scholarly journals Evaluation and Characterization of High Yielding Cassava Mosaic Resistant Variety YTP2

2021 ◽  
pp. 198-208
Author(s):  
L. Pugalendhi ◽  
M. Velmurugan ◽  
P. S. Kavitha ◽  
M. K. Kalarani ◽  
N. Senthil ◽  
...  
Keyword(s):  
Tamil Nadu ◽  
Starch Content ◽  
Disease Incidence ◽  
Mosaic Disease ◽  
Dna Fingerprint ◽  
Cassava Mosaic Disease ◽  
Resistant Variety ◽  
Research Station ◽  
Internodal Length ◽  
New Variety

The cassava variety YTP2 (Me 681) has been developed through selection from Thondamuthur type at Tapioca and Castor Research Station, TNAU, Yethapur. The performance of YTP2 in the Adaptive Research Trial (ART) and On Farm Trial (OFT) in the farmer’s field inferred that this new variety is well adapted to cassava growing districts of Tamil Nadu. In addition to the above, YTP2 was found to be resistant to cassava mosaic disease incidence (CMD). Plants are erect, medium growing and non-branching type and suitable for growing under irrigated and rainfed conditions. The internodal length is shorter and the leaf size is medium with sufficient canopy. The leaves of the plants droop down to reduce the transpiration loss which is more advantageous to overcome or escape from drought and heat stress during summer season. It is a dual purpose variety wherein the tubers contain high starch content which is much favourable for the manufacture of starch, sago and also suited for table purpose. The overall performance of this variety showed higher tuber yield (42.20 t ha-1) and starch content (28.40%) which is 15.94% and 18.20% increase over the check varieties YTP1 and H226 respectively. The results of DNA fingerprint data involving SSR markers (SSRY235, NS169 and NS928) showed that it is genetically distinct from the existing commercial varieties viz., YTP1, H226 and Sree Athulya.

scholarly journals Evaluation of whitefly population and weather effect of cassava mosaic incidence on commonly grown cassava in Benue State, Nigeria

2020 ◽  
Vol 24 (10) ◽  
pp. 1839-1846
Author(s):  
I Time ◽  
E Okoroafor ◽  
J.O. Nwogwugwu ◽  
A.A. Batcho
Keyword(s):  
Wind Speed ◽  
Wind Direction ◽  
Disease Incidence ◽  
Natural Infection ◽  
Block Design ◽  
Mosaic Disease ◽  
Cassava Mosaic Disease ◽  
Whitefly Population ◽  
North East ◽  
Vector Population

Vector population and weather are critical in virus disease incidence and could be strategic for its management in agriculture. To investigate the influence of whitefly population and weather on Cassava Mosaic Disease (CMD) in cassava, TMS 419 and TME 30572, commonly grown in the state were planted. The varieties were laid out in Randomized Complete Block Design in four replicates and left to natural infection by CMD viruses. At two weeks after planting and fortnightly, whitefly population counts were taken, CMD incidence was estimated and severity scored on 5- point scale. Daily temperature, humidity, wind speed and wind direction were obtained as secondary data. Data were analysed using ANOVA at p=0.05. Whitefly population (18/plant) was significant (P≤0.05) in the first 30 days at 26.9-27.1oC, 42% humidity, 10 Km/hr wind speed and when the wind direction was in the East or North-East. The vector population then declined until the end of experiment. Cassava mosaic incidence changed with whitefly population, humidity and wind speed. Disease incidence in cassava plots was low (3.6%). TME30572 maintained lower disease incidence (3.0%) and severity (2.0) during the study. R2 indicated that 27, 42 and 57% of whitefly population could be explained by temperature, humidity and wind speed, respectively while 4% of the disease incidence could be explained by the whitefly population. The number of CMD infected plants peaked (4%) when population of whitefly was 18/plant, above which the disease reduced at 0.0017 rate per unit change in the vector population. Mosaic disease incidence in cassava plots was influenced by vector population as conditioned by the weather. Keywords: Bemisia tabaci, Cassava, Cassava Mosaic Disease, Nigeria, Weather, Whitefly vector

Cassava mosaic disease. [Distribution map].

