Diagnostic of Tomato Nematode in Daloa (Côte d’Ivoire)

Symptomatological studies were carried out in two tomato growing areas in Daloa to estimate and identify the associated nematode populations. Symptoms were assessed by visual observation. The soil and root nematodes were extracted by Bermann's method and identified by observing morphological characteristics. The symptomatological study showed the presence of symptoms of plants wilting, yellowing of the leaves as well as galls on the nematodes characteristic roots. The results also highlighted diversity within the nematode population that colonizes tomato in Daloa with four genera of nematodes. The genera Tylenchus, Helicotylenchus, Partylenchus and Meloidogyne were identified. The presence of the genus Meloidogyne in all plots shows that it is responsible for the yellowing symptoms associated with root galls. These nematodes are known for their action on the formation of galls on the roots of the tomato.

Impact of biochar amendment on soil nematode communities in a West African rain-fed rice cropland

Summary Nematode population and diversity in a West African rain-fed rice cropland amended with biochar (B), biochar plus inorganic fertiliser (B + NPK), inorganic fertiliser (NPK) and control (CK) without amendments were investigated in a 3-year field study. Results demonstrated that significant differences exist between treatments and years of study for total nematode population and nematode trophic groups. Total nematode density, nematode trophic group (bacterivore and plant-parasitic) density were increased and dominant in B + NPK compared with CK after 3 years. Relative abundance of nematode genera according to trophic group across treatments showed Hirschmanniella (23%) as the dominant plant parasites in NPK, and Heterocephalobus (27%), Aphelenchoides (22%) and Eudorylaimus (9%) as dominant bacterivores, fungivores and omnivores-predators, respectively, in B + NPK. Trophic group indicators showed that the fungivore plus bacterivore to plant-parasitic ratio (73%) was significantly increased by B + NPK treatment in comparison to CK. Conversely, treatments exerted no significant effect on the fungivore to bacterivore ratio (F/B) throughout the period of study, which implies less disturbance and adverse impact of biochar on nematode communities. Apart from treatments and environmental factors, changes in nematode trophic groups were strongly related to soil chemical properties, such as soil pH, total nitrogen and available phosphorus, which shows their influence on soil nematode community. Our result shows the positive effect of integrated addition of biochar and inorganic fertiliser in balancing nematode diversity and building a resilient soil ecosystem in a low input rain-fed rice cropping system.

Eco-friendly based Integrated Management Practice against Root-Knot Nematode, Meloidogyne incognita on Cluster bean (Cyamopsis tetragonoloba L.)

AimThe experiment was carried out during two consecutive Kharif seasons to test the combined efficacy of biochemicals i.e. salicylic acid, ascorbic acid and L-arginine each at 2 % w/w as seed treatment and botanicals viz. neem, lantana and parthenium leaves powder each at 5 g per plant for the management of root-knot nematode, Meloidogyne incognita infecting cluster bean..Method All treatments applied as soil application at the time of sowing. Before sowing observation on initial nematode population/100 cc soil and at the termination of experiment number of galls/plant, number of egg masses/plant, number of eggs and larvae/egg mass, final nematode population/100 cc soil and yield (q/ha) were recorded. ResultAmong different combinations, minimum nematode population were observed with ascorbic acid at 2 per cent w/w + neem leaves powder at 5 g per plant followed by ascorbic acid at 2 per cent + lantana leaves powder at 5 g per plant and salicylic acid at 2 per cent + neem leaves powder at 5 g per plant.Conclusion: Results of experiment showed that application of biochemicals along with botanicals significantly reduced galls per plant as compared to untreated check.

