scholarly journals Efficacy of Three Nematicides and Two Oil Cakes for Control of Root-Knot Nematode (Meloidogyne incognita) on Potato Seedlings

10.5109/23894 ◽  
1989 ◽  
Vol 34 (1/2) ◽  
pp. 115-121
Author(s):  
Sakhawat Hossain ◽  
Ismail Hossain Mian ◽  
Kazunori Tsuno
2018 ◽  
Vol 3 (1) ◽  
pp. 214-219
Author(s):  
A. Nirosha ◽  
S. Rajeshkanna ◽  
G. Mikunthan

Abstract Root-knot nematode, Meloidogyne incognita (Kofoid and White) is a major threat to chilli (Capsicum annum) cultivation, by forming root galls and subsequent wilting. These nematodes live in soil, roots debris and reported surviving in other Solanaceae crops. Chemical application of nematicides cause impact on environment, therefore biocontrol using antagonistic fungi is desired to tackle this problem. This research is aimed to evaluate the effect of Trichoderma viride and its formulations on management of M. incognita. Oil cakes such as neem (Azadiracta indica), gingelly (Sesamum indicum), Mahua (Madhuca longifolia) and garlic (Allium sativum) extracts were used to evaluate the growth and sporulation of T. viride. Chilli variety MI-2 was used. Among the four preparations, neem oil cake recorded high spore yield of 1.75 ×107 spores/ml. Similarly gingelly oil cake and garlic produced the spore yields of 1.57 ×107 spores/ml and 1.368 ×107 spores/ml, respectively. Comparatively Mahua oil cake obtained low spore yield of 7.87×106 spores/ml. Plant growth was significant (P<0.05) in the application of neem oil cake formulation (30.42 cm). Extent of galling was significantly low with garlic (9.00) and neem (9.25). These results confirmed that the formulations of neem, gingelly oil cake extracts and garlic aqueous extract stimulated the chilli plant growth, productivity and reduced the nematode infestation. Above all, neem oil cake and garlic are the best formulations that can be used to manage M. incognita


Fruits ◽  
2009 ◽  
Vol 64 (5) ◽  
pp. 295-303 ◽  
Author(s):  
Hang Ye ◽  
Wen-jun Wang ◽  
Guo-jie Liu ◽  
Li-xin Zhu ◽  
Ke-gong Jia

Plant Disease ◽  
2017 ◽  
Vol 101 (6) ◽  
pp. 948-956 ◽  
Author(s):  
Alois A. Bell ◽  
Robert C. Kemerait ◽  
Carlos S. Ortiz ◽  
Sandria Prom ◽  
Jose Quintana ◽  
...  

Locally severe outbreaks of Fusarium wilt of cotton (Gossypium spp.) in South Georgia raised concerns about the genotypes of the causal pathogen, Fusarium oxysporum f. sp. vasinfectum. Vegetative complementation tests and DNA sequence analysis were used to determine genetic diversity among 492 F. oxysporum f. sp. vasinfectum isolates obtained from 107 wilted plants collected from seven fields in five counties. Eight vegetative complementation groups (VCG) were found, with VCG 01117B and VCG 01121 occurring in 66% of the infected plants. The newly recognized VCG 01121 was the major VCG in Berrien County, the center of the outbreaks. All eight VCG resulted in significant increases in the percentages of wilted leaves (27 to 53%) and significant reductions in leaf weight (40 to 67%) and shoot weight (33 to 60%) after being stem punctured into Gossypium hirsutum ‘Rowden’. They caused little or no significant reductions in shoot weight and height or increases in foliar symptoms and vascular browning in a soil-infestation assay. Soil infestation with Meloidogyne incognita race 3 (root-knot nematode) alone also failed to cause significant disease. When coinoculated with M. incognita race 3, all VCG caused moderate to severe wilt. Therefore, the VCG identified in this study belong to the vascular-competent pathotype, and should pose similar threats to cotton cultivars in the presence of the root-knot nematode. Use of nematode-resistant cultivars, therefore, is probably the best approach to control the disease in Georgia.


Author(s):  
Anil Baniya ◽  
Soumi Joseph ◽  
Larry Duncan ◽  
William Crow ◽  
Tesfamariam Mengistu

AbstractSex determination is a key developmental event in all organisms. The pathway that regulates sexual fate has been well characterized at the molecular level in the model free-living nematode Caenorhabditis elegans. This study aims to gain a preliminary understanding of sex-determining pathways in a plant-parasitic nematode Meloidogyne incognita, and the extent to which the roles of the sex determination genes are conserved in a hermaphrodite species, C. elegans, and plant-parasitic nematode species, M. incognita. In this study, we targeted two sex-determining orthologues, sdc-1 and tra-1 from M. incognita using RNA interference (RNAi). RNAi was performed by soaking second-stage juveniles of M. incognita in a solution containing dsRNA of either Mi-tra-1or Mi-sdc-1 or both. To determine the effect of RNAi of the target genes, the juveniles treated with the dsRNA were inoculated onto a susceptible cultivar of cowpea grown in a nutrient pouch at 28 °C for 5 weeks. The development of the nematodes was analyzed at different time points during the growth period and compared to untreated controls. Our results showed that neither Mi-sdc-1 nor Mi-tra-1 have a significant role in regulating sexual fate in M. incognita. However, the silencing of Mi-sdc-1 significantly delayed maturity to adult females but did not affect egg production in mature females. In contrast, the downregulation of Mi-tra-1 transcript resulted in a significant reduction in egg production in both single and combinatorial RNAi-treated nematodes. Our results indicate that M. incognita may have adopted a divergent function for Mi-sdc-1 and Mi-tra-1distinct from Caenorhabditis spp. However, Mi-tra-1 might have an essential role in female fecundity in M. incognita and is a promising dsRNA target for root-knot nematode (RKN) management using host-delivered RNAi.


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