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ThesisItem Open Access Epidemiology and management of downy mildew of vegetable pea incited by Peronospora viciae f. sp. pisi Sydow Boerema & Verhoeven(G. B. Pant University of Agriculture & Technology, Pantnagar, Uttarakhand. PIN 263145, 2022-09) Bathula, Jagadeesh; Singh, R. P.Downy mildew caused by Peronospora viciae f. sp. pisi (Sydow) Boerema & Verhoeven is a serious foliar disease of vegetable pea. It may cause yield losses up to 55 per cent in susceptible varieties. Seed treatment and foliar fungicides provide an effective means of disease management but when this management strategy combined with sustainable approaches, the disease can be managed successfully. In the present study, efforts were made to investigate the yield loss due to downy mildew, use of chemical and biological seed treatments to reduce seed borne inoculum, cost-effective chemical control through new molecules, effect of sowing, varieties and influence of weather parameters on disease development. Screening of vegetable pea germplasms against downy mildew was also undertaken. Maximum avoidable yield losses due to protection by foliar spray of Cymoxanil 8% + mancozeb 64% were found in Arkel (34.29%), followed by AP-3 (29.44%) on first date of sowing (17th November), while in PSM-3 maximum (23.52%) avoidable yield losses was found at 3rd date of sowing (1st December). Among the fungicides and biological seed treatments under glasshouse conditions, seed treatment with combination of Metalaxyl 35% WS + Bacillus subtilis var. amyloliquefaciens and Metalaxyl 35% WS + Streptomyces lydicus found to be the best with less disease incidence and severity. Seed treatment with Metalaxyl 35% WS and 2 foliar sprays at 15 days interval starting 30 days after sowing by Fluopicolide 4.44% + fosetyl-Al 66.67% WG @ 2000 g ha-1 provided the minimum disease severity (15.78 PDI) and highest yield (52.53 q ha-1) followed by Iprovalicarb 5.5% + propineb 61.25% WP @ 1600 g ha-1 and Famoxadone 16.6% + cymoxanil 22.1% SC @ 500 g ha-1 but, Famoxadone 16.6% + cymoxanil 22.1% SC provided highest net benefit cost ratio (2.22) followed by Cymoxanil 8% + mancozeb 64% WP (2.05). Lesser disease and higher yield were obtained from variety PSM-3 sown on 24th November. The maximum increase in downy mildew was recorded 40 days after sowing, and temperature range of 5.5-22.05°C and 55-96.05% relative humidity along with 7.5 mm rainfall favored the disease development. Disease severity was found to be positively correlated with minimum temperature and rainfall. Out of 89 vegetable pea germplasms screened under natural epiphytotic conditions, PSM-11, PCPGR-6091 and Selection-23 were found to be resistant, while Multi frozen, Pila Lubix, Little Marvel Lincoln, EFL-9, PSM-3, Pant Upahar were found to be moderately resistant to downy mildew.ThesisItem Open Access Development of microbial consortia for f the management of chickpea wilt caused by Fusarium oxysporum.sp. ciceris(G.B. Pant University of Agriculture and Technology, Pantnagar, District Udham Singh Nagar, Uttarakhand. PIN - 263145, 2022-10) Amirtha Lingam. V; Tewari, A.K.Chickpea wilt caused by F. oxysporum f.sp ciceris is one of the most devastating disease of chickpea in India and all over the world, this pathogen can cause yield losses up to 10-94 per cent depending on inoculum and environmental conditions. Use of chemical fungicides could not effectively manage this disease due to its soil borne nature. The pathogen survives in soil up to 6 years in the form of chlamydospores as a source of primary inoculum. Presently, single microbe-based biocontrol strategies are used for plant disease management. Inconsistent performance of single antagonists can be related to limited competition in the soil microbiome. In view of above present study “Development of microbial consortia for the management of chickpea wilt caused by Fusarium oxysporum f. sp. ciceris” was undertaken. During the Rabi season (2017-18), chickpea plants showed wilt symptoms were collected, isolated and identified up to molecular level as Fusarium oxysporum f.sp. ciceris. Fungal and bacterial antagonists (T.asperellum strains Th-14, Th-17, Th-19 and TCMS 36 