Nazir Javed

Toxin production by Fusarium solani from declining citrus plants and its management

The core purpose of this current research was to meticulously survey four tehsils of Sargodha district and to probe the present status of citrus decline in infected citrus orchards. The utmost fungi (39.52%) were secluded from the roots followed by the soil (38.86%). The highest Fusarium sp. followed by Aspergillus, Phytophthora, Pythium, Penicillium and Alternaria species were remote from the collected samples of roots and soil from the four tehsils of Sargodha district of Pakistan. The maximum Fusarium sp. was isolated from the roots of declining citrus trees from tehsil Bhalwal (68.57%) followed by Kot Momin (65.87%), Sillanwali (55.87%) and Sargodha (50.32%). Toxin studies were also carried out using thin layer chromatography which revealed that F. solani produces toxins (anhydrofusarubin) which may cause decline in citrus. In vitro effect of fungicides on the mycelial growth rate of Fusarium solani exposed aliete to be more effective at 50 and 100 ppm, respectively. Ridomil Gold and Dithane M-45 showed same effect while Deconil showed least effect. Key Words: Citrus, citrus decline, Fusarium solani, toxin, Anhydrofusarubin, aliete.

Bio-management of tomato wilt complex caused by Meloidogyne incognita and Fusarium oxysporum f. sp. lycopersici

The potential of biocontrol agents Purpureocillium lilacinum (Paecilomyces lilacinus) and Trichoderma harzianum was evaluated against tomato wilt complex, caused by a combination of Meloidogyne incognita and Fusarium oxysporum f. sp. lycopersici, under both laboratory and field conditions. Biocontrol agents at spore concentration of 1 × 106 spores ml−1 were applied alone and in combined treatments. The results of combined application revealed maximum mortality and inhibition of hatching of M. incognita under in vitro conditions. Combined application of both antagonistic fungi was found to be more effective in mycelial inhibition of Fusarium oxysporum f. sp. lycopersici. In glasshouse trials, application of T. harzianum promoted overall plant growth, followed by combined application of P. lilacinum and T. harzianum; nematode development parameters and fungus damage were significantly reduced. Under field conditions, the combined application of P. lilacinum and T. harzianum increased the number of leaves, shoot length, shoot weight and root length, and decreased root weight, with minimum number of females and egg masses of M. incognita per root system and mycelia inhibition of F. oxysporum.

EFFICACY OF RHIZOSPHERIC ORGANISM Rhizobium leguminosarum AGAINST Meloidogyne incognita IN SOYBEAN

Present investigation was carried out to assess the biocontrol potential of Rhizobium leguminosarum against root-knot nematode, Meloidogyne incognita on soybean. Effect of Rhizobium strains LSI-21 and CRI-29 was assessed individually and concomitantly on reproduction of M. incognita. In vitro studies were conducted to check the effect of Rhizobium strains on egg hatching and juvenile mortality of M. incognita. Concomitant application of Rhizobium strains was more effective in reducing egg hatching and causing juvenile mortality as compared to individual treatment. In green house, Rhizobium strains were used as soil drench and seed dressing for the management of root knot nematode on soybean. It caused considerable reduction in reproduction of root knot nematode as well as improved plant growth parameters of soybean. Seed dressing showed most significant results than soil drenching. It is interesting to note that Rhizobia not only controlled reproduction of M. incognita but also an increase in plant height, fresh and dry root shoot weight was observed. It would seem that Rhizobium being a good rhizosphere organism for field and vegetable crops presumably prevent the contact of pathogenic organisms on roots.

Monitoring of rust virulence pattern through avirulence/virulence formula

The idea of this study was to be vigilant with rust virulence pattern changes in the region and to organise wheat breeding and variety release programmes in the light of findings of rust virulence patterns. The survey was carried out during March–April (2010 and 2011) on the rust trap nurseries planted at different Agra-ecological condition in Pakistan. The rust trap nursery consisted of 40 Lr differentials and 24 Yr differentials and data were recorded following modified Cobb’s scale. The studies revealed that there were no virulence for Lr9, Lr19, Lr23+, Lr25, Lr28, Lr27+31 Lr32, Lr34, Lr36 and Lr37 and Yr3, Yr5, YR8, Yr10, Yr15, Yr18, and Yrsp observed during this period. Among the varieties Iqbal-2000, Uqab-2000, Lasani-2008, Faisalabad-2008, AARI-2011, Millat-2011 and Pb-2011 exhibited resistance path for LR and YR. Moderate YR was observed on Shafaq-2006 & Chenab-2000 ranging from 20–30 M RMS. In these studies the susceptible check variety Morocco was almost 80–100S for LR and YR.

