Cassava Plants Research Articles

Effects of cassava meal on carcass characteristics and cholesterol of growing pig

Twenty growing pigs with an average initial weight of 20.00 + 0.5 kg were randomly assigned to five dietary treatments in a completely randomized design with two replicates per treatment and two animals in each replicate. Cassava Plant Meal (CPM) prepared from sundried unpeeled cassava tubers, leaves and tender cassava stems, mixed at ratio 3:1 of unpeeled tuber meal to cassava leaf meal plus tender stem meal with the ratio of cassava leaf meal to tender stem meal as 5:1 was included in balanced rations at graded levels of 0, 25, 50, 75 and 100 percent in a fifty-six days feeding trials. The experimental pigs were weighed before and after slaughtering, dressing percent was evaluated and carcass length and back fat depth were measured on treatment basis. Meat samples were collected at the ribs (2nd and v3rd and also 12th and 13th) for cholesterol analysis. The 50 % CPM diet produced the heaviest slaughter weight. There was no significant (p >0.05) difference in the dressing percentage of pigs across dietary treatments although pigs on the control diet dressed well while pigs on 100 % CPM dressed the poorest. The 100 % CPM diet induced the leanest carcass. All the carcass and organ measurements were significantly (p <0.05) affected by dietary treatments. There was non-significant (p >0.05) influence of dietary treatments on total and high density lipoprotein cholesterol although the 50 % CPM diet produced the least and highest values respectively. Low density and very low density lipoprotein cholesterol were significantly (p <0.05) affected by dietary treatments. Replacement of maize by varying levels of cassava plant meal diets enhanced production of leaner carcass.

The Future of Livestock Management: A Review of Real-Time Portable Sequencing Applied to Livestock.

Oxford Nanopore Technologies’ MinION has proven to be a valuable tool within human and microbial genetics. Its capacity to produce long reads in real time has opened up unique applications for portable sequencing. Examples include tracking the recent African swine fever outbreak in China and providing a diagnostic tool for disease in the cassava plant in Eastern Africa. Here we review the current applications of Oxford Nanopore sequencing in livestock, then focus on proposed applications in livestock agriculture for rapid diagnostics, base modification detection, reference genome assembly and genomic prediction. In particular, we propose a future application: ‘crush-side genotyping’ for real-time on-farm genotyping for extensive industries such as northern Australian beef production. An initial in silico experiment to assess the feasibility of crush-side genotyping demonstrated promising results. SNPs were called from simulated Nanopore data, that included the relatively high base call error rate that is characteristic of the data, and calling parameters were varied to understand the feasibility of SNP calling at low coverages in a heterozygous population. With optimised genotype calling parameters, over 85% of the 10,000 simulated SNPs were able to be correctly called with coverages as low as 6×. These results provide preliminary evidence that Oxford Nanopore sequencing has potential to be used for real-time SNP genotyping in extensive livestock operations.

Physiological mechanism of resistance antibiosis to anthracnose of different Manihot varieties

Cassava is one of the main food crops in Africa, particularly in Côte d'Ivoire. However, the cultivated varieties are prone to attack by diseases. The present work focused on the role of phenolic and in particular flavonoid resistance markers in the Manihot esculenta-Colletotrichum gloeosporioides pathosystem. The aim was to elucidate the involvement of flavonoid antibiosis in the natural defense of three cultivars of M. esculenta when confronted with attacks by C. gloeosporioides. The quantitative dosage approach for total phenolics and flavonoids as well as the identification of flavonoid antibiosis have been carried out. The results revealed that the cultivars 9620A, TMS30572 and YACE of M. esculenta have, after the C. gloeosporioides inoculation tests, reacted early 2 days after inoculation (JAI) and accumulated relatively high levels of antibiosis phenolic and flavonoid 9JAI. The three cultivars accumulated constitutive flavonoid antibiosis and 3 neosynthesized antibiosis from 7JAI to 9JAI. The accumulation of flavonoid antibacterials neosynthesized in the stems and in the leaves testify to the expression of a systemic resistance of the cassava plants. The cultivars 9620A and TMS30572 are more tolerant than cultivar YACE. This study approach has made it possible to discriminate between cultivars and can therefore be used as a complementary selection tool to traditional selection tests.Keywords: Manihot esculenta, anthracnose, flavonoïd antibisis, glyphosate.

