Diseases Of Lentil Research Articles

Screening of Lentil Genotypes Against Wilt of Lentil (Lens culinaris Medik L.) Caused by Fusarium oxysporum F. SP. Lentis in Glasshouse Condition

Wilt of lentil is most damaging disease of lentil caused by the fungus Fusarium oxysporum f. sp. lentis. It causes severe crop damage from vegetative to reproducing stage which results in yield reduction. Fol isolates shows high variability and aggressiveness according to the climatic condition. So to overcome from this disease there are many ways of management like by cultural, mechanical, biological and chemical practices. Resistant variety selection is one of the best ecofriendly cultural management of the disease. So for this purpose one hundred genotypes were taken and screened through pot screening technique under glasshouse was carried out at the Student Instructional Farm (SIF), in the department of Plant Pathology, Acharya Narendra Deva University of Agriculture and Technology, Kumarganj, Ayodhya, which is situated in the IndoGangatic plains of eastern Uttar Pradesh at a latitude of 26.470 and an altitude of 113 meters above sea level during Rabi 2020-21. One hundred genotypes of lentil were obtained from the Department of Genetics and Plant breeding, N.D. University of Agriculture and Technology, Kumarganj, Ayodhya and IIPR, Kalyanpur, Kanpur (U.P.).Out of 100 genotypes, 41 genotypes were found highly resistant, 30 genotypes resistant, 8 genotypes moderately resistant, 10 genotypes susceptible and 11 genotypes highly susceptible to Fusarium wilt.

Screening of Lentil Germplasm against Stemphylium Blight and Studies on Association between Disease and Biochemical Parameters

Background: Stemphylium blight, an important fungal disease of lentil caused by Stemphylium botryosum Wallr, has been reported to cause an estimated yield loss of 62% in India and Bangladesh. Considering the importance of the crop vis-à-vis the severity of the disease under terai agro-climatic region of West Bengal, the present study was undertaken to evaluate the germplasm of lentil for Stemphylium blight resistance for their utilization in future resistance breeding programme. Methods: The present experiment was carried out during the rabi season of 2019-20 and 2020-21 with forty lentil germplasm including two checks viz; WBL77 and IPL220 in an alpha lattice design under field condition and in completely randomized design under artificial inoculation respectively. Statistical analysis was carried out using R v. 4.1.1 software. Result: ANOVA revealed significant variation among the genotypes for the studied characters. PCV was found to be higher than GCV for all the studied characters. High heritability (broad sense) accompanied with high genetic advance as percent of mean indicated the presence of additive type of gene action. Based on per cent disease index germplasm were categorized as resistant or moderately resistant types for both under field condition and artificial inoculation. AUDPC was significantly but negatively associated with change in phenol and change in OD phenol under field condition same as that was observed between AUDPC and PPO content under artificial inoculation. Above study state that selection based on disease reaction and their associated parameters gives fruitful result to provide disease resistance parent against Stemphylium blight.

Morphological, molecular and pathogenic characterization of Macrophomina pseudophaseolina the causal agent of charcoal rot disease on lentil (Lens culinaris) in Algeria

Charcoal rot disease is one of the emerging diseases, recently detected on lentil plants in Algeria and worldwide. The present study was conducted to isolate, identify and characterize the causal agent of charcoal rot of lentil. Macrophominapseudophaseolina, responsible of this disease, was isolated from infected lentil plants from five different fields in the northwest of Algeria: Mascara, Tiaret and Relizane. A total of six isolates were obtained, their pathogenicity was evaluated on lentil Cv. Syria 229. The most virulent isolate M1, was selected for further studies. Molecular identification and phylogenetic analysis using concatenated sequences of ITS and TEF1-α regions confirmed the identity of M1 as Macrophominapseudophaseolina. A histopathological study was conducted on lentil plants infected with M1 to detect the presence of the pathogen, and the damage caused as a result of the invasion. The observations of histological sections of stems and roots revealed the presence of the pathogen's mycelium and microsclerotia inside the host as well as the colonization of the fundamental tissues. A morphological characterization was carried out using eleven different culture media, different temperatures and pH. The results showed an impressive adaptation of M.pseudophaseolina on the different physiological parameters. This study provides valuable information on the diagnostic of charcoal rot disease of lentil in the field, and the behavior of the pathogen which can be useful for the development of control strategies.

