Theses

Browse

Search Results

Now showing 1 - 9 of 143

Open Access
Characterization of variability in Cercospora sojina K. Hara causing frogeye leaf spot and identification of resistant sources in soybean
(CSK HPKV, Palampur, 2023-01-18) Sharma, Abhilasha; Singh, Amar
The present investigation entitled “Characterization of variability in Cercospora sojina Hara causing frogeye leaf spot and identification of resistant sources in soybean” was undertaken during Kharif season to study pathogen isolation and culture production techniques, development of differential set, pathogen variability (morpho-cultural, pathogenic and molecular), mating type distribution, evaluation of resistant sources, inheritance of resistance, and biochemical basis of resistance against Cercospora sojina. Frogeye leaf spot of soybean (Glycine max (L) Merill) caused by Cercospora sojina Hara emerged as most destructive disease in Himachal Pradesh as PDI recorded was ranged between 0.00 to 95.56 per cent. Thirty isolates of C. sojina were collected from different locations of five districts (Kangra, Mandi, Solan, Hamirpur and Bilaspur) representing 3 agro-climatic zones of Himachal Pradesh. Isolations were done by using three different methods viz; inoculation by bits, inoculation by using moist-chamber technique and inoculation by using toothpick method. Out of these, moist chamber technique was the most reliable as most of the isolates were recovered by using this technique. Thirty isolates were identified as Cercospora sojina based on symptomatology, morphological characters and confirmed with molecular characterization. Culture technique for C. sojina was also standardized as the fungus was slow growing in nature. Among nine tested media, PCDA (Potato Cellulose Dextrose Agar) was found best with 4g concentration of cellulose whereas FRCA (Flat Rice Cellulose Agar) media (4g cellulose) was found best at 25 ± 1ºC to produce long conidia. The pathogen was found variable on the basis of morpho-cultural variability. A differential set was finalized to study the virulence structure of C. sojina. Initially sixty soybean lines were selected from 200 genotypes and tested against six isolates, out of which 25 soybean lines were selected as pre-differential set which was tested against all the 30 isolates of C. sojina and finally a differential set of 10 lines was developed. On the basis of disease reaction on differential set C. sojina isolates were grouped into 10 pathotypes. Virulence analysis of the pathotypes (PCS 1 – PCS 10) revealed that PCS 1 and PCS 2 were highly virulent whereas PCS 3, PCS 8 and PCS 10 were least virulent. Variability studies on morpho-cultural, pathogenic and molecular characters categorized 30 isolates of C. sojina into 11, 10 and 6 groups, respectively. There is no or less correlation among the three types of variability studies. Molecular variability was also studied and analyzed with POPGENE analysis software which revealed that thirty isolates were divided into 2 populations on the basis of geography (Latitude and longitude) and there is substantial gene flow among the two populations. There was occurrence of maximum variability within the population i.e.>90 per cent as PhiPT value ranged between 0.004 - 0.127. Mating type distribution of 30 isolates of C. sojina was studied using MAT1-1 and MAT1-2 primers which revealed the presence of both the idiomorph (MAT1-1 & MAT1-2) found in CSH09 isolate revealed that population in Himachal Pradesh probably undergoing sexual reproduction. Out of a total two hundred lines evaluated under field conditions 30 lines found resistant which were screened against diverse pathotypes (PCS1- PCS-10) and four resistant lines viz.; Harder, JSM 285, CAT 195 and GP465 were identified as highly resistant against all pathotypes. Biochemical basis of resistance was also studied in a resistant line ‘Himso 1685’ and a susceptible line ‘Shivalik’ revealed that the tested enzymes i.e., Phenols, PPO and PO had no or less role in defence as there may be other enzymes which can affect the defence mechanism upon infection in soybean against C. sojina. Inheritance of resistance for C. sojina studied and results revealed that the inheritance was controlled by single dominant gene.
Open Access
Management of false smut of rice caused by Ustilaginoidea virens (Cke.) Tak.