and P. fluorescens strains Psf-2, and Psf-173) recommended for the management of chickpea wilt pathogen were selected for the consortia study. Antagonists were prepared in 14 different combinations and compatibility was checked by three methods and in all the methods it has been observed that all the consortia combinations were found compatible with each other. Antagonism action of consortia against pathogen was also studied using three different methods. In dual culture (mycoparasitism) study Th14+TCMS36 showed 61 per cent mycelial parasitization. In paired plate technique effect of volatile compounds of Th14+Psf173 showed significant maximum mycelial inhibition (66.67%). In cell free culture method the effect of non- volatile compounds of Th14+Psf173 showed maximum mycelial growth inhibition (74.81%). In glasshouse studies Th17+Psf173 and TCMS36+Psf173 were showed maximum per cent seed germination (96.67 % in each) with minimum pre-emergence mortality (3.33% in each) as compared to control (71.67% & 28.33% respectively) at 07 DAS. At 60 DAS, Th14+Psf173 showed minimum wilt incidence (6.84%) as compared to control (58.25%) and maximum wilt reduction (88.25%) over control and was at par with TCMS36+Psf173 (8.60% & 85.39 % respectively). Th14+Psf173 showed maximum vigor index (4783.17) followed by TCMS36+Psf173 (4505.67) as compared to control (2603). In field experiment pooled data revealed that Th14+Psf173 showed maximum per cent seed germination (84.80%) followed by Th17+Psf173 (83.27%) and TCMS36+Psf173 (82.93%) as compared to control (69.13%). At 120 DAS maximum wilt disease reduction was observed in Th14+Psf173 (88.54%) followed by TCMS36+ Psf173 (84.55%). Maximum mean yield was recorded in Th14+Psf174 (17.30 q/ha) followed by TCMS 36+Psf173 (16.47q/ha) and Th17+Psf173 (15.26 q/ha) as compared to control (8.05 q/ha). Consortia Th14+Psf173 and TCMS36+Psf173 were found significantly better in the induction of defence related enzymes/ compounds (Peroxidase, polyphenol oxidase, Phenylalanine ammonia lyase, Total Phenolic Content, and Superoxide dismutase) against chickpea wilt disease in glasshouse and in field.Population dynamics of antagonists were increased upto 50 DAS and it was maximum in Th14+Psf173 (22.33 & 12.67 ×104 cfu/g respectively) followed byTCMS36 + Psf173 (19.33 & 11.00 ×104 cfu/g respectively). Thereafter, population were declined till the last date of observation (125 DAS Further best performed treatment were confirmed by re isolation and characterized up to molecular level. Based on cultural, morphological, biochemical and molecular characteristics the superior introduced consortia (Th14+Psaf173 and TCMS36+ Psf173) were re-isolated and confirmed that Th14, TCMS36 and Psf173 have similar matching characteristics as of their mother culture. These findings revealed that potential introduced antagonists survived in the rhizosphere of chickpea plant instead of native strains. On the basis of present studies these two consortia could be recommended for the cost effective, ecofriendly management of chickpea wilt disease.ThesisItem Open Access Molecular characterization, epidemiology and management of bacterial blight of soybean (Pseudomonas savastanoi pv. glycinea)(G.B. Pant University of Agriculture and Technology, Pantnagar, District Udham Singh Nagar, Uttarakhand. PIN - 263145, 2022-10) Kumari Surbhi; Singh, K.P.Soybean (Glycine max L. Merill) is one of the oldest and most important oilseed crop grown throughout the world. Bacterial blight of soybean caused by Pseudomonas savastanoi pv glycinea is one of the major constraints in successful cultivation of soybean causing up to 40 per cent yield losses in different areas of world. During the course of field surveys from 2019 to 2021, the disease was found to be prevalent in different districts of Uttarakhand with highest incidence in Udham Singh Nagar, Pithoragarh and Champavat. The bacterial isolates from different regions were found to slightly differ in morphology with round colonies of diameter 1 to 4 mm, white to creamish white in colour, raised and flat elevation with filamentous and entire margins. The bacterial cells were seen as rod-shaped with rounded ends in TEM photographs, with size of 0.84 