Management of Stemphylium Blight of Lentil by the Application of Different Dose of Chemical and Biological Fungicides

Field experiment was conducted at Plant Pathology block of Grain Legumes Research Program, Khajura, Banke during 2018 to evaluate the different doses of chemical and biological fungicides against Stemphylium blight disease of Lentil. The experimental design was laid in Randomized Complete Block design in field condition with three replications. Altogether 3 fungicides, 2 chemical {Saff (Carbendazim 12%+ Mancozeb 63%); Farm guard (Chlorothalonil 75% WP} at the dose of 1.5 gm, 2 gm and 2.5 gm per liter water and one biological {Commericial Phytoderma (Trichoderma harzianum) at the dose of 2.5 gm, 3 gm and 3.5 gm per liter water along with no fungicide application (control) was evaluated. Lowest mean disease severity (28.89) was obtained when Farm guard (Chlorothalonil @ 2.5 gm/ water) was applied followed by Saff (30) at the same dose. Highest mean disease severity (43.33) was obtained when no fungicide was applied. Similarly lowest Area Under Disease Progress Curve (AUDPC) (204.2) was obtained when Saff @ 2.5 gm/lit water was applied followed by Chlorothalonil (210) at the same dose. Highest AUDPC (291.7) was obtained in control plot. In case of grain yield Chlorothalonil @2gm per liter water obtained highest yield (836 kg/ha) with highest yield increase percent (34.6%). Lowest grain yield was obtained from control plot (546 kg/ha) followed by Trichoderma (624 kg/ha) when sprayed at 2.5 gm per liter water. Thus, from the study it is concluded that Chlorothalonil @ 2 gm when applied timely for three times can manage the Stemphylium blight disease.

Antifungal Activity of Botanicals and Biological agents against Sclerotium rolfsii Causing Foot and Root Rot Disease of Lentil

Background: Foot and root rot disease caused by Sclerotium rolfsii is a destructive soil borne disease of lentil (Lens culinaris). The present experiment was conducted to determine the inhibitory effect of thirteen plant extracts and two bio-control agents on in vitro mycelium growth of S. rolfsii. Methods: The experiment was conducted in the Laboratory of Pulse Research Center, RARS, BARI, Ishurdi, Pabna, Bangladesh during rabi season in 2015. Seven isolates of S. rolfsii were collected from foot and root rot affected lentil plant. Antifungal activity of thirteen botanicals and two biocontrol agents (T. harziznum and T. viride) was tested against a fast growing isolate (Sc-38) of the pathogen following poisoned food technique. Result: Out of thirteen botanicals, only Black cumin inhibited colony growth of S. rolfsii, where the colony diameter ranged 0.00-6.00 cm at different days after incubation. A moderate inhibition was achieved with Tulsi at 3, 6 and 9 DAI compared to control. Amendment of PDA with compost and liquid T. harziznum and T. viride remarkably inhibited the colony growth of S. rolfsii compared to control. Efficacy of four treatments of biocontrol agents was much better than botanical treatments. Two botanical extracts (Black cumin and Tulsi) and biocontrol agents (T. harzianum and T. viride) were found effective against S. rolfsii.