(CSK HPKV, Palampur, 2023-02-08) Preeti; Upamnyu, Sachin
False smut of rice caused by Ustilaginoidea virens (Cke.) Tak. is an emerging production constraint in rice growing regions of India and Himachal Pradesh. The investigation on “Management of false smut of rice caused by Ustilaginoidea virens (Cke.) Tak.” was undertaken during 2020-22 in the Department of Plant Pathology, CSKHPKV, Palampur and RWRC, Malan. The pathogen was confirmed as Ustilaginoidea virens on the basis of its morphological and cultural characteristics. Systematic surveys were conducted in different rice growing areas in eight districts of State showed that false smut incidence varied from 0.2 to 55.5 per cent during kharif-2022. The incidence of false smut was the highest at Rampur (55.5%) followed by Surajpur (45.5%), Dhaulakuan (40.5%) and Puruwala (40.0%) of district Sirmour, while it was the least in district Shimla. The relation between disease incidence and weather variables was non-significant in all date of sowing except in 2nd date of sowing i.e. 5th June with maximum temperature. Disease incidence was comparatively higher in 21st May sown crop than in 5th June and 20th June sown crop The coefficient of determination (R2 ) revealed that selected weather variables i.e. temperature and relative humidity contributed 72.8, 95.3 and 99.8 per cent towards incidence of false smut on the crop sown at 21st May, 5th June and 20th June, respectively. Out of sixty one genotypes, seventeen genotypes (HPR 3236, HPR 3239, HPR 3243, HPR 3248, HPR 3250, HPR 3251, HPR 3253, HPR 3254, HPR 3260, HPR 3261, HPR 3262, PB 1121, Kasturi, HPR 2612, HPR 3228, HPR 3218, HPR 3226) showed highly resistant reaction, seven (HPR 3256, HPR 3259, HPR 2929, HPR 3213, HPR 3211, HPR 2703, HPR 2696) resistant, twenty three moderately resistant, five moderately susceptible while all the nine hybrids (Arize 6129, Arize 6444, Arize Swift, AZ 6508, BS 10008, DR 8101, PAC 834, PAC 807 Plus, Arize 6129 Gold (Check) showed susceptible reaction. In vitro evaluation of fungicides showed a complete inhibition of mycelial growth of the pathogen with propiconazole (Tilt 25 EC), tebuconazole (Folicur 250 EC), tebuconazole 50% + trifloxystrobin 25% WG (Nativo 75 WG), mancozeb 63% + carbendazim 12% WP (Companion) and mancozeb (Indofil M-45) at different concentrations ranging from 25-1000 ppm. However, under field conditions, application of two sprays of propiconazole 25 EC one at booting stage and second 10 days later proved to be the most effective resulted in the maximum (51.94%) reduction in disease incidence with highest grain yield of 57.95 q/ha and provided 28.46 per cent increase over control followed by two sprays of tebuconazole 50% + trifloxystrobin 25% WG registering around 50 per cent reduction in disease incidence with 24.60 per cent increase in grain yield over control. Two sprays of propiconazole 25 EC also provided the maximum reduction in smut ball formation (97.34%) followed by two sprays of tebuconazole 50% + trifloxystrobin 25% WG (96.76%).
