Cassava Cuttings Research Articles

Determinants of household participation in the cassava value-chain in South Africa

Cassava’s adaptability to different agroecological conditions, high yield, as well as its ability to thrive under harsh climatic conditions, makes it an essential food security crop. In South Africa, the cassava value chain is currently uncoordinated and underdeveloped, with a couple of smallholder farmers growing the crop for household consumption and as a source of income. Other farmers regard it as a secondary crop and hardly any producers grow it for industrial purposes. Hence, this study sought to analyze the determinants of household participation in the cassava value chain in South Africa. The study employed the multivariate probit model to analyze the determinants of household participation in the cassava value chain in South Africa, using a primary dataset collected through a simple sample method from smallholder farmers in KwaZulu-Natal, Mpumalanga, and Limpopo provinces. Results show that livestock ownership has a positive and significant effect on the likelihood of farmers participating in the value chain by growing cassava for household food consumption. Also, findings reveal that hiring labour in cassava production and an increase in the yield during the previous season increases the probability of farmers’ interest in selling cassava tubers along the value chain. Hence, the positive and statistically significant influence of hiring labour during cassava production in driving the farmers’ interest in selling cassava tubers and cuttings implies that the development of the cassava value chain presents great opportunities for creating jobs (employment) in the country. Also, policy interventions that ensure land tenure security and empower farmers to increase their cassava yields are bound to encourage further participation in the value chain with an interest in selling fresh tubers, among other derived products to generate income. Lastly, programmes that empower and encourage youth participation in the cassava value chain can increase the number of farmers interested in selling cassava products.

Resource productivity and determinants of technical efficiency among cassava farmers’ in north central, Nigeria

This research analyzed resource productivity and determinants of technical efficiency among cassava farmers in North Central, Nigeria. This research employed a multi-stage sampling technique. Primary data were used based on a well-designed questionnaire. Inferential and descriptive statistics were employed for data analysis. The results of resource productivity of inputs show that cassava cuttings and fertilizer have the highest and lowest elasticities, respectively. The mean-TE (Technical Efficiency) score of 74% (0.74) indicates that an average smallholder cassava producer in the sample needs about 26% (0.26) additional inputs to get to the frontier. In the TE components, the coefficients of labour, and fertilizers are significant different from zero at 1% probability level. The coefficients of agrochemicals, land inputs are significantly different from zero at 5% probability level, while the coefficient of cassava cuttings are significant different from zero at 10% probability level. In the TIE (technical inefficiency), component the coefficients of age, credit received, members of cooperatives are significant different from zero at 1% probability level. The policy formulations should be directed towards considering technological substitutions and mechanized agriculture. Excessive labour supply, characteristics of the developing agriculture in sub-Saharan Africa, could be pushed into the secondary sector of the Nigerian economy such as the cassava processing industry, therefore generating income, employment and maintaining Nigeria in the first (1st) position in the world ranking in term of cassava output. Also, it is recommended that improved cuttings, agrochemicals, and fertilizers should be made available to cassava farmers at appropriate time to increase productivity. Furthermore, credit should be made available to cassava farmers at a single digit interest rate, devoid of cumbersome administrative procedures. Keywords: Resource productivity, technical efficiency, cassava farmers, stochastic frontier model, Nigeria

Experiences of participants in an agricultural livelihood support initiative for people living with HIV in central Uganda

This study aimed at assessing the experiences of people living with HIV who participated in an agricultural livelihood support initiative in selected districts of Uganda. The initiative, implemented from 2017 to 2018, involved the provision of agricultural inputs such as beans, cassava cuttings, goats, chickens, and pigs to participants. In-depth interviews were conducted with 37 people (28 women and 9 men) from the districts of Kampala, Masaka and Wakiso (specifically Entebbe) in central Uganda, who had participated in the project. Data were analysed thematically focusing on facilitators, challenges and outcomes from the project. The following themes emerged as facilitators: access to land and animal feed, prior farming experience and supportive family and friends. Some participants experienced challenges including animal/poultry diseases, livestock theft, “low quality” agricultural inputs, unfavourable weather conditions, limited finance and land to support livelihood activities and difficulties working in groups. Several participants reported positive livelihood outcomes including improved food security, better nutrition, increased income and improved mental health. However, some participants reported negative outcomes which took the form of a loss of money and time invested when their livestock died from disease. Although participants in the agricultural livelihood initiative faced challenges which reduced the profitability of their projects, the initiative was regarded as beneficial and worthwhile. These findings have relevance to the broader field of livelihoods programming. Future interventions can draw from the experiences of our participants while also taking seriously into consideration the different circumstances of individuals in a targeted population so as to increase the chances of producing more positive outcomes.