μm - 1.04 μm x 0.35 - 0.43 μm. On the basis of biochemical tests, the bacterium was characterized as genus Pseudomonas. Specific markers used in the study were found useful in detecting presence of pathogen. Sequence analysis of 21 Psg isolates yielded a similarity of 93.02 to 99.33 per cent with Pseudomonas savastanoi in NCBI. The disease initiation was noticed during last week of July to first week of August. The highest and lowest values of PDI, infection rate and AUDPC were noticed in variety Shilajeet and PK-472, respectively. Highest infection rate was observed from 33 to 36th SMW. The correlation with maximum and minimum temperature and evening RH was found to be negative, while rainfall and sunshine hour show positive correlation with the disease. The multiple regression analysis yielded R2 values of 0.91 to 0.93, indicating greater than 90 per cent involvement of weather factors in affecting variation of disease severity. Minimum temperature and evening RH were found to be the most contributing factor to disease development with the help of step-wise regression. Gompertz and Logistic models were found to predict most accurate values of disease severity. Fifteen genotypes including PS-1092, PS-1611, PS-1024, PS-1042, PS-1241, PK-564, PS-20, PS-22, Alankar, PS1025, Type-49, Bhatt, Shivalik, VLS-59 and SL-688 were found to harbour the Rpg1b gene and also exhibited resistance response to the disease in the field. The random primers used in the study were found useful for study of polymorphism among soybean genotypes. Under in vitro trial a comparable size of inhibition zone was obtained in case of Streptocycline (100 ppm) + Copper oxychloride (100 ppm), Streptocycline (100 ppm) + Copper hydroxide (200 ppm) and Streptocycline alone at 400 ppm whereas, Copper oxychloride was found to provide a similar control at a high concentration of 1600 ppm. Seed treatment with Streptocycline (0.01 %) + Copper oxychloride (0.1% ppm) was found to be most effective. Foliar spray of Streptocycline (0.015 %) provided at par control with combination of Streptocycline and copper fungicides and was found to be most economical.ThesisItem Open Access Epidemiology and molecular characterization of leaf rust resistance genes in wheat(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2022-01) Elangbam Premabati Devi; Singh, K.P.Leaf rust, caused by Puccinia triticina Eriks. is one of the most destructive disease of wheat. It is a serious constraint in wheat cultivation of India with great potential to cause yield losses of 50-80 per cent. The most useful and economically effective measure for management of leaf rust is utilization of resistant cultivars. The evolution of new physiological races or pathotypes with time render earlier reported resistant variety to susceptible one which made the management strategies a very challenging task. The breakdown of effective high yielding varieties was reported due to breakdown of Lr9, Lr19, Lr26, Lr28 genes by development of new matching virulence in pathosystems. The present investigations were carried out to identify the promising varieties with durable resistance in field conditions along with the epidemiological studies by referring statistical models and validation of effective Lr genes in wheat varieties by SSR, STS and SCAR markers. The survey of different wheat growing areas resulted that 60 per cent severity with susceptible response were recorded in Pune, Powerkheda, Ludhiana areas while Pantnagar, Faizabad, Kanpur, Mehsana, Junagadh in Gujarat were recorded with less infection of severity ranged from 5 per cent of resistant response to 20 per cent of moderately susceptible response. The result of seedling resistance test in glasshouse condition for 51 varieties has indicated that 18 varieties viz. HP1633, Chakwal86, Gourab, HD2160, HW2021, HW2008, Kharachia Mutant, HP1731, DL784-3, RNB1001, UP2628, UP2526, UP2855, UP2865, UP2572, UP2748, UP2785 and UP2425 were recorded with less infection types so characterized as resistant against 15 pathotypes of leaf rust. Gene postulation of 51 varieties also result that 7 Lr genes viz. Lr1, Lr9, Lr10, Lr13, Lr23, Lr26 and Lr34 were postulated either singly or in combination. Assessment of