Open Access
Studies on black point disease of wheat in Himachal Pradesh
(CSK HPKV, Palampur, 2022-12-26) Rana, Nikhil; Sharma, Bipan Kumar
Black point disease of wheat is common in all the wheat growing areas and has become a major constraint in recent years for successful and profitable cultivation of wheat in India. The investigations on different aspects of the disease were carried out at Plant Pathology Laboratory, Department of Plant Pathology, CSK HPKV Palampur and Research Sub Station Akrot (HP). There was considerable variation in the level of black point infection in grain samples collected from seven districts of Himachal Pradesh. The highest disease occurrence (83.33%) was recorded in Kangra district during Rabi 2021-22 cropping season. Out of five pathogens isolated, namely Alternaria alternata , Helminthosporium sativum, Aspergillus niger, Fusarium spp. and Curvularia spp. A. alternata was found to be the predominant pathogen associated with black point infection. The agar plate technique outperformed moist blotter technique for growth and spore formation by the fungus A. alternata. Potato dextrose agar was found most suitable media for A. alternata due to profuse growth of mycelia growth under lab conditions followed by Oat meal, Malt extract and least in Corn meal agar. The mycelium was light greenish to greenish black in most media. A. alternata growth was found to be maximum at 30 ± 2°C. Artificial screening of twenty five wheat cultivars showed varying degrees of susceptibility to black point incidence, ranging from 42.50 (VL-907) to 68.0 per cent (HS-240). The black point index ranged from 5.0 (VL-907) to 9.32 (HPW-360) with an overall range of 0-15.33. When exposed to conidial suspension sprays (20,000 conidia/ml) at various crop stages, susceptible varieties PBW-343 and HS-240 developed varying level of black point infection and ear head half outside boot leaf stage was found to be most susceptible stage for black point infection. Among quality characters tested under laboratory conditions in twenty five cultivars, there was 7.7- 18.96 per cent decrease in seed germination due to black point infection and overall 12.78 per cent increase in seed weight of infected seeds over healthy seeds.
Open Access
Fortification of substrates to produce bio-enriched Oyster mushrooms
(CSK HPKV, Palampur, 2023-01-03) Nidhi; Sud, Deepika
The present investigation entitled “Fortification of substrates to produce bio-enriched Oyster mushrooms” were undertaken to evaluate various cultural aspects, morphological and yield attributes on different agro-based substrates or fortified and non-fortified substrates, nutrient content and analysis of Se and Zn content after fortification in different doses. Cultural studies were carried out to determine the best solid, liquid media, temperature, pH and light intensity on mycelial growth of Pleurotus ostreatus. Yeast malt agar (8.50 cm) and potato dextrose yeast broth (10.17 g/ml) supported the best growth of P. ostreatus. Temperature of 25oC was found optimum for both solid and liquid media with mycelial growth of 8.53 cm (YMA) and mycelial mat of weight 9.91 g/ml (PDYB). The maximum mycelial diameter was recorded at pH 6.5 with mycelial growth of 8.19 cm in solid medium (YMA) and in liquid (PDY) broth maximum mycelial mat of weight 9.98 g/ml was recorded at pH 6. Light intensity of 200 lux supported the best mycelial growth in solid (8.26 cm) as well as liquid medium (10.11g/ml). Various agricultural waste viz., cereal substrates (wheat, paddy straw and maize cob), leguminous substrates (soybean and urd bean straw) and oilseed substrates (linseed and mustard straw) were evaluated. The results revealed that rice straw had the highest yield (363 g) and biological efficiency (103 %) among cereal substrates. Among leguminous substrates, the maximum yield (375 g) and biological efficiency (107 %) was found on soybean straw. Whereas, on oilseed substrates the maximum yield (282 g) and biological efficiency (80 %) was found on mustard straw. The best cereal (paddy straw), leguminous (soybean straw) and oilseed substrate (mustard straw) on the basis of highest biological efficiency were further used for fortification with three concentrations (25, 50, 75 mg/1000g) of sodium selenite and zinc sulphate. The results on morphological characters revealed that after being fortified with selenium and zinc, the size and colour of fruit bodies remain unchanged. Soybean straw resulted in maximum yield (313 g) and biological efficiency (89 %) after Se fortification at dose 25 mg/kg followed by 50 mg. Similarly, on rice and mustard straw the maximum