Kasule, F Farmer Preference of Cassava Cultivars in Eastern Uganda: A Choice Beyond Disease Resistance

The cassava breeding program in Uganda has released many improved cultivars resistant/tolerant to cassava brown streak disease (CBSD) and cassava mosaic disease (CMD). However, many farmers have continued to use cultivars that are susceptible to these major viral diseases but with diverse attributes. There is a need to understand farmers’ cassava cultivar attribute preferences and CBSD, CMD prevalence on the preferred cultivars. A total of 150 cassava farmer fields (74 in Bukedea district and 76 in Kumi district) located in eastern Uganda were evaluated for farmers’ cultivars and attribute preferences, as well as prevalence of CBSD and CMD on the farmer selected cultivars. The eastern region was of interest in the study, due to it-being the major cassava producing area in the country. In addition, 30 cassava plants of different genotypes were chosen randomly along transects of each field and assessed for CBSD/CMD incidence and severity on preferred cultivars. Results showed that more than 64% of the farmers in eastern Uganda preferred NASE 03 due to its sweet taste and high yields, followed by NASE 14 (21%) because of its high yields. There was a significant (P≤0.001) correlation between cassava cultivars preferred and CBSD severity (r = -0.56), CBSD incidence (r = -0.53), CMD severity (r = -0.51) and CMD incidence (r = -0.39). In corroboration, the most preferred cultivar, NASE 03 was found most susceptible to CBSD and CMD in both Bukedea and Kumi districts with CBSD incidence of 62.2% and 52.7% and CMD incidence of 56.9% and 34.3% respectively. The results showed that CBSD and CMD are prevalent on farmer preferred cassava cultivars, and that farmer cultivar preference depends not only on disease resistance but also other attributes.

Genetically Different Isolates of the Arbuscular Mycorrhizal Fungus Rhizophagus irregularis Induce Differential Responses to Stress in Cassava.

Water scarcity negatively impacts global crop yields and climate change is expected to greatly increase the severity of future droughts. The use of arbuscular mycorrhizal fungi (AMF) can potentially mitigate the effects of water stress in plants. Cassava is a crop that feeds approximately 800 million people daily. Genetically different isolates of the AMF R. irregularis as well as their clonal progeny have both been shown to greatly alter cassava growth in field conditions. Given that cassava experiences seasonal drought in many of the regions in which it is cultivated, we evaluated whether intraspecific variation in R. irregularis differentially alters physiological responses of cassava to water stress. In a first experiment, conducted in field conditions in Western Kenya, cassava was inoculated with two genetically different R. irregularis isolates and their clonal progeny. All cassava plants exhibited physiological signs of stress during the dry period, but the largest differences occurred among plants inoculated with clonal progeny of each of the two parental fungal isolates. Because drought had not been experimentally manipulated in the field, we conducted a second experiment in the greenhouse where cassava was inoculated with two genetically different R. irregularis isolates and subjected to drought, followed by re-watering, to allow recovery. Physiological stress responses of cassava to drought differed significantly between plants inoculated with the two different fungi. However, plants that experienced higher drought stress also recovered at a faster rate following re-watering. We conclude that intraspecific genetic variability in AMF significantly influences cassava physiological responses during water stress. This highlights the potential of using naturally existing variation in AMF to improve cassava tolerance undergoing water stress. However, the fact that clonal progeny of an AMF isolate can differentially affect how cassava copes with natural drought stress in field conditions, highlights the necessity to understand additional factors, beyond genetic variation, which can account for such large differences in cassava responses to drought.

Karakteristik Morfologi dan Kelimpahan Populasi Parasitoid (Hymenoptera) pada Hama Invasif Kutu Putih Ubi Kayu, Phenacoccus manihoti Matile-Fererro (Hemiptera: Pseudococcidae) di Bali