Genetic diversity and incidence of cassava bacterial blight (CBB) caused by Xanthomonas phaseoli pv. manihotis in Burkina Faso

AbstractCassava bacterial blight (CBB), caused by Xanthomonas phaseoli pv. manihotis (Xpm), poses a significant threat to cassava production in Burkina Faso. Prior to this study, the geographical distribution, incidence and origin of CBB introductions were poorly understood. In this investigation, we assessed the incidence of CBB in major cassava‐cropping regions and analysed the genetic diversity of 344 Xpm strains collected from 19 fields between 2015 and 2016, using a multilocus variable number of tandem repeat analysis (MLVA) scheme targeting 14 microsatellite markers. Our results reveal the presence of CBB in three out of four cropping regions, with incidences ranging from 0% to 100% at locality and variety scale. Burkina Faso's Xpm strains exhibited high genetic diversity at multiple levels, including country scale (He = 0.6), cropping region (0.43 to 0.57), locality (0.25 to 0.50) and field (0.25 to 0.52). Pairwise comparisons among populations from different cropping areas indicated a strong genetic differentiation. The categorical minimum spanning tree reveals that the Cascades region has the higher diversity indices and consequently could be the origin site of dispersion of Xpm in the other cropping regions of cassava. Human activities play a major role in the dissemination of Xpm through cassava cuttings. The importance of the sanitary state of cuttings must be emphasized in order to avoid CBB and ensure good cassava production.

A random forest-based analysis of cassava mosaic disease-related factors affecting the on-farm livelihoods of cassava farmers

This study aimed to identify key CMD-related factors affecting Cameroon cassava farmers’ incomes originating from both the sale of cassava cuttings (V215) and the sale of cassava roots (V216). To achieve this, nine CMD-related variables were used to independently train two Random Forest models. These models were later employed for regression-based prediction of both financial targets V215 and V216. The Random Forest (RF)-based mean absolute percentage error for targets V215 and V216 were 0.19 and 1.25 respectively. The RF-based mean Gaussian deviance for targets V215 and V216 were 0.07 and 0.51 respectively. Based on RF feature importance scores (RFFI), the top 3 factors affecting income originating from the sale of cassava cuttings were found to be: late appearance of symptoms as a difficulty associated with regular field monitoring (RFFI of 0.2594), removal of infected plants as a method of controlling frequent occurrence of viral diseases in respondents’ cassava fields (RFFI of 0.1633) and lack of healthy planting material due to frequent occurrence of viral diseases in respondents’ cassava fields (RFFI of 0.1495). Also, the top 3 factors affecting income originating from the sale of cassava roots were found to be: the replacement of infected plants with healthy cuttings as a method of controlling the frequent occurrence of viral diseases in respondents’ cassava fields (RFFI of 0.1974), decrease in yield due to frequent occurrence of viral diseases in respondents’ cassava fields (RFFI of 0.1530) and poor plant growth due to frequent occurrence of viral diseases in respondents’ cassava fields (RFFI of 0.1388).