yield and biological efficiency was recorded at dose 25 mg/kg of Se (300 g and 85 %, 279 g and 79 % respectively). After zinc fortification, the dose of 25 mg/kg on rice straw resulted in maximum yield (335 g) and biological efficiency (95 %) followed by 50 mg. Soybean and mustard straw also showed maximum yield and biological efficiency at dose 25 mg/kg of Zn (305 g and 87 %, 287 g and 82 % respectively). Among all the substrates, the minimum yield and biological efficiency was recorded at dose 75 mg/kg of Se and Zn. Nutrient analysis of fruit bodies harvested after fortification of best substrates with salts of Se and Zn exhibited maximum carbohydrate (60.29 %) and protein content (32.32 %) at 75 mg in Se fortified mushroom on soybean straw. However, at 50 mg/kg of Zn the maximum fat content (2.74 %) was recorded on soybean straw and maximum fibre content (18.12 %) was recorded on rice straw. The best dose of both the salts (25 mg/ 1000g of substrate) on the basis of maximum yield were combined and evaluated. The results revealed that soybean straw produced the maximum yield (324 g) and nutrient content (55 % of carbohydrate and 27.72 % of protein) followed by rice straw and mustard straw. Maximum Se uptake (69.95 µg/g) at dose 75 mg was recorded on soybean straw followed by rice (61.67 µg/g) and mustard straw (57.75 µg/g). Similarly, at dose 75 mg the maximum Zn uptake was recorded on rice straw (120.67 µg/g) followed by soybean (117.27 µg/g) and mustard straw (107.23 µg/g). The minimum Se and Zn uptake was recorded on combined dose on mustard straw (37.5 µg/g of Se and 81.03 µg/g of Zn). Amongst the tested substrates and doses soybean and rice straw were best suited for Se and Zn fortification at dose 50 and 75 mg
Open Access
Biology of Colletotrichum truncatum causing anthracnose of soybean and identification of resistant sources
(Palampur, 2022-12-08) Sharma, Anshul Kumar; Singh, Amar
The present investigation entitled “Biology of Colletotrichum truncatum causing anthracnose of soybean and identification of resistant sources” was undertaken to study the morpho-cultural characteristics, standardization of pathogen culture technique, physiological requirements of the pathogen, efficacy of bioagents, yield loss assessment and evaluation of resistant sources both under field conditions and in vitro against the pathogen associated with soybean anthracnose. Anthracnose of soybean (Glycine max (L) Merrill) was found as a major disease in soybean growing areas of Himachal Pradesh with per cent disease index (PDI) recorded between 17.77 to 46.66 per cent. The pathogen was isolated on PDA and identified as Colletotrichum truncatum (Schw.) Andrus and Moore based on morpho-cultural characters and confirmed with molecular characterization. Pure culture of six isolates of C. truncatum from three districts (Kangra, Mandi and Hamirpur) of Himachal Pradesh were used in present study. In pathogenicity test, pathogen caused pre-emergence and post-emergence mortality and isolate Ct-3 and Ct-6 was found most virulent and caused up to 56 per cent pre-emergence and 16 per cent post emergence mortality. Among seven tested media, PDA (potato dextrose agar) was found best medium for mycelial growth as well as sporulation of the pathogen at temp. 25±1ºC and pH 7.0. Mathur’s medium was also found suitable for sporulation of the pathogen. Rapid disease development was observed at ≥ 90 per cent humidity and favours sporulation of the pathogen. Bio-control agents showed great potential in the management of the disease as Trichoderma koningii showed good inhibition of the pathogen in dual culture study and also found effective in improving per cent seedlings stand under glass house conditions. Screening of two hundred germplasm lines of soybean found 10 resistant and 33 moderately resistant lines under field conditions which were further screened at seedling as well as on young pods with artificial inoculation. Out of 43 genotypes found resistant or moderately resistant under field evaluation, two germplasm lines viz. PK 25 and CAT 01 were found resistant at seedling stage against virulent Colletotrichum truncatum isolate (Ct-3). Four germplasm lines viz. UPSM 780, AGS 164, PK 472 and PK 25 were found resistant against all the six isolates when evaluated with young pods inoculation method under lab conditions. Yield loss studies revealed that two sprays of Propiconazole 25 EC @ 0.1% at full bloom + young pod stage leads to 41.93 per cent avoidable yield loss as compare to untreated control and was most beneficial in reducing disease severity and increasing yield over total cost of the fungicidal spray.
