scholarly journals Evaluation for Released and Promising Genotypes of Potato against Red Ant

2019 ◽  
Vol 5 ◽  
pp. 81-87
Author(s):  
Prem Nidhi Sharma ◽  
Ram Chandra Adhikari ◽  
Bhim Bahadur Khatri ◽  
Kalika Prasad Upadhyay
Keyword(s):  
Insect Pest ◽  
Damage Index ◽  
Potato Tubers ◽  
Varietal Resistance ◽  
Natural Infestation ◽  
Potato Resistance ◽  
Index Value ◽  
Resistant Genotypes ◽  
Combined Data

Red ant is the most destructive insect pest of potato tubers in the field. Utilization of varietal resistance is the best option to control the pest. The resistance of five released and nine promising genotypes of potato were evaluated against red ant (Dorylus orientalis Westwood) under natural infestation in red ant prone field. Potato resistance was evaluated based on tuber damage index value (0.00 to 1) which was calculated on the bases of the percentage of damaged tubers and number of injuries on per kilogram of tubers made by the pest. Based on the results of combined data, the levels of varietal damage were categorized to be less damaged (TDI value ranging from 0.35 to 0.49), moderately damaged (TDI value ranging from 0.50to 0.64) and highly damaged (TDI value ranging from 0.65 to 0.79) types. Among the 14 genotypes compared for levels of tuber damage, the fivegenotypes: IPY-8 (TDI value: 0.35), Khumal Seto (TDI value: 0.39), PRP-056267.1 (TDI value: 0.40), Janak Dev (TDI value: 0.44) and PRP-25861.1 (TDI value: 0.49) were determined to be the less damaged types. The less damaged potato genotypes can be used by farmers as the relatively resistant genotypes against red ant.

Étude du rôle des sucres dans la résistance des pommes de terre au flétrissement bactérien

1969 ◽  
Vol 15 (8) ◽  
pp. 907-916 ◽  
Author(s):  
Roger Paquin ◽  
Guy Pelletier
Keyword(s):  
Storage Temperature ◽  
Sugar Content ◽  
Rapid Decrease ◽  
Causal Agent ◽  
Potato Tubers ◽  
Varietal Resistance ◽  
Corynebacterium Sepedonicum ◽  
Ring Rot ◽  
Potato Resistance

Potato resistance to ring rot does not seem to be related to sugars present in stems and tubers in opposition to the conclusions of Rozhalin. Sugars contained in those organs exceed the amount required by the causal agent, Corynebacterium sepedonicum (Spieck. & Kott.) Skapt. and Burkh., for its growth. Moreover, no correlation could be shown between sugar content and varietal resistance. Sugars added to potato extracts did not influence the growth of C. sepedonicum on these extracts. Moreover, a rise of the storage temperature of potato tubers which caused a rapid decrease in their sugar content did not influence the growth of C. sepedonicum on extracts of the same tubers.

Diverse sources of resistance to Spodoptera litura (F.) in groundnut

2019 ◽  
Vol 79 (01S) ◽  
Author(s):  
M. A. Saleem ◽  
G. K. Naidu ◽  
H. L. Nadaf ◽  
P. S. Tippannavar
Keyword(s):  
Recombinant Inbred ◽  
Spodoptera Litura ◽  
Hot Spot ◽  
Recombinant Inbred Lines ◽  
Insect Pest ◽  
Inbred Lines ◽  
Leaf Damage ◽  
Botanical Variety ◽  
Resistant Genotypes ◽  
Botanical Varieties

Spodoptera litura an important insect pest of groundnut causes yield loss up to 71% in India. Though many effective chemicals are available to control Spodoptera, host plant resistance is the most desirable, economic and eco-friendly strategy. In the present study, groundnut mini core (184), recombinant inbred lines (318) and elite genotypes (44) were studied for their reaction to Spodoptera litura under hot spot location at Dharwad. Heritable component of variation existed for resistance to Spodoptera in groundnut mini core, recombinant inbred lines and elite genotypes indicating scope for selection of Spodoptera resistant genotypes. Only 29 (15%) genotypes belonging to hypogaea, fastigiata and hirsuta botanical varieties under mini core set, 15 transgressive segregants belonging to fastigiata botanical variety among 318 recombinant inbred lines and three genotypes belonging to hypogaea and fastigiata botanical varieties under elite genotypes showed resistance to Spodoptera litura with less than 10% leaf damage. Negative correlation existed between resistance to Spodoptera and days to 50 per cent flowering indicating late maturing nature of resistant genotypes. Eight resistant genotypes (ICG 862, ICG 928, ICG 76, ICG 2777, ICG 5016, ICG 12276, ICG 4412 and ICG 9905) under hypogaea botanical variety also had significantly higher pod yield. These diverse genotypes could serve as potential donors for incorporation of Spodoptera resistance in groundnut.