effective inoculation methods has revealed that spraying of spore suspension at seedling stage and injection of spore suspension at booting stage were statistically highly effective for creating an artificially created epiphytotic condition. Based on multilocation field screening conducted at Pantnagar and Wellington which is a hotspot area for leaf rust, among 51 varieties, 24 and 27 varieties exhibits less than 20 per cent and more than 20 per cent of average coefficient of infection, respectively, so these varieties were considered as resistant and highly susceptible to leaf rust. Linear regression between pooled final rust severity score and pooled area under disease progress curve value has depicted that these two parameters has linearly related with 82 percent with corresponding linear equation as y = 8.267x - 93.70 (R2 0.823) for Pantnagar and 92 per cent with the corresponding linear equation as y = 20.24x - 20.54 (R2 0.92) for Wellington. Positively significant correlation coefficient were obtained with maximum temperature (r ranged from 0.660** to 0.819**) and minimum temperature (r ranged from 0.603** to 0.837**) with disease severity suggesting possible involvement of these temperature in imparting resistant /susceptible against leaf rust. Artificial epiphytotics of leaf rust of wheat were studied in Rabi season during 2014-15, 2015-16 and 2020-21 crop year for developing environmental based prediction models to predict rust a week before the actual appearance of the disease using Logistic, Gompertz, Monomolecular and Exponential models. The Logistic and Gompertz equation best linearlized the disease progress data so identified as the most appropriate and best fitted model. Polymorphism analysis by gene specific marker has confirmed four markers (csLV34 for Lr34, SCS5 for Lr9, Xwmc332 for Lr48 and STS123 for Lr19) exhibits polymorphism while four markers (cfd71 for Lr67, Xwmc313 for Lr28, csGs for Lr68 and Xwmc44 for Lr46) were found to be monomorphic. The dendogram constructed based on markers profile has categorized into two main clusters A and B having 13 varieties each in cluster group with the similarity coefficient of 0.58. Moreover, the distribution of Jaccard similarity coefficient value of all 26 varieties ranged from 0.50 to 0.92. Therefore, those identified resistant varieties both in phenotypic and genotypic level could be employed for the effective management of leaf rust in field conditions.ThesisItem Open Access Development of biofortified oyster mushroom (Pleurotus spp.) using Zinc Sulphate nanoparticle(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-11) Shivani; Kushwaha, K.P.S.Pleurotus spp. commonly known as oyster mushroom in english and Dhingri in hindi, is one of the most important edible mushrooms cultivated in all around the world and is rich in nutritional as well as medicinal properties. Zinc is an essential trace element next to iron and its deficiency can lead to growth retardation, loss of appetite, and impaired immune function. Since the human body does not store excess zinc, it must be consumed regularly as part of the diet. Biofortification of food crops for increasing the zinc content and its bio-availability is one of the potential alternatives for combating zinc deficiency. The present study pertains to the development of zinc bio-fortified Pleurotus spp. (P. sajor-caju, P. florida and P. flabellatus) using zinc sulphate nanoparticles (ZnSO4 NPs). Zinc sulphate nanoparticles was sprayed at different concentrations (10 ppm, 20 ppm, 30 ppm and 40 ppm) after complete spawn run and nutritional and antioxidant properties of the fruiting bodies were analysed. The maximum mycelial radial growth and growth rate per day (mm) was obtained in all the tested species of Pleurotus at 10 ppm concentration of ZnSO4 NPs. Moreover, there was maximum increase in the growth parameters (pileus width, stipe length and stipe width), total yield and biological efficiency was obtained at10 ppm concentration of ZnSO4 NPs of as compared to the control. The highest increase in zinc content was obtained in 40 ppm concentration of ZnSO4 NPs i.e., 115.63% in P. sajor-caju followed by P. flabellatus (113.58%) and P. florida (106.35%). Similarly, at 