Host-plant-preference and Mortality Analysis of Phenacoccus solenopsis in Association with Biochemical Traits of Different Plant Species

Dietary requirement and fitness of phytophagous insect pest depend upon the nutrient chemistry of host plant. The present research was carried out to investigate the association of host-plant-preference and mortality of Phenacoccus solenopsis first instar influenced by chemical characteristics of plant species. The experiment was carried out at (25 + 5oC and 60 + 5% RH) in Integrated Pest Management Laboratory, University of Agriculture, Faisalabad, Pakistan during 2012. First instar exhibited maximum (attractiveness index = 0.75) toward Gossypium hirsutum followed by Trianthema portulacastrum (0.34) as compared Hibiscus rosa-chinensis (1.00) kept as standard. Mortality percentage of 1 instar of CMB among 25 tested plant species ranged from 10% in cotton to 80% in Conyza bonariensis. Cluster analysis for biochemical traits showed that cluster-1 comprised of Lantana camara, H. rosa-sinensis, Helianthus annuus, Parthenium hysterophorus, Withania somnifera, Euphorbia prostrate, Portulaca oleracea, Solamum melongena, T. portulacastrum, G. hirsutum, Abelmoschus esculentus and Capsicum frutescens that had maximum attractiveness and less mortality. Cluster-2 Convolvulus arvensis, Eclipta prostrate, Amaranthus spinosus, Clerodendron inerme and Tribulus terrestris had medium whereas cluster-3 Launea nudicaulis, Chinopodium morale, C. album, Achyranthes aspera, C. bonariensis and Digera arvensis least attractiveness index but highest mortality. Principal component analysis (PCA) depicted that first three PCs expressed 83% of the total variability. Mortality of pest was negatively correlated with nitrogen and but positively with potassium, phosphorus, sodium, reducing sugar and total sugar. In conclusion, chemical contents affected attractiveness index and mortality of P. solenopsis; however there is need to explore allelochemicals imparting resistance against P. solenopsis.

Exploitation of Nematicidal Potential of Paecilomyces lilacinus against Root Knot Nematode on Eggplant

ABSTRACT Root knot nematodes cause severe losses in vegetables throughout the world because its management is difficult due to its wide host range. The nematicidal potential of Paecilomyces lilacinus (Thom.) Samson was evaluated against root knot nematode, Meloidogyne incognita (Kofoid & White) Chitwood, on eggplant (Solanum melongena L.) under greenhouse conditions. Inoculation with M. incognita and P. lilacinus was carried out individually, in combination, and sequentially. Inoculation of 1000 juveniles (J2) of M. incognita reduced plant growth. The sequential application of P. lilacinus 7 days prior to M. incognita was more effectual than sequential application of M. incognita 7 days prior to P. lilacinus. Our findings concluded that P. lilacinus has the aptitude to adjust the nematode population and may serve as an alternative to nematicide.

Efficacy of Biopesticides for Management of Root Knot Nematode on Tomato

Biopesticides are being tested in control parasitic nematodes as a replacement for synthetic chemicals. This study was undertaken to investigate effects of the biopesticides abamectin, emamectin, and biosal on egg hatch and mortality of second instar juveniles (J2) of Meloidogyne incognita (Kofoid and White) Chitwood under laboratory and field conditions on tomato (Solanum lycopersicum L). Treatments consisted of the biopesticides and water (control). Numbers of J2 hatched was determined at 1, 3, and 6 days and mortality of J2 at 12, 24, and 48 h after inoculation. Evaluation of biopesticides under field conditions was for yield, number of flowers, numbers of fruit per plant, average fruit weight, shoot and root length, numbers of galls and egg masses per root system, and nematode rate of reproduction. Abamectin was more effective than emamectin and biosal against M. incognita under laboratory and field conditions. Application of abamectin produced the highest juvenile mortality and increased fruit weight, reduction in egg hatch, gall number, egg mass number, and rate of reproduction. Abamectin can be used under field conditions for management of M. incognita.

Evaluation of persistence and effectiveness of bacterial cell suspensions and culture filtrates against M. incognita on brinjal

Keeping in view the staid health and ecological apprehensions coupled with the use of pesticides, entomopathogenic nematodes have the potential to supersede pesticides for the management of various pests. Brinjal plants are the most seriously affected by Meloidogyne incognita. The main objective of this study was to evaluate the persistence effectiveness of bacterial cell suspensions (Xenorhabdus and Photorhabdus spp.) and their culture filtrates in soil up to 7, 14 and 21 days and their response against M. incognita as a source of biological control for nematode management. In a life cycle study, Xenorhabdus and Photorhabdus spp., isolated from Steinernema asiaticum and Heterorhabditis bacteriophora, were proved more effective in influencing the life cycle of RKNs. It was found that all the treatments of bacterial cell suspensions and their culture filtrates at all persistent times proved effective in reducing the number of females and egg masses as compared to control. It delayed penetration of nematode juveniles (J2) into host roots. It was concluded that persistence effectiveness of bacteria and their metabolites decreased in soil with time.