Morphological Characteristics and Populations Abundance of Parasitoid (Hymenoptera) on Invasive Pests Cassava Mealybug, Phenacoccus manihoti Matile-Fererro (Hemiptera: Pseudococcidae) in Bali. This study aims to know the morphological characteristics of parasitoid, population abundance and distribution patterns of parasitoid associated with P. manihoti on cassava crop in Bali. The study was conducted on all cassava crop in Bali with a field observation method that was determined by taking shoots of cassava plants attacked by cassava mealybug P. manihoti, then cassava mealybug P. manihoti were nurtured, then observation was carried out every day until parasitoid appeared and being identified. The results of the study showed that there were three dominant types of parsitoid that were found to be associated with invasive pest P. manihoti, namely Anagyrus lopezi, Acerophagus papayae and Blepyrus insularis. The abundance of parasitoid populations was dominated by parasitoid A. lopezi with a range of values 48.6–81.8%. Then followed by parasitoid A. papayae 7.7 - 37.1%, and B. insularis 3.4 - 14.3%. The distribution pattern of parasitoid varies in each species, parasitoid A. lopezi spreads in groups categories, Parasitoid A. papayae and B. insularis spread random-regulary on cassava crop throughout on each of the Regencies in Bali.

DISTRIBUTION AND DYNAMICS OF NEMATODE POPULATIONS ASSOCIATED WITH CASSAVA (MANIHOTESCULENTA CRANTZ) CULTIVATION IN TWO MAIN PRODUCTION AREAS IN COTE DIVOIRE

Plant parasitic nematodes associated with cassava cultivation in Cote dIvoire have received very little public attention. This study aimsat updating information on nematodes associated with cassava. Surveys were carried out in cassava fieldsin five localities spread over two agroecological zones so as to collect cassava soil and root samples. The nematodes were extracted, identified, quantified and their distributionmapped. Sixteen nematode genera were extracted from cultivation soils, six of which includingGracilacus, Helicotylenchus, Meloidogyne, Pratylenchus, Radopholus and Tylenchulus were extracted from cassava roots. Gracilacus and Meloidogyne were extracted from cassava roots from all localities. Local and improved cassava varieties were infected with nematodes. Gracilacus was mainly extracted from cassava roots in Adzope, Agboville and Dabou at frequencies ranging from 48.43 to 56.58%. Meloidogyne and Pratylenchus were the main nematodes extracted from cultivation soils in Gagnoa (46.81%) and Yamoussoukro (78.15%) respectively. The numbers of Gracilacus in Adzope, Agboville and Dabou, Meloidogyne in Agboville, Dabou and Gagnoa, Pratylenchus in Dabou and Yamoussoukro and Radopholus in Adzope increased in cultivation soils with the age of cassava plants.

Molecular cloning and expression analysis of sucrose phosphate synthase genes in cassava (Manihot esculenta Crantz)

Sucrose phosphate synthase (SPS), a key rate-limiting enzyme in the sucrose biosynthesis pathway in plants, is encoded by a multi-gene family. Until recently, the identification and characterization of the SPS gene family have been performed for dozens of plant species; however, few studies have involved a comprehensive analysis of the SPS family members in tropical crops, such as cassava (Manihot esculenta Crantz). In the current study, five SPS genes (MeSPS1, MeSPS2, MeSPS3, MeSPS4, and MeSPS5) were isolated from cassava, and their sequence characteristics were comprehensively characterized. These MeSPS genes were found distributed on five chromosomes (Chr2, Chr14, Chr15, Chr16, and Chr18). Phylogenetic analysis showed that the MeSPS protein sequences were clustered into three families, together with other SPS sequences from both dicot and monocot species (families A, B, and C). The spatio-temporal expression pattern analysis of MeSPS genes showed a tissue-specific and partially overlapping expression pattern, with the genes mainly expressed in source tissues during cassava growth and development. Correlation analysis revealed that the expression of MeSPS genes correlated positively with root starch content, indicating that the expression of MeSPS genes might accelerate the rate of starch accumulation in the roots of cassava plants.

A cassava protoplast system for screening genes associated with the response to South African cassava mosaic virus

