scholarly journals Sampling Error in Relation to Cyst Nematode Population Density Estimation in Small Field Plots

2017 ◽  
Vol 49 (2) ◽  
pp. 150-155 ◽  
Author(s):  
VESNA ZUPUNSKI ◽  
RADIVOJE JEVTIC ◽  
VESNA SPASIC JOKIC ◽  
LJUBICA ZUPUNSKI ◽  
MIRJANA LALOSEVIC ◽  
...  
Keyword(s):  
Population Density ◽  
Density Estimation ◽  
Sampling Error ◽  
Cyst Nematode ◽  
Nematode Population ◽  
Small Field ◽  
Nematode Population Density ◽  
Field Plots

scholarly journals Mineral composition of beetroot treated with potential elicitors and inoculated with Meloidogyne javanica

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Paula Juliana Grotto Débia ◽  
Beatriz Cervejeira Bolanho ◽  
Claudia Regina Dias-Arieira
Keyword(s):  
Population Density ◽  
Mineral Composition ◽  
Integrated Management ◽  
Meloidogyne Javanica ◽  
Nematode Population ◽  
Root Knot Nematode ◽  
Cu Content ◽  
Manganese Zinc ◽  
Nematode Population Density ◽  
Elicitor Treatments

Abstract Background The root-knot nematode Meloidogyne javanica can infect beetroots, causing extensive damage to this food crop. As chemical and genetic control tactics have shown limited efficacy, new strategies are needed to improve the integrated management of this parasite. This study assessed the influence of potential defence elicitors and M. javanica infection on the mineral composition of beetroot. Plants were treated with acibenzolar-S-methyl (ASM), citrus biomass, or a mannanoligosaccharide-based product (MOS) and inoculated with 1000 eggs and second-stage juveniles of M. javanica. At 60 days after inoculation, beetroot plants were harvested and evaluated for nematode population density, vegetative growth, and mineral content. Results All potential elicitors reduced nematode population density in beetroots (p ≤ 0.10) and improved the vegetative parameters of inoculated plants (p ≤ 0.05), except shoot fresh weight. Some minerals were found to be negatively affected by treatments, particularly calcium, whose levels were consistently lower in treated plants. On the other hand, M. javanica inoculation increased magnesium, iron, manganese, zinc, and copper contents in beetroots. However, the latter mineral (Cu content) of inoculated plants was positively influenced by MOS and ASM. Conclusion Potential elicitor treatments did not improve the mineral composition of beetroot, but were effective in reducing nematode population density. Plants inoculated with M. javanica had higher mineral levels. However, gall formation decreases the commercial value of the crop and might render it unsuitable for commercialisation. M. javanica-infected beetroots may be used for nutrient extraction or sold to food processing industries.

Efficacy of the fungi Hirsutella minnesotensis and H. rhossiliensis from liquid culture for control of the soybean cyst nematode Heterodera glycines

Nematology ◽  
2005 ◽  
Vol 7 (1) ◽  
pp. 149-157 ◽  
Author(s):  
Shufen Liu ◽  
Senyu Chen
Keyword(s):  
Heat Treatment ◽  
Population Density ◽  
Soybean Cyst Nematode ◽  
Liquid Culture ◽  
Heterodera Glycines ◽  
Nematode Population ◽  
Solid Culture ◽  
Nematode Population Density ◽  
Biological Control Potential ◽  
Shoot Weight

AbstractHirsutella minnesotensis and H. rhossiliensis are endoparasites of nematodes, and their biological control potential against Heterodera glycines when cultured and applied on corn grits has been reported. In this study, the potential of liquid cultures of the two fungi was evaluated in two glasshouse experiments. Both liquid culture at 0.2, 0.4 and 0.8 g of fresh mycelium/300 cm3 soil (per pot) and solid culture at 1% (corn grits: soil, w/w) reduced nematode egg population densities in both autoclaved and unheated soils as compared with soil-only control or corn-grits control. However, the liquid culture at 0.2–0.8 g of mycelium/pot appeared to be more effective in reducing the nematode population than the solid culture of 1%. Hirsutella rhossiliensis resulted in lower nematode population density than H. minnesotensis only in unheated soil in one experiment. The soil heat treatment generally increased the nematode population density but did not affect percentage reduction of the nematode population density as compared with respective controls, except that reduction by H. rhossiliensis was greater in unheated soil than heat-treated soil in one experiment. Percentage of second-stage juveniles (J2) parasitised by fungi at the end of the experiment (60 days after planting) was generally higher with H. minnesotensis than with H. rhossiliensis. The percentage parasitism was positively correlated with initial fungal inoculation level. The soil heat treatment increased fungal parasitism in one experiment but not in the other. Plant growth was unaffected by treatments except that the soil heat treatment increased plant shoot weight as compared with unheated soil in one experiment.

