scholarly journals Effects of organic and inorganic fertilization with bio-inoculants on the sustainable management of plant-parasitic nematodes infesting okra (Abelmoschus esculentus)

2021 ◽  
Vol 49 (4) ◽  
pp. 12544
Author(s):  
Safiuddin ANSARI ◽  
Gufran AHMAD ◽  
Abeer ELHAKEM ◽  
Rose RIZVI ◽  
Sartaj A. TIYAGI ◽  
...  

Root-knot nematodes are believed to be amongst the biological constraints causing severe damage and a great reduction in the productivity of okra. The purpose of this study was to apply organic matter and non-symbiotic nitrogen-fixing bacteria to minimize the addition of chemical fertilizers that constantly pollute the environment.  Experimental studies were conducted in the field for two summers to determine the effect of inoculations of non-symbiotic nitrogen-fixing bacteria, such as Azotobacter chroococcum and Azospirillum brasilense singly and in combinations, with different recommended doses of inorganic nitrogen as well as organic matter such as neem seed cake on the growth, yield, and organic parameters of the okra crop towards the management of plant-parasitic nematodes. The results show a significant reduction in nematode multiplication through soil application of nitrogen-fixing bacteria and neem seed cake along with different recommended doses of nitrogen inoculated plants. Azotobacter was found to be less effective than Azospirillum in agronomic parameters and nematode control. The most pronounced increases were observed in the yield and growth parameters such as plant height, fresh as well as dry weights, fruit weights/plant, number of total fruits/plant and primary branches, chlorophyll content, and ascorbic acid content when A. chroococcum and A. brasilense were added concomitantly in various combinations. Agronomic parameters such as NPK content in the plant as well as in residual soil increased considerably in almost all the combinations irrespective of these biofertilizers and neem seed cake. In conclusion, the combined application of a 100% recommended dose of nitrogen fertilizer along with Azospirillum and neem seed cake is recommended for better growth and yield of okra with better control of nematodal population.

2007 ◽  
Vol 47 (5) ◽  
pp. 620 ◽  
Author(s):  
B. L. Blair ◽  
G. R. Stirling

Damage to sugarcane caused by root-knot nematode (Meloidogyne spp.) is well documented in infertile coarse-textured soils, but crop losses have never been assessed in the fine-textured soils on which more than 95% of Australia’s sugarcane is grown. The impact of nematodes in these more fertile soils was assessed by repeatedly applying nematicides (aldicarb and fenamiphos) to plant and ratoon crops in 16 fields, and measuring their effects on nematode populations, sugarcane growth and yield. In untreated plant crops, mid-season population densities of lesion nematode (Pratylenchus zeae), root-knot nematode (M. javanica), stunt nematode (Tylenchorhynchus annulatus), spiral nematode (Helicotylenchus dihystera) and stubby-root nematode (Paratrichodorus minor) averaged 1065, 214, 535, 217 and 103 nematodes/200 mL soil, respectively. Lower mean nematode population densities were recorded in the first ratoon, particularly for root-knot nematode. Nematicides reduced populations of lesion nematode by 66–99% in both plant and ratoon crops, but control of root-knot nematode was inconsistent, particularly in ratoons. Nematicide treatment had a greater impact on shoot and stalk length than on shoot and stalk number. The entire community of pest nematodes appeared to be contributing to lost productivity, but stalk length and final yield responses correlated most consistently with the number of lesion nematodes controlled. Fine roots in nematicide-treated plots were healthier and more numerous than in untreated plots, and this was indicative of the reduced impact of lesion nematode. Yield responses averaged 15.3% in plant crops and 11.6% in ratoons, indicating that nematodes are subtle but significant pests of sugarcane in fine-textured soils. On the basis of these results, plant-parasitic nematodes are conservatively estimated to cost the Australian sugar industry about AU$82 million/annum.