First report of using Trichoderma longibrachiatum as a biocontrol agent against Macrophomina pseudophaseolina causing charcoal rot disease of lentil in Algeria

BackgroundLentil (Lens culinaris Medik.) is one of the major pulse crops in the world. The present study aimed to evaluate the effect of Trichoderma isolates to control the charcoal rot disease caused by Macrophomina pseudophaseolina recently reported on lentil plants.ResultsIn this study, antagonistic effects of seven isolates of Trichoderma spp. isolated from the rhizosphere of lentil were evaluated in vitro against Macrophomina pseudophaseolina M1. All isolates of Trichoderma significantly reduced the mycelial growth of M1 in vitro. Maximum reduction of the pathogen growth was observed at T10 (72.53%), followed by T5 (63.7%) and T6 (62.88%), while T2 caused the minimum reduction (37.33%). Likewise, Trichoderma isolates significantly reduced the size and number microsclerotia. M1 produced the minimum number of microsclerotia in the presence of T10, followed by T1 causing reduction of 68.56 and 53.37% over control, respectively. The maximum reduction of microsclerotia’s size was observed in the presence of T10 (54.92%), followed by T1 (49.84) and T8 (48.68%). Results also revealed that production of volatile metabolite, components and inhibition of the test pathogen by volatile metabolites varied among different antagonistic Trichoderma. T1 produced the most volatile compounds, followed by T2 and T3 and T10 causing mycelial growth inhibition of 41.66, 33.88, 30.55 and 30.37%, respectively. The efficacy of the antagonistic biocontrol agents on charcoal rot was evaluated in vivo. Seed treatment with T10 significantly protected lentil seedlings from M. pseudophaseolina as compared to untreated plants and also improved their growth. T10 isolate was identified based on molecular tools, using internal transcribed spaces and Translation elongation factor of ribosomal DNA. The results identified T10 as Trichoderma longibrachiatum with accession number MW818102 and OK500004 deposited in NCBI GenBank database.ConclusionThe study revealed the first report of using Trichoderma longibrachiatum as a promising biological agent against M. pseudophaseolina causing charcoal rot disease of lentil.

Species composition of lentil disease causes in the forest-steppe zone

Aim. The research aimed to assess fungal infection of lentil seeds and to identify the most common diseases of this crop, which was grown by organic agricultural enterprises in the forest-steppe zone of the Poltava region. Identification of the species composition of disease-causing agents will enable the development of protective measures against certain diseases in the conditions of organic agriculture. Methods. In recent years, the area under lentil cultivation in our country reaches 20,000 hectares [1]. According to forecasts of «UkrAgroConsult», in the 2022–2023 season, there will be a significant reduction in the production of lentils and chickpeas, because the main areas of cultivation of these crops are in the south of Ukraine [2]. Results. Lentil diseases can cause a significant reduction in yield and quality. Most major economically important diseases are found in all lentil-growing regions. The species composition of the mycobiota and the infectious load are essential factors that determine the quality of grain and the susceptibility of plants to diseases in the field. Field, phytopathological, and mycological methods were used in the research process. Over the years of research, it was found that plants are most affected by diseases in the flowering phase, especially after heavy rains. Conclusions. Mycological analysis of contamination of lentil seeds revealed the presence of different types of fungi in the mycobiota: Penicillium, Mucor, Trichothecium, Fusarium, Alterneria. Representatives of penicillous, mucoral fungi, and Trichothecium roseum were the most common among those detected. As a result of the studies conducted in 2017-2018 on the identification of the species composition of fungi on the Linza lentil variety, 8 isolates of fungi were isolated and identified from 556 pure culture samples: Fusarium oxysporum f. ciceri Schlecht, F. culmorum Sacc., F. avenaceum Sacc., Alterneria alternata (Fr.) Keissl, Pythium ultimum, Stemphylium botryosum, Rhizoctonia solani, Ascochyta lentis. The dominant species parasitizing lentils on all parts of the plant was Fusarium oxysporum f. sp.lentis.