Rooting performance of cassava cuttings due to the number of nodes and rooting media

AbstractCassava is a major food security crop in the developing world, providing a basic diet for over half a billion people. Stem cutting is the major propagation technique in commercial cassava production, despite its limitations in bulkiness and high cost. Research is lacking in optimizing the number of nodes for the most economical use of the planting material. It can be hypothesized that one or two node cuttings can be used in proper rooting media. Hence, a study was conducted to determine the appropriate number of nodes on selected rooting media for better rooting and shoot growth of cassava. A factorial combination of four number nodes (one, two, three, and standard, or 4–6 nodes) and four types of rooting media (sawdust, cocopeat, topsoil, and sand) was used in a completely randomized design with three replications. Nursery and field establishment data were collected. The result revealed that the interaction between the number of nodes and the media significantly (p < 0.05) affected all fresh and dry weights of root and shoot. Sawdust and cocopeat performed best in terms of root number, root length, leaf number, branch number, shoot length, and rooting percentage. Root fresh weight, root dry weight, shoot fresh weight, and shoot dry weight were higher when stem cuttings were planted using two or more nodes on cocopeat or sawdust as compared to planting them on topsoil or sand. The use of two or more nodes on cuttings using cocopeat or sawdust found outstanding results for rooting. However, the standard cutting was better for survival percentage during field establishment. The result confirmed that two nodes of cassava stem cutting are enough for the successful rooting of cassava, and sawdust promotes the rooting of cuttings. Hence, we recommend sawdust as a rooting medium and two or more nodes of stem cuttings of cassava.

Multifarious Characterization and Efficacy of Three Phosphate-Solubilizing Aspergillus Species as Biostimulants in Improving Root Induction of Cassava and Sugarcane Stem Cuttings.

Several soil fungi significantly contribute to the enhancement of plant development by improving nutrient uptake and producing growth-promoting metabolites. In the present study, three strains of phosphate-solubilizing fungi, namely, Aspergillus chiangmaiensis SDBR-CMUI4, A. pseudopiperis SDBR-CMUI1, and A. pseudotubingensis SDBR-CMUO2, were examined for their plant-growth-promoting capabilities. The findings demonstrated that all fungi showed positive siderophore production, but only A. pseudopiperis can produce indole-3-acetic acid. All fungi were able to solubilize insoluble phosphate minerals [Ca3(PO4)2 and FePO4] by producing phosphatase enzymes and organic acids (oxalic, tartaric, and succinic acids). These three fungal species were grown at a water activity ranging from 0.837 to 0.998, pH values ranging from 4 to 9, temperatures between 4 and 40 °C, and 16-17% NaCl in order to evaluate their drought, pH, temperature, and salt tolerances, respectively. Moreover, the results indicated that A. pseudopiperis and A. pseudotubingensis were able to tolerate commercial insecticides (methomyl and propargite) at the recommended dosages for field application. The viability of each fungal strain in the inoculum was higher than 50% at 4 and 20 °C after 3 months of storage. Subsequently, all fungi were characterized as plant-growth-promoting strains by improving the root inductions of cassava (Manihot esculenta Crantz) and sugarcane (Saccharum officinarum L.) stem cuttings in greenhouse experiments. No symptoms of plant disease were observed with any of the treatments involving fungal inoculation and control. The cassava and sugarcane stem cuttings inoculated with fungal strains and supplemented with Ca3(PO4)2 exhibited significantly increased root lengths, shoot and root dry biomasses, chlorophyll concentrations, and cellular inorganic phosphate contents. Therefore, the application of these phosphate-solubilizing fungi is regarded as a new frontier in the induction of roots and the promotion of growth in plants.

Occurrence of cassava mosaic begomoviruses in national cassava germplasm preserved in two agro‐ecological zones of Ivory Coast