Efficacy of Leaf Extract of Piliostigma Thonningii for Control of Root-Knot Nematode (Meloidogyne javanica) on Eggplant

Extracts of Piliostigma thonningii were tested for their effectiveness in controlling Meloidogyne javanica eggs and juveniles in the laboratory and on eggplant cv ‘Yalon Data’. A thousand juveniles were placed in 12 petridishes and extracts of P. thonningii (Crude extracts, 5 ml dilution and 10 ml dilution of the crude extracts) were dispensed into the petridishes. One thousand eggs of the M. javanica were placed in 12 petridishes and treated with the same extracts used on the juveniles. For the field experiment, 12 plots of size 2m x2m were prepared and planted with nine plants of eggplant cv ‘Yalon Data’. Seedlings of eggplants were transplanted after three weeks in the nursery to the field into holes drenched with 10 ml of the extracts used in the laboratory tests. Subsequent applications of extracts were done weekly for eight weeks. The results showed that the crude extract was the most effective against both the eggs (87.43 % hatch inhibition) and juveniles (90.23 % mortality). In the field, eggplants treated with the crude extract recorded the tallest plants ((124.78 cm -2017 and 125.00 cm-2018), highest number of fruits/plant (18.51-2017 and 19.55-2018), highest yield (50.45t/ha-2017 and 53.78t/ha-2018) and the lowest galling indices and final nematode population. It is therefore concluded that the crude extract of P. thonningii can be employed for the control of M. javanica in the field.

Management of rice root-knot nematode (Meloidogyne graminicola Golden and Birchfield)–An integrated approach

An experiment was conducted to know the efficacy of bio agents viz., Purpureocillium lilacinum, Trichoderma harzianum, Bacillus subtilis,Bacillus megaterium, Vermicompost and Consortium of bio-agents (Purpureocillium lilacinum + Trichoderma harzianum + Bacillus subtilis +Bacillusmegaterium +Vermicompost) and Carbofuran3G @ 0.3 i.e., alone for management of rice root-knot nematode Meloidogyne graminicola for one season at Chikadadakatte village of Honnali taluk, Davanagere district during Kharif- 2018. The results revealed that all the treatments were significantly superior over check with respect to growthparameters and nematode population. However, carbofuran 3G significantly reduced the nematode population (275.11 /200 cc soil)which was found to be the best treatment as it recorded highest plant height (114.06 cm), root length (23.13 cm), maximum grain yield (44.60 q/ha) with least RKI (1.20) followed byConsortium of bio-agents (Purpureocilliumlilacinum + Trichoderma harzianum + Bacillus subtilis +Bacillusmegaterium +Vermicompost).

QUANTIFICATION OF DAMAGE AND YIELD LOSSES AND MANAGEMENT OF ROOT-KNOT NEMATODES IN CONILON COFFEE

ABSTRACT Commercial exploitation of the coffee crop is one of the most important activities in the world’s agricultural sector. One of the main phytosanitary problems affecting the crop is the presence of Meloidogyne incognita. Several measures have been tested for the management of this pathogen, albeit with low efficiency. The objective of this work was to quantify the damage and losses and to manage M. incognita race 1 with Pochonia chlamydosporia and Trichoderma harzianum biological nematicides, comparing them to a chemical nematicide. The experiment was carried out in a commercial area naturally infested by the nematode and cultivated with the conilon coffee variety ‘Vitória INCAPER 8142’, clone V02. The treatments were tested with Carbofuran nematicide and with biological nematicides composed of P. chlamydosporia Pc-10 and T. harzianum ESALQ 1306. The biological products were applied alone or in combination. The lowest NPF (final nematode population) occurred in plants treated with P. chlamydosporia and Carbofuran. P. chlamydosporia was the most effective biological agent in the management of M. incognita. There was a reduction in production with an increase in the nematode population. The highest application costs of management methods for M. incognita race 1 per hectare were for three and two applications of Carbofuran and three applications of P. chlamydosporia + T. harzianum. The treatments with lowest application costs were one application of T. harzianum and one application of P. chlamydosporia. It was concluded that all treatments were efficient for the management of M. incognita race 1, causing a decrease in the roots and soil population.