Fertiliser use efficiency of soybean cultivars infected with Meloidogyne incognita and Pratylenchus penetrans

Nematology ◽  
2006 ◽  
Vol 8 (1) ◽  
pp. 129-137 ◽  
Author(s):  
Haddish Melakeberhan
Keyword(s):  
Population Density ◽  
Meloidogyne Incognita ◽  
Sandy Loam ◽  
Tap Water ◽  
Nematode Population ◽  
Pratylenchus Penetrans ◽  
Soybean Cultivars ◽  
Nematode Population Density ◽  
Use Efficiency ◽  
Fertiliser Use

AbstractThe most appropriate use of fertilisers to offset damage caused by nematode infestations can benefit greatly from determining fertiliser use efficiency (FUE). FUE is defined as increase in host productivity and/or decrease in nematode population density in response to a given fertiliser treatment. This study describes new and integrated approaches to identify FUE in nematode-infected plants. In two consecutive experiments, Heterodera glycines-resistant 'Bryan', susceptible-tolerant 'G88-20092', and susceptible-intolerant 'Tracy M' soybean cultivars were inoculated with 0 or 15 000 eggs of Meloidogyne incognita or mixed stages of Pratylenchus penetrans per 800 cm3 of sandy loam soil and maintained under glasshouse conditions (28 ± 2°C) for 25 and 26 days. Plants received 83 ± 21 and 89 ± 19 ml either full-strength Hoagland solution (HS), HS without N (HS-N), or tap water daily in Experiments 1 and 2, respectively. Photosynthesis and nematode population dynamics were chosen to test FUE because the relationship between these two parameters, for the most part, determines the outcome of crop yield in the presence of nematodes. Although the FUE varied by fertiliser source, cultivar and nematode, the data were conclusive in identifying the interactions. FUE was high for photosynthesis in all three cultivars, and more so in HS than in HS-N. FUE was high for suppressing population densities of both nematodes and increasing photosynthesis in cv. Tracy M and for M. incognita in cv. G88-20092. Fertiliser application against P. penetrans in cv. Bryan was unproductive because nematode population density increased. FUE for P. penetrans in cv. G88-20092 and for M. incognita in cv. Bryan was less conclusive because there was some increase in nematode population density. Overall, these new approaches to identifying FUE for host productivity in the presence of nematodes provide quantitative data that should be of great interest to plant breeders, soil scientists, agronomists and plant protection specialists.

scholarly journals Vertical Distribution of Pratylenchus Alleni and P. Scribneri in Soybean Roots

1969 ◽  
Vol 66 (1) ◽  
pp. 60-64
Author(s):  
N. Acosta
Keyword(s):  
Population Density ◽  
Vertical Distribution ◽  
Root Zone ◽  
Lateral Roots ◽  
Nematode Species ◽  
Nematode Population ◽  
Infested Soil ◽  
Nematode Population Density ◽  
Soybean Roots ◽  
Total P

In a study of the distribution of Pratylenchus alleni and P. scribneri within Clark 63 soybean roots from nematode-infested soil, populations of both nematode species were most abundant in the first 10-15 cm of the root zone, 30 days after planting. There was a distinct decrease in nematode population density in both species with depth of the taproot. Fifty percent of the total P. alleni population in lateral roots was located in the first 5 cm from the taproot, whereas only 26% of P. scribneri population occurred in this region.

Sampling procedures and damage thresholds for root-knot nematode (Meloidogyne javanica) on pineapple

2000 ◽  
Vol 40 (7) ◽  
pp. 1003 ◽  
Author(s):  
G. R. Stirling ◽  
R. Kopittke
Keyword(s):  
Population Density ◽  
Crop Yields ◽  
Meloidogyne Javanica ◽  
Root Knot Nematode ◽  
Ratoon Crop ◽  
Nematode Density ◽  
Root Knot Nematodes ◽  
Nematode Population Density ◽  
Sampling Procedures ◽  
Field Plots

The relationship between the population density of root-knot nematode (Meloidogyne javanica) and pineapple yield was studied by establishing different nematode densities in field plots at 3 sites. Differences in nematode populations between treatments were apparent 9–22 months after planting, but yields in the plant crop were similar, regardless of nematode density. In the ratoon crop, yields in treatments with less than 10 nematodes/200 mL soil at 9–22 months were reduced by about 10%. Yield reductions of more than 25% occurred when population densities were greater than 50 nematodes/200 mL soil. These results demonstrate that economically significant crop losses from root-knot nematodes can occur in pineapple when the population density at 12 months is greater than 1–5 nematodes/200 mL soil. The sampling procedures required to obtain reliable estimates of M. javanica in pineapple fields were determined by studying nematode distribution in 2 fields in south-east Queensland. Nematodes were extracted from more than 100 individual soil cores on a 5 by 5 m grid and populations were found to have a clumped rather than random distribution. A composite sample of 41 cores in 1 field and 72 cores in the other gave a relatively precise estimate of the population of root-knot nematodes (i.e. standard error : mean ratio of 0.3). These data suggest that a 50-core sampling unit is appropriate when nematode population density is being estimated for decision-making purposes.

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