AbstractCassava production in Ivory Coast is hampered by cassava mosaic disease (CMD), which is caused by several begomovirus species. To increase cassava production and conserve genetic resources, the Centre National de Recherche Agronomique (CNRA) maintains a germplasm collection of 610 cassava accessions of various origins, which is kept in open fields in Bouaké and Man. We carried out an epidemiological assessment of the collection and a molecular characterization of the viruses infecting the CNRA cassava germplasm. The field in Man was less affected by CMD (incidence 49.78%, severity 2.23, whitefly infection 2.23%), despite the abundant whitefly populations (1.34 per plant), compared to Bouaké (incidence 74.54%, severity 2.92, whitefly infection 8.04% and whitefly population of 0.34 per plant). However, the predominant mode of CMD transmission was through infected cassava cuttings at both sites. PCR analysis showed that the East African cassava mosaic Cameroon virus (EACMCMV) was always found in co‐infection with African cassava mosaic virus (ACMV), which also occurred in single infection. Co‐infections of EACMCMV and ACMV were more prevalent in Bouaké (52.64%) than Man (13.87%). Eleven complete genome sequences of cassava mosaic begomoviruses infecting the CNRA germplasm were obtained, and phylogenetic analysis showed that they are closely related to ACMV and EACMCMV isolates from Ghana, Burkina Faso and Nigeria. The results of this study will assist breeders to screen accurately for CMD resistance in progeny resulting from parental lines, enabling the strategic distribution of new clean cassava planting materials to reduce the impact of CMD.

Survey of cassava brown streak disease and association of factors influencing its epidemics in smallholder cassava cropping systems of coastal Kenya

Cassava productivity is threatened by viral diseases which have become the main phytosanitary problems in cassava farmers. Cassava brown streak disease (CBSD) is a devastating viral disease caused by Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV) which are transmitted by whitefly vectors and mainly disseminated through the use of infected stem cuttings as planting materials. The aim of the current study was to: (1) assess farmers' knowledge, perceptions on spread, causes and current management practices of CBSD; (2) determine the factors associated with farmers' satisfaction with cassava planting material; and (3) determine the distribution, incidence, and severity of CBSD and association of factors influencing the disease epidemics in smallholder cassava cropping systems in coastal Kenya. Information was collected using semi-structured questionnaire administered to 250 smallholder farmers through face-to-face interviews coupled with field visits to assess the incidence, severity and distribution of CBSD. Symptomatic and asymptomatic cassava leaf samples were collected for reverse transcription-polymerase chain reaction (RT-PCR) analysis of the causal viruses of CBSD. The results revealed that majority of the farmers (96.6%) could recognize CBSD symptoms on the roots, and only 11.5% could recognize the foliar symptoms of the disease. The cause of the disease was unknown to the farmers, with no effective management methods available to them. Majority of farmers (82.5%) recycled own cassava cuttings from previous season's crop as planting material followed by exchanging/borrowing from neighbors (67.5%). The field incidence of CBSD was highest in Kilifi (27.9%) followed by Kwale (24.7%) and Taita Taveta (10.8%), with severities ranging from 2 to 3 in the three Counties. RT-PCR analysis indicated that 91% of the symptomatic samples tested positive for either of the two viruses occurring either singly or as dual infection. Approximately 3.2% of the asymptomatic samples tested positive for only CBSV. Findings from this study demonstrates the need for awareness creation of farmers on the causes, spread and management practices to control CBSD and the importance of strengthening certified cassava seed systems to reduce the impact of the disease. The study provides base-line information imperative for development of management strategies of CBSD.

AN EMPIRICAL AND ECONOMIC ANALYSIS OF CASSAVA PRODUCTIVITY IN SELECTED AREAS OF SOUTHERN SIERRA LEONE

This study examined the productivity and economic analyses of the cassava production in three communities—Nyallay, Sammamie, and Sindeh sections in Bo districts, Southern Sierra Leone. The crop is processed into garri, fufu, akara, and other foods. Cassava can also be used to make flour, pellets, and chips for animal consumption, as well as biofuel and particle boards The data was gathered using a questionnaire and interview schedule that were both well organized. Descriptive statistics, financial techniques, and a multiple regression model were all employed in the data analysis. The main data came from a sample of 300 cassava growers from three regions. The collected data were evaluated using econometric regression analysis. The findings indicated that, the net farm income was Le 214,361 and the net return on investment was almost Le 258, 375. The findings of a regression analysis showed that the number of cassava cuttings, hired labor, farm size, farming experience, and age statistically substantially influenced the output of cassava in the research region. It is indicated that the availability of improved cassava cuttings in the area and farmers’ access to subsidized inputs like fertilizer. In the study it was suggested that farmers be prodded to invest in the cultivation of cassava because of its economic worth and profitability. Cassava growers should be encouraged to obtain instruction on correct agronomic practices and input usage, and inputs should be made available and at reasonable costs, especially improved types of cassava cuttings, this will increase productivity.

