Cassava In Brazil Research Articles

Assessing management factors limiting yield and starch content of cassava in the western Brazilian Cerrado

AbstractCassava (Manihot esculenta Crantz) was declared the “crop of the 21st century” by the Food and Agriculture Organization of the United Nations due to its high starch content and low input requirements. The management factors that govern yields and starch content in cassava in Brazil are still unclear. The aim of this study was to identify the main factors that limit the yield and starch content of cassava fields in Brazilian Cerrado. The data were collected as part of a survey covering 300 cassava fields in two growing seasons (2020–2021 and 2021–2022). Throughout the development cycle, management practices, yield, and percentage starch content in the roots were described. The database was divided into high and low yield tertiles. Mean comparison tests, regression tree analyses, and boundary functions were applied. The importance of genetics, environment, and associated crop constraints on cassava production (yields and starch content) was assessed. The yield gap in cassava was 44.6 Mg ha−1. The most important factors leading to yield and starch losses were variety, planting date, and potassium fertilization. By adapting optimal practices, it is possible to produce an additional 1.5 million tons of cassava on the current cultivation area in the western Brazilian Cerrado, which corresponds to 8.3% of total production in Brazil and could increase the production of cassava starch by more than 400,000 Mg.

Diversity, Prevalence and Virulence of Colletotrichum Species Causing Anthracnose on Cassava Leaves in the Northern Region of Brazil.

Cassava (Manihot esculenta Crantz) is a staple crop widely cultivated by small farmers in tropical countries. However, despite the low level of technology required for its management, it can be affected by several diseases, with anthracnose as the main threat. There is little information about the main species of Colletotrichum that infect cassava in Brazil. Thus, the objective of this work was to study the diversity, prevalence and virulence of Colletotrichum species that cause anthracnose in cassava leaves in northern Brazil. Twenty municipalities of the Pará and Tocantins states were selected, and leaves with symptoms were collected in those locations. Pure cultures were isolated in the laboratory. Species were identified using phylogenetic analyses of multiple loci, and their pathogenicity, aggressivity and virulence levels were assessed. Our results showed the greatest diversity of Colletotrichum associated with anthracnose in cassava plants of the "Formosa" cultivar in the Tocantins and Pará states. We determined the presence of Colletotrichum chrysophilum, C. truncatum, C. siamense, C. fructicola, C. plurivorum, C. musicola and C. karsti, with C. chrysophilum as the most aggressive and virulent. Our findings provide accurate identifications of species of Colletotrichum causing anthracnose in cassava crops, which are of great relevance for cassava breeding programs (e.g., the search for genotypes with polygenic resistance since the pathogen is so diverse) and for developing anthracnose management strategies that can work efficiently against species complexes of Colletotrichum.

O POTENCIAL DA ROCHAGEM NO NORDESTE DO PARÁ PARA O CULTIVO DE MANDIOCA

The technology, called rochagem (stonemeal), is a recent and sustainable technical solution, increasingly used for the recovery and refertilization of agricultural areas with impoverished soils, using rock dust. In the Northeast of Pará – NEPA, cassava has great economic and social importance, and this region is the largest producer of cassava in Brazil. The great regional limit for the growth of this agricultural activity, in terms of productivity, is the nature of its soils and the human action of intensive and not very rational agricultural practices. To face this situation, in addition to detailing a little more what is Rocha do Solo and Remineralization, we consider geological and lithological aspects of the region in focus, aiming at the potential of sustainable cultivation of the culture. The edaphic parameters evaluated indicate its high geodiversity, which could provide the regional soils with all the macro and micronutrients necessary for their refertilization and, thus, the development of cassava. Keywords: Cassava culture; manioc culture; rockfill; sustainability.

Historical Features Regarding the Neuropathic Outbreaks in Brazilian Troops in the Paraguayan War.

During the Paraguayan War, Brazilian army and navy officers attributed outbreaks of combatant limb weakness with particular features such as tingling to palustrian causes. A dietary basis was not fully suspected at the time, and the popular name beriberi had not been coined. During wartime, there was a shortage in the food supply in addition to poor environmental conditions and diarrheal diseases, and many reports of "palustrian cachexia" were made. There are also reports of the use of native flora to feed troops, as well as alcoholism. There are also accounts of the death of horses with symptoms similar to those of combatants. It was reported that black soldiers were more resistant to "palustrian cachexia." This article presents the disease ecology and clinical manifestations of beriberi at wartime, linked to starvation and consumption of pickled food and native flora. These military explorations and operations in the Paraguayan War happened more than 150 y ago and present some aspects of wilderness medicine in the past.