Open Access
Eco friendly management of stem rot of berseem caused by Sclerotinia spp
(palampur, 2022-10-07) Upadhyay, Parul; Banyal, D. K.
The investigation on the eco-friendly management of stem rot of berseem caused by Sclerotinia spp. was undertaken in the Department of Plant Pathology, CSK HPKV, Palampur during 2020-22. The pathogen was isolated from the diseased berseem samples and pathogenicity of the associated pathogen was proved. On the basis of symptoms, the disease was identified as stem rot and on the basis of morpho-cultural & molecular identification the pathogen was identified as Sclerotinia sclerotiorum. Temperature was observed as the most important factor in the disease development having significant negative correlation with disease severity. Twenty fungal and one bacterial bioagents isolated from berseem rhizosphere along with five established bioagents from department of Plant Pathology were evaluated for their antagonistic activity against S. sclerotiorum in dual culture. Bioagent TRN-10 was found the most effective with 75.20 per cent mycelial inhibition, which was followed by TRN-9 (73.00%), TRN-14 (72.20%), TRN 12 (71.90%), TRD-2 (64.07%) and BN-1 (51.90%). These six bioagents were tested for their effect of volatile and non-volatile compounds in which TRN-10 gave the maximum mycelial inhibition i.e. 34.44 per cent using volatile metabolites with 56.00 per cent inhibition of sclerotial germination. However, bioagent TRN-9 provided maximum mycelial inhibition i.e. 50.74 per cent using non-volatile metabolites with 51.99 per cent inhibition of sclerotial germination. Among the botanicals, extracts of Eucalyptus camaldulensis (aqueous) and Melia azedarach (alcoholic) gave maximum mycelial inhibition i.e. 15.93 & 39.26 per cent, respectively at 50 per cent concentration under in vitro. Panchgavya as an organic input and Brahmastra as a natural product, were found most effective with 65.50 & 70.70 per cent mycelial inhibition, respectively at 25 per cent concentration under in vitro conditions. The five most effective bioagents i.e. TRN-9, TRN-10, TRN-12, TRN-14 and TRD-2 were evaluated for their disease management potential in pot culture. TRN-10 was found most effective which provided maximum disease control when applied as soil (58.33%) and seed treatment (60.00%). Bioagent TRN-9 gave maximum increase in seedling root (34.45%) & shoot length (51.13%) however, TRN-12 provided maximum increase in green fodder yield (50.00%) under in vivo conditions. Among the botanicals, extract of Eupatorium adenophorum was found the best with 23.48 per cent disease control in pot culture. Panchgavya and Brahmastra as organic and natural product provided 48.74 & 45.09 per cent disease control under in vivo conditions, respectively. The integration of eco-friendly components in pot culture showed that T7 {Trichoderma spp. (TRN-10) + Eupatorium adenophorum + panchgavya + ghanjeevamrit} was found most effective for the management of the stem rot disease with 75.00 per cent disease control after 35 days of inoculation
Open Access
Ecofriendly management of bacterial wilt of tomato
(palampur, 2022-09-23) Sharma, Sachin; Kumar, Pardeep
Bacterial wilt is a major hindrance to the production of solanaceous crops in both tropical and temperate regions of world and it causes substantial yield losses in tomato. The investigation on “Ecofriendly management of bacterial wilt of tomato” was undertaken during 2021-22 in the Department of Plant Pathology, CSK HPKV, Palampur. Systematic surveys were conducted in 9 districts of Himachal Pradesh for the prevalence of bacterial wilt in tomato. The highest wilt incidence (90-100%) was recorded at Solan, Shimla and Kangra districts. A total of 70 PGPR isolates were obtained from the wilt affected fields and after biochemical testing, the isolates were designated as Pf (P. fluorescens) and Bc (Bacillus spp.). R. solanacearum was isolated on TZC agar and identified with the help of biochemical tests. All the PGPR isolates were subjected to in vitro laboratory assay and 6 potential PGPR were found effective against R. solanacearum which showed inhibition zone of 9.53 to 14.73 mm. The effect of potential