DETERMINANTS OF OUTPUT OF CASSAVA (MANIHOT SPECIES) PRODUCTION IN ABUJA, NIGERIA

This research study focused on determinants of the output of cassava (Manihot species) production in Abuja, Nigeria. Multi-stage method of sampling was used. One hundred (100) cassava farmers were sampled and selected. Primary data were obtained through the use of a well-designed and also well-structured questionnaire. Data were analyzed using econometrics and statistical tools. The results show that 87% of cassava producers were between 31 to 50 years of age. About 72% had formal education and were literate. Averagely, they had 4.76 hectares of cassava farmland. The estimated gross margin (GM) and net farm income (NFI) of cassava production per hectare were 1,464, 162.72 Naira and 1, 453, 752.49 Naira respectively. This implies that cassava production was profitable and worthwhile. Farm size and fertilizer input were statistically significant factors influencing the output of cassava production. Age, labour input, and cassava cuttings were statistically significant factors influencing the output of cassava production. While chemical input statistically and significantly influenced the output of cassava production. The constraints facing cassava producers were the unavailability of improved cassava cuttings, the high cost of farm inputs, insecurity, inadequate extension services, and inadequate finances. The research study recommends that improved cassava cuttings should be made available to farmers for increased productivity. Extension officers should be employed to disseminate innovations, research findings, and new farm technologies to cassava farmers. Credit or loan facilities should be made available to cassava producers at low-interest rates.

Women’s Involvement in Cassava Value Chain Activities in Akpabuyo Local Government Area of Cross River State, Nigeria

The main purpose of this study was to investigate women’s involvement in cassava value chain activities in Akpabuyo LGA of Cross River State, Nigeria. The specific objectives were to identify the major value chain activities in the study area; investigate the value chain activities participated by women in the area; identify the constraints affecting effective involvement of women in cassava value chain in the area; and evaluate possible suggestions to improve effective involvement of women in cassava value chain activities in the area. Multi-stage and purposive sampling techniques were adopted to select 216 respondents for the study. The result revealed that the major cassava value chain activities in the area were processing ( =3.07), marketing ( =2.92), production ( =2.87) and packaging ( =1.86). The findings of this research also indicated that women participate more in cassava processing ( =1.94), rank=1st), followed by production ( =1.85). The respondents indicated that lack of adequate production and processing tools ( =3.81), poor access to land ( =3.78) and lack of financial support ( =3.72), as the three most critical constraints affecting effective involvement of women in cassava value chain activities in the study area. The respondents’ suggestion to improve their involvement in cassava value chain activities revealed that financial support, ease of transportation and access to improved cassava cuttings, with means of 3.79, 3,78 and 3.63, respective, were the most rated factors. The study concluded that women in Akpabuyo local government area are significant actors in the country’s agricultural sector, particularly the cassava sub-sector, and as a result, food security. Thus, it was recommended that value chain actors and promoters should make credit facilities available to women in order to encourage their effective involvement in cassava value chain activities in the area, among others.

Evaluation and Selection of Elite Cassava Varieties for Storage Root Yield in the Transition and Guinea Savannah Ecologies of Ghana