Magnitude of aphid infestation, root rot and rust disease of lentil

Lentil is the major cultivated pulse crop of Bangladesh. Even if there are available high-yielding modern varieties of this crop but because of the higher yield gap, its demand is largely met by import. Thus, to evaluate the pest-related factors of low yield seven modern lentil varieties viz. Binamasur-5, Binamasur-8, Binamasur-9, Binamasur-10, BARI Masur-5, BARI Masur-6, and BARI Masur-8 were assessed to enquire the extent of aphid infestation, foot rot and rust disease incidence, and severity on seed yield. The experiment was laid out in a Randomized complete block design during Rabi season at BINA Sub-station, Magura. Data on insects and disease were recorded at definite SMW (standard meteorological week) and DAS (days after sowing). Outcomes divulged that maximum aphid infestation (number of aphids/plant) was noted between 7th to 9th SMW; where BARI Masur-6 had significantly lowest infestation level on 7th and 8th SMW. Summative foot rot disease incidence (%) was most in Binamasur-8 and Binamasur-9, but least in BARI Masur-6 and Binamasur-5. For rust, the highest incidence (%) was recorded with Binamasur-8 and Binamasur-5; contrary the lowest was seen with BARI Masur-6 and BARI Masur-8. Severity index (DSI) of foot and root rot was abundant by Binamasur-8 (72.89%) and Binamasur-9 (71.56%); conversely, Binamasur-10 (52.11%) and BARI Masur-8 (50%) had scarce DSI. In the case of rust, BARI Masur-5 (74.00%) showed top DSI accompanied by Binamasur-8 (58.33%). The utmost seed yield of 8.25 g/plant was produced by Binamasur-10; in contrast, the least was yielded by Binamasur-8 (5.45 g/plant). Weather factors (temperature, relative humidity, rainfall) were positively related to the number of aphids per plant. However, seed yield was negatively affected by aphid population, foot rot, and rust disease incidence. Overall, Binamasur-10 corroborated having better resilience to biotic and abiotic factors for delivering desirable economic yield

Combined Effects of Compost and Trichoderma spp. on Reducing Damping-off and Root Rot Diseases of Lentil Plants

Dual treatments of compost and Trichoderma spp. to control damping-off and root rot diseases of lentil were investigated.The obtained results showed that T. harzianum and T. viride were suppressive against lentil pathogen (R. solani). Likewise, both types of compost showed suppression on pathogen at 50%. The microbial population in the two composts was determined, where Com 2 showed the higher population of the recovered microbial load than Com1. Under greenhouse and field conditions, application of Trichoderma spp. and both composts individually or in combination significantly reduced the percentage of damping-off and root rot diseases of lentil caused by R. solani and increased plant survival rate of lentil compared to the infected control. It has been observed that a combined inoculation of Trichoderma spp. and both types of compost significantly increased the plant height, number of nodules and crop parameters, i.e., number of pods, number of seeds, weight of seeds as well as protein content.

Genetic and Morphological Variability among the Isolates of Fusarium oxysporum f. sp. lentis causing Wilt of Lentil

Background: Lentil wilt is one of the most important diseases of lentil directly contributing to the yield losses of the crop. It is caused by Fusarium oxysporum f. sp. lentis which shows the great genetic and morphological diversity. Methods: Present investigation was conducted during 2017-2019 with 22 isolates of the pathogen, collected from lentil grown areas of Uttarakhand and Uttar Pradesh to explore genetic and morphological variability employing eight ISSR and five SSR primers. Result: The isolates showed huge morphological variability based on the color, pigmentation and shape of conidia. Study on molecular variability revealed the versatility in the genome of different isolates of pathogen. The diversity among the isolates of pathogens collected from Uttarakhand and Uttar Pradesh was also evident. Generated work on genetic and morphological variability and the population diversity among the different isolates of the pathogen impact on developing ideal disease management strategies.

Molecular Mapping of a Gene Conferring Fusarium Wilt Resistance in Lentil (Lens culinaris Medikus subsp. culinaris) using Bulked-segregant Analysis