scholarly journals Effective selection criteria for assessing the resistance of stink bugs complex in soybean

2014 ◽  
Vol 14 (3) ◽  
pp. 174-179 ◽  
Author(s):  
Fabiani da Rocha ◽  
Felipe Bermudez ◽  
Mônica Christina Ferreira ◽  
Kênia Carvalho de Oliveira ◽  
José Baldin Pinheiro
Keyword(s):  
Geometric Mean ◽  
High Yield ◽  
Stink Bug ◽  
Stink Bugs ◽  
Effective Selection ◽  
Natural Infestation ◽  
Soybean Plants ◽  
Resistant Genotypes ◽  
Control Management ◽  
Selection Of

Soybean plants with resistance to the stink bug complex are currently selected by extremely labor-intensive methods, which limit the evaluation of a large number of genotypes. Thus, this paper proposed the use of an alternative trait underlying the selection of resistant genotypes under field conditions with natural infestation: the weightof healthy seeds (WHS). To this end, 24 genotypes were evaluated under two management systems: with systematic chemical control of insects (management I), and without control (management II). Different indices were calculated using grain weight (Y P) of management I and WHS ofmanagement II (Y S). The high correlation between Y Sand the indices mean productivity, stress tolerance and geometric mean productivity, plus the agreement in determining the groups of genotypes with resistance and high yield indicate that WHS is a useful character insimultaneous selection for these traits.

scholarly journals Host Plant Resistance to Leafminers in Lettuce

2004 ◽  
Vol 129 (3) ◽  
pp. 383-388 ◽  
Author(s):  
Beiquan Mou ◽  
Yong-Biao Liu
Keyword(s):  
Insect Pest ◽  
Choice Test ◽  
Agricultural Crops ◽  
Unit Leaf ◽  
Lactuca Serriola ◽  
Choice Tests ◽  
Highly Correlated ◽  
Leaf Lettuce ◽  
Resistant Genotypes ◽  
Cage Test

Leafminer (Liriomyza spp.) is a major insect pest of many important agricultural crops including lettuce (Lactuca sativa L.). The goals of this study were to evaluate lettuce genotypes for resistance to leafminers and to estimate the heritabilities of leafminer-resistant traits in the field, to examine the association among different resistant traits, and to study the mechanism of leafminer resistance in lettuce. Seventy-eight lettuce accessions and 232 F2 plants of crosses were evaluated for leafminer stings and the production of pupae and flies in the field in 2001 and 2002, and resistant genotypes were subjected to no-choice test. Wild species (Lactuca serriola L., L. saligna L., and L. virosa L.) had significantly fewer stings than cultivated lettuces. Among cultivated lettuces, sting densities were lowest on leaf lettuce and highest on romaine types. The sting results from the field were highly correlated with the results from insect cages (r = 0.770 and 0.756 for 2001 and 2002 tests, respectively), suggesting that a cage test can be used to screen for resistance in the field. Broad-sense heritability estimates for stings per unit leaf area in the field were 81.6% and 67.4% for 2001 and 2002 tests, respectively. The number of pupae produced per plant or per leaf was moderately correlated with sting density but was not correlated with leaf weight. Results suggest that both antixenosis and antibiosis exist in lettuce germplasm and resistant genotypes from choice tests remain resistant under no-choice conditions. These findings suggest that genetic improvement of cultivated lettuce for leafminer resistance is feasible.

Effect of sowing date and cultivars of sorghum on infestation by Atherigona yorki, Sesamia cretica and Chilo partellus in Yemen

1985 ◽  
Vol 104 (1) ◽  
pp. 61-66
Author(s):  
S. A. Ba-Angood ◽  
M. A. Hubaishan
Keyword(s):  
Chilo Partellus ◽  
Democratic Republic ◽  
Insect Pest ◽  
Sowing Date ◽  
Stem Borers ◽  
High Yielding Variety ◽  
Sowing Dates ◽  
Sesamia Cretica ◽  
Natural Infestation ◽  
High Yielding Varieties

SummarySeveral introduced high-yielding varieties of grain sorghum were screened for natural infestation of shootfly Atherigona yorki Deeming, and stem borers, Sesamia cretica Led. and Chilo partellus (Swinhoe), at different sowing dates in 1980–1 and 1981–2 sowing seasons in People's Democratic Republic of Yemen (PDR Yemen).The recently introduced high-yielding variety Dwarf White Milo (DWM) was found to be more prone to infestation by shootfly and stem borers than the local variety ‘Baini’ although it gave higher yield. All varieties tested gave higher yields when sown in March, August, September than when sown in April, May, October or November; 26 August and 16 September sowings gave the highest yields. B815, W823 and 8454 gave higher yields than the recently recommended high-yielding variety DWM, in response to lower infestation with the shootfly and stem borers; B815 and 8454 gave higher yields when sown on 26 August than when sown on 16 September. On the contrary, W823 gave higher yield when sown on 16 September than when sown on 26 August. This information could be used in formulating insect pest management programmes for sorghum pests in PDR Yemen.