This study was carried out to identify and select local and improved cassava varieties suitable for cultivation in the transition and Guinea savannah agroecology of Ghana against climate change. Two agroecologies; transition and Guinea savannah ecologies were considered for the study. Four cassava growing communities were chosen in the transition zone whilst three cassava growing communities were chosen for the Guinea savannah ecology. The cassava varieties representing the treatments were arranged in a randomized complete block design with three replications at each location. A total of 13 cassava varieties were used for the study. Cassava cuttings measuring 20-25 cm were planted using a spacing of 1m × 1m. Harvesting was done at 12 months after planting to assess storage root yield of the cassava varieties at the different locations. Analysis of variance indicated significant (P≤ 0.05) varietal differences among the local varieties for root yield (11.25 - 29.27 t/ha), harvest index (0.46 – 0.75), storage root number per plant (2 - 8 roots/plant) and mean storage root weight (307.0 - 972.4 g) in Transition zone. However, there were no significant varietal differences between the improved varieties for root yield. The best performing improved varieties in the transition zone were Bankyehemaa (28.06 t/ha), Eskamaye (27.76 t/ha) and Nkabom (26.99 t/ha) whilst Filindiakong (22.65 t/ha) and Nyerikobga (31.17 t/ha) were identified to be suitable for the Guinea savannah ecology. Therefore, these cassava varieties can be cultivated to mitigate the effects of climate change on cassava and ensure food security.

Upaya Meningkatkan Hasil Tanaman Ubi Kayu Varietas Lokal Maluku Utara

The increasein cassava production is aimed at increasing yields that remain high according to needs and demand, therefore the target of increasing the weight of fresh tubers needs to be achieved with the method of development of cultivation technology. This research aims to examine the influence of cuttings sliced models and the number of shoots on the growth and yield of cassava crops. The study used local variety cassava cuttings from Tobelo, North Maluku. The study was arranged in factorial Randomized Block Design, as the first factor is the cuttings sliced model, consisting of 3 levels namely flat slice, one-sided sliced, and two-sided sliced, and the second factor is the number of buds consisting of 3 levels namely one bud, two buds, and three buds. Each treatment is repeated 3 times so there are 27 trial units. The results showed the treatment of the two-sided sliced model provided the highest average value on all observation parameters, while in the treatment of the number of buds, the number of buds one tended to provide the highest average value. The highest cassava production result was obtained in the combination of two-sided sliced model treatment with the number of buds one which is 15.96 tons ha-1.

Determinants of the choice of cassava cuttings by farmers on the outskirts of the city of Kananga in D.R. Congo

Determinants of the choice of cassava cuttings by farmers on the outskirts of the city of Kananga in D.R. Congo

Characteristics and production of cassava stem cuttings for rapid multiplication method

Selection of stem cuttings is an important step for production of high-quality seedlings by rapid multiplication method. This study aimed to assess the sprouting capacity of cassava stem cuttings of different diameters. Experiments were conducted at five planting seasons (June, July, August, September, and October) under a completely randomized design in a factorial scheme (5 × 2), with ten treatments and 20 replications. Treatments consisted of combinations between planting seasons and stem cuttings with diameters lower (15 to 19.99 mm) and higher (20 to 25 mm) than 20 mm. Each stem cutting was measured regarding length, diameter, and weight. The mean number of days for emergence, percentage of survival, and sprouting index were assessed at each plot. Planting of stem cuttings with diameter between 20 and 25 mm in September was adequate for obtaining cassava cuttings for the rapid multiplication method.

TECHNICAL EFFICIENCY DYNAMICS IN SMALLHOLDING CASSAVA-BASED FARMING IN RURAL NIGERIA

Dynamics of production efficiency is a key factor in assessing resource-use patterns and production growth. Raising technical efficiency of smallholder farmers in rural areas would not only increase their income but also stimulate the rest of the economy. This study therefore assessed movement of smallholder farmers in and out of technical efficiency regime over time in Nigeria. Panel data from Living Standard Measurement Survey was analysed using stochastic production frontier model, Markov chain and multinomial logit model. Farm size, labour, cassava cuttings and the use of pesticides, significantly influenced the productivity of cassava production while age squared, household size, no access to extension services and membership of a cooperative society reduced the efficiency of the farming households. A higher percentage (64.83%) of cassava farms under mono-cropping system were efficient in 2010/2011, while a large proportion of about 92.91% were inefficient in 2015/2016. Further, the rate of entry into technical inefficiency (31.32%) was more than the rate of exit from technical inefficiency (14.89%). Transition into technical inefficiency was explained by age, age squared, farm size, gender, household size, marital status, secondary school education and farming systems. In the long run, the probability that rural cassava farmers will be technically efficient was higher than that of being technically inefficient in the future.