Background: Vascular wilt caused by Fusarium oxysporum f.sp. lentis Vasu. and Srini. is a serious disease of lentil (Lens culinaris Medikus), causes severe yield losses worldwide. For effective disease resistance breeding the inheritance and mapping of wilt resistance gene (s) is necessary. Therefore, the present investigation was focused on study the mode of inheritance and tag/map gene (s) for fusarium wilt resistance in lentil. Methods: Bulked segregant analysis (BSA) approach was used to identify markers that were tightly linked to Fusarium wilt resistance gene. The inheritance and mapping of wilt-resistance gene (s) in lentil was investigated in F2 and F2:3 populations derived from L9-12×ILL10965 cross, whereas L9-12 and ILL10965 were susceptible and resistant parents, respectively. Result: More than two hundreds SSRs markers were surveyed for the parental polymorphism, of which twenty nine were found polymorphic. These polymorphic SSRs were used for the bulked-segregant analysis (BSA) using both parents and its respective resistant and susceptible bulks, and three SSRs viz. PBALC233, PBALC1409 and PBALC203 could distinguish the respective bulks. Linkage analysis showed two SSR markers, PBALC203 and PBALC1409 flanking the wilt resistance gene at 8.2 cM and 9.4 cM distance, respectively. Further, PBLAC233 was also found present on the same linkage group at a distance of 10.2 cM from PBLAC1409.

​​Eco-friendly Management of Collar Rot of Lentil by Introduced Native Rhizobacterial Candidates

Background: Collar rot is an important disease of lentil in India and causes significant yield loss annually. Considering the recent focus on the development and use of environmentally feasible management strategies, the objectives of the study was to identify resistant sources and evaluation of native antagonists as well as plant growth promoting rhizobacteria (PGPRs) in yield improvement and disease management of lentil. Methods: Eleven popular lentil varieties were screened for resistance/susceptibility reaction against collar rot in vivo. The efficacy of two bacterial and fungal biocontrol agents (BCAs) was tested against a virulent isolate of Sclerotium rolfsii. Four PGPRs were also evaluated to study their influence on the growth parameters as well as their ability to manage S. rolfsii. Result: Three genotypes were found to be tolerant, four genotypes were moderately susceptible, while four genotypes were highly susceptible. Among the BCAs, the highest average inhibition % was observed in treatment with Bacillus sp. Among the PGPR treatments, Rhizobium in combination with phosphate solubilizing bacteria and Trichoderma or Bacillus was the most effective in controlling the collar rot when used as seed treatment and hence can be used for disease management.

Identification of anthracnose race 1 resistance loci in lentil by integrating linkage mapping and genome-wide association study.

Anthracnose, caused byColletotrichum lentis, is a devastating disease of lentil (Lens culinaris Medik.) in western Canada. Growing resistant lentil cultivars is the most cost-effective and environmentally friendly approach to prevent seed yield losses that can exceed 70%. To identify loci conferring resistance to anthracnose race 1 in lentil, biparental quantitative trait loci (QTL) mapping of two recombinant inbred line (RIL) populations was integrated with a genome-wide association study (GWAS) using 200 diverse lentil accessions from a lentil diversity panel. A major-effect QTL (qAnt1.Lc-3) conferring resistance to race 1 was mapped to lentil chromosome 3 and colocated on the lentil physical map for both RIL populations. Clusters of candidate nucleotide-binding leucine-rich repeat (NB-LRR) and other defense-related genes were uncovered within the QTL region. A GWAS detected 14 significant single nucleotide polymorphism (SNP) markers associated with race 1 resistance on chromosomes 3, 4, 5, and 6. The most significant GWAS SNPs on chromosome 3 supported qAnt1.Lc-3 and delineated a region of 1.6 Mb containing candidate resistance genes. The identified SNP markers can be directly applied in marker-assisted selection (MAS) to accelerate the introgression of race 1 resistance in lentil breeding.

QTL mapping of lentil anthracnose (Colletotrichum lentis) resistance from Lens ervoides accession IG 72815 in an interspecific RIL population

Anthracnose, caused by Colletotrichum lentis, is one of the most damaging diseases of lentil (L. culinaris) in western Canada. Lens ervoides accession IG 72815 exhibits high levels of resistance to the pathogenic races 0 and 1. The objective of this study was to identify quantitative trait loci (QTL) associated with anthracnose resistance in lentil using a recombinant inbred line (RIL) population from the interspecific cross between IG 72815 and the susceptible cultivar Eston. A total of 168 RILs were genotyped and evaluated for anthracnose race 0 and race 1 reaction in the growth chamber and polyhouse. QTL analysis identified major resistance loci on chromosomes 3 and 7 for both races, accounting for 20.1–31.2% and 8.3–18.4%, respectively, of the total phenotypic variation for anthracnose resistance. Multiple classes of putative defense-related genes are located within both loci. Further characterization of these regions will facilitate the introgression of anthracnose resistance from Lens ervoides into elite lentil cultivars via marker-assisted selection.

