava plantations. In summary, image segmentation for detecting driveways can improve weed management in cassava fields, and the further automation of low-cost mechanical weeders in tropical climates can be performed based on the YOLACT algorithm.

Effect of non-thermal acidic and alkaline modifications on the structural, pasting, rheological, and functional properties of cassava (Manihot esculenta) starch.

This study aimed to investigate the effects of acid or alkali modification of isolated cassava starch (ICS) on its physicochemical properties. Acetic acid concentrations of 5%, 10%, and 20% v/v (0.87, 1.73, and 3.46M, respectively) and calcium hydroxide concentrations of 0.15%, 0.20%, and 0.30% w/w (0.02, 0.025, and 0.04M, respectively) were tested independently and compared with untreated isolated starch. The scanning electron microscope (SEM) shows starches with polyhedral and semispherical shapes; these modifications do not change the surface of the starch granules. Nanocrystals with orthorhombic crystal structure were extracted from ICS. Transmission electron microscopy (TEM) shows crystallites with a size (two-dimensional) of 20±5nm in length and 10±2nm in width and reveals that this starch contains nanocrystals with orthorhombic crystal structure. The X-ray patterns show that these nanocrystals are unaffected by acidic or alkaline treatments. The Ca+2 and CH3COO- ions do not interact with these nanocrystals. The alkaline treatment only affects the gelatinization temperature at a Ca(OH)2 concentration of 0.30%. Low concentrations of acidic and alkaline treatments affect the ability of cassava starch to absorb water and reduce the peak and final viscosity. The infrared spectra show that the modifications lead to C-H and C═C bond formations. ICS-B 0.30 can modify the amorphous regions of the starch, and the acid treatment leads to acetylation, which was confirmed by the presence of an IR band at 1740cm-1.

Effect of gamma irradiation on proliferation and growth of friable embryogenic callus and in vitro nodal cuttings of ugandan cassava genotypes.

Cassava (Manihot esculenta Crantz) production and productivity in Africa is affected by two viral diseases; cassava mosaic disease (CMD) and cassava brown streak disease (CBSD). Induced mutagenesis of totipotent/embryogenic tissues or in vitro plant material can lead to the generation of CMD and/or CBSD tolerant mutants. To massively produce non-chimeric plants timely and with less labor, totipotent cells or tissues are a pre-requisite. This study aimed to determine the effect of gamma radiation on the proliferation and growth of friable embryogenic callus (FEC) and in vitro nodal cuttings respectively. To obtain FEC, 2-6 mm sized leaf lobes of nine cassava genotypes were plated on Murashige and Skoog (MS) basal media supplemented with varying levels (37, 50, 70, 100) μM of picloram for production of organized embryogenic structures (OES). The OES of five cassava genotypes (Alado, CV-60444, NASE 3, NASE 13 and TME 204) were crushed and plated in Gresshoff and Doy (GD) basal media in combination with the amino acid tyrosine in varying concentrations for FEC production. FEC from five cassava genotypes and in vitro nodal cuttings of nine genotypes were irradiated using five different gamma doses (0, 5, 10, 15, 20 and 25 Gy) at a dose rate of 81Gy/hr. The lethal dose (LD)50 was determined using the number of roots produced and flow cytometry was done to determine the ploidy status of plants. The highest production of OES was noted in Alado across varying picloram concentrations, while TME 204 obtained the highest amount of FEC. The irradiated FEC gradually died and by 28 days post irradiation, FEC from all five cassava genotypes were lost. Conversely, the irradiated in vitro nodal cuttings survived and some produced roots, while others produced callus. The LD50 based on number of roots varied from genotype to genotype, but plants remained diploid post-irradiation. Accordingly, the effect of gamma irradiation on Ugandan cassava genotypes (UCGs) was genotype-dependent. This information is foundational for the use of in vitro tissues as target material for cassava mutation breeding.