BackgroundThe study of transient gene expression in cassava plants during virus infection using existing protocols is laborious and may take approximately fifteen weeks due to cassava’s recalcitrance to transformation. The combination of a protoplast system with CRISPR-mediated gene editing promises to shorten the turnaround time from plant tissue culture to high-throughput gene expression screening for candidate genes. Here, we detail a protocol for screening genes associated with the response to South African cassava mosaic virus (SACMV) in cassava protoplasts, with reference to the ubiquitin E3 ligase gene, MeE3L.MethodsCassava protoplasts of model, and SACMV-susceptible and -tolerant genotypes, were transformed with SACMV infectious clones and/or a CRISPR-editing construct targeting the MeE3L using PEG4000-mediated transfection. DNA and RNA were extracted from transformed protoplasts at 24 h post-transfection. Relative SACMV DNA accumulation was determined via qPCR using DpnI-digested total DNA, MeE3L relative expression was determined via reverse transcriptase qPCR, and results were analysed using one-way ANOVA, Tukey’s HSD test and the 2−ΔΔCTstatistical method. The MeE3L exonic region was sequenced on the ABI 3500XL Genetic Analyzer platform; and sequences were analysed for mutations using MAFTT and MEGA-X software. Construction of a phylogenetic tree was done using the Maximum Likelihood method and Jones-Taylor-Thornton (JTT) matrix-based model.ResultsThe differential expression of unedited and mutant MeE3L during SACMV infection of model, susceptible and tolerant cassava protoplasts was determined within 7 weeks after commencement of tissue culture. The study also revealed that SACMV DNA accumulation in cassava protoplasts is genotype-dependent and induces multiple mutations in the tolerant landrace MeE3L homolog. Notably, the susceptible cassava landrace encodes a RINGless MeE3Lwhich is silenced by SACMV-induced mutations. SACMV also induces mutations which silence the MeE3L RING domain in protoplasts from and tolerant cassava landraces.ConclusionsThis protocol presented here halves the turnaround time for high-throughput screening of genes associated with the host response to SACMV. It provides evidence that a cassava E3 ligase is associated with the response to SACMV and forms a basis for validation of these findings by in planta functional and interaction studies.

THE EFFECT OF ADHESIVE PAPER WASTE WEIGHT PERCENTAGE IN BIOBRIQUET DERIVED FROM CASSAVA SKIN WASTE

Cassava skin waste is waste originating from cassava plants from tapioca flour factories or cassava processed product factories. Indonesia is one of the biggest countries that produces cassava. The number of cassava processing industries in Indonesia is large so that a positive correlation can be drawn that the high amount of cassava processed will produce more cassava skin waste. Based on the results of tests conducted, the higher the composition of the Each cassava can produce 10-15% of cassava skin waste. Cassava skin waste is directly removed, can cause buildup that results in environmental damage. Cassava skin waste is obtained from local farmers, where on average each cassava produces 10-15% of waste. In general, this waste is not used and just thrown away. This research was conducted with the main ingredients of cassava peel waste and adhesive made from used paper. The composition of the mixture of cassava peel and used paper varies, where the percentage by weight of the adhesive starts from 7.0% to 10% with an increase in the composition every 0.5%. Then the biobriquette carbonization process was carried out at a temperature of 400 ° C. The biobriquette characterization was carried out based on ASTM standards to analyze water and ash, volatile matter and heating value. The results of the analysis on the composition of the lowest cassava bark had the highest heating value of 5888 cal / gr with the lowest water, ash and volatile matter content.

Nutrient uptake and nutrient use efficiency of cassava genotypes with different starch bulking periods as affected by different planting dates

Information on macronutrient uptake and nutrient use efficiency (NUE) of cassava genotypes under different planting dates is limited. The aims of this study were 1) to investigate the responses of cassava genotypes to planting dates for nutrient uptake and NUE and 2) to identify the superior genotypes based on these traits. Three cassava genotypes (Kasetsart 50 (KU50), Rayong 11 (RY11) and CMR38-125-77) were planted in a randomized complete block design with four replications at four planting dates (20-Apr, 30-Jun, 5-Oct and 15-Dec 2016) and harvested at 12 months after planting (MAP). Planting cassava on 20-Apr and 15-Dec produced the highest total crop nutrient uptake and nutrient uptake for storage roots. Whereas planting cassava on 5-Oct and 15-Dec with higher solar radiation, temperature, relative humidity and longer photoperiod during canopy establishment until high carbohydrates translocation and with lower temperature and shorter photoperiod during a dormancy period resulted in greater NUE for biomass and storage roots and nutrient harvest index for all genotypes and most elements. CMR38-125-77 and KU50 showed good performance in terms of total nutrient uptake across planting dates (1.45–38.31 g plant−1) for most elements. CMR38-125-77 seems to be the best genotype on the basis of high storage root dry weight, high NUE for both biomass (90.1–1,594.6) and storage roots (39.9–927.1) and nutrient harvest index (0.14–0.58) for almost all planting dates, except in planting date 20-Apr in which RY11 was the highest for these traits. The genotype identified is useful as parental source for further breeding programs to improve genotypes with high NUE and high storage root yield.