Evaluation of different inoculation techniques on Pathogenecity of Sclerotium rolfsii

Collar rot is one of the most destructive diseases of lentil. Yield losses can be attributed to fungal growth at collar region near soil line which leads to smaller and fewer seeds, premature ripening, shattered pods. The stem rot fungus overwinters as sclerotia in the soil, stubble or mixed with seed. Sclerotia can remain viable for five years or more when conditions are suitable sclerotia will germinate myceliogenically and directly infect plants near soil line. The present investigations were carried out the efficacy of various inoculation techniques of Sclerotium fungus in lentils. Maximum disease severity 44.5% were recorded in wheat inoculums method followed by agar disc method (40%) and the minimum disease severity 12% was observed in toothpick method.

Stemphylium blight reduces milling qualities of lentil

AbstractStemphylium blight (SB) (Stemphylium botryosum) is a major disease of lentil (Lens culinaris Medik.) in many global production regions. In Canada, SB typically occurs after canopy closure in the second half of the growing season when weather conditions become warm and humid. Experiments were carried out to assess the impact of SB disease on milling qualities of lentil. In 2014, milling qualities of red lentils were compared between seed obtained from an uninfected site and those produced at a naturally SB‐infected site. In 2016 and 2017, controlled field experiments were conducted by artificially inoculating the plots with SB conidia at the early flowering stage. Seed yield in the infected plots was reduced by 52, 22, and 30% compared with control plots in 2014, 2016, and 2017, respectively. The percentages of stained and deformed seeds were increased in infected plots in 2016 and 2017. Seeds infected with SB have reduced milling qualities. Dehulling efficiency was reduced by 25.3, 23.0, and 15.9%, and milling recovery was reduced by 23.7, 25.4, and 15.1% compared with the uninfected control plots, respectively, in 2014, 2016, and 2017. Stemphylium blight had minimal impact on football lentil recovery. These results suggest that SB is potentially the leading cause of the reported poor milling quality of Canadian red lentils that reduces the economic value in years when the growing season is favorable for development of SB. These results have major implications for agronomy, pathology, and breeding strategies of the lentil crop in temperate production regions.

Ecofriendly Disease Management of Lentil (<i>Lens culinaris</i>) Seedlings

To determine the effect of Biofertilizer and Integrated Pest Management (IPM) biopesticide for controlling foot and root rot diseases of lentil it is very important for conducting experiment in the field. It was marked that both Biofertilizer and IPM Biopesticide found significantly lower disease incidence of Bangladesh Institute of Nuclear Agriculture (BINA) released popular lentil variety Binamasur-1 and Binamasur-2 seedlings compared with the control treatment. Soil treatment with Biofertilizer as Bangladesh Agricultural Research Institute (BARI) released Bari-Biofertilizer performed the lowest disease incidence of lentil variety Binamasur-1 and Binamasur-2 at 20 days after sowing (DAS) showed a reduction of disease incidence up to 68.80% and 71.70% over the control. While after 28 DAS, it was found up to 91.27% and 91.34% reduction of disease incidence over control. Furthermore, after 35 DAS, it exhibited up to 69.37% and 69.28% reduction of disease incidence over control. Bari-Biofertilizer significantly increased the fresh weight and the number of nodules per plant.