Fatigue damage analysis of steel components subjected to earthquake loadings

2019 ◽  
Vol 10 (1) ◽  
pp. 25-40
Author(s):  
Chien-Yuan Hou ◽  
Yung-Feng Lee ◽  
Yen-Hao Peng
Keyword(s):  
Plastic Deformation ◽  
Fatigue Failure ◽  
Fatigue Cracks ◽  
Damage Index ◽  
Steel Frames ◽  
Building Structures ◽  
Northridge Earthquake ◽  
Content Type ◽  
Moment Resisting ◽  
Index Value

PurposeExamination of steel moment resisting frames after the 1994 Northridge earthquake showed fatigue cracks presented in the beam–column connections of the frames. These observations indicate that fatigue failure may occur in the steel components of building structures in an earthquake event. To apply the fatigue design approach using the Palmgren–Miner’s rule for steel components of the moment resisting frames requires the knowledge regarding the damage index value at fatigue failure. The purpose of this paper is to perform fatigue tests to give the first damage values of steel components subjected to real earthquake-induced loadings.Design/methodology/approachThe added-damping-and-stiffness steel plates which are used in building structures for earthquake mitigation were fabricated and tested by constant amplitude, SAC block and earthquake-induced loadings to failure. The earthquake loadings were obtained from the dynamic analysis of a steel frame with the mentioned plates. The load cycles of the SAC block and the calculated earthquake loadings were counted using the rainflow-counting method, and the damage index value of each specimen were calculated using the Palmgren–Miner’s rule.FindingsReverse stiffness obtained from cyclic load-displacement loops is a robust and consistent parameter that can be used for determining fatigue failure of tested components. The Palmgren–Miner’s damage values at failure, caused by earthquake loadings, are smaller than 1, and in addition, are also smaller than those obtained from the tests of the SAC block loading. The large-amplitude cycles in the earthquake loading produce large damage on the specimens, and intermediate range cycles also produce damage that should not be neglected in the fatigue analysis.Originality/valueToday’s building design code allows large plastic deformation to occur in steel frames during an earthquake. However, the pre-Northridge earthquake steel frames showed fatigue cracks without the expected substantial plastic deformation at beam flanges. Proposed solutions to this problem were the reduced beam section neglecting the existence of the cracks at beam–column connections. This study considered the fatigue phenomenon in steel frames and provided the first set of tested fatigue damage values for steel components subjected to realistic earthquake loadings, which offered a possible method of dealing with fatigue cracks in the steel components of a building structure.

scholarly journals Efficiency of Cultural Practices of Mulching and Nipping in the Management of Eggplant Infestation and Damage by Leucinodes orbonalis Gueéne (Lepidoptera: Pyralidae)

2019 ◽  
Vol 1 ◽  
pp. 1-7
Author(s):  
U Zakka ◽  
N ES Lale ◽  
L C Nwosu ◽  
O J Adolphus
Keyword(s):  
Cultural Practices ◽  
Block Design ◽  
Insect Pest ◽  
Fruit Weight ◽  
Leucinodes Orbonalis ◽  
Port Harcourt ◽  
Significant Difference ◽  
Lepidoptera Pyralidae ◽  
Natural Infestation ◽  
Individual Ability

The objective of the study was to evaluate the effectiveness of cultural practices of mulching and nipping in the management of eggplant infestation and damage by Leucinodes orbonalis Guenée (Lepidoptera: Pyralidae). Therefore, a field experiment using six eggplant varieties was carried out under tropical mean ambient temperature (30.4 oC) and relative humidity (73.3 %). The experimental site was Teaching and Research Farm of Faculty of Agriculture, University of Port Harcourt, Nigeria. Each bed measured 2 m x 1.3 m and eggplant varieties were planted at a distance of 0.3 m x 0.4 m. The experiment was arranged in a randomized complete block design, left to natural infestation and had three replications. The eggplants were mulched and nipped every two weeks in the study. The results revealed that all the test varieties were susceptible to attack by the insect pest under the two management techniques. Fruit weight of all varieties increased progressively (25.06 g) up to the third week after planting and declined thereafter (18.09 g) probably due to damaging effect of L. orbonalis. Mulching and nipping supported good fruit weight but were not highly effective in protecting eggplants against L. orbonalis infestation and damage. There was no significant difference (P > 0.05) in their individual ability to manage L. orbonalis attack irrespective of resistance status except at second-week after maturity in the number of exit holes/fruit and number of larvae/fruit (P < 0.001).