40 ppm concentration of ZnSO4 NPs the phenol and flavonoid content was also found maximum. Whereas, the highest sodium and potassium content was bioaccumulated at 10 ppm concentration. The nutritional status of Pleurotus spp., measured in terms of crude protein, total ash and total soluble sugars, was found highest at 10 ppm concentration. The maximum increase in DPPH, ABTS and FRAP radical scavenging activity was observed at 10 ppm concentration of zinc sulphate nanoparticle. In case of, DPPH radical scavenging activity the highest increase was observed in P. sajor-caju followed by P. flabellatus and P. florida. Whereas, in case of ABTS radical scavenging activity the highest increase was obtained in P. sajor-caju followed by P. florida and P. flabellatus. Furthermore, in case of FRAP radical scavenging activity the highest increase was obtained in P. flabellatus followed by P. sajor-caju and P. florida. Therefore, Pleurotus spp. when biofortified with zinc sulphate nanoparticle at 10 ppm concentration has positive effect on the mycelial growth, biological efficiency, growth parameters, bioaccumulation of micronutrients, nutritional as well as antioxidant activities of Pleurotus spp. Thus, 10 ppm ZnSO4 NPs can be used for getting maximum yield of oyster mushroom and to combat zinc deficiency.ThesisItem Open Access Development of Iron–biofortified button mushroom (Agaricus bisporus) using nanoparticle(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-08) Singh, Omkar; Kushwaha, K.P.S.Nutrient deficiency is one of the major global health problem, with iron deficiency being a leading cause of many ailments. Amongst several approaches that have been tried to combat this problem, use of bio-fortified foods is one of the most promising one. It not only increases the intake of nutrient but also augments its bioavailability. Mushrooms have been a source of good nutrition since ancient times; among which Agaricus bisporus is a widely consumed species. Due to its high nutritional value, but relatively low iron content, an attempt was made in the present investigations to developed iron bio-fortified Agaricus bisporus, using iron oxide and iron sulfide nanoparticles. Different concentrations of iron nanoparticles (0, 3, 6, 9, 12 and 15 ppm) were used to supplement the mushroom at three different stages i.e at spawning stage, before casing stage and pin head initiation stage. Treated mushroom was analyzed for various attributes viz. mycelial growth, crop yield, iron content, sensory evaluation and antioxidant activity. Highest mycelial growth, crop yield and iron content were obtained in 9ppm in case of iron oxide and at 12 ppm in case of iron sulfide nanoparticle treated Agaricus bisporus. The antioxidant status measured in terms of flavonoid and phenol content was also recorded to be highest in 9ppm in and 12 ppm treated samples respectively. Phenol content increased with increasing concentration of iron nanoparticles, with 15ppm having maximal content. Proline and hydrogen peroxide content decreased continuously from 0 to 15 ppm. Thus from the above investigations it can be concluded that use of nano-biotechnology could be an efficient way to bio-fortify Agaricus bisporus along with enhanced iron and antioxidant activity.ThesisItem Open Access Survey, identification and management of potato cyst nematode (Globodera spp.)(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-07) Joshi, Vijay; Satya KumarPotato is an important root vegetable and staple food in world over. It is produced throughout the year in terrain and hilly regions of Uttarakhand and also plays a significant role in the economy of the state. Phytoparasitic nematodes are one of the limiting factors in potato production leading to a yield loss of 23%. Among phytoparasitic nematodes related to rhizosphere of Potato, the Potato Cyst Nematode (Globodera spp.) causes significant yield loss of up to 80% reducing the quality and quantity of the potato tuber. Keeping in view the importance of crop and visualizing the emergence of PCN in Uttarakhand extensive survey were conducted in nine districts of the state, focusing on major potato growing areas and GPSMF to assess the status of important phytoparasitic