Cassava production in Nigeria: trends, instability and decomposition analysis (1970–2018)

This study analyzed the compound growth rate (CGR) and the contributions of yield and area to cassava production output in Nigeria. During the period, TE1970 – TE2018, production followed an upward trajectory from 9.3 million tonnes (1970) to 59.5 million tonnes (2018) while yield oscillated between 7.9tonnes/ha (TE2014) and 11.9tonnes/ha (TE2010). At this period, the CGR per year for yield declined (-0.2%), harvested area increased (10.9%) and production increased (10.6%). The decomposition analysis for the period revealed that, increase in output was largely due to expansion of harvested area (152%) while the interaction between area and yield effect declined production output by 45.8%. Regrettably, during the period, cassava yield also declined production output by 5.8%. The study also found that harvested area has the highest instability index (11.8). In order to further increase and sustain cassava production in Nigeria, intense planting of high yield cassava stems instead of solely expanding cropped area is recommended.

Cassava common mosaic virus infection causes alterations in chloroplast ultrastructure, function, and carbohydrate metabolism of cassava plants

AbstractCassava common mosaic virus (CsCMV) is a potexvirus that causes systemic infections in cassava plants, leading to chlorotic mosaic and producing significant yield losses. To date, the physiological alterations and the mechanism underlying biotic stress during the cassava–CsCMV compatible interaction remains unknown. In this study, we found that CsCMV infection adversely modified chloroplast structure and had functional effects on chloroplasts in source leaves during the course of viral infection. Extrusion of the chloroplast membrane with amoeboid‐shaped appearance and disorganized grana stacks were observed in infected mesophyll cells. These alterations were associated with up to 35% reduction of relative chlorophyll content, and a decline of CO2 fixation (13.5% and 24.2% at 90 and 210 days after planting, respectively). The effects of CsCMV infection on the performance index on absorption basis dropped up to 37%. The analysis of chlorophyll a fluorescence showed a progressive loss of both oxygen evolving complex activity and “connectivity” within the tripartite system (core antenna‐LHCII‐reaction centre). Here, we report the latter phenomenon for the first time in a viral infection. The oxidative stress process was observed in CsCMV‐infected plants (20.8% reduction of antioxidant capacity with respect to noninfected plants). Other effects of the pathogen included reduction of starch and maltose content in source leaves, and a significant increase (24.7%) of the sucrose:starch ratio, which indicates an altered pattern of carbon allocation. Our results suggest that CsCMV induces chloroplast distortion associated with progressive chloroplast function loss and diversion of carbon flux in source leaf tissue, leading to the loss of cassava tuber yield.

Analysis of Cyanide Acid Content in Cassava (Manihot esculenta) Based on Storage Time

Cassava is a tuber of cassava plants which is a source of carbohydrates that can be consumed as food and as snack foods such as chips. However, cassava and the leaves contain cyanide acid (HCN) which is dangerous for the human when consumed in excess. Cyanide acid reduction can be done by washing as well as immersion because of its volatile nature. The aim of this research is to investigate the difference of cyanide acid (HCN) content on peeled and unpeeled cassava with the variation of storage time 0, 2, 4, 6, and 8 days. A preliminary test was done to know the existence of cyanide acid (HCN) in cassava. Method analysis of cassava was titrated with the NH4CNS solution using the argentometric principle of the Volhard method. The results showed that cyanide acid (HCN) content in peeled cassava was higher than unpeeled cassava which was 3.9, 4.7, 5.2, 5.6, and 6.0% respectively for shelled cassava and 3.9, 4.6, 5.1, 5.5, and 5.9% respectively for unpeeled cassava.