Resistance to Anthracnose (Colletotrichum lentis, Race 0) in Lens spp. Germplasm

Anthracnose, caused by the fungal pathogen Colletotrichum lentis, is a severe disease of lentil (Lens culinaris) causing premature defoliation, necrotic stem lesions that lead to plant wilting and death in susceptible varieties. Two races of C. lentis (0 and 1) have been described so far. Race 0 is the most virulent one and limited genetic resistance is available to date. To address this scarcity of resistance, we screened a germplasm collection covering different Lens spp. originating from different countries for C. lentis race 0 resistance. Leaf and stem damage and plant mortality were assessed on seedlings inoculated under controlled conditions. A significant variability was observed among accession. Most of the collection studied was highly susceptible, but some levels of resistance were identified in about 15% of the accessions. The highest levels of resistance were identified in L. ervoides accessions PI572330, PI572334 and PI572338. Moderate resistance was also identified in 10 L. culinaris ssp. culinaris accessions but not in the remaining species studied. Selected accessions showed potential to integrate several breeding programs.

Biointensive management of wilt disease of lentil through biocontrol agents and organic amendments

Lentil ( Lens culinaris M.) is an important dietary source of protein and other essential nutrients in South and West Asia, North and East Africa. Lentil crops are susceptible to a number of diseases caused by fungi and other parasites. Among them, the most significant and serious soil-borne disease is Fusarium wilt ( Fusarium oxysporum f.sp. lentis : Fol ). Systematic studies in laboratory, cage house and field trials were conducted (2016-17 to 2017-18). Laboratory experiments were carried out in completely randomized design with four replications and field trials were carried out consecutively during 2016-17 and 2017-2018 crop season in Randomized Block Design (RBD) with four replications using L9-12, a susceptible cultivar. Under in vitro, bio efficacy of selected bio agents, maximum 81.33 per cent mycelial growth inhibition of pathogen was recorded in Trichoderma harzianum (local isolate) and minimum mycelial growth inhibition 55.00 per cent was recorded in Bacillus subtilis . Under in vivo condition, effect of selected bio agents and organic amendments on disease incidence, percent disease control, pathogen spore in per gram soil and yield ha -1 of lentil was recorded. Application of Trichoderma harzianum (Local isolate) @ 6g/Kg seed was found most effective with maximum seed germination 91.95 and 90.62 per cent, lowest disease incidence of 24.22 and 25.39 per cent and higher pooled mean grain yield 774.31 kg/ha over check during 2016-17 and 2017-18, respectively. Among organic amendments, maximum disease control (42.02 per cent), minimum average disease incidence (36.33 per cent) and minimum pathogen spores (1.3x10 4 per gram soil) were observed in neem cake amendment followed by poultry manure and vermicompost amendments. This indicates that these treatments can be effectively used for controlling Fusarium wilt disease under organic mode of lentil cultivation in Rajasthan.

Exploiting plant growth promoting Trichoderma for lentil wilt management

Fusarium wilt caused by Fusarium oxysporum f. sp. lentis (Fol) has been considered as destructive seed and soil-borne disease of lentil which causes severe yield loss every year. For its biological control, twenty isolates of Trichoderma spp. were tested against thirty Fol isolates using dual culture technique. Out of twenty Trichoderma isolates, seven isolates (5593, ThL-1, ThL-4, TaL- 2, TaL- 4, ThaL-3 and TvL-6) showed maximum percent inhibition of radial growth against pathogens between 82.4% to 78.0% as compared to the rest of Trichoderma isolates. As far as molecular identification is concerned the effective six isolates after dual culture assay and highly virulent Fol isolate were molecularly identified by using ITS primers (ITS 1 and ITS 4) and remaining one isolate was taken from ITCC which was already identified as T. harzianum (5593). Seven efficient isolates of Trichoderma were used to evaluate volatile and non- volatile assay against Fol (NFLRJ-3). Isolates, 5593 and ThL-4 showed significant growth inhibition against Fol at 48 hours of incubation in both the assays as compared to the rest Trichoderma isolates. In volatile organic compound (VOC) assay ThL-4 showed highest number of seed germination and showed good seed health condition. Out of seven selected isolates of Trichoderma, all isolates were found effective to control disease and stimulated plant growth promotion activity of lentil (2017-2019). Therefore, these isolates can be utilized to formulate bio-fungicides which is the need of the hour as far as disease management is concerned.