Aims: Meloidogyne incognita adversely affects numerous crop plants worldwide. Therefore, the modern world has been moving towards biocontrol methods to prevent nematode attacks. This study was aimed to (i) investigate the potential use of Trichoderma harzianum NFCF160 and T. virens Isf-77 in managing M. incognita in soil and (ii) identify trapping mechanisms employed by both Trichoderma strains to suppress M. incognita. Methodology and results: Three weeks old, Basella alba L. plants were subjected to five different treatments. The above and below ground growth parameters and the galling indices of these plants were measured every four weeks for three sampling times. Trapping mechanisms employed by Trichoderma strains were examined following plate assays. Plants treated with T. harzianum NFCF160 and T. virens Isf-77 had significantly higher values for the total number of leaves (34 ± 2.84) and (27 ± 2.61), fresh weight of the shoot (81 ± 9.51 g) and (91 ± 9.70 g), dry weight of the shoot (71 ± 5.24 g) and (62 ± 5.81 g), respectively eight weeks after inoculation of M. incognita. Significantly low galling indices (2 and 2) were recorded in B. alba treated with Trichoderma strains. Both Trichoderma strains exhibited various nematode-trapping mechanisms, such as non-constricting rings and adhesive spores. Conclusion, significance and impact of study This investigation highlighted the potential of both Trichoderma strains as biocontrol agents to control M. incognita effect in sustainable agriculture.
Tylenchoidea ; Trichoderma ; Soil Microbiology

Pot studies were carried out to evaluate the reactions of 23 selections of field pea (Pisum sativum) against Meloidogyne incognita (2000 freshly hatched juveniles (J2)/pot). Experiment was conducted under greenhouse conditions ((24.7+/-3) degrees C and (62+/-7)% RH) and terminated 45 d after inoculation. The roots of all the selections were assessed to determine root-knot indices (RKI) on a 0-4 scale. Out of 23 selections HFP-990713, Pant P-25, and HFP-0129 were resistant; Pant P-2005, NDP-2 and Pant P-42 were tolerant; LFP-305, HFP-8909, HFP-4, HUP-31, HFP-0128, Pant P-31, Pant P-40, LFP-363, and HFP-0118 were moderately resistant; HFP-0110, HUDP-28, HUDP-15, HUDP-27, HUP-30, HUP-2 and HUDP-26 were moderately susceptible; and only Ambika was susceptible to M. incognita. It was observed that reproduction of nematode was favored on tolerant and susceptible cultivars but inhibited on resistant ones. Strong negative correlation was observed between the total fresh and dry plant weights and the root-knot index. The selection Pant P-42 showed highest tolerance among all the selections tested and can be recommended for field trials, whereas, selection Ambika showed highest susceptibility and should be avoided.
Animals ; Peas ; classification ; genetics ; parasitology ; Plant Roots ; classification ; parasitology ; Tylenchoidea ; pathogenicity ; physiology

The root-knot nematode, Meloidogyne incognita caused a serious damage to many plants. The phenolic components of the leaves of Schinus terebinthifolius were investigated as potential nematicidal agents for M. incognita. Nine compounds were isolated and characterized as viz., 1,2,3,4,6-pentagalloyl glucose (1), kaempferol-3-O-α-L-rhamnoside (Afzelin) (2), quercetin-3-O-α-L-rhamnoside (Quercetrin) (3), myricetin (4), myricetin-3-O-α-L-rhamnoside (Myricetrin) (5), methylgallate (6), protocatechuic acid (7), quercetin (8), and gallic acid (9) using nuclear magnetic resonance (NMR) spectroscopy. Compound 1 showed pronounced nematicidal activity compared to Oxamyl as a positive control. It showed the lowest eggs-hatchability (34%) and the highest mortality in nematode population (21% after 72 hours of treatment) at a concentration of 200 µg/mL. It exhibited the best suppressed total nematode population, root galling and number of eggmasses in infected tomato plants. The total carbohydrates and proteins were also significantly induced by 1 with reduction in total phenolics and increase in defense-related proteins. Thus, compound 1 could be a promising, more safe and effective natural nematicidal agent for the control of root-knot nematodes.
Anacardiaceae ; Carbohydrates ; Gallic Acid ; Glucose ; Lycopersicon esculentum ; Magnetic Resonance Spectroscopy ; Mortality ; Phenol ; Quercetin ; Spectrum Analysis ; Tylenchoidea

A laboratory experiment was conducted to study the induction of constricting rings and test predation of Dactylaria brochopaga isolates against second stage juveniles (J2s) of Meloidogyne graminicola. Among the five fungal isolates, isolate D showed the greatest number of predatory rings and, consequently, trapped the maximum number of M. graminicola J2s in dual cultures. Another pot experiment was conducted to study the effect of D. brochopaga (isolate D) on the management of wheat root-knot disease. Applying a mass culture (10 g/pot) and a spore suspension of the fungus with and without cow dung manure to soil infested with 2,000 M. graminicola juveniles significantly improved plant height, root length, weights of shoots, roots, panicles and grains per hill compared to those in the control. Moreover, the fungus significantly reduced the number of root-knots, the number of egg masses, juveniles, and females per hill compared to those in the control. Bio-efficacy of the fungus was heightened when the mass culture and a spore suspensions were used in combination with cow dung manure to improve the plant growth parameters and reduce the number of root-knot and reproductive factors. Further investigations should be conducted to identify the impact of this fungus in the field.
Edible Grain ; Female ; Fungi ; Humans ; Manure ; Ovum ; Plants ; Soil ; Spores ; Suspensions ; Triticum ; Tylenchoidea ; Weights and Measures