Characterization and Pulping of Crops Residue: Eggplant, Cassava, Okra and Mulberry Plants

In this paper, four crops residues such as eggplant, cassava, okra and mulberry plants were assessed as papermaking raw materials. These crops residues had lower α-cellulose and holocellulose and moderate lignin content with syringyl:guaiacyl range of 1.05–1.63. The fiber length of eggplant, cassava, and mulberry plants were shorter (0.58–0.65 mm), while the same for okra plant was medium (1.14 mm). The Runkle ratios of these plant fibers were low (0.208–0.678), and flexibility coefficient was low to medium (55–79). All these non-wood plants were difficult to cook except eggplant plant. Eggplant plant produced screened pulp yield of 33.21 with kappa number of 22.9 at the conditions 3 h cooking at 170 °C with 20 alkali charge. Cassava plant showed the lowest screened pulp yield of 17.7% with kappa number 30.3 at the conditions 2 h cooking at 170 °C with 20 alkali charge. The okra plant pulp showed the best papermaking properties among these crops residues. Eggplant and okra plants can be used for brown packaging grade pulp.

Response of parasitoids to invasive pest Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae) on cassava crop in Bali, Indonesia

Abstract. Supartha IW, Yudha IKW, Wiradana PA, Susila IW. 2020. Response of parasitoids to invasive pest Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae) on cassava crop in Bali, Indonesia. Biodiversitas 21: 4543-4549. Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae) is an invasive pest that entered Indonesia in 2010 and attacks cassava plants, especially in Bali Province. This study aimed to identify species and establish the population distribution mapping, community structures (diversity, abundance, and dominance), and parasitization rate on cassava crops in Bali. This study conducted with a field observation method by taking infested shoots of cassava plants by P. manihoti purposively in the field. The cassava mealybug that was present in the leaves or shoots were kept in the laboratory until the parasitoid appeared. The results showed that four species of parasitoids were found to respond to invasive pest, namely Anagyrus lopezi (Encyrtidae), Acerophagus sp. (Encyrtidae), Blepyrus sp. (Encyrtidae) and Encarsia sp. (Aphelinidae). Structurally the parasitoid community had a low abundance (R1 = 0.50–0.87) and low diversity index value (H'= 0.27-0.28). While the parasitoid dominance index was in the moderate category with a value D = 0.33–0.59 in Bangli, Klungkung, Badung, Tabanan, and Buleleng Districts. But it had high dominance index values in Gianyar, Denpasar, Jembrana, and Karangasem Districts with a value D = 0.62-0.72. The three species of parasitoid spread evenly in all districts and cities in Bali according to the host distribution map, namely P. manihoti on cassava crop. The four parasitoids showed varying parasitic levels in the field with the highest parasitization rate was A. lopezi followed by Acerophagus sp., Blepyrus sp., and Encarsia sp.

Cassava Cultivars Response to Different Levels of Potassium Fertilization under Drip Irrigation and Sandy Soil Conditions

Two field experiments were conducted at Nubaria region (Behira Governorate), Egypt, during the two successive seasons of 2016/2017 and 2017/2018 to study the response of vegetative growth, yield and quality of cassava crop. Three cassava cultivars (i.e., American, Brazilian and Indonesian cultivar) and three levels of potassium fertilizers (i.e., 75, 150 and 250kg K2Ofed-1) were investigated. The results indicated that, American cassava cultivar recorded the highest vegetative growth, yield and its quality as well as higher chemical composition plants, which were received 250 kg K2Ofed-1. This study also confirmed that the optimum K- nutrition for cassava under sandy soils might support the cultivated cassava plants in their growth, yield and yield quality. This work also could present more details about the suitability of some cassava cultivars to cultivate under sandy soils and drip irrigation and which dose of K-nutrient should be applied. Further investigations are needed to carry out to make a complete program for the fertilization and irrigation of different cassava cultivars under arid conditions in Egypt.