Assessing the diversity of whiteflies infesting cassava in Brazil.

BackgroundThe necessity of a competent vector for transmission is a primary ecological factor driving the host range expansion of plant arthropod-borne viruses, with vectors playing an essential role in disease emergence. Cassava begomoviruses severely constrain cassava production in Africa. Curiously, begomoviruses have never been reported in cassava in South America, the center of origin for this crop. It has been hypothesized that the absence of a competent vector in cassava is the reason why begomoviruses have not emerged in South America.MethodsWe performed a country-wide whitefly diversity study in cassava in Brazil. Adults and/or nymphs of whiteflies were collected from sixty-six cassava fields in the main agroecological zones of the country. A total of 1,385 individuals were genotyped based on mitochondrial cytochrome oxidase I sequences.ResultsA high species richness was observed, with five previously described species and two putative new ones. The prevalent species were Tetraleurodes acaciae and Bemisia tuberculata, representing over 75% of the analyzed individuals. Although we detected, for the first time, the presence of Bemisia tabaci Middle East-Asia Minor 1 (BtMEAM1) colonizing cassava in Brazil, it was not prevalent. The species composition varied across regions, with fields in the Northeast region showing a higher diversity. These results expand our knowledge of whitefly diversity in cassava and support the hypothesis that begomovirus epidemics have not occurred in cassava in Brazil due to the absence of competent vector populations. However, they indicate an ongoing adaptation process of BtMEAM1 to cassava, increasing the likelihood of begomovirus emergence in this crop.

Three decades of cassava cultivation in Brazil: Potentialities and perspectives

Cassava (Manihot esculenta) shows high phenotypic plasticity, acclimatization, wide adaptability, and resilience to adverse edaphoclimatic conditions. In this context, this systematic review aims to identify what were the factors that determined the production of cassava in Brazil in the last three decades, and to direct what are the possible perspectives of the crop in the country. The methodology to produce this review was based on studies that which integrate the academic information produced in different situations (1990-2020), environments, states, groups of researchers and existing scientific evidence for this theme. Based on the information, a binary matrix of information was assembled based on the following characters, plant density per hectare, soil type, city, state, average air temperature, planting line spacing, plant spacing on the planting line, implantation date, implantation station, harvesting station, productivity per hectare, days for harvest, liming, fertilization, precipitation and climate. It is evident that in the last 30 years the productivity of cassava in Brazil has been increased, mainly in low-income populations and those located in rural areas. There are prospects for increasing cassava production for fresh sale and industry. The crop is characterized as rustic, highly adaptive, tolerant of water stress and acidic soils, being highly influenced by the climate, rainfall, air temperature, and incident solar radiation. Productivity is determined by the time of implantation, liming, fertilization, density, and plant arrangement.

Genetic diversity and population structure analysis by SNP and InDel markers of cassava in Brazil

<p indent=0mm>As a typical tropical crop, cassava (<italic>Manihot esculenta </italic>Crantz) has the characteristics of drought resistance, barren resistance, high biomass and so on. In addition to being used for food and forage, it can also be used for production, processing and starch extraction. Due to highly heterozygous cassava genome, breeding is more difficult. Enriching the genetic diversity of cassava germplasm, comprehensively evaluating its genetic background and traits, and discovering superior alleles that control excellent traits are of great significance for cassava breeding in the future. In order to analyze the genetic diversity, genetic relationship and population structure of cassava germplasm in Brazil, 7946 SNPs and 1997 InDels molecular markers were used. Population structure analysis was performed by ADMIXTURE software, and principal component analysis was performed by GCTA software. Brazilian cassava was divided into nine subgroups, and was roughly consistent with the results of cluster analysis using PHYLIP. Among them, subgroup 1, subgroup 2, subgroup 4, subgroup 6, and subgroup 8 could be clustered together respectively, while the samples of other subgroups could be roughly clustered, and there was a certain cross between the samples. The genetic diversity of cassava germplasm in Brazil (0.274) was higher than the genetic diversity level of cassava germplasm in China and Nigeria. Subgroup 5 of Brazil cassava had a relatively high genetic diversity (0.29). The genetic differentiation of subgroups was low (the genetic differentiation vary from 0.03 to 0.15), but higher than domestic cassava germplasm. The genetic distance between cassava accessions varied from 0.084 to 0.297, with the average of 0.228. The results of this study can provide a basis for subsequent association analysis to identify great alleles and introduction.