nematodes. The multilocation trials were conducted to study the effect of different altitudes, soil temperature and weather temperature on development of PCN Cyst at different locations followed by management experiments at GPSMF Balanti (Munsyari) to explore the effect of new chemical nematicides viz., Fluensulfone, Fluopyram and Fluazaindolizine and biological control agents viz., Pochonia chlamydosporia, Paecilomyces lilacinus, Pant Bioagent-1 (Trichoderma harzianum) and Pant Bioagent-3 (Trichoderma harzianum + Pseudomonas fluorescens). Survey studies revealed the presence of three cyst forming nematodes viz., Globodera spp. (G. rostochiensis and G. pallida), Cactodera spp. and Punctodera spp. along with eleven other genera of phytoparasitic nematodes viz. Meloidogyne spp., Ditylenchus spp., Pratylenchus spp., Helicotylenchus spp., Tylenchus spp., Tylenchorhynchus spp., Hoplolaimus spp., Trichodorus spp., Criconemoides spp., Xiphinema spp. and Aphelenchus spp. Three GPSMF viz., Balanti Farm, Tixen Farm (Munsyari, Pithoragarh) and Koti Farm Auli (Chamoli) were found to be highly infested with PCN. While, PCN was not observed in the soil samples of Bhattka Farm (Pithoragarh), Patwariya Farm (Almora), Dwari Farm, Kund Farm (Uttarkashi) and Khateda Farm (Champawat). Based on the morphological and molecular identification studies it was confirmed that there are two species of genus Globodera prevalent in Uttarakhand i.e., G. rostochiensis and G. pallida. Multilocation experiment studies revealed that reproduction factor of PCN is positively correlated to increasing altitude, while it is negatively correlated to increasing weather and soil temperature. Among nine locations, PCN cyst were developed in Gagar Farm (Nainital), Mukteshwar (Nainital), Nathuakhan (Nainital), Tixen Farm (Pithoragarh) and Shama Dana (Bageshwar). New nematicides molecules viz. Fluopyram @ 1000 ml/ha, Fluazaindolizine @ 0.06% and Fluensulfone @ 3kg a.i./ha effectively reduced PCN reproduction factor and subsequently increased Yield and Chlorophyll content as compared to Carbofuran. Biological Control Agents viz. Paecilomyces lilacinus, Pochonia chlamydosporia, Pant Bioagent-1 and Pant Bioagent-3 were more efficient in managing PCN as compared to chemicals reducing PCN reproduction factor and increasing yield and chlorophyll content.ThesisItem Open Access Survival of Rhizoctonia solani kühn f. sp. saskii Exner incitant of BLSB of maize under varied soil conditions(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2020-02) Hemalatha, Pagoti; Singh, R.P.Banded leaf and sheath blight (BLSB) caused by Rhizoctonia solani (Kühn) f. sp. Sasakii Exner is widely spread and destructive disease of maize in India especially in tarai region of Uttarakhand. In the present study efforts were made to know the effect of soil temperature, moisture, pH, organic matter content, type of soil, depth of inoculum and cropping sequence on survival of primary inoculum. Application of various pesticides for managing broad spectrum of pests is common in intensive maize cultivation. How it affects microbes including pathogen are not well understood. Therefore, efforts were also made to see the effect of commonly used pesticides and their combination on mycelia growth and sclerotia formation and sclerotia germination of R. solani. Growth of R. solani under in vitro condition was faster in mycelia inoculated plate as compared to sclerotia inoculated plate. Mycelia growth was fast at 25 0C temperature, at range of 6 to 7 pH under dark condition. Whereas higher number of sclerotia formed at 350C temperature at 7 pH in dark condition. Mycelial growth of R. solani was completely inhibited by carbendazim and penflufen at 10 μg/ml concentration while at 50 μg/ml concentration by mancozeb. Sclerotia germination was completely arrested by carbendazim at 10 μg/ml, penflufen at 50 μg/ml while mancozeb failed even at 100 μg/ml concentration. Among insecticides chlorpyriphos, carbofuran and cartap hydrochloride and in herbicides pendimethalin, 2, 4-D ethyl ester and atrazine at 50 μg/ml concentration effectively inhibited the mycelia growth and sclerotial formation but moderately inhibited the sclerotia germination. Germination of sclerotia