Agricultural zoning as tool for expansion of cassava in climate change scenarios

Improvement of planting season and crop growth time, considering climatic and soil needs of plants, is important to increase cassava (Manihot esculenta) production in Midwestern Brazil. Thus, we sought to develop an agricultural zoning for cassava cultivation in the Midwest of Brazil in different climate change scenarios. Mean air temperature and precipitation data from localities of the Midwest of Brazil were obtained from the Brazilian National Institute of Meteorology (INMET). Clay (%) data from localities of the Midwest of Brazil were obtained from SoilGrids. Regions where the air temperature was within the range from 20 to 27 °C were considered climatically favorable for commercial exploitation of cassava, in addition to precipitation between 1000 and 1500 mm year−1, and clay content was less than ≤ 35%. Moreover, regions with air temperature below 16 °C and above 38 °C, precipitation below 1000 mm and above 1500 mm year−1, and clay content > 35% were considered unsuitable for cassava cultivation. Raster or matrix images, corresponding to mean annual air temperature, annual precipitation, and clay (soil), were superimposed to create cassava suitability classes, according to crop requirements. The climate change scenarios were established by changing the air temperature (°C) and rainfall (mm). The air temperature was increased by 1.5, 3.0, 4.5, and 6.0 °C as adopted by Pirttioja et al. (Clim Res 65:87–105, 2015). We changed in precipitation − 30, − 15, + 15, and 30% according to the future projections simulated by the IPCC (2014). Maps were made using geographic information systems. In the states of Mato Grosso do Sul, Mato Grosso, and Goias, mean precipitation was around 1200 to 4000 mm year−1. Northern Mato Grosso showed the highest annual precipitation, with values above 3500 mm. A large extension of the Midwest region of Brazil is climatically and soil favorable for cassava. The Midwest is a region with high rainfall, so we recommend planting in well-drained soils to avoid phytosanitary problems. Producers taking this care can plant cassava in 86.6% of the territory. The climate change scenarios demonstrated different Agriculture zonings for cassava in the Midwest of Brazil. With the increase in air temperature, greater marginal classes occurred, but cassava is resistant to this condition. But, this increase in temperature can reduce the cycle and consequently reduce production.

Phenotypic and molecular changes in cassava (Manihot esculenta Crantz.) genotypes as a response to water-deficit stress

Three local Indonesian cassava (Manihot esculenta Crantz) genotypes, Adira 4, Roti, and Ubi Kuning retained their growth under a water deficit environment. To understand the physiological and molecular responses of cassava plants under such stress, we observed leaf stomata characteristics, i.e. stomata dimension (width and length) and density, and molecular expression of aquaporin (AQP) gene, respectively. The observation was performed on all genotypes on day 26 and 45 after water-deficit treatment. Quantification of gene expression was performed by comparing the threshold cycle (Ct) values of AQP with Ct values β-tubulin for each genotype. Results showed that water deficit treatment significantly affected both stomata density, length and width in all genotypes. On day 26 after treatment, the density of stomata in Roti and Ubi Kuning increased two times higher than the stomata density in plants under well-watered supply. Stomata length of Roti and Adira 4 under water stress was 0.4 times shorter than those under normal water supply. Relative expression of AQP, encoding AQP PIP2 proteins, in the Roti genotype showed that the gene transcripts have no significant elevation after experiencing water stress. In Adira 4, the expressions of AQP increased two-times at day 26 under water-deficit treatment compared with AQP expressions in well-watered treatment and continued to elevate up to three times higher at day 45 than those of expressed in Adira 4 plants under well-water treatment. In addition to stomata phenotypic changes, Ubi Kuning may regulate its water channel proteins AQP PIP2 to control turgor pressure in the beginning phase of water stress conditions. These results showed that three cassava genotypes responded differently under water deficit stress and these may serve as basic knowledge for further analysis.

Response of Cassava Crop Cultivated In Sandy Soil To Different Sources of Potassium Fertilizers

Field experiment was carried out in new reclaimed lands at the experimental Station of National Research Centre in Nubaria Region, Behira Governorate, North of Egypt, during the two growing seasons of 2017/2018 and 2018/2019. This studyaimed to enhance cassava(Indonesian cultivar) productivity by using differentsources of potassium fertilizers treatments. Six treatments, i.e.,potassium sulphate as mineral fertilizer, K feldspar + bio fertilizer as bio fertilizer, compound K, Aloe extract as natural fertilizer and Humic acid as organic fertilizer were compared to non-potassium fertilizerapplication (control). The experiments were carried out in a Complete Randomized Blocks Design in four replicates. The characters of vegetative growth, (plant height, leaves number per plant, main stems number per plant, main stem diameter,leaves dry matter, total chlorophyll content and leaf area) total yield per fed., tuber roots characters (average tuber roots number, average tuber roots diameter, average tuber roots length, average tuber roots weight and tuber roots dry matter) and chemical contents of tuber roots (starch % and potassium %)were evaluated.The increment in vegetative growth and productivity of cassava plants was evident with fertilizered plantsby mineral potassium, Aloe extract and Humic acid. On the other hand, decrement in vegetative growth and productivity of cassava was observed withnon-adding potassium fertilizertreatment (control).