Colletotrichum species causing cassava (Manihot esculenta Crantz) anthracnose in different eco-zones within the Recôncavo Region of Bahia, Brazil.

A survey to investigate the occurrence of cassava anthracnose disease (CAD) and distribution of Colletotrichum spp. in cassava plantations in different eco-zones of the Reconcavo Region in Bahia, Brazil, investigated during the rainy season of 2014. A total of 50 cassava fields distributed among 18 municipalities were visited and intensity of anthracnose evaluated. The highest disease incidence (DI) (83.3%) was in samples collected in São Félix, and the lowest (34.4%), in Varzedo. Municipalities that presented the highest values for DI were located within the ‘Af’ Köppen–Geiger eco-zone, also presenting the highest values for the estimated McKinney disease index. Based on previous studies of multilocus phylogeny, seven different species of Colletotrichum were identified (Colletotrichum fructicola, Colletotrichum tropicale, Colletotrichum gloeosporioides s.s, Colletotrichum theobromicola, Colletotrichum siamense, Colletotrichum brevisporum and Colletotrichum plurivorum) and a new approach based on ERIC-PCR was used aiming to group the 82 isolates according to these findings. The highest percentage of genetic variance (> 78%) was among isolates within fields. Based on the survey and genetic analysis, C. fructicola is probably the main causal agent of cassava anthracnose in the Recôncavo Region, since this species was present with highest incidence in all eco-zones, 47.61, 42.86 and 57.14% for Af (tropical rainforest climate), As (tropical dry savanna climate) and Aw (tropical wet savanna climate), respectively. This study is the first report of C. fructicola lineages as the most likely pathogen causing anthracnose disease of cassava in Brazil, and these findings may be used to guide the selection of resistant varieties.

Migdolus fryanus Damage Causes Decrease in the Starch Content in Manihot esculenta

The beetle M. fryanus causes serious damage to cassava in Brazil. However, due to the subterranean behavior of the larvae and the recent appearance of this pest in cassava, little is known about the main behavioral characteristics and damage caused to this crop. The main aim of this study is to demonstrate the variation of starch production in the roots of M. esculenta as a result of the intensity of damage caused by M. fryanus. The study was carried out in a commercial cassava farm in Paran&amp;aacute;, Brazil. The proposed scale for damage was: (1) No apparent root damage; (2) roots with scrapings; (3) roots with scraping across the cortex; (4) damaged roots and galleries; (5) roots with galleries and presentation of rot. The parameters evaluated were the damage caused by M. fryanus in roots and starch content, estimated by using a hydrostatic scale, starch extracted by cassava processing, and the starch reduction percentage in damaged roots, assessed by using the hydrostatic scale (SC) and processing methods (SCP). It was observed that there was manifestation of damage in approximately 60% of the roots collected directly from the ground, with levels representing loss of starch produced by the plant. Decreases in the productive parameters, such as starch content, were measured according to the increase of the proposed damage levels in the two cassava cultivation cycles, with a starch reduction rate higher than 20% when the roots suffered the most severe damage.

GRANULOMETRY AND ENERGY CONSUMPTION AS INDICATORS OF DISINTEGRATION EFFICIENCY IN A HAMMER MILL ADAPTED TO EXTRACTING ARROWROOT STARCH (Maranta arundinacea) IN COMPARISON TO STARCH EXTRACTION FROM CASSAVA

ABSTRACT The commercial sector of starch extraction has fully automated plants with a minimum scale of 200 ton.day–1, which extracts starch from maize and cassava in Brazil. Although these starches are commodities, the market demands starches with special properties obtained without chemical modifications. A higher-priced starch can compensate for small-scale extraction, as in the case of arrowroot starch, which would correspond to an alternative income for the producer. As a small-scale equipment was not available in Brazil, it was necessary to adapt a hammer mill for arrowroot starch extraction, which should have a performance similar to that obtained from cassava roots using industrial grinders. The degree of disintegration and energy consumption were adopted as the efficiency indexes. The hammer mill was equipped with two perforated plates. The results showed that use of an adapted hammer mill provides an average diameter of 74.64 ± 0.09 μm for perforated plate 1 (TP1) and 76.62 ± 0.06 μm for TP2; these results were equivalent to those obtained with cassava in the respective perforations which, in turn, was comparable to the degree of grinding obtained with large industrial equipment. The specific energy consumption needs for arrowroot disintegration varied from 31.47 to 48.91 kJ.kg–1, which was considered close to that calculated for large-scale industrial cassava roots grinders, reported at 37.03 kJ.kg–1.