Effect of intercropping on cassava bacterial blight caused by Xanthomonas axonopodis pv. manihotis in Togo

Bacterial blight is one of the biotic constraints to cassava production, affecting yield and cuttings. To contribute to preventing farmers from yield losses, the present study investigated the effect of intercropping cassava with common staple crops in Togo on the development of cassava bacterial blight under field conditions in four agroecological zones of the country. Cassava was intercropped with maize (Zea mays L.) in the forest-savanna transition zone at Davié, in the forest lowland zone at Adéta, in the forest highland zone at Danyi, and in the wet savanna zone in Sotouboua. Additionally, cassava was intercropped with taro (Colocasia esculenta (L.) Schott.) in the forest highland zone at Danyi. Border plants of cassava for each treatment were inoculated with a bacterial suspension of 107 cfu/ml. Bacterial blight severity was significantly reduced compared to sole cassava in the forest highland in cassava-taro and cassava-maize intercropping (p < 0.05 and p < 0.01 in 2000 and 2001, respectively), in the forest lowland in cassava-maize intercropping (p = 0.002 in 2001), and in cassava-maize intercropping in the wet savanna zone (p < 0.001 and p < 0.01 in 2000 and 2001, respectively), with generally no significant negative effect on cassava root yield. Though significant, disease reductions by intercropping generally were low (10 to 24%). Since no varieties with complete resistance to the disease had been identified among local and local improved varieties across ecozones in Togo, the combination of medium resistant varieties and an intercropping system, both adapted to the respective ecozone, can be recommended to farmers as part of integrated control measures against bacterial blight of cassava. Keywords: Cassava, bacterial blight, intercropping, control, Togo.

Posição de plantio e da aplicação de diferentes doses de nitrogênio em diferentes épocas em mandioca

ABSTRACT In this study, we evaluated the impact of two planting positions of cassava cuttings, cv. ‘Vassourinha’, combined with different times and doses of nitrogen application, on productivity and other agronomic traits. In the experiment, the treatment was completely randomized using a 2 × 3 × 4 factorial scheme with two positions of the cuttings [horizontal (PH) and vertical (PV)], three instances of N application (45, 90, and 135 days after planting), and four doses of N (0, 80, 160, and 240 kg ha-1), with six repetitions. We recorded and evaluated the plant height, number of shoots, stem diameter, biomass of the aerial part, number of commercial roots, the total production, and the collection index. The addition of 240 kg ha-1 N and PH increased plant height and stem diameter but did not affect the number of commercial roots, total production, or the collection index. The treatment involving the addition of nitrogen fertilizer 135 days after planting with 240 kg ha-1 N and planting in the PV provided the highest amount of shoot biomass without influencing crop productivity.

Evaluation of agronomic descriptors of two cassava varieties (Manihot esculenta Crantz) on ten innovative substrates in Daloa (Côte d'Ivoire)

In Côte d'Ivoire, cassava production is carried out by small-scale planters who use very few technical means and local cultivars that are not very productive and susceptible to diseases. The objective of this study is to maximize the recovery of cassava cuttings after planting. To this end, ten substrates of single, double, triple and quadruple composition were made from soil supplemented with sawdust, chicken droppings, carbonized rice husks and NPK 10 18 18 to regenerate dehydrated cassava Bocou 1 and Yavo mini-cuttings. The recovery rate of the mini-cuttings was evaluated as well as the agro-morphological parameters of the seedlings for 21 days. Results showed that the recovery rate was very high on the carbonized rice husk substrate (86.5% in Bocou 1 and 85.5% in Yavo). In addition, the substrates significantly influenced the growth parameters of the seedlings. Thus, the substrate composed of carbonized chicken-bale soil had the highest number of leaves, with 6 leaves per plant in Bocou 1 and 10 leaves in Yavo, with an average height ranging from 10.99 ± 1.22 (Bocou 1) to 20.23 ± 1.16 (Yavo). The results of this study will help orient the actors of the cassava sector towards a new cultivation technique.