Nematology ◽  
2019 ◽  
Vol 21 (5) ◽  
pp. 445-457 ◽  
Author(s):  
Arjun Upadhaya ◽  
Guiping Yan ◽  
Julie Pasche ◽  
Audrey Kalil

Summary Plant-parasitic nematodes restrict crop growth and cause yield loss in field pea (dry edible pea). A 4-year survey of commercial pea fields was conducted in North Dakota, one of the leading producers of field pea in the USA, to investigate nematode distribution, prevalence, abundance and association with soil properties. Beginning in 2014, a total of 243 soil samples were collected from 16 counties, and soil properties of 115 samples were analysed to determine the association of nematodes with soil factors (texture, organic matter, nutrients). The plant-parasitic nematode genera, Paratylenchus (absolute frequency = 58-100%; mean density = 470-1550 (200 g soil)−1; greatest density = 7114 (200 g soil)−1) and Tylenchorhynchus (30-80%; 61-261; 1980, respectively), were the most frequent and widely distributed. Pratylenchus and Helicotylenchus were identified in one-third of the counties surveyed with mean densities ranging from 43 to 224 and 36 to 206 (200 g soil)−1, respectively. Xiphinema was found relatively frequently but at low densities. Hoplolaimus and Paratrichodorus were rarely detected at lower densities. Canonical correspondence analysis revealed that soil factors explained 19% of the total variance of nematode genera abundance. The relationship between nematode abundance and soil sand content and pH was significant, while clay, silt, organic matter and nutrients were not significantly related to nematode abundance. This is the first multi-year study investigating nematodes associated with field peas and their relationship with soil factors in a major field pea production region of the USA.


2020 ◽  
Vol 9 (1) ◽  
pp. 43-49
Author(s):  
Timothy I. Olabiyi ◽  
Samuel O. Akinrinola ◽  
Olajumoke E. Ayanda

Three different plant extracts (Khaya ivorensis, Azadirachta indica and Daniella oleifera) and two Trichoderma species (T. harzianum and T. atroviride), singly and in combination, were assessed on nematode population changes and also in the control of plant parasitic nematodes on tomato under field condition during 2018 and 2019 planting seasons. During each trial, plant parasitic nematodes encountered in the field were Meloidogyne, Pratylenchus, Xiphinema and Helicotylenchus species. The experiment was a randomized complete block design with 4 x 3 factorial scheme and five replications. Factor A being plant extracts (Khaya ivorensis, Azadirachta indica, Daniella oleifera) and control, and factor B being bio-control agents (Trichoderma harzianum, T. atroviride) and control, resulting in 12 treatments. Significant reductions were observed on the population of the plant parasitic nematodes at all treatment levels with neem plant extract, in combination with either T. harzianum or T. atroviride resulted in the greatest significant decrease. Applications of different plant extracts and Trichoderma species, singly and in combination, enhanced the growth and yield of tomato infected with parasitic nematodes.


Nematology ◽  
2009 ◽  
Vol 11 (1) ◽  
pp. 23-38 ◽  
Author(s):  
Ben Leroy ◽  
Dirk Reheul ◽  
Maurice Moens ◽  
Howard Ferris ◽  
Nancy De Sutter

AbstractThe food specificity of nematodes, their high number of species and high abundance in every habitat where decomposition takes place, indicate that the structure of the nematode assemblage has a high information content. Since nematodes respond quickly to changes in soil management and since the nematode fauna can be efficiently analysed, the structure of the nematode assemblage offers an interesting instrument to assess changes in soil conditions. We studied the effect of five organic amendments on the short-term nematode population dynamics and compared them to minerally fertilised and unfertilised plots. The experiment was started in 2005, and samples were taken in spring and autumn 2006 and spring 2007. In spring 2006, no clear differences among treatments in the diversity of free-living nematodes were observed, probably since the organic amendments were applied only twice, of which the last application was carried out 7 months before the sampling. At the second and third sampling, the enrichment index in the organically amended plots was higher than in the unamended plots, owing to the organic matter application. However, in plots amended with farmyard manure and cattle slurry the number of bacterivores increased significantly, while in the compost plots the fungivorous nematodes tended to be higher. This resulted in a low channel index for the manure and slurry plots, indicating a predominant bacterial decomposition pathway, and a higher channel index in the compost plots, suggesting a greater proportion of fungal decomposition. These assumptions on the decomposition of the applied organic matter were strongly supported by the composition of the soil microbial community, determined through PLFA analysis: in the compost plots the bacteria to fungi ratio was lower than in the manure and slurry plots. At all sampling occasions there was a remarkably lower abundance of plant-parasitic nematodes in plots amended with slurry and manure, indicating a negative impact of both amendments on plant-parasitic nematodes. We can conclude from this study that the fertiliser regimes affected the nematode assemblage, but that more samplings in the future are certainly necessary to assess adequately the impact of the different organic amendments.


Sign in / Sign up

Export Citation Format

Share Document