scholarly journals Survey on Nigerian Castor Germplasm for Potential Resistant Genotypes to Cercospora Leaf Spot

2019 ◽  
Vol 11 (3) ◽  
pp. 440-446
Author(s):  
Bolaji Zuluqurineen SALIHU ◽  
Mathew Omoniyi ADEBOLA ◽  
Maryam Alfa KABARAINI ◽  
Sunkanmi Tokunbo GBADEYAN ◽  
Adijat Abolore AJADI ◽  
...  
Keyword(s):  
Leaf Spot ◽  
Disease Incidence ◽  
Block Design ◽  
Damage Index ◽  
Principal Component ◽  
Average Score ◽  
Economic Damage ◽  
Limiting Factor ◽  
Cercospora Leaf Spot ◽  
Resistant Genotypes

Fungal diseases cause a lot of economic damage in castor and in some instances; it is a limiting factor to commercial cultivation of the crop. In the present study, survey on castor germplasm for sources of resistant genes to Cercospora leaf spot was carried out at National Cereals Research Institute Badeggi, Nigeria. The genotypes were grown in a resolvable incomplete block design with three replications. The results obtained revealed high variability of host resistance among the genotypes. Percentage disease incidence ranged between 16.67% and 100%.  A range between 1.43 score and 4.17 scores with average score of 2.89 were recorded for disease severity among the genotypes. Highest (95.92%) and lowest (13.03%) damage index were observed in the genotypes Acc. 059 and Acc. 022 respectively. The Principal component (PC) 1 to 4 explained 100% of the variability in the germplasm. PC1 explained 69.72% of the variability with the major contributory parameters being the disease incidence, severity and damage index. Significant negative correlations were recorded between the seed yield and all the three disease indices. The result of cluster analysis revealed six cluster groups among the germplasm with cluster membership ranging between 4 and 40 members. The cluster I contained members (Acc. 002, Acc. 017, Acc. 022, Acc. 026, Acc. 027, Acc. 048 and Acc. 061) with low average disease incidence, severity and damage index. The results reported here could serve as a basis for further screening of the potential resistant genotypes under controlled condition to develop resistant lines.

scholarly journals Resistance to Leafminers in Lettuce

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 766C-766
Author(s):  
Beiquan Mou* ◽  
Yong-Biao Liu
Keyword(s):  
Insect Pest ◽  
Choice Test ◽  
Agricultural Crops ◽  
Unit Leaf ◽  
Lactuca Serriola ◽  
Choice Tests ◽  
Highly Correlated ◽  
Leaf Lettuce ◽  
Resistant Genotypes ◽  
Cage Test

Leafminer (Liriomyza spp.) is a major insect pest of many important agricultural crops including lettuce (Lactuca sativa L.). The goals of this study were to evaluate lettuce genotypes for resistance to leafminers and to estimate the heritabilities of leafminer-resistant traits in the field, to examine the association among different resistant traits, and to study the mechanism of leafminer resistance in lettuce. Seventy-eight lettuce accessions and 232 F2 plants of crosses were evaluated for leafminer stings and the production of pupae and flies in the field in 2001 and 2002, and resistant genotypes were subjected to no-choice test. Wild species (Lactuca serriola L., L. saligna L., and L. virosa L.) had significantly fewer stings than cultivated lettuces. Among cultivated lettuces, sting densities were lowest on leaf lettuce and highest on romaine types. The sting results from the field were highly correlated with the results from insect cages (r = 0.770 and 0.756 for 2001 and 2002 tests, respectively), suggesting that a cage test can be used to screen for resistance in the field. Broad-sense heritability estimates for stings per unit leaf area in the field were 81.6% and 67.4% for 2001 and 2002 tests, respectively. The number of pupae produced per plant or per leaf was moderately correlated with sting density but was not correlated with leaf weight. Results suggest that both antixenosis and antibiosis exist in lettuce germplasm and resistant genotypes from choice tests remain resistant under no-choice conditions. These findings suggest that genetic improvement of cultivated lettuce for leafminer resistance is feasible.

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