PGPR on growth parameters viz., root length, shoot length, vigor index and seed germination were studied and it was found that all of them significantly improved growth parameters as compared to control. Maximum seed germination (94.60%) was recorded in seed bacterization with Pseudomonas isolate Pf 22 followed by 93.50 per cent in Bacillus isolate Bc 17. The isolate Pf 22 showed minimum wilt incidence (51.8%) followed by Bc 17 (56.9%). Commercial Trichoderma formulations were also evaluated and it was found that inhibition zone varied from 10.74 to 12.56 mm. Maximum shoot length, root length and vigor index was observed in seed treatment with Trichoshield (T. harzianum) followed by Guard TH (T. harzianum). Seed germination (92.05%) was significantly higher in seed treatment with Trichoshield. Highest disease control (41.14%) was noted in seed treatment with Trichoshield followed by Guard TH (38.27%). Combined effect of potential PGPR and commercial Trichoderma formulations on shoot length, root length and vigor index were studied using roll towel method. Combination treatments gave significantly enhanced results as compared to individual treatment of PGPR and commercial Trichoderma formulations. Maximum shoot length, root length and vigor index were observed in combined treatment with Pseudomonas isolate Pf 22 and commercial Trichoderma formulation Trichoshield followed by Pf 22 and Guard TH. Maximum germination was observed in Pf 22 + Trichoshield (95.72%) followed by Pf 22 + Guard TH (94.58%) as compared to control (81.50%). In pot experiment, lowest wilt incidence was observed in combined treatment of seed with Pf 22 + Trichoshield (47.94%) and resulted in 48.67 per cent protection against bacterial wilt. This study indicated the potential benefits of using combined treatments of PGPR and commercial Trichoderma formulations which effectively enhanced plant growth and suppression of pathogen
Open Access
EPIDEMIOLOGY AND MANAGEMENT OF FUSARIUM HEAD BLIGHT OF WHEAT
(palampur, 2022-06-30) KAUR, GURPREET; Rana, S. K.
The investigation entitled “Epidemiology and management of Fusarium head blight of wheat” was conducted at the Department of Plant Pathology, CSK HPKV, Palampur and Research farm of Rice and Wheat Research Centre (RWRC), Malan during 2019-21. The average disease incidence and severity of FHB at different locations of Himachal Pradesh varied from 3.25 to 7.74 and 15.08 to 25.29 per cent during 2019-20 and 2020-21, respectively. Three Fusarium species viz., Fusarium graminearum, F. compactum and F. avenaceum were found associated with the disease but F. graminearum was more prevalent in all the surveyed locations of Himachal Pradesh. The temperature of 25°C and pH of 5.0 were found to be optimum for mycelial growth, sporulation and perithecia formation of the fungus. The seed and crop residue of maize, wheat and rice served as the primary source of inoculum for the disease development. All the weather parameters viz., temperature, relative humidity and rainfall contributed for the disease development as all of them individually and collectively showed positive correlations with disease severity. Out of 200 tested genotypes of wheat, 13 were found free from disease, 26 as resistant and 54 as moderately resistant to FHB under artificial inoculations. Under in vitro conditions, beejamrit, extracts of Acorus calamus (aqueous and alcoholic), Trichoderma harzianum (TH-5) and carbendazim 50 WP gave highest inhibition of F. graminearum. In a pot experiment, seed treatment and two foliar sprays of carbendazim 50 WP gave maximum reduction (71.85 & 77.16%) in disease incidence and severity, respectively. However, among non-chemical management components beejamrit, aqueous extract of Acorus calamus and Trichoderma harzianum (TH-5) gave maximum reduction in disease incidence and severity. An integrated treatment viz., seed treatment with carbendazim 50 WP (0.2 %) followed by three foliar sprays each of jeevamrit (1 %), aqueous extract of Acorus calamus (1 %) and carbendazim 50 WP (0.1 %) at 10 days interval was found to be most effective giving 57.26 and 61.56 per cent reduction in disease incidence and severity, respectively.