A new technique for single spore isolation was developed for predacious fungi forming constricting rings directly on the spores using Dactylaria brochopaga and Arthrobotrys dactyloides. Constricting rings were induced directly on the spores by transferring the spores in 25 ppm solution of DL-Valine in sterile distilled water. Freshly hatched and thoroughly washed second stage juveniles of Meloidogyne incognita were transferred into cavity blocks containing induced rings for trapping and killing of nematodes. The killed nematodes were surface sterilized with streptomycin and inoculated into petri dishes containing maize meal agar media with 100 ppm streptomycin. The petri dishes were incubated at 29+/-1degrees C for few days which yielded axenic culture of these fungi.
Agar ; Axenic Culture ; Fungi* ; Homicide ; Meals ; Spores* ; Streptomycin ; Tylenchoidea ; Water ; Zea mays

Pasteuria penetrans will build-up faster where there is a high initial nematode density and can suppress root-knot nematode populations in the roots of tomato plants. The effect of different initial densities of nematode (Meloidogyne javanica) (150, 750, 1500, 3000) and P. penetrans infected females (F1, F3) densities (F0=control and AC=absolute control without nematode or P. penetrans inoculum) on the build-up of Pasteuria population was investigated over four crop cycles. Two major points of interest were highlighted. First, that within a confined soil volume, densities of P. penetrans can increase >100 times within 2 or 3 crop cycles. Second, from a relatively small amount of spore inoculum, infection of the host is very high. There were more infected females in the higher P. penetrans doses. The root growth data confirms the greater number of females in the controls particularly at the higher inoculum densities in the third and fourth crops. P. penetrans generally caused the fresh root weights to be higher than those in the control. P. penetrans has shown greater reduction of egg masses per plant at most densities. The effects of different initial densities of M. javanica and P. penetrans on the development of the pest and parasite populations were monitored. And no attempt was made to return the P. penetrans spores to the pots after each crop so the build-up in actual numbers of infected females and spores under natural conditions may be underestimated.
Animals ; Bacillus ; pathogenicity ; physiology ; Lycopersicon esculentum ; growth & development ; parasitology ; Pest Control, Biological ; methods ; Tylenchoidea ; growth & development ; microbiology ; Women

Four rhizobacteria selected out of over 500 isolates from rhizosphere of the vegetables in China were further studied for suppression of the root-knot nematode and soil-borne fungal pathogens in laboratory and greenhouse in Belgium. They were identified as Brevibacillus brevis or Bacillus subtilis by Biolog test and partial 16s rDNA sequence comparison. They not only inhibited the radial growth of the root-infecting fungi Rhizoctonia solani SX-6, Pythium aphanidermatum ZJP-1 and Fusarium oxysporum f.sp. cucumerinum ZJF-2 in vitro, but also exhibited strong nematicidal activity by killing the second stage larvae of Meloidogyne javanica to varying degrees in the greenhouse. The toxic principles of bacterium B7 that showed the highest juvenile mortality were partially characterized. The active factors were heat stability and resistance to extreme pH values. B7 used either as seed dressing or soil drench significantly reduced the nematode populations in the rhizosphere and enhanced the growth of mungbean plants over the controls in the presence or absence of R. solani.
Alphaproteobacteria ; physiology ; Animals ; Pest Control, Biological ; methods ; Phaseolus ; microbiology ; parasitology ; Seeds ; microbiology ; parasitology ; Survival Analysis ; Survival Rate ; Symbiosis ; physiology ; Tylenchoidea ; microbiology ; pathogenicity

Studies were conducted under pot conditions to determine the comparative efficacy of carbofuran at 1 mg a.i./kg soil, bavistin at 1 mg a.i./kg soil, neem (Azadirachta indica) seed powder at 50 mg/kg soil, green mould (Trichoderma harzianum) at 50.0 ml/kg soil, rhizobacteria (Pseudomonas fluorescens) at 50.0 ml/kg soil against root-knot nematode, Meloidogyne incognita-wilt fungus, Fusarium oxysporum disease complex on green gram, Vigna radiata cv ML-1108. All the treatments significantly improved the growth of the plants as compared to untreated inoculated plants. Analysis of data showed that carbofuran and A. indica seed powder increased plant growth and yield significantly more in comparison to bavistin and P. fluorescens. Carbofuran was highly effective against nematode, bavistin against fungus, A. indica seed powder against both the pathogens and both the bioagents were moderately effective against both the pathogens.
Animals ; Benzimidazoles ; administration & dosage ; Carbamates ; administration & dosage ; Carbofuran ; administration & dosage ; Fusarium ; drug effects ; pathogenicity ; Glycerides ; administration & dosage ; Pest Control ; methods ; Phaseolus ; drug effects ; microbiology ; parasitology ; Plant Diseases ; microbiology ; parasitology ; Terpenes ; administration & dosage ; Tylenchoidea ; drug effects ; microbiology ; pathogenicity

Experiments were carried out to study the effect of two fungal bioagents along with mustard oil cake and furadan against root knot nematode Meloidogyne incognita infecting tomato under greenhouse condition. Bioagents viz., Paecilomyces lilacinus and Trichoderma viride alone or in combination with mustard cake and furadan promoted plant growth, reduced number of galls/plant, egg masses/root system and eggs/egg mass. The fungal bioagents along with mustard cake and nematicide showed least nematodes reproduction factor as compared to untreated infested soil.
Animals ; Carbofuran ; pharmacology ; Lycopersicon esculentum ; drug effects ; growth & development ; parasitology ; Mustard Plant ; chemistry ; Paecilomyces ; Pest Control, Biological ; methods ; Plant Oils ; pharmacology ; Plant Roots ; drug effects ; growth & development ; parasitology ; Trichoderma ; Tylenchoidea ; drug effects ; growth & development ; microbiology