of R. solani in soil was completely inhibited by penflufen and pendimethalin. In combinations mancozeb + 2,4- D ethyl ester carbendazim + atrazine , carbendazim + cartap hydrochloride , 2,4-D ethyl ester + cartap hydrochloride, penflufen + 2,4-D ethyl ester + chloropyriphos, mancozeb+2,4-d ethyl ester + cartap hydrochloride significantly inhibited sclerotia germination in soil. Sclerotia of R. solani survived for longer duration as compared to infected tissues. Dry soil condition favoured survival compared to moist soil and decreased from 15 to 40 0C temperature and 5 to 9 pH. Survival of inoculum was inversely proportional to the added organic matter quantity and increased soil pH. On soil surface and 30 cm depth of inoculum R. solani survived for shorter duration as compared to 15 cm depth of soil. Survival of inoculum reduced in fallow condition followed by maize-wheat-maize and maize-potato-maize cropping sequence. In loam soil inoculum survived for shorter duration followed by sandy loam and silty clay loam soil. Based on above findings it can be concluded that for managing BLSB deep summer ploughing, high soil temperature with sufficient moisture maintained by fallowing or solarization of field during off season and raising the soil pH by adding lime, supplemented with sufficient quantity of organic matter significantly reduced primary inoculum of R. solani. Growing maize in loam soil following maize-wheat-maize cropping sequence will further help to minimize incidence of BLSB.ThesisItem Open Access Effect of crop intensification on important diseases of Maize (Zea mays L.)(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2020-02) Sharma, Bhuwan Chandra; Singh, R.P.Maize (Zea mays L.) is not only an important cereal crop for food, feed and fodder but also a basic element of raw material for manufacturing of many industrial products. There is a necessity and opportunity to increase India’s maize production in coming years. Increasing the maize production by enhancing the crop productivity through crop intensification is a viable strategy to achieve the goal. Diseases are the major constrains in limiting the production of maize. About 65 diseases are known to occur in India causing about 15-20 percent yield losses annually. In tarai region of Uttarakhand Banded leaf and sheath blight (BLSB), Bacterial stalk rot (BSR) and Maydis leaf blight (MLB) is considered as serious problem in kharif maize. Production practices like cultivars, tillage practices, sowing methods, plant density nutrition management etc. strive to maximize the yield, but how plants respond to these practices in different environments are not well understood. Therefore, present investigations were undertaken to know the influence of cultivars, plant spacing, tillage practices, different sowing methods, nutrition and disease management practices over important diseases of maize. Field experiments were carried out at NEBCRC of GBPUA&T, Pantnagar during the Kharif season of 2017 and 2018 and disease assessment was done under natural conditions. Low incidence and severity of BLSB, BSR and MLB were recorded in hybrid DH 296 as compared to P1844 under spacing of 67.5 cm × 20 cm but 67.5 cm × 15 cm provided higher yield. Site specific nutrient management (SSNM) found to be better in minimizing disease incidence and severity but higher yield was recorded in Soil test crop response (STCR) which was found at par with SSNM. Lowest incidence and severity of BLSB, BSR and MLB was recorded in Conventional tillage followed by zero tillage and Permanent beds but no significant difference was seen in yield. Minimum incidence and severity of BLSB, BSR and MLB were observed in raised bed planting which was at par with paired row planting followed by flat planting protected with Chemical management followed by Integrated management. Biological control was found the least effective. It is concluded that hybrid DH 296 with spacing of 67.5 cm × 15 cm planted on raised beds under Conventional tillage practices with SSNM, if protected against various diseases either with chemicals or Integrated management practices found superior in minimizing the major diseases like BLSB, BSR, MLB and increasing the maize yield.