First report of Macrophomina pseudophaseolina causing stem dry rot in cassava in Brazil

First report of Macrophomina pseudophaseolina causing stem dry rot in cassava in Brazil

First Report of Phytopythium sp. Causing Storage Root Rot and Foliage Blight of Cassava in Brazil

First Report of <i>Phytopythium</i> sp. Causing Storage Root Rot and Foliage Blight of Cassava in Brazil

New occurrences of Botryosphaeriaceae causing black root rot of cassava in Brazil

Despite the occurrence of several diseases of cassava, the cassava black root rot (CBR) represents one of the main limiting factor for crop rentability in the world. However, the etiology of CBR is complex and it needs to be revised based on current molecular analysis. On this work, molecular and morphological studies allowed for the identification of three species of Botryosphaeriaceae causing black root rot disease of cassava in the states of Maranhao and Paraiba, Brazil, namely: Lasiodiplodia euphorbicola, Lasiodiplodia pseudotheobromae and Neoscytalidium hyalinum. This is the first report of these three fungal species as causal agents of CBR in the world.

Weeds as hosts for new crop pests: the case of Protortonia navesi (Hemiptera: Monophlebidae) on cassava in Brazil

SummaryWeeds may serve as reservoirs for new and invasive insect pests. The cassava root scale (Protortonia navesi) is a recent pest in the Brazilian ‘Cerrado’ that causes qualitative and quantitative damage by sucking plant sap. Recently, field surveys revealed that many common weeds in this region act as host for P. navesi in cassava fields. In a discrete survey, 15 weed species were identified that were hosting P. navesi. Among these, 13 species occurred during the cropping season and five were observed 4 months after cassava harvest. Eight months after harvest, only cassava volunteer plants were found to be hosting P. navesi. This survey provided a real example of the problem created when weeds host new crop pests. The management of weeds (including crop volunteers) needs to be considered as part of generalised pest management and pest invasion prevention schemes. Effective weed management can be a means of limiting the survival of new pests and the re‐infestation of susceptible crop species in subsequent years. Simple studies like this point to a practical need to create greater collaborations between pest management researchers working within discrete pest categories.

Identification, distribution and host-plants of the pest species of Scirtothrips (Thysanoptera: Thripidae)

AbstractNotes are given on the host range, distribution and recognition of the ten species of Scirtothrips recorded as pests: S. aurantii Faure on citrus in South Africa and bananas in Yemen; S. bispinosus (Bagn.) on tea in S. India; S. citri (Moult.) on citrus in California; S. dorsalis Hood on groundnuts in India, tea in Japan and strawberries in Queensland; S. inermis Priesn. on citrus in New Zealand; S. kenyensis Mound on tea in Kenya; S. longipennis (Bagn.) in glasshouses; S. mangiferae Priesn. on mango in Egypt and Israel; S. manihoti (Bondar) on cassava in Brazil; S. oligochaetus (Karny) on cotton in India. S. acaciae Moult, from Ghana is synonymised with S. aurantii Faure, and S. fragariae (Gir.) from Queensland is synonymised with S. dorsalis Hood. Drepanothrips reuteri Uzel, a grapevine pest from Europe and America which is very similar to Scirtothrips species, is newly recorded from Japan on Castanea.

Immigration, population growth and mortality of insects and mites on cassava in Brazil

AbstractA small isolated cassava field in Minas Gerais, Brazil, was readily invaded by species of insects and mites already known as cassava pests. Most immigrants were small (&lt; mm) piercing-rasping feeding types. Three of these (the lace-bug Vatiga illudens (Drake), the thrip Scirtothrips manihoti (Bondar) and the mite Mononychellus tanajoa (Bondar)) showed an exponential population increase in the absence of their natural enemies. The onset of the wet microclimate from dew and rain was a key mortality factor for these three species. Storms resulted in a catastrophic decline of the populations, especially that of M. tanajoa. Predators and interspecific competition from S. manihoti were secondary suppressive factors on the M. tanajoa population. Three other species (the caterpillar of Erinnyis ello (L.) and the mites Tetranychus urticae Koch and T. cinnabarinus (Boisd.)) were completely eliminated in the experimental area by parasites or predators. Other feeders, such as the shoot-inhabiting larva of the flies Neosilba spp. and the fungivorous beetle Psyllobora spp., as well as more minor species, were also studied.