Open Access
Epidemiology and management of flag smut (Urocystis agropyri (Preuss) Schroet) of wheat
(palampur, 2022-05-02) Bhargava, Priya; Rana, S. K.
The investigation entitled “Epidemiology and management of flag smut (Urocystis agropyri (Preuss) Schroet.) of wheat” was conducted at the Department of Plant Pathology, CSK HPKV, Palampur and Research Sub Station, Akrot during 2018-21. The average disease incidence at different locations of Himachal Pradesh varied from 2.11 to 17.77 per cent during two consecutive years. Based on molecular characterization, the pathogen was confirmed to be Urocystis agropyri. The maximum spore germination (18.92 %) was recorded after 8 months of inoculum burial in soil while, no germination occurred till 4 months of storage due to the spore dormancy. Inoculation of germinating seed with dry inoculum @ 10 g inoculum/ kg seed proved to be the best method to incite disease with highest incidence of 58.18 per cent. Inoculum load of 20 g inoculum/ kg seed adversely affected the seed health parameters like germination percentage and vigour index of seed as well as growth rate and dry weight of the seedlings with 13.70, 52.96, 54.41 and 6.73 per cent reduction, respectively. However, the maximum reduction in speed of seedling germination/ emergence (15.01 %) was found at 17.5 g inoculum/ kg seed. The maximum incidence of disease (44.87 and 40.64 %) was recorded at soil moisture and temperature of 30 % and 22℃, respectively. Among the weather parameters, the maximum and minimum temperatures were the most important factors for disease development as an increase in the temperature from 11.78 - 22.75℃ at Palampur and 09.20 - 26.13℃ at Akrot increased the disease incidence during both the years. The disease incidence was found to be maximum (13.28 and 16.47%) in 15th November sown crop at Palampur during both the years. While, at Akrot, it was maximum in 15th November sown crop (25.50 %) during 2019-20 and in 30th November sown crop (37.49 %) during 2020-21. Out of 210 wheat germplasm lines/ genotypes, 71 were found immune, 45 as highly resistant and 34 as moderately resistant. The late sowing of wheat was found to be the best with minimum disease incidence of 10.79 per cent followed by early sowing (21.47 %). The sowing depth of 2 cm showed minimum disease incidence of 12.98 per cent. Among the tested organic amendments, Jeevamrit @ 10 ml/ kg soil gave the maximum reduction (82.94 %) in the incidence of flag smut. While, amongst biocontrol agents as seed and soil treatments, resident Trichoderma viride @ 10 g or ml/ kg seed or soil was found to be most effective against the disease with maximum reduction of 47.50 and 34.02 per cent, respectively. From botanicals, the seed treatment with aqueous extracts of Eucalyptus tereticornis @ 15 % concentration was found to be the best with maximum disease control of 79.44, 71.85, 80.30 and 77.55 per cent under two approaches of pathogen inoculation in pot and field experiments, respectively. Among fungicides, tebuconazole 060 FS at 1, 2 and 3 ml/ kg seed, carboxin 37.5% + thiram 37.5% DS, carbendazim 50 WP and carboxin 75 WP at 3 g/ kg seed were found most effective giving complete control of the disease under both the approaches of pathogen inoculation in pot and field experiments. The integration of tebuconazole 060 FS @ 1 ml/ kg seed with Jeevamrit @ 10 ml/ kg soil (as soil treatment); E. tereticornis @ 15 % concentration (as seed treatment); and soil treatment with Jeevamrit and seed treatment with E. tereticornis gave complete control of the disease. On the basis of morphological and molecular characterizations, 17 isolates of U. agropyri were grouped into four groups each i.e. FSG 1 to FSG 4 and FSV1 to FSV4, respectively. The group FSV 1 and FSV 2 were further subgrouped into six subgroups i.e. FSV 1a, FSV 1b, FSV 2a, FSV 2b, FSV 2c and FSV 2d

Theses

Browse

Thesis Type

Type

Author

Date

Subject

Search Results