1998 ◽  
Author(s):  
Keyword(s):  
Sierra Leone ◽  
Tamil Nadu ◽  
Andhra Pradesh ◽  
Central African Republic ◽  
Democratic Republic ◽  
Mosaic Disease ◽  
Equatorial Guinea ◽  
Cassava Mosaic Disease ◽  
Distribution Map ◽  
New Distribution

Abstract A new distribution map is provided for Cassava mosaic disease Viruses: Geminiviridae: Begomovirus Hosts: Cassava (Manihot esculenta). Information is given on the geographical distribution in ASIA, India, Andhra Pradesh, Karnataka, Kerala, Tamil Nadu, Sri Lanka, AFRICA, Angola, Benin, Burkina Faso, Burundi, Cameroon, Cape, Verde, Central African Republic, Chad, Congo, Congo Democratic Republic, Cote d'Ivoire, Equatorial Guinea, Ethiopia, Gabon, Ghana, Guinea, Guinea-Bissau, Kenya, Lesotho, Liberia, Madagascar, Malawi, Mauritania, Mauritius, Mozambique, Nigeria, Rwanda, Sao Tome & Principe, Senegal, Seychelles, Sierra Leone, South Africa, Sudan, Tanzania, Togo, Uganda, Zambia, Zimbabwe.

Effect of African cassava mosaic disease on morphological characteristics of cassava, Manihot esculenta (Crantz)

2015 ◽  
Vol 11 (2) ◽  
pp. 258-265
Author(s):  
TF Oyadiran ◽  
JA Osakwe
Keyword(s):  
Disease Incidence ◽  
Morphological Characteristics ◽  
Field Trials ◽  
Mosaic Disease ◽  
Cassava Mosaic Disease ◽  
Petiole Length ◽  
Manihot Esculenta Crantz ◽  
Key Word ◽  
Mechanized Agriculture ◽  
Number Of Branches

Field trials were conducted with 10 improved clones of cassava to study the effect of ACMD on their morphological characteristics. The clones used were: 97 / 4763, 97/2205, 91/02324, 98/0505, M98/0068, 96/1089A, 96/1632, M98/0040, 99/2123 and 97/0162. The parameters measured were plant height, leaf area, number of branches and petiole length. The research revealed differences within the clones for the parameters studied, these differences seemed to be mainly genetic, as they were not positively correlated to the disease incidence and severity. Based on the findings in this research the following recommendations were made. On the basis of their branching pattern, highly branched clones 97 / 2205, 97/4763 and 98 /0505 are recommended for selection. The heavy branches bear a lot of leaves or produce a thick canopy which helps to reduce the need for weeding, and also reduce the effect of loss of leaves that occur due to disease incidence. However, for industrial / mechanized agriculture, clones that are less branched should be selected as they are easier to harvest mechanically. Though there is disadvantage with their small leaf areas; the crops would have to be highly resistant to fungal attack which tends to cause leaf drop that will reduce leaf material for food / starch production (examples of less branching clones are, M98 / 0068, 96/1632,91/02324).Key Word: African Cassava Mosaic Disease (ACMD), Cassava Mosaic Virus.(CMV)

Starch content and cassava mosaic disease genetic diversity with relation to yield in south Indian cassava (Manihot esculenta Crantz) germplasm

2011 ◽  
Vol 14 (3) ◽  
pp. 179-189 ◽  
Author(s):  
Raghu Duraisamy ◽  
Sakthi Ambothi Rathinasamy ◽  
Senthil Natesan ◽  
Raveendran Muthurajan ◽  
Jana Jeevan Ramineni ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Manihot Esculenta ◽  
Starch Content ◽  
Mosaic Disease ◽  
Cassava Mosaic Disease ◽  
Manihot Esculenta Crantz ◽  
South Indian

ROOT ROT RESISTANCE IN NEW CASSAVA VARIETIES INTRODUCED TO FARMERS IN NIGERIA

2009 ◽  
Vol 45 (1) ◽  
pp. 15-24 ◽  
Author(s):  
R. U. OKECHUKWU ◽  
A. G. O. DIXON ◽  
M. O. AKORODA ◽  
M. MWANGI ◽  
R. BANDYOPADHYAY
Keyword(s):  
Root Rot ◽  
Matter Content ◽  
Mosaic Disease ◽  
Cassava Mosaic Disease ◽  
Resistant Variety ◽  
Environment Interaction ◽  
Dry Matter Content ◽  
Humid Forest ◽  
New Varieties ◽  
Cassava Varieties

SUMMARYIn 2004 and 2005 through field trials in over 2500 locations in several agroecological zones, 40 new cassava varieties were introduced in Nigeria. The trials were managed by scientists, extension workers and farmers. The aim in introducing these new varieties was to pre-emptively manage cassava mosaic disease, to avert an imminent threat from the Ugandan strain of the pathogen and prevent damage to the Nigerian cassava economy. From these trials, 10 new varieties were selected and officially released for high root yield, high dry matter content and acceptability for food, industry and livestock. Cassava root rot is a major source of yield loss in Nigeria, especially where farmers practice late harvest because they wait for a good price from the market before harvest and sales. This paper investigated how the 40 varieties together with three old improved varieties currently in farmers' fields during the formal trials responded to root rot disease. No absolutely resistant variety was found, indicating that early harvest (9–11 months after planting) is still the best way to reduce losses from root rot. Root rot is also significantly (p ≤ 0.05) influenced by genotype and environment interaction. Most root rot was recorded in the humid forest and the least was in the Sudan savanna agroecological zone. Using a rank-sum method, the 43 varieties were separated into highly resistant, resistant, moderately resistant, moderately susceptible, susceptible and highly susceptible classes.

scholarly journals A cassava mosaic disease epidemiologic factors analysis in the Bas-Congo (DR Congo) zone of savannah. case study: “Secteur de Boko”

2015 ◽  
Vol 3 (1) ◽  
pp. 56
Author(s):  
Bansimba Mukiese J.-Roger
Keyword(s):  
Disease Incidence ◽  
Mosaic Disease ◽  
Cassava Mosaic Disease ◽  
Dr Congo ◽  
Local Varieties ◽  
Epidemiologic Factors ◽  
Factors Analysis ◽  
Foliar Symptoms ◽  
The Mean

<p>This paper aims at evaluating epidemiologic parameters of the African Cassava Viral Mosaic Disease (CMVD) in 25 cassava farmer's fields of «Secteur de Boko» (DR Congo) on the basis of foliar symptoms observation. The results showed that the infection of the local varieties comes mainly from the cuttings whereas that of the improved varieties comes from the flies. The disease incidence varied between 10% and 88.33% with an average of 43.8%. Severity varied between 2.42 and 3.42 with an average of 2.913. The gravity varied between 17.86% and 87.81% while the systemicity varied between 21.42 and 96.66%. The mean number of whiteflies (<em>Bemisia tabaci</em>) by plant (2.068) revealed a preference of the vectors for the improved variety Kindombe which, however, presents a low severity and a less marked gravity. Globally, the CMVD was more severe for the local variety Mpeko with a score of 3.00. A high correlation was found between the gravity and the number of neighbour fields (-0,437*), the density of culture (-0,431*) and also the systemicity of the disease (0,779**). In addition; it appeared that the land topography strongly influences the disease severity (-0,542**).</p>

scholarly journals EFFECT OF ORGANIC AND BIOFERTILIZERS ON GROWTH PARAMETERS IN BLACK PEPPER (PIPER NIGRUM L.)

2021 ◽  
Vol 21 (no 1) ◽  
Author(s):  
Ravanachandar A ◽  
Rex B ◽  
Lakshmanan V ◽  
Sudhakaran M
Keyword(s):  
Leaf Area ◽  
Tamil Nadu ◽  
Growth Parameters ◽  
Block Design ◽  
Black Pepper ◽  
Piper Nigrum ◽  
Research Station ◽  
Flowering Stage ◽  
Internodal Length ◽  
Harvesting Stage

India is known as the “Land of spices” from time immemorial and emerged as a leading country in respect of area, production and export of spices in the world. Black pepper (Piper nigrum), known as “king of spices”, is a perennial export cash crop in India. An experiment was conducted at Horticultural Research Station, Yercaud, Tamil Nadu Agricultural University, Coimbatore with an objective to study the effect of organic and biofertilizers on growth parameters in Black Pepper. Experiment was laid out with six treatments replicated four times in a randomized block design. Among the treatments of organic manures and biofertilizers viz., vine lengths were recorded at initial stage (before the commencement of trial), flowering stage and harvesting stage. Internodal length and leaf area were recorded at flowering stage and harvesting stage, the vine length (8.91,9.01 & 9.12 m), internodal length (5.11 & 5.20 cm) and leaf area (88.17 & 89.35 cm2 ) was higher in the combined application (T3 ) of FYM, Neem Cake, Azospirillum and Phosphobacteria compare to over control.

scholarly journals Survey and molecular detection of Sri Lankan cassava mosaic virus in Thailand

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0252846
Author(s):  
Kingkan Saokham ◽  
Nuannapa Hemniam ◽  
Sukanya Roekwan ◽  
Sirikan Hunsawattanakul ◽  
Jutathip Thawinampan ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Disease Severity ◽  
Disease Incidence ◽  
Rolling Circle Amplification ◽  
Mosaic Disease ◽  
Cassava Mosaic Disease ◽  
Pcr Analysis ◽  
Nucleotide Sequencing ◽  
Sri Lankan ◽  
Cassava Mosaic Virus

Cassava plantations in an area of 458 hectares spanning five provinces along the Thailand–Cambodia border were surveyed from October 2018 to July 2019 to determine the prevalence of cassava mosaic disease (CMD) caused by Sri Lankan cassava mosaic virus (SLCMV) in the region. CMD prevalence was 40% in the whole area and 80% in Prachinburi, 43% in Sakaeo, 37% in Burium, 25% in Surin, and 19% in Sisaket provinces. Disease incidence of CMD was highest 43.08% in Sakaeo, followed by 26.78% in Prachinburi, 7% in Burium, 2.58% in Surin, and 1.25% in Sisaket provinces. Disease severity of CMD symptoms was mild chlorosis to moderate mosaic (2–3). The greatest disease severity was recorded in Prachinburi and Sakaeo provinces. Asymptomatic plants were identified in Surin (12%), Prachinburi (5%), Sakaeo (0.2%), and Buriram (0.1%) by PCR analysis. Cassava cultivars CMR-89 and Huai Bong 80 were susceptible to CMD. In 95% of cases, the infection was transmitted by whiteflies (Bemisia tabaci), which were abundant in Sakaeo, Buriram, and Prachinburi but were sparse in Surin; their densities were highest in May and June 2019. Nucleotide sequencing of the mitochondrial cytochrome oxidase 1 (mtCO1) gene of whiteflies in Thailand revealed that it was similar to the mtCO1 gene of Asia II 1 whitefly. Furthermore, the AV1 gene of SLCMV—which encodes the capsid protein—showed 90% nucleotide identity with SLCMV. Phylogenetic analysis of completed nucleotide sequences of DNA-A and DNA-B components of the SLCMV genome determined by rolling circle amplification (RCA) indicated that they were similar to the nucleotide sequence of SLCMV isolates from Thailand, Vietnam, and Cambodia. These results provide important insights into the distribution, impact, and spread of CMD and SLCMV in Thailand.

Yield and quality evaluation of ginger (Zingiber officinale Rosc) genotypes under high rainfall zone of Tamil Nadu

1970 ◽  
pp. 95
Author(s):  
R Balakumbahan ◽  
J P Joshua
Keyword(s):  
Tamil Nadu ◽  
Quality Evaluation ◽  
Zingiber Officinale ◽  
Fibre Content ◽  
Research Station ◽  
Local Strains ◽  
High Rainfall ◽  
Yield And Quality ◽  
Rainfall Region ◽  
Horticultural Research

An experiment on ginger was undertaken between April 2012 to March 2015 at Horticultural Research Station, Pechiparai with an objective to identify suitable ginger cultivar or accession with higher yield and quality attributes suitable for high rainfall zone of Tamil Nadu. Twenty four ginger genotypes, local strains and varieties were collected from different ginger growing tracts of India and evaluated for their performance in high rainfall region. Among the twenty four genotypes tested, the accession Z. O- 4 recorded higher fresh rhizome yield (22.16 ha-1) than other genotypes whereas Z. O - 6 recorded highest dry recovery per cent (22.47%). Higher oleoresin and fibre content was recorded in genotypes Z. O – 5 (9.56%) and Z . O – 17 (11.20%) respectively. 

scholarly journals Effects of Vector Maturation Time on the Dynamics of Cassava Mosaic Disease

2021 ◽  
Vol 83 (8) ◽  
Author(s):  
F. Al Basir ◽  
Y. N. Kyrychko ◽  
K. B. Blyuss ◽  
S. Ray
Keyword(s):  
Time Delay ◽  
Plant Density ◽  
Plant Viruses ◽  
Mosaic Disease ◽  
Plant Diseases ◽  
Cassava Mosaic Disease ◽  
Maturation Time ◽  
Negative Effect ◽  
Dynamical Regimes

AbstractMany plant diseases are caused by plant viruses that are often transmitted to plants by vectors. For instance, the cassava mosaic disease, which is spread by whiteflies, has a significant negative effect on plant growth and development. Since only mature whiteflies can contribute to the spread of the cassava mosaic virus, and the maturation time is non-negligible compared to whitefly lifetime, it is important to consider the effects this maturation time can have on the dynamics. In this paper, we propose a mathematical model for dynamics of cassava mosaic disease that includes immature and mature vectors and explicitly includes a time delay representing vector maturation time. A special feature of our plant epidemic model is that vector recruitment is negatively related to the delayed ratio between vector density and plant density. We identify conditions of biological feasibility and stability of different steady states in terms of system parameters and the time delay. Numerical stability analyses and simulations are performed to explore the role of various parameters, and to illustrate the behaviour of the model in different dynamical regimes. We show that the maturation delay may stabilise epidemiological